37th International Symposium on Intensive Care and Emergency Medicine (part 1 of 3)

¹George P. Livanos and Marianthi Simou Laboratories, Athens, Greece; ²Rigel Pharmaceuticals, Inc, South San Francisco, CA, USA; ³Evangelismos Hospital, Athens, Greece

Introduction: Aberrant inflammation is a hallmark of acute respiratory distress syndrome (ARDS) pathophysiology. JAK/STAT3 pathway is critical for macrophages and neutrophils activation and persistent inflammation. This study aims to investigate the therapeutic potential of inhibiting JAK1/3 activity using the small-molecule R548 inhibitor in LPS induce lung injury model.

Methods: Lung injury was induced in adult male C57BL/6 mice, by intratracheal LPS administration followed by post subcutaneous injection of R548 inhibitor R548 inhibitor, prodrug for the active compound, R507 (Rigel Pharmaceuticals Inc.). Mice sacrificed at 6 h and 24 h after LPS administration. Lung inflammation was examined by protein content, number and type of inflammatory cells in bronchoalveolar lavage fluid (BALF). Protein expression levels of JAK1, p-STAT3, ERK1/2 were analysed by Western blotting.

Results: LPS administration increased BALF cellularity, total protein content, and neutrophils cells number at both 6 h and 24 h. Elevated levels of JAK1, p-STAT3 and ERK1/2 protein expression were observed. In addition, post LPS treatment with the JAK 1/3 inhibitor significantly reduces BALF protein content (P < 0.05), total cells number (P < 0.01), neutrophils cells number (P < 0.01) as early as 6 h. Moreover, R548 treatment decreased JAK1 protein expression by 2 fold (P < 0.01) and p-STAT3 levels by 2.7 fold (P < 0.001) below the LPS group.

Conclusions: These data suggest the JAK/STAT3 signaling pathway plays a critical role in ARDS mediated lung inflammation and injury. Additional studies are warranted to further investigate JAK/STAT3 inhibition as a therapeutic treatment for this serious and life threatening disease.

Department of Critical Care Medicine, Nanjing Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China

Introduction: Mesenchymal stem cells (MSCs) have several properties that make them attractive therapeutic candidates for treatment of acute disease, but in vivo homing, MSCs does not appear to be highly efficient. CXCL12/CXCR7 axis not only improves the motility of stem cells, but also regulates many essential biological processes. The aim of this study is to evaluate the effects of overexpressing or suppressing CXCR7 on proliferation and migration abilities of mice mesenchymal stem cells.

Methods: The lentivirus vector overexpressing and suppressing the murine CXCR7 gene was transducted into mMSCs. The transfection efficiency of LV in passage 20 transduced-mMSCs was identified using fluorescence microscopy, and the percentage of ZsGreen positive cells was determined by flow cytometry analysis (FCM). CXCR7 mRNA expression in mMSCs was verified by quantitative real-time PCR, and CXCR7 protein expression was analyzed by FCM. The effect of CXCR7 on the migration of mMSCs was evaluated using the scratch assay and the transwell migration assay. In transwell assay, 50 ng/ml CXCL12 was added in two groups to simulation inflammation microenvironments. The ELISA assay was used to detect the concentration of VCAM-1, CXCL12 the supernatant.

Results: The efficiencies of the lentiviral vector transduction of MSC-OE-CXCR7 (overexpression of CXCR7), MSC-OENC-CXCR7 (normal control of overexpression of CXCR7), MSC-Sh-CXCR7 (suppression of CXCR7) and MSC-ShNC-CXCR7 (normal control of suppression of CXCR7) after 20 passages in mMSCs were 91.29%, 91.39%, 91.69% and 91.28% respectively. The CXCR7 mRNA and protein expression were significantly higher in the MSC-OE-CXCR7 cells than in the MSC-OENC-CXCR7 cells, and were significantly lower in the MSC-Sh-CXCR7 when compared with the MSC-ShNC-CXCR7. Moreover, CXCR7 gene overexpression promoted mMSCs migration. In contrast, the suppression of CXCR7 inhibited mMSCs migration when compared with the MSC-ShNC-CXCR7 group. Overexpression CXCR7 increased MSC-secreted CXCL12 and VCAM-1, which contributed to the improvement of mMSCs homing.

Conclusions: Overexpression CXCR7 improved the homing abilities of mMSCs, which might attribute mainly to increasement of CXCL12 and VCAM-1 secreted by mMSCs.

¹Hôpital Erasme, Brussels, Belgium; ²SRLF, Paris, France

Introduction: Limited information exists about the prevalence, subsequent management, and outcomes of hypoxemia among ICU patients.

The aim of the study was to assess the prevalence of hypoxemia among ICU patients and to stratify them according to the severity of hypoxemia (PaO2/FIO2 between 300 and 201 in mild, between 200 and 101 in moderate, and <101 mm Hg in severe). Management and outcomes of hypoxemic patients and the proportion of them who met the criteria for acute respiratory distress syndrome (ARDS) were analyzed

Methods: This study was an international, multicenter, 1-day point prevalence study conducted in 117 units during the spring of 2016. All patients already hospitalized or newly admitted the day of the study were susceptible to be enrolled.

Hypoxemia was defined as a P/F ratio of 300 mmHg or less

Results: Of 1604 patients included, 859 (54%) were hypoxemic, 440 (51%) were mildly, 345 (40%) moderately and 74 (9%) severely hypoxemic. Among hypoxemic patients, 183 (21%) had ARDS (37% mild, 46% moderate and 16% severe). Characteristics of patients according to hypoxemia severity are reported in the Table 1. Pneumonia was the main cause of hypoxemia (53%) and of ARDS (79%). Modalities of oxygen treatment vari.

Among hypoxemic patients under invasive mechanical ventilation, 77% received a tidal volume of 8 mL/kg or less of predicted body weight with a median PEEP level of 6 [5–10] cmH2O. Among ARDS patients, 145 (83%) received a tidal volume of 8 mL/kg or less with a median PEEP of 8 [6–12] cmH2O and a median plateau pressure of 23 [19–27] cmH2O.

In the whole population, median ICU length of stay was 12 days [5–28] and the ICU mortality was 20%. In the hypoxemic population, median ICU length of stay appeared to be higher (16 [7–32] days) and further increased in ARDS patients (20 [11–38] days, P < 0.001). ICU mortality was 27% in hypoxemic patients (21% in mild hypoxemic patients, 26% in moderate hypoxemic patients, and 50% in severe hypoxemic patients, P < 0.001)

Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Istanbul, Turkey

Introduction: In definition of ARDS PaO2 and PaO2/FiO2 (Horowitz) ratio are the most reliable parameters used. In this study it is aimed to investigate the correlation of Horowitz ratio with oxygenation saturation index (OSI) derived from SpO2 instead of PaO2.

Methods: Demographical data of 307 patients treated with mechanical ventilation in our ICU between 01.01.2014–31.12.2015 due to respiratory failure were revised from iMDsoft (Metavision) system together with FiO2, SpO2, PaO2, Paw parameters. Oxygenation saturation index was calculated with the formula using [FiO2 x Paw]/SpO2. ROC (receiver operator characteristic) analysis was used to search for the relation of Horowitz ratio and OSI.

Results: The median age of the patients were 58,5 years (IQR 18–96). For the patients with Horowitz ratio < 100 cut-off value for OSI was found to be 7,0768 (sensitivity 94.4% and specificity 86.9%). OSI cut-off value was 3,7178 for Horowitz ratio < 200 (sensitivity 90.2% and specificity 79%). For those with Horowitz ratio < 300, OSI cut-off value was calculated as 2,561 (sensitivity 83.3% and specificity 72%).

Conclusions: OSI was defined for ARDS diagnosis in pediatric population which includes the parameter of mean airway pressure in its formula rendering this index a more objective parameter for ventilatory support instead of PaO2/FiO2 ratio. It was a big controversy before Berlin definition that ARDS definition was relying on cirteria which do not directly consider the extent of ventiatory support on oxygenation, however there is still a debate that Berlin definition did not bring a solution in that aspect. Therefore, we think that this study, which we aim to reveal the OSI values that correlate with Horowitz values of mild, moderate and severe ARDS, should be supplemented with other studies and validated by further prospective studies, considering OSI as a reflection of positive pressure changes affecting oxygenation in ARDS.

References

1. Thomas NJ, et al. Pediatr Crit Care Med. 2010; 11(1): 12–17

2. Rotta AT, et al. Rev Bras Ter Intensiva. 2015;27(3):266–273

Emergency Hospital Floreasca, Bucharest, Romania

Introduction: ARDS is an independent risk factor for death in burn patients, with appreciable mortality of 26–58%. More than 30% of thermal injured patients have a concomitant smoke inhalation injury

Methods: A retrospective observational study which include 14 young patients 21–36 y.o. with severe burns to the face, neck, chest, extremities, admitted in the ICU of level I trauma Center after a deadly fire in Bucharest in an enclosed space with air temperature in 60 seconds between 900–1500 degrees C, in which 64 people were killed and 147 severely injured.

All of them had signs and symptoms of acute hypoxia requiring mechanical ventilation.

We asses the incidence of smoke inhalation injury, the CO toxicity, the etiology, the development time, the relation between severity of ARDS and % of BSA, the mortality

Results: All of them have smoke inhalation injury and CO toxicity, the etiology was multifactorial (trauma, multiple transfusion, sepsis, smoke injury, resuscitated cardio-respiratory arrest), there was a strong correlation between the severity of ARDS and the % of Burn Surface Area, the mortality was extremely high

Conclusions: The severity of burn associated with inhalatory injury dramatically increase the incidence of ARDS and despite new promising therapeutic interventions, ARDS still remain a devastating disease in severe burn patients.

¹Università degli Studi di Milano, Milano, Italy; ²ASST Santi Paolo e Carlo, Milano, Italy; ³Humanitas, Rozzano, Italy; ⁴University of Gottingen, Gottingen, Germany

Introduction: Tidal volume, pressure and flow are components of the energy load (EL). We investigated the relationship between intra-tidal lung inflation status variation and EL in mechanically ventilated ARDS patients.

Methods: Twenty-eight ARDS patients underwent end-inspiratory and end-expiratory low dose CT scans at PEEP 5 and 15 cmH2O, maintaining the same tidal volume 7 ± 1.8 mL/kg and respiratory rate 15 ± 4.2 breaths/min. Quantitative CT scan analysis was performed to obtain the amount of not, poorly, well and over inflated tissue (g). EL was computed as the area between the inspiratory limb of pressure-volume curve and the y axis, summed to the energy needed to inflate the PEEP volume. EL at PEEP 5 and 15 cmH2O was then normalized by the End-Expiratory Lung Volume at 5 cmH2O (EELV5).

Results: EL/EELV5 (mJ/mL) is lower at PEEP 5 than 15 cmH2O (1.3 ± 0.73 and 2.4 ± 0.95, p < 0.001). Higher EL/EELV5, respectively for PEEP 5 and 15 cmH2O, is associated with a decrease in not inflated tissue (Δ not inflated tissue = −22.87–61.38*EL/EELV5, r2 = 0.28, p < 0.0001 and Δ not inflated tissue = −4.35–24.59*EL/EELV5, r2 = 0.15, p < 0.01) and with an increase in well inflated tissue (Δ well inflated tissue = 67.72 + 55.91*EL/EELV5, r2 = 0.27, p < 0.0001 and Δ well inflated tissue = −25.13 + 51.91*EL/EELV5, r2 = 0.46, p < 0.0001) at the end of inspiration (Fig. 4). No relationships were found between poorly or over inflated tissue and total energy load.

Conclusions: Higher PEEP is associated to higher EL. Higher EL, increasing lung stress and intra-tidal opening and closing, could be unprotective.

¹Università degli Studi di Milano, Milano, Italy; ²ASST Santi Paolo e Carlo, Milano, Italy; ³Humanitas, Rozzano, Italy; ⁴University of Gottingen, Gottingen, Germany

Introduction: In ARDS patients lung collapse is due to lung superimposed pressure (SP) [1].

SP seems to change as a function of pleural pressure, and both these pressures change as a function of the sterno-vertebral level [2].

Absolute esophageal pressure (Pes) reflects mid-lung pleural pressure, according to the level where the esophageal balloon is placed [1]. However, Pes is unrelated to all morphological indexes of disease severity (not inflated tissue, lung weight, functional residual capacity) and is unrelated to maximal SP [1].

Our aim is to verify if Pes is related to the total and/or the lung SP at the esophageal catheter balloon level.

Methods: Ninety-two ARDS patients underwent an end-expiratory CT scan at PEEP 5 cmH2O. Quantitative CT scan analysis was performed to compute the total and the lung SP at the esophageal catheter balloon level in the slice above the diaphragm.

Pes was recorded at PEEP 5 cmH2O.

As shown, Pes is greater than either the total and the lung SP at the level of the esophageal balloon.

Conclusions: If the increased total or lung SP is the main mechanism for lung collapse in ARDS patients and PEEP keeps the lung open mainly by counter-balancing the SP, Pes could not be used to select the best PEEP.

References

[1] Pelosi P. Am J Respir Crit Care Med 2001; 164:122–130

[2] Bottino N. Crit Care 2000; 4:P115

¹Università degli Studi di Milano, Milano, Italy; ²ASST Santi Paolo e Carlo, Milano, Italy; ³Humanitas, Rozzano, Italy; ⁴University of Gottingen, Gottingen, Germany

Introduction: In ARDS patients, lung is inhomogeneous [1]. Energy load (EL) describes the interaction between the ventilator and the respiratory system [2]. We investigated the relationship between intra-tidal lung inhomogeneity variation and EL in ARDS patients.

Methods: Twenty-eight ARDS patients underwent a series of end-inspiratory and end-expiratory low dose CT scans at 2 different levels of PEEP, 5 and 15 cmH2O, maintaining the same tidal volume 7 ± 1.8 mL/kg and respiratory rate 15 ± 4.2 breaths/min.

Lung inhomogeneity extent is defined as the fraction of lung volume presenting an inflation ratio greater than 1.61 (95th percentile of homogeneous lungs) [1].

The airway pressure-volume curve at the 2 ventilatory settings was obtained. EL was computed as the area between the inspiratory limb of that curve and the volume axis, summed to the energy needed to inflate the PEEP volume [2].

Conclusions: During mechanical ventilation, the EL applied to the respiratory system is spent to increase homogeneity of the lung parenchyma. We could speculated that EL is spent at the interfaces between regions with different inflation status.

References

[1] Cressoni M. Am J Respir Crit Care Med 2014; 189:149

[2] Gattinoni L. Intensive Care Med 2016; 42:1567

¹Policlinico di Bari, Bari, Italy; ²Uppsala University Biomedical Center, Uppsala, Sweden; ³Akademiska Sjukhuset, Uppsala University, Uppsala, Sweden

Introduction: The transforming growth factor β (TGF-β) pathway is activated in experimental ARDS and is associated with increased pulmonary edema (1) because it reduces transepithelial sodium transport by inducing endocytosis of ENaC (the epithelial sodium channel). In this way TGF-β decreases the osmotic gradient for re-absorption of water from the alveolar and interstitial spaces (2). We hypothesized that blocking TGF-β signaling with Galunisertib (LY2157299 monohydrate, a TGFβ R1 kinase inhibitor) would reduce edema and tested this in a porcine model of ARDS using aerosolized Galunisertib.

Methods: Five piglets (25–30 kg) were randomized to receive (n = 3) or not (n = 2) Galunisertib 50 μM by aerosol. The animals were anesthetized, tracheotomized and ventilated in volume controlled mode (VT: 8 ml/kg, FiO2: 70%, RR:30, PEEP:5 cmH2O, I:E = 1:2). Cardiac output and extravascular lung water (EVLW) were continuously measured (PiCCO, Pulsion Medical System). We measured pressure/volume curves and arterial pH, paO2, paCO2, HCO3- at baseline, immediately after induction of ARDS and then hourly for 6 h. ARDS was induced by repeated lung lavages and injurious ventilation. After the establishment of the ARDS model, Galunisertib was administered and the experiment was continued for 6 h, after which the animals were sacrificed. Histological samples from lungs, heart, kidney and liver were taken. Activation of the TGF-β pathway was immunohistochemically evaluated using an antibody against phosphorylated Smad2 (Small Mother Against Decapentaplegic) and activation of mechanical signaling in the lungs was evaluated using an antibody against phosphorylated FAK (Focal Adhesion Kinase). Moreover, we measured the wet/dry weight ratio of the lung samples.

Results: Two animals did not survive the experiment. The sample size is too small to draw any strong conclusion. However, we could not find any major difference in EVLW, wet/dry ratio, blood gas parameters or in lung mechanics between the two groups during the tested time period. However, the lung samples from the treated group showed a lower degree of TGF-β pathway activation, while the control samples from liver or heart showed no influence by Galunisertib.

Conclusions: We cannot prove or disprove that TGF-β blockade reduces pulmonary edema associated with experimental ARDS. However, the TGF-β blocker seemed to reach its target as indicated by reduced activation of the TGF-β pathway in the lungs, suggesting that aerosol administration is feasible.

References

1. Acta Anaesthesiol Scand. 2016;60(1):79–92,

2. Proc Natl Acad Sci USA. 2014;111(3):E374-83

Department of Critical Care Medicine, Nanjing Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China

Introduction: Bone marrow derived mesenchymal stem cells (BMSCs) are proved to have potential therapeutic effects in ARDS models. However, the mechanism of differentiation in MSCs is still unknown. There is growing evidence suggesting p130 or E2F4 plays an important role in regulating cellular differentiation. Our aim is to evaluate the role of p130/E2F4 in regulating the differentiation of mouse MSCs (mMSCs).

Methods: mMSCs with p130 or E2F4 overexpression were constructed using lentiviral vectors. The transfection efficiency of mMSCs was identified using fluorescence microscopy, and the percentage of GFP positive cells was determined by flow cytometry analysis. The mRNA and protein levels in MSC-p130 (overexpressing p130) and MSC-E2F4 (overexpressing E2F4) were detected by qRT-PCR and Western blotting assay, respectively. The effect of p130/E2F4 on the multipotential differentiation abilities of mMSCs were evaluated by adipogenesis, osteoblastic and chondrogenic differentiation medium respectively. The expression of the osteogenic gene OSX, adipogenisis gene PPAR-¦Ã and chondrogenic gene Sox9 measured by qRT-PCR were used to evaluate the differentiation of each group of mMSCs treated with differentiation induction media.

Results: The transduction efficiencies mediated by the lentiviral vectors were 80.3–84.4% and were maintained over 20 passages of mMSCs. The p130 or E2F4 mRNA expression was significantly higher in the MSC-p130 and MSC-E2F4 cells than in the MSC-NC cells. Similar results for p130 or E2F4 protein expression were also observed in Western blotting. Moreover, p130/E2F4 gene overexpression promoted the differentiation of mMSCs into osteoblasts, while inhibiting adipogenesis and chondrogenic differentiation of mMSCs.

Conclusions: The successful construction of stable and long-term mMSCs lines with overexpressing p130/E2F4 change the multipotential differentiation of mMSCs.

References

1. Liu AR et al.: J Cell Physiol 2013; 228: 1270.

Department of Critical Care Medicine, Nanjing Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China

Introduction: The low efficiency of homing to injured organ in mesenchymal stem cells (MSCs) has become the bottleneck for the treatment of acute respiratory distress syndrome (ARDS). In a previous in vitro study, the results showed that the CXCL12/CXCR7 axis promoted the migration of MSCs. It is hypothesized that MSCs overexpressing CXCR7 could further benefits LPS-induced ARDS mice.

Methods: mMSCs were transfected with CXCR7 by a lentiviral vector and were transplanted into mice following LPS-induced intratracheal lung injury. Histopathology with haematoxylin and eosin staining and lung injury scoring was performed to evaluate lung tissue injury. Homing of mMSCs were assayed by NIR815 fluorescence imaging and immunofluorescent staining.

Results: The administration of MSC, MSC-GFP and MSC-CXCR7 all improved both lung histopathology (Fig. 9) and lung injury score. Moreover, the MSC-CXCR7 showed lower lung/body weight and lung injury score especially at 24 h compared with MSC-GFP. NIR fluorescence imaging and immunofluorescent staining showed that overexpressing CXCR7 significantly increased the accumulation of mMSCs in the lung especially at 24 h compared to MSC (Fig. 10).

Conclusion: It is demonstrated that overexpressing CXCR7 in mMSCs could further promote their homing to injured lung and improve the pathological damage in ARDS mice.

Rihard Knafelj, Ljubljana, Slovenia

Introduction: ILV remains valuable rescue therapy for refractory hypoxemia in patients with predominantly single sided lung injury (contusion, aspiration, hemorrhage, bronchopleural fistula) especially in centers with no extracorporeal membrane oxygenation (ECMO). Special intubation technique, double lumen endotracehal tube and 2 ventilators are needed.

Methods: Single center prospective observational study. Characteristics of consecutive patients assigned to ILV from 2010–2016 are reported.

Results: Total 8 patients underwent ILV during observed period (0,9% of all ventilated patients). All patients had paO2/FiO2 < 200, all were ventilated in pressure modes (P-AC, BiLEVEL), ventilators were not synchronized - PEEP, RR, FiO2 and Vt were set individually for each ventilator following blood gas results. Recruitment manuvers and NO were used at physician discretion. In 5 patients oxygenation improved significantly within 2 hours of ILV. 2 patients were upgraded to V-V ECMO (Wegener’s, pneumonia), in 4 contraindication to ECMO was present. 3 patients died (lung carcinoma, emphysema, Wegener’s). All tube placements were confirmed radiologically, 1 intubation with double lumen tube was performed via bougie and proper placement confirmed bronhcoscopically. In all patients left sided double lumen tubes were used only. In one patient carinal decubitus was observed due to double lumen tube’s hook. Patients underwent ILV for median 4 days (range 2–10 days).

Conclusions: In severe single sided lung injury necessitating MV, ILV should be considered as it represents valuable adjunct in treating refractory hypoxemia. With lung separation both lungs can be ventilated according to protective ventilation strategy. Special care is needed to prevent tube dislocation, cuffs overinflation and trauma to larynx, trachea and bronchi. Since tubes’ lumens are narrower special attention to possible tube blockage must be paid. Daily reevaluation and conventional tube placement is warranted as soon as possible.

¹Cankaya Hospital, Ankara, Turkey; ²Atasehir Memorial Hospital, Istanbul, Turkey; ³Acibadem Fulya Hospital, Istanbul, Turkey; ⁴Acibadem University School of Medicine, Istanbul, Turkey

Introduction: We hypothesized that in patients with ARDS, a pH level >7.20 can be achieved by using a tidal volume (TV) of 6 ml/kg. It was demonstrated that low TV (6–8 ml/kg) strategy was related with decreased volutrauma in patients with ARDS (1–3). According to ARDSNet (ARMA) trial, the initial mechanical ventilation (MV) settings should be 8 ml/kg TV, 7–9 L/min minute volume and a respiratory rate up to 35/min to provide pH > 7.20 and it is suggested to reduce the TV to 7 ml/kg and then gradually to 6 ml/kg (4).

Methods: The present study was designed in 2015 as prospective observesional. Patients with ARDS who were >18 years old were included in this study. The initial MV was set with TV:6 ml/kg, MV:7–9 L/min as recommended by ARDSNet (ARMA) trial. Blood gas samples were taken at the 1st and 2nd hours of MV. In patients with pH < 7.20, TV was increased by 1 ml/kg. Demographic data, 1st and 2nd hours blood gas values and ventilation parameters were recorded.

Results: One hundred and ten patients were included in this study. At the 1st hour, pH values in 86.4% (95) of all patients were above 7.20. In patients with pH < 7.20, while pH-corrected-APACHE II and lactate values were significantly higher; HCO3 and SBE were significantly lower than patients with pH > =7.20 (P = 0.006 and P < 0.001 for others). In patients with pH < 7.20, pH values were increased above 7.20 by increasing TV to 7 ml/kg.

Conclusions: In a significant percentage of patients with ARDS, targeted pH value can be achieved by using the lower threshold of recommended initial TV value. In patients with severe hyperlactatemic acidosis, higher initial TV values may be required.

References

1. Petrucci N et al. Cochrane Database Syst Rev 2004; 2:CD003844

2. Petrucci N et al. Cochrane Database Syst Rev 2013; 28:CD003844

3. Needham DM et al. Am J Crit Care Med 2015; 191:177–85

4. ARDSNet Study I, ARMA trial 1998.

Maasstad Hospital, Rotterdam, Netherlands

Introduction: Lung protective ventilation may improve patient outcome on ICU’s and clear guidelines are available for ventilator settings. It is unknown whether nurses and doctors adhere to these guidelines. The purpose of this study was to determine the effect of predefined lung-protective ventilation regime in pressure support ventilation (PS) introduced via an educational programme on tidal volumes and airway occlusion pressure.

Methods: The study was a case control single-center study. For the intervention group, an education programme was integrated consisting of eight clinical lessons of ±30 min, bed side teaching, four times written instruction by email and twice a dissemination of an educational presentation to the entire ICU team, in the period from May to June 2016. This program set guidelines for mechanical ventilation, with the specific instructions to ventilate patients with a tidal volume of 6–8 ml/kg/ideal body weight (IBW) and airway occlusion pressure (P0.1) of 2.8 to 6.0 cmH2O. Prior to ventilation instruction a control group was obtained from the general ICU population.

Inclusion criteria were: mechanical ventilation (PS) within 7 days after presentation on the ICU, exclusion criteria were: any neurological diagnosis, re-intubation and delirium.

Results: In total 14 patients were included in the intervention group versus 17 in the control group (baseline, Table 3).

Thirteen parameters were monitored during the study, primary endpoints where tidal volume ml/kg/IBW and the P0.1. In the intervention group (Table 3) finale tidal volumes were 1.2 ml/kg/IBW lower (p = 0.04). The P0.1 shows no difference between the two groups (p =0.75).

¹Fiona Stanley Hospital, Perth, Australia; ²Hadassah University Hospital, Jerusalem, Israel

Introduction: Intra-abdominal hypertension (IAH) is associated with increased morbidity and mortality. IAH reduces lung volumes and oxygenation and increases airway pressures. The optimal level of positive end-expiratory pressure (PEEP) to be applied in such patients remains unknown.

Animal data suggests that high PEEP adjusted for intra-abdominal pressure (IAP) may counteract IAH-induced lung volume and arterial oxygen level reductions.

In this pilot trial, our primary aim was to assess whether high and PEEP, adjusted for IAP, can be safely applied in patients with IAH requiring mechanical ventilation. Our secondary aim was to assess the effect of such PEEP levels on oxygenation.

Methods: Prior to enrolment, the patients next of kin were asked for written informed consent. Patients were excluded if deemed unsuitable or if predefined severe cardiovascular dysfunction or severe hypoxemia were present.

Ventilation was standardized. Following a recruitment manoeuvre, the following PEEP levels in cmH2O were randomly applied: 5 (baseline), PEEP = 50% of IAP, and PEEP = 100% of IAP. At each measurement step, we allowed 30 min for equilibration before measuring arterial blood gases and respiratory parameters. For the safety of our patients, predefined stopping criteria were applied.

Results: 15 patients were enrolled. The protocol was stopped in one patient (excluded from analysis) due to an unexpected hypertensive episode (drug error unrelated to protocol). Three patients did not tolerate PEEP = 100% IAP due to hypoxemia, hypotension, or ETT cuff leak in one patient each. PaO2/FiO2 ratios (maen and SD) were 234 (68), 271 (99), and 329 (107) at each PEEP level respectively. The difference was significant (p = 0.009) only between baseline and PEEP = 100% IAP.

Conclusions: PEEP = 100% was commonly not tolerated and only marginally improved oxygenation in ventilated patients with IAH. Such high PEEP pressures can therefore not be recommended for routine clinical practice.

¹King’s College London, London, UK; ²King’s College Hospital, London, UK; ³Guy’s and St Thomas’ Hospital, London, UK

Introduction: Neurally adjusted ventilatory assist (NAVA) is a complex intervention involving diaphragmatic monitoring and a proportional, neurally triggered ventilation mode [1]. Clinical effectiveness has not been demonstrated and feasibility data are required prior to larger definitive randomised controlled trials (RCTs). Although there is no agreement on minimum levels in clinical trials, low protocol compliance will impact on statistical power and interpretation of results in a definitive study [2]. The aim of this trial is to assess feasibility by measuring protocol compliance in the setting of a pragmatic RCT.

Methods: A feasibility RCT in 76 ventilated adult ICU patients, currently being conducted in a central London hospital. Patients at high risk of prolonged ventilation are randomly assigned to NAVA or Pressure Support (PSV) in the weaning phase. Feasibility end-points include protocol compliance (time in the NAVA mode), recruitment rate and acceptability. Secondary outcomes include ventilator free days and sedation load. The data from the first 48 patients (n = 25 and 23 in the NAVA and PSV groups respectively) are presented.

Results: At 14/11/2016 480 patients had been screened and 55 recruited with a mean recruitment rate of 1.8 patients per month. 71 patients were approached for inclusion with 16 patients (22.5%) excluded due to personal or professional consultee refusal. 68.2% of patients in the intervention group were compliant [CI 47.3–83.6] with a median adherence to the NAVA mode of 87.5% [38.9, 99]. Ventilator free days to day 28 were 18 [8, 24] days in the NAVA group vs. 19 [0, 23] days in the PSV group. There were no adverse events related to the intervention.

Conclusions: These data suggest an acceptable protocol compliance of > 65%. Further analysis of the reasons for non-compliance will be conducted; initial data suggest that a mix of technological, clinical and human factors underlie reduced adherence and protocol compliance. This is the first trial to compare NAVA to PSV in prolonged ventilation in the context of a pragmatic RCT. The results will provide guidance for the design of future trials.

References

1. Sinderby, C., et al., Neural control of mechanical ventilation in respiratory failure. Nature medicine, 1999. 5(12): p. 1433–6.

¹Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy; ²University of Milan, Milan, Italy; ³University of Ferrara, Ferrara, Italy; ⁴University of Milan-Bicocca, Monza, Italy

Introduction: Prone position (PP) improves survival and delays the risk of ventilation-induced lung injury in severe ARDS [1]. PP may exploit its benefits in the presence of optimized alveolar recruitment. Thus, we performed prone positioning in combination with recruitment manoeuvres (RMs) to assess the effects on aeration and oxygenation.

Methods: Eleven intubated, volume-controlled, ARDS patients (1 severe, 8 moderate, 2 mild) were studied in supine and PP before and after RMs (40 cmH2O airway pressure for 10 breaths). In each phase electrical impedance tomography (EIT) was recorded for 15 minutes to assess global and regional (dependent and non-dependent) respiratory system compliance (Crs), tidal volume (VT) distribution, end-expiratory lung volume changes (ΔEELV). Gas exchange and respiratory mechanics were monitored at the end of each phase.

Results: PaO[sub]2[/sub]/FiO[sub]2[/sub] was 159 ± 71 mmHg. Clinical PEEP (13 ± 3 cmH[sub]2[/sub]O), VT (6.6 ± 1.2 ml/kg IBW), RR (25 ± 5 bpm) and FiO[sub]2[/sub] (0.6 ± 0.2) were left unchanged. PaO[sub]2[/sub]/FiO[sub]2[/sub] improved after RMs (p = 0.054) and by interaction between PP and RMs (p = 0.046). ΔEELV significantly increased after RM performed in supine (p = 0.032; 40 ± 53 ml vs. pre-RM), in PP (p = 0.002; 95 ± 78 ml vs. pre-RM) but by similar magnitude (p = 0.089) post-RM supine vs. prone. PP didn’t modify Crs, but dependent Crs significantly improved (p = 0.006) and non-dependent Crs (p = 0.009) decreased. VT distribution was more homogenous during PP and lung homogeneity index improved, albeit non-significantly. Neither regional Crs nor homogeneity were affected by RMs.

Conclusions: PP improves regional mechanics and homogeneity; RM performed after proning seems efficacious and might increase PP protective effects.

References

¹Hospital Clinic, Barcelona, Spain; ²Policlinico di Milano, Milan, Italy; ³National Institutes of Health, Bethesda, USA; ⁴Ospedale San Paolo, Milan, Italy; ⁵Massachusetts General Hospital, Boston, USA; ⁶Ospedale Nuovo del Mugello, Borgo San Lorenzo, Italy; ⁷Gruppo Ospedaliero San Donato, San Donato Milanese, Italy; ⁸Arcispedale S. Maria Nuova, Reggio Emilia, Italy; ⁹Ospedale San Giovanni Bosco, Torino, Italy; ¹⁰Policlinico San Matteo, Pavia, Italy; ¹¹Policlinico di Modena, Modena, Italy; ¹²Azienda Ospedaliero-Universitaria di Parma, Parma, Italy; ¹³Ospedale Citta di Sesto San Giovanni, Sesto San Giovanni, Italy; ¹⁴Policlinico Gemelli, Roma, Italy; ¹⁵University Hospital Frankfurt, Frankfurt, Germany; ¹⁶University Hospital Zagreb, Zagreb, Croatia; ¹⁷Ospedale Santa Chiara, Trento, Italy

Introduction: We recently completed a large randomized clinical trial in critically ill patients to test the LTP vs. SRP in the prevention of ventilator-associated pneumonia (VAP). Here we focus on the feasibility of the study interventions.

Methods: We randomized 194 and 201 critically ill patients into LTP and SRP group, respectively. Patients in LTP were placed in semi-lateral (60°) - Trendelenburg position and turned from one side to the other every 6 hours. LTP was encouraged specifically during the first days of mechanical ventilation, in compliance with the patient’s wish. In the SRP group, patients were kept with the head of the bed elevated > = 30°. We assessed interventions feasibility, and nursing feasibility/workload

Results: Patients in the LTP and SRP group were kept in the randomized position for 38% and 90% of the study time, respectively (p = 0.001). Median fraction of time in LTP reached up to 51.8% (interquartile range 20.7–79.2) during the first 2 days; yet, it progressively decreased in subsequent days and was inversely related to the level of sedation. Median lorazepam equivalents was 46.7 mg/day (interquartile range, 20.8–120.0) and 58.0 (28.0–124.2) in the SRP and LTP groups, respectively (p = 0.37); propofol dose was 1393 mg/day (627–2345) and 1661 (826–2700) (p = 0.13). Finally, morphine equivalents were 112 mg/day (30–217) in the SRP and 119 (31–234) in the LTP (p = 0.56). Nurses reported greater difficulties in positioning the patient in LTP and higher workload (p < 0.001) vs SRP. However, approximately 50% of the LTP patients were easily or very easily positioned. Finally, these nursing challenges slightly ameliorated through practice, as more patients were enrolled in each center.

Conclusions: The LTP was specifically applied during the first days of MV. Of note, higher level of sedation/analgesia was not needed to keep the patient in LTP. At times, the nurses encountered difficulties in executing the LTP.

¹Policlinico di Milano, Milan, Italy; ²Hospital Clinic, Barcelona, Spain; ³National Institutes of Health, Bethesda, USA; ⁴Ospedale San Paolo, Milan, Italy; ⁵Massachussets General Hospital, Boston, USA; ⁶Ospedale Nuovo del Mugello, Borgo San Lorenzo, Italy; ⁷Gruppo Ospedaliero San Donato, San Donato Milanese, Italy; ⁸Arcispedale S. Maria Nuova, Reggio Emilia, Italy; ⁹Ospedale San Giovanni Bosco, Torino, Italy; ¹⁰Policlinico San Matteo, Pavia, Italy; ¹¹Policlinico di Modena, Modena, Italy; ¹²Azienda Ospedaliero-Universitaria di Parma, Parma, Italy; ¹³Ospedale di Sesto San Giovanni, Sesto San Giovanni, Italy; ¹⁴Policlinico Gemelli, Rome, Italy; ¹⁵University Hospital Frankfurt, Frankfurt, Germany; ¹⁶University Hospital Center Zagreb, Zagreb, Croatia; ¹⁷Ospedale Santa Chiara, Trento, Italy

Introduction: The semi-recumbent position (SRP) could increase risk of gravity-driven pulmonary aspiration and ventilator-associated pneumonia (VAP) (1–2). We investigated whether the lateral-Trendelenburg position (LTP) vs. the SRP would prevent microbiologically confirmed VAP.

Methods: 194 patients were randomized into the LTP group and 201 in SRP, and analyzed in an intention to treat approach. Patients in LTP were turned from one side to the other every 6 hours. Whereas, in the SRP group, patients were kept with the head of the bed elevated > = 30°. Primary outcome was VAP incidence rate, based on quantitative bronchoalveolar lavage fluid culture. Secondary outcomes were duration of mechanical ventilation, intensive care unit (ICU) and hospital stays, and ICU/hospital/28-day mortality.

Results: The data safety monitoring board recommended stopping the study at the second interim analysis for low incidence of VAP in the control group, lack of benefits in any major secondary outcome and adverse events in the LTP group. Microbiologically confirmed VAP was 0.5% (1/194 patients) in patients positioned in LTP, and 4.0% (8/201 patients) in patients in SRP, risk ratio (RR) between groups 0.13, 95% confidence interval (CI) 0.02–1.03, p = 0.04. Microbiologically confirmed VAP per 1000 ventilator days was 7.19, 95%CI 3.60–14.37 and 0.88, 95%CI 0.12–6.25 in the LTP and SRP, respectively, RR 0.12, 95%CI 0.01–0.91, p = 0.02. Competing risk analysis, which accounted for the concomitant risk of death and discontinuation of MV on VAP, confirmed lower cumulative probability of VAP in the LTP (cause-specific hazard ratio 0.13, 95% CI 0.02–1.00, p = 0.05). No statistically significant between-group differences were observed in secondary outcomes.

Conclusions: Critically ill patients positioned in the LTP had a statistically significant reduction in the incidence of VAP, in comparison with the SRP. Yet, further clinical examinations are mandatory to corroborate our findings, specifically in populations at high risk of VAP.

References

1) Li Bassi G et al. Crit Care Med 2014; 42: e620–7

2) Panigada M et al. Crit Care Med 2003; 31: 729–37

Ospedale San Paolo, Università degli Studi di Milano, Milano, Italy

Introduction: Airway pressure (Paw) based respiratory mechanics is used to guide ventilation. As an altered chest wall may influence the interpretation of Paw, aim of the study was to investigate the behavior of lung and chest wall during different phases of thoracic surgery

Methods: 20 patients undergoing pulmonary resection were enrolled. Double-lung ventilation (DLV) setting: PEEP 8 cmH2O, tidal volume (TV) 8 ml/kg; in one-lung ventilation (OLV) TV was reduced to 5 ml/kg and respiratory rate increased accordingly. Esophageal pressure (Pes) was measured and used to assess partitioned respiratory mechanics (ie. elastance of the respiratory system - Ers, chest wall - Ecw and lung - El). Respiratory mechanics was assessed during DLV in supine and lateral decubitus, OLV in lateral decubitus during closed and open chest

Results: Supine Ers (cmH2O/L) in DLV was 15.8 ± 4.6; no change in lateral position and DLV (19.3 ± 4.4, p > 0.05); significant increase in lateral position with OLV, with no difference between closed and open chest (31.2 ± 9.6 vs. 27.2 ± 8.9, p > 0.05). Figure 12 shows changes of El and Ecw: Ecw increased in lateral position and decreased when chest was opened. El was unchanged in lateral position but significantly increased during OLV.

Conclusions: Paw-based monitoring of respiratory mechanics did not allow to differentiate the cause of an alteration. Partitioned respiratory mechanics gives a deeper insight into the behavior of lung and chest wall.

¹Hôpital Sainte Musse, Toulon, France; ²Hamilton medical, Bonaduz, Switzerland

Introduction: Hyperoxemia occurs up to 50% of mechanical ventilation days in the ICU [1] and is associated with increased mortality as compared to patients ventilated in normoxemia [2]. INTELLiVENT-ASV is a full closed loop ventilation mode adjusting automatically oxygenation parameters according to SpO2 for passive and spontaneously breathing mechanically ventilated patients. This post-hoc analysis of a monocentric randomized controlled parallel group study compared hyperoxemia (PaO2 > 120 mm Hg or SpO2 > 96%) and hypoxemia (PaO2 < 60 mm Hg or SpO2 < 90%) between INTELLiVENT-ASV and conventional ventilation mode in mechanically ventilated ICU patients.

Methods: This randomized controlled trial was performed in the general ICU of Hôpital Sainte Musse, Toulon, France. Eligible participants: adult invasively ventilated for less than 24 h at the time of inclusion with an expected duration of mechanical ventilation of more than 48 h. Exclusion criteria: broncho-pleural fistula, ventilation drive disorder, moribund patients. Patients were allocated to INTELLiVENT-ASV group or to conventional ventilation group (volume assist control and pressure support) using blocked randomization. The post-hoc analysis was performed by the comparison of all arterial blood gases (ABG) performed during the study period: the number of ABG with hyperoxemia and hypoxemia, the median PaO2 and SpO2 for these ABG and FiO2 associated were compared.

Results: 60 patients were included, 30 patients in each group.

Conclusions: The closed loop control of oxygenation settings provided by INTELLiVENT-ASV decreases significantly the number of blood gas with hyperoxemia as compared to manual oxygenation setting without increasing the risk of hypoxemia.

References

[1] Suzuki et al. J Crit Care 28(5):647–654, 2013.

[2] Girardis et al. JAMA 316(15) :1583–1589, 2016.

University of Toronto, Toronto, Canada

Introduction: Databases from large trials are more frequently used to test new hypotheses about the impact of mechanical ventilation. In absence of direct measurement of respiratory effort, it is challenging to know if patients are breathing spontaneously. We sought to establish if the presence of spontaneous breathing can be predicted from readily available clinical variables.

Methods: Logistic regression, extreme gradient boosting, and random forest models were built from clinical variables to predict a diaphragm thickening fraction > 0.2 (mean value in healthy subjects breathing at rest [1]) as reference standard for inspiratory effort. Data from 195 patients was randomly split into a training (75%) and a test dataset (25%). The models were derived from the training dataset by cross-validation and validated on the test dataset. All models were implemented in R using the caret package.

Results: The AUROC for the logistic regression, extreme gradient boosting, and random forest models was 0.65 (0.59 to 0.70), 0.69 (0.63 to 0.72) and 0.68 (0.61 to 0.78). Diaphragm thickening fraction was most closely related to tidal volume, SAPS II score, and minute ventilation (Fig. 15).

Conclusions: We present an approach to detect spontaneous breathing during mechanical ventilation. Our models may be useful to identify spontaneously breathing patient subsets in cohort studies, but predictive accuracy is insufficient to replace direct monitoring of individual patients.

References

[1] Harper CJ et al., J Orthop Sports Phys Ther. 2013; 43(12):927–31

Chinese University of Hong Kong, Sha Tin NT, Hong Kong

Introduction: We studied the effectiveness of a flipped classroom approach using e-learning and a one-hour face-to-face (FTF) practical training in teaching medical students to manage basic mechanical ventilation (MV). Teaching MV is challenging due to teacher time limitations.

Methods: We performed a prospective cohort evaluation of the level of MV competence of final year medical students who participated in this optional training. The courseware consisted of an e-chapter (to introduce basic MV settings and physiology); online interactive cases and practice tests with a MV simulator (to facilitate scenario-based practice); a one-hour FTF tutorial (1 teacher to 6 students).

Two critical care educators, informed only of the syllabus outline, created the knowledge and skills assessments at a level expected of interns. Knowledge was assessed by pre- and post-course multiple choice questions (MCQs) testing 10 domains of MV. For each student, two MCQs of equal difficulty per domain were randomized to pre- and post-course tests. The two educators conducted 10-minute post-course skills testing of students’ practical competence in setting the correct MV mode, FiO2, tidal volume, respiratory rate (RR), PEEP in a case scenario; performing appropriate action in response to desaturation, pressure or RR alarms; reassessing after setting or adjusting MV. Students’ feedback on the course’s usefulness was surveyed.

Results: 179(81%) students consented to participate. Mean MCQ score pre-course was 29% and post-course was 53% - with a mean increment (95% CI) of 32.6(28.7–36.6) in students who completed the course including FTF, 7.0(0.8–13.1) when courseware was used without FTF, and 7.7(−1.6–17.1) in those who did not attempt the course (p < 0.001). MCQ score improved in every domain (McNemar’s test, P-values varied from <0.001 to <0.03) and for all domains combined (McNemar’s test P <0.001). 23 randomly selected students participated in the skills test - median score was 8/10(IQR 6.75–8.5). Students reported the course useful for improving their MV competence. Median score of individual course components was 4–5(IQR 4–5); 4 = agree, 5 = strongly agree.

Conclusions: The course is a time-efficient and effective approach to improve students’ MV knowledge and skills. Although FTF appeared to be necessary, we believe that it must be preceded by e-learning as one-hour FTF is insufficient to provide the background and practice skills teaching. Students showed motivation to participate and found the training useful. The courseware is freely available to other educators and therefore only requires clinical teachers to provide one-hour FTF sessions.

UZ Leuven, Leuven, Belgium

Introduction: The objective of our study was to identify predictors for prolonged mechanical ventilation (PMV) in patients after lung transplantation (ssLTx).

Methods: We performed a retrospective analysis of 36 patients admitted to our ICU after ssLTx, between 2011 and 2014. Baseline characteristics are summarized in Table 6. Cox proportional Hazard model was used to assess the risk of PMV.

Results: Of the preoperative risk factors (listed in Table 6), the indication pulmonary hypertension (PHT) was a statistical significant predictor, compared with COPD (P 0.04) and other pathology (P 0,0079) but not compared to pulmonary fibrosis (P 0,0927) when corrected for age, APACHE II >20, BMI < 20, dexmedetomidine or conventional sedation.

After transplantation, the only significant predictor of PMV (P 0,0238) was extracorporeal membrane oxygenation (ECMO), corrected for age, APACHE II > 20, BMI <20, Dexdor or conventional sedation and reperfusion edema.

Limitations of this study are the retrospective and single-center design, and the low sample size.

Conclusions: PMV after ssLTx is mainly explained by the indication for lung transplantation (PHT) and the postoperative need for ECMO.

Preoperative risk factors
Age med (IOR)	57.5 (43.25/61.75)
BMI mean (SD)	22.96 (+ − 3.71)
APACHE II med (IQR)	19.5 (18/24.75)
COPD N(%)	17 (47)
Pulmonary hypertension N(%)	2 (5.5)
Other (MUCO, Kartagener, Hemangioblastoma)	4 (11)
Lung fibrosis N(%)	13 (36)
Preoperative use of corticosteroids N(%)	15 (41.6)
Preoperative use of oxygen N(%)	16 (44)
Postoperative risk factors
ECMO N(%)	7 (19.4)
Sedation with Dexmedetomidine	24 (66)
Tracheostomy N(%)	2 (5.5)
Reperfusion edema N(%)	14 (38)

Legend Table 6 Baseline characteristics

¹Karolinska Institutet, Stockholm, Sweden; ²Lund University, Karlstad University, Lund, Sweden; ³Uppsala University, Uppsala, Sweden

Introduction: Treatment with extracorporeal membrane oxygenation (ECMO) and/or hypoxaemia in patients with acute respiratory failure (ARF) has been suggested to cause short and long-term cognitive impairment. To explore the evidence for this, we performed a systematic review.

Methods: We searched the databases Medline, PsycInfo, Cochrane Library, and Embase to identify publications, i.e. randomised controlled trials, nested case–control studies and cohort studies, reporting the possible association between hypoxaemia and cognitive impairment in patients treated for ARF with or without ECMO.

Results: We identified 2606 citations. After eliminating duplicates, two reviewers screened 1825 publications for eligibility and read 30 full text papers. No study fulfilled the inclusion criteria. We identified six studies, mainly case series, which dealt with the study question. One case series reported a correlation between hypoxaemia (haemoglobin oxygen saturation < 90%) and cognitive dysfunction at discharge but not at 1 and 2-year follow-up. In another study which concerned cognitive impairment after ECMO treatment for all causes, no direct correlation was found between ECMO and cognitive impairment. Cognitive impairment was more common after veno-arterial ECMO, which is rarely used in ARF. Mikkelsen et al. reported that a lower PaO2 was significantly associated with cognitive impairment at 12 months follow-up.

Conclusions: The evidence is sparse that that ECMO treatment for ARF or hypoxaemia during the course of ARF leads to long-term cognitive impairment. Therefore, any estimation of the actual risk of cognitive impairment as a result of using ECMO or employing hypoxaemia, permissively or inadvertently, in ARF cannot be made. More, high quality studies are needed to explore these clinically important questions.

References

Mikkelsen ME et al. American journal of respiratory and critical care medicine 2012; 185(12): 1307–15.

Risnes I et al. The Annals of thoracic surgery 2006; 81(4): 1401–6.

Hopkins RO et al. American journal of respiratory and critical care medicine 1999; 160(1): 50–6.

¹Careggi Teaching Hospital, Florence, Italy; ²University of Siena, Siena, Italy

Introduction: Extracorporeal membrane oxygenation (ECMO) can be used in patients with ARDS and life-threatening hypoxia, also to reduce VILI. We described 4 patients requiring ECMO treatment with massive lung consolidation and impaired lung ventilation.

Methods: Patient 1, a 63 years old woman, was admitted for ARDS in S. pneumoniae pneumonia with massive bilateral consolidations requiring ECMO treatment; for 4 days she was minimally ventilated (2 mL/kg); after ECMO weaning, protective ventilation was applied for other 5 days. After 16 days she was discharged; CT scan showed residual minimal consolidation of the right lung. She had a good recovery after 6 months. Patient 2, a 50 years old woman, was admitted from another ICU for ARDS in bilateral P. aeuriginosa pneumonia. After 7 days of ECMO and 5 more days of protective ventilation, minimal bilateral consolidation with cystic areas were seen at CT scans; at discharge, after 18 days, she had a good recovery of respiratory function. Patient 3, a 49 years old woman, was admitted for A(H1N1) influenza virus pneumonia evolved in ARDS. Massive lung bleeding and complete pulmonary consolidation occurred; ECMO and minimal ventilation lasted 66 days, mechanical ventilation continued for 10 days after ECMO weaning. She was discharged after 81 days spontaneously breathing, with a reduction of bilateral consolidation at CT. She had a good recovery after 6 months. Patient 4, a 54 years old woman, arrived from another ICU for severe ARDS due to viral pneumonia and massive bilateral consolidations. ECMO treatment was started and for 30 days she was not ventilated for massive bilateral consolidations; weaning from ECMO was not possible for bacterial infection and evolution in pulmonary fibrosis. The patient died in ICU for multi organ failure after 300 days.

Results: Massive pulmonary consolidation is not a terminal event in ECMO patients. Pulmonary consolidation can be related to an infection or may depend on massive intra-alveolar bleeding. In our series of 4 ECMO patients, pulmonary consolidation were caused in one case by bleeding, in the others by infectious diseases.

Conclusions: We experienced that massive pulmonary consolidation can resolve, provided that patients is kept alive and VILI is minimized by ECMO support. In our series, outcome and long term sequelae seems mainly related to the underling disease, rather than to the extension of pulmonary consolidation. Periods of limited or absent ventilation do not seem to prevent recovery of alveolar function. Bleeding does not seem to exclude a full lung recovery, while infections may cause abscesses and pulmonary disruption with possible long term sequelae and residual lung dysfunction. The authors confirm that written consent for publication had been obtained.

Phramonkutklao hospital, Bangkok, Thailand

Introduction: Extracorporeal membrane oxygenation (ECMO) may be a lifesaving procedure in patients with severe respiratory and/or circulatory failure (1,2). We present the first 19 adult patients treated with ECMO at medical intensive care unit (MICU) of Phramongkutklao Hospital, a Thai tertiary referral hospital.

Methods: A descriptive observational study was performed in 19 patients who received ECMO as a rescue therapy. Initial patient’s characteristics, technical aspects, and ECMO-related complications were described.

Results: Our adult ECMO program was started in August 2014. Since then we supported seventeen respiratory failure patients on veno-venous (VV) ECMO, one electrical shock patient on veno-arterial (VA) ECMO, and one cardiac arrest patient on VA ECMO-assisted extracorporeal cardiopulmonary resuscitation (E-CPR). Ultrasound-guided femero-jugular cannulation was percutaneously done, by intensivist, in all VV ECMO patients, while femoro-femoral cannulation was done by cardiothoracic surgeon using open technique in both cases of VA ECMO. The most frequent indication was severe pneumonia with acute respiratory distress syndrome (n = 10). Mean duration on mechanical ventilation before ECMO was 6 days. Before ECMO was initiated, mean Murray score was 3.4, respiratory compliance was 18 mL/cmH2O, PaO2/FiO2 was 102.5, and blood lactate was 5.7 mmol/L. Mean duration of ECMO was 10 days, average length of MICU and hospital stay were 18 and 21 days, respectively. Eight out of nineteen (42%) were decannulated after improvements, while remaining eleven cases who developed multiorgan failure resulting in death while on ECMO. ECMO-related complications were found in eleven cases (58%), which the most complication was active bleeding at the cannulation site.

Conclusions: Team organization and meticulous care during ECMO are crucial for minimizing ECMO-related complication. Even number of patients treated with ECMO in Thailand is increasing, a higher ECMO case volume may be required to increase the experience and improve quality of care.

References

1. Peek GJ, Mugford M, Tiruvoipati R, Wilson A, Allen E, Thalanany MM, et al. Efficacy and economic assessment of conventional ventilatory support versus extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR): a multicentre randomized controlled trial. Lancet 2009;374:1351–63.

2. Noah MA, Peek GJ, Finney SJ, Griffiths MJ, Harrison DA, Grieve R, et al. Referral to an extracorporeal membrane oxygenation center and mortality among patients with severe 2009 influenza A (H1N1). JAMA 2011;306:1659–68.

Careggi Teaching Hospital, Florence, Italy

Introduction: Deep vein thrombosis (DVT) continues to be a serious complication in (intensive care unit) ICU patients despite the extensive use of pharmacological and mechanical prophylaxis. During extracorporeal membrane oxygenation (ECMO) treatment, the risk of cannula-related DVT is markedly increased, because the large calipter of cannulas causes endothelium damage and significantly decreases venous flow around the cannula. In this perspective it is possible to assume that during ECMO treatment cannula-related DVT could represent an additional risk of mortality and morbidity for ICU patients. We studied the incidence of cannula-related and not related DVTs in ECMO patients and their potential impact on the mortality and length of stay in this high risk subgroup of ICU patients.

Methods: This is a retrospective study on 116 patients, 53 + 19 years old, with ARDS unresponsive to conventional treatments, who fulfilled the criteria for ECMO positioning set by the the Italian Ministry of Health. ECMO configuration included 78 (67.2%) patients with bicaval dual lumen mono-cannulation (J-ECMO), 21 (18.1%) with jugular-femoral cannulation (JF-ECMO) and 17 cases (14.6%) with femoro-femoral cannulation (FF-ECMO). Ultrasound exams for DVT diagnosis at the jugular-subclavian-axillary and the femoral-popliteal and sottopopliteal venous axes were performed within the first 48 hours after ECMO placement, once a week during ECMO treatment and within 48 hours after cannulas removal. During ECMO treatment the heparin infusion was adjusted to maintain aPTT target between 50 and 80 seconds.

Results: We diagnosed 45 cannula-related DVT: 39 DVTs were located at the jugular vein and 8 at femoral veins. We found 36 (56.25%) not cannula-related DVTs; 9 cases were central venous catheter (CVC)-related DVTs. No DVT was symptomatic and all were diagnosed by scheduled ultrasound sourvellaince; asymptomatic pulmonary embolism was diagnosed in 5 cases, 3 of which in not cannula-related DVT. In our study, the overall incidence of cannula-related DVT was independent of vascular configuration of ECMO (J; FF; JF). The diagnosis of cannula related DVT was not associated with a higher ICU mortality or longer ICU length of stay; on the contrary Not cannula-related DVT significantly increased ICU mortality and ICU length of stay (p < 0.005).

Conclusions: In our ECMO population only DVTs occurring in veins not involved in cannulation were significantly associated with increased mortality and ICU length of stay. These data strongly suggest that different pathophysiologic mechanisms are involved in the occurrence of cannula-related and not related DVT.

Careggi Teaching Hospital, Florence, Italy

Introduction: The role of extracorporeal membrane oxygenation (ECMO) remains controversial in adult patients with septic shock and data are so far scare and not univocal. We investigated the outcome of 26 patients with refractory ARDS and septic shock, consecutively admitted to our Intensive Care Unit (which is an ECMO referral center) from January 2013 to December 2015 and treated with venous-venous ECMO (VV-ECMO).

Methods: According to our center protocol, all patients were submitted to an echocardiography (transthoracic and/or transesofageal) before VV-ECMO implantation. Mortality during ICU stay was the primary outcome.

Results: During the study period, 74 patients with refractory ARDS were consecutively treated with VV-ECMO at our center, among whom 16 patients had concomitant septic shock (35.1%). When compared to patients without septic shock, septic patients showed higher values of SOFA (sepsis: 13.1 ± 3 vs no sepsis: 10.2 ± 2, p < 0.001), lactate values (sepsis: 6.12 ± 5.90 vs no sepsis: 3.09 ± 5.65, p = 0.07) and procalcitonin (sepsis: 76.85 ± 95.37 vs no sepsis: 12.05 ± 30.15, p < 0.01). At echocardiography, no differences was observed between the two subgroups in the incidence of left ventricular dysfunction (chi-square: p = 0.657), right ventricle dilation (chi-square: p = 0.347) and right ventricle dysfunction (chi-square: p = 0.688). The overall mortality rate was 44% (33/74) but it did not differ between patients with and without septic shock (chi-square: p = 0.218).

Conclusions: In patients with refractory ARDS requiring VV ECMO, septic shock is quite common. The use of VV-ECMO in these patients is associated with a comparable survival rate when compared to nonseptic patients. According to our data, VV ECMO is not contraindicated in patients with refractory ARDS and septic shock.

Republican Scientific and Practical Center for Organ and Tissue Transplantation, Minsk, Belarus

Introduction: The H1N1 strain of Influenza A is associated with a number of complications including acute respiratory distress syndrome (ARDS). Invasive mechanical ventilation (IMV) does not always provide an optimal solution. Extracorporeal membrane oxygenation (ECMO) has been shown to be a rescue treatment of severe H1N1-induced ARDS.

Methods: Here we describe first series of successful application of ECMO in these settings in Belarus.

Results: From January to April 2016 three patients with positive serodiagnostics of H1N1 requiring IMV for severe ARDS were admitted in different urban hospitals. Despite ARDS-Net recommended approach to IMV, it was not possible to achieve PaO2 > 60 mmHg, SpO2 > 54%. Ad-hoc veno-veinous ECMO with femoral and internal jugular cannulation was initiated shortly. IMV parameters were adjusted as follow: tidal volume reduced to 3–4 ml/kg PBW; PEEP 12–16 cmH2O, FiO2 40–50%. Patients were further transferred to the ICU of our tertiary care center. No adverse effects of transportation were noted. Median time of transfer was less than 60 min. Ultraprotective IMV was applied using APRW mode with Pinsp 20–22 cmH2O, PEEP 12–16 cmH2O, and FiO2 35–45%. Target tidal volume was 3–4 ml/kg PBW, and inspiration/expiration ratio was 1.5:1–2.5:1. Two patients required myoplegia. After 1 to 4 days of IMV an APRW mode was changed to IntelliVent-ASV™. ECMO settings were as following: flow 3–4 l/min (60–80% of minute volume); fresh gas flow 1.5–2.5 (max 9.7) l/min depending on PaCO2; and oxygen fraction 60–100% to achieve SpO2 92–94%.

The durations of ECMO were 9, 11 and 42 days. All patients received transcutaneous tracheostomy on 3–5 day of IMV, ventilator-associated pneumonia prevention bundle. We followed standard ECMO weaning procedure protocol after stabilization of respiratory function and achieving control of SIRS. Spontaneous breathing test was successful in two patients on day two after ECMO weaning. One patient with the longest duration of ECMO developed nosocomial septic shock with lung abscess complicated by hemopneumothorax, hemorrhagic shock and further left lung inferior lobectomy. He required additional 10 days of IMV following ECMO weaning, with successful return to natural airway breathing at day 67 after hospitalization. All patients survived hospitalization.

Conclusions: We successfully used ECMO as a rescue therapy in three patients with severe H1N1 induced ARDS that allowed weaning of IMV and recovery.

Medical University of Vienna, Vienna, Austria

Introduction: Severe thrombocytopenia yields a high risk for bleeding thus representing a relative contraindication for anticoagulation and therefore ECMO. We herein report on a series of haematological patients with severe thrombocytopenia undergoing long-term ECMO without anticoagulation.

Methods: Retrospective analysis of patient charts undergoing veno-venous gas exchange between 2012 and 2016. Data were extracted from charts and the local ECMO registry. Six patients fulfilling the criteria of severe thrombocytopenia < 50 G/L without anticoagulation for more than 3 days were identified.

Results: Patients suffered from acute myelogenous leukemia (n = 3), multiple myeloma (1) and acute lymphoblastic leukemia and consecutive stem cell transplantation (n = 2), respectively. ECMO was performed due to ARDS (n = 4) and graft versus host disease involving the lungs (n = 2). All ECMO systems used were heparin coated. Platelet count was 21 G/L (median, range 1–138), ECMO duration was 31 days (6–262), and ECMO was run without any anticoagulation for 17 days (7–262). Altogether, three clotting events were seen leading to oxygenator changes. Bleeding was common, leading to one fatal intracerebral bleeding, a minor subarachnoidal bleeding, a temporary gastric bleeding and persistent haematuria. Altogether, 27 packed red blood cells per patient (median, range 4–280) or 0,78 per day (0.57–1.25) and 22 platelet concentrates per patient (range 7–207) or 0.8 per day (0.57–1.26) were administered. Three of six patients could be weaned from ECMO, one patient survived ICU.

Conclusions: In patients with severe thrombocytopenia, ECMO can be run without anticoagulation even for longer periods. Nevertheless, bleeding is common while clotting events seem to be rare. Given the high mortality rate in this population, however, the indication for ECMO should be scrutinized rigorously.

Careggi Teaching Hospital, Florence, Italy

Introduction: Patients who develop acute respiratory distress syndrome (ARDS) have high mortality and morbidity rates and survivors could have clinically significant physical and psychological disabilities. Several studies have reported that extracorporeal membran oxygenation(ECMO) may improve survival in severe ARDS but there have been only few studies evaluating long-term outcomes in ECMO-treated ARDS survivors (1). The purpose of the study was to assess intensive care unit (ICU) outcomes and long term outcome and quality of life of patients with ARDS receiving ECMO for refractory hypoxemia.

Methods: We conducted a retrospective observational study in adult ARDS patients who had veno-venous-ECMO in a tertiary centre from January 2014 until April 2016. We collected demographic factors, Simplified acute physiology score (SAPS II) at admission, diagnosis, mechanical ventilation and ECMO duration, ICU outcome. We contacted telephonically all ICU-survivors and organized, when possible, a follow-up visits on average 6 months after discharge from ICU. The primary outcome variable was ICU survival and health related quality of life (HRQoL) measured with the Short-Form 36 (SF-36). Long-term quality of life assessment were assessed and compared to normative individual age- matched Italian population.

Results: Sixty-four patients (mean age 50.4 ± 14.7 years, 62% males) were studied; 44 patients (69%) were retrieved from external intensive care units (ICUs) by a dedicated ECMO retrieval team. SAPS II at admission was 42.0 ± 15.1 (mean ± DS). Infectious disease were the leading causes of ARDS: 46% bacterial and 21% A(H1N1) influenza pneumonias. Mean duration of vv-ECMO support was 18.8 ± 27.5 days (median of 11 days). 38 patients (59%) survived to ICU discharge; 15 were discharged to other hospitals. Of the 38 ICU-survivors, 25 patients (65.7%) had a follow-up visit after 6 months from ICU discharge. 5 patient died within 6 months and 8 patients were lost/unable to come to visit. HRQoL was evaluated for 21 patients: compared with age-matched controls, our ARDS survivors had significantly lower (p < 0.005) SF-36 physical function and physical role functioning; vitality, bodily pain, general health perceptions, emotional role functioning, social role functioning and mental health were comparable with those of general population.

Conclusions: In this ARDS cohort treated with ECMO the ICU-survival and six months after ICU discharge survival rate was similar to other findings (1). Long term survivors had reduced physical health but their psychological domain scores were comparable with those of the general population.

References

1. Schmidt M et al.: Intensive Care Med 2013;39:1704–13

¹Aurelia and European Hospital, Rome, Italy; ²Istituti clinici S Donato MI, Milan, Italy; ³Marino Hospital, Cagliari, Italy; ⁴Ospedale dell’ Angelo, Mestre, Italy; ⁵Santo Stefano Hospital, Prato, Italy

Introduction: Extracorporeal CO2 removal is used in COPD/moderate ARDS patients to avoid barotrauma and VILI. When renal failure coexists, a combined ECCO2 removal with RRT may be useful to improve CO2 clearance and kidney function in a single treatment.

The aim of this study is to evaluate 1- the clinical feasibility of a CO2 removal device integrated in a CRRT platform.2 - The clinical safety of the system. 3 - The changes of main respiratory and metabolic indices

Methods: Ten patients have been enrolled into the study. All patients had renal failure, were hypercapnic and mechanically ventilated, but one.

The patients were connected to a low -flow CO2 removal device (Prismalung ®) integrated into a conventional RRT platform (Prismaflex) by a two single lumen catheters inserted in jugular and femoral vein or by a bilumen catheter in a femoral vein. Pump blood flow was started at 300 ml/min and progressively increased to 400 ml/min. RRT was delivered in a CVHDF mode with an effluent flow of 45 ml/kg/hour. Heparin or citrate infusion (three cases) was used to anti coagulate the circuit. ACT and thromboelastography were used to monitoring the coagulation parameters.

At basal time (T 0), 12 th (T 1), 24 th (T2) hours, the main respiratory parameters and the renal indices were evaluated. Bleeding complications, hemofilter clottings, catheter malfunctions were recorded. All data are expressed as Mean ± SD… ANOVA TEST one way with Bonferroni correction was used to compare the changes of the parameters in the time. P < 0.05 was considered statistically significant.

Results: At Table 7 are reported the main results of this study. All patients, but one, survived to the treatment and 4/10 were weaned from the ventilator at the end of ECCO2R. The duration of the treatments was 60 ± 30 hours. There was a clotting of the circuit and two cases of catheter malfunction. No major bleeding episodes were observed.

Conclusions: This study confirms previous study of Prismalung on animals.(1) ECCO2 removal with a membrane oxygenator integrated in a CRRT platform is clinically feasible and devoid of major complications. It allows clearance of CO2, with improvement of respiratory acidosis and control of renal failure.

References

¹Egas Moniz Hosp., Lisboa, Portugal; ²Fernando da Fonseca Hosp., Lisboa, Portugal

Introduction: The aim of this study was to assess safety and performance of the new ECCO2R device, i.e. Prismaflex® + Prismalung® (Baxter), with citric acid as regional anticoagulant by calcium chelating effect and acidification to displace the dissolved CO2 from HCO3- and removing it through a membrane lung (Prismalung®, PL) with a blood flow (Qb) of 250 ml/min.

Methods: This study was conducted on 6 male pigs (68 ± 4.5 kg) separated in two groups, 2 pigs in the control group (Group A) and 4 pigs in the intervention group (Group B). Both groups were submitted to Phase I consisting of 4 hours with citrate anticoagulation (3.3 mmol/L) no CO2 removal (circuit bypass). In Phase II, for 8 hours both groups were submitted to ECCO2R with a FiO2 100% sweep gas flow of 15 L/min; Group A was submitted to the same citrate anticoagulation system as in Phase I while Group B was switched to citric acid anticoagulation (2.7 mmol/L) and acidification (2.0 mEq/min). All pigs were sedated and paralysed and connected to a ventilator (Servoi®, Maquet). The ventilator parameters were fixed mean tidal volume (7.11 ± 0.48 ml/kg) with PEEP 5cmH2O, FiO2 40%, V/min 8.1 ± 1.5 L/min (respiratory rate 18–20).

Results: CO2 content pre and post PL and CO2 removal is depicted in Fig. 17. The systemic pH and pCO2 did not differ statistically between the two groups. The systemic ionized calcium was stable in both groups. During the study no major critical events were recorded (death, cardiac arrest, arrhythmias, etc.). PL CO2 removal in intervention group (51.8 ± 7.8 ml/min) was significantly higher than in control group (35.2 ± 6.9 ml/min).

Conclusions: Using citric acid as a regional anticoagulant and acidification during ECCO2R is safe and more effective to remove the CO2 comparing standard ECCO2R.

¹Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, University of Milan, Milano, Italy; ²Sant’Anna Hospital, University of Ferrara, Ferrara, Italy

Introduction: Over the last few years, high flow nasal cannula (HFNC) is increasingly adopted as first line treatment of acute hypoxemic respiratory failure (AHRF) patients [1]. One of the key features of HFNC efficacy seems to be elevated patients comfort, which might critically depend from set temperature and flow. Aim of the study is to assess the comfort of patients undergoing HFNC at different temperatures and flows.

Methods: We conducted a prospective, randomized, cross-over study on 18 AHRF patients, admitted to the intensive care unit (ICU) and receiving respiratory support by HFNC as per clinical indication. We randomly applied 2 flows (HFNC 60 l/min and 30 l/min) and 2 temperatures (31 °C and 37 °C) for 15 minutes (four steps per patient). Clinical FiO2 was left unchanged during all steps. We investigated during the last minutes of each step: comfort by numerical scale from 0 (extreme discomfort) to 5 (very comfortable); dyspnea by modified Borg scale form 0 (none) to 10 (unbearable); physiologic respiratory parameters. Data of each step were compared using linear mixed-effects model analysis (parametric or non-parametric, as appropriate) for repeated measures with Bonferroni or Tukey post-hoc test.

Results: We enrolled 18 patients, aged 51 ± 14 year-old, 6 females. At enrollment, SpO2 was 97 ± 2% with FiO2 43 ± 13%, the etiology of AHRF was various. Main study results are reported in Table 8. Patient comfort level was significantly higher during HFNC at lower flow and temperature (p = 0.015 and p < 0.001 respectively), but interaction was not significant. Peripheral saturation was significantly increased by higher flow rate (p = 0.026). Interestingly, in this convenience sample, higher HFNC support didn’t modify the respiratory rate likely indicating clinical stability.

Conclusions: Lower flow and temperature grant improved patient comfort. Titration of HFNC setting to obtain best comfort might be relevant to exploit clinical efficacy.

References

Mahidol university, Bangkok, Thailand

Introduction: Extubation failure and reintubation after planned extubation are associated with high mortality [1]. Multiple factors including impair secretion drainage, hypoxemia or hypercarbia are possible causes of extubation failure [2]. Therefore, giving appropriate oxygen therapy and respiratory care after extubation in critically ill patients should decrease incidence of reintubation. Recently, high flow nasal cannula (HFNC) has been used increasingly in critically ill patients because it has many advantages over conventional oxygen therapy (COT). HFNC provides higher flow rate and more humidity which facilitated secretion drainage. Moreover, PEEP causing from HFNC decreases work of breathing [3]. Previous study shown that HFNC decreased incidence of reintubation in post-extubated critically ill patients [4]. Although there is a meta-analysis compared HFNC with other methods of oxygen therapy, patients who failed extubation criteria were included in the study [5]. Therefore, we conduct a meta-analysis comparing HFNC with other methods of oxygen therapy in preventing reintubation in planned extubated critically ill patients.

Methods: MEDLINE, OVID and the Cochrane Library databases were searched. RCTs and cohorts studies comparing HFNC with other methods of oxygen therapy in post-extubated critically ill patients were included. The primary outcome was re-intubation rate. The secondary outcomes were ICU mortality, length of stays (LOS) in ICU and post-extubated respiratory failure.

Results: 6 studies were analyzed in the meta-analysis. HFNC significantly reduced re-intubation rate (RR = 0.4, 95% CI 0.26–0.61) and post-extubated respiratory failure (RR = 0.51, 95% CI 0.35–0.73) comparing to COT. However, there were no significant difference in ICU mortality (RR = 0.93, 95% CI 0.47–1.83) and LOS (PMD = −0.14, 95% CI −0.65–0.36)

Conclusions: HFNC reduced re-intubation rate and post-extubated respiratory failure compared to COT. There were no difference in ICU mortality and LOS.

References

1. Thille AW, et al. Am J Respir Crit Care Med 187:1294–302, 2013

2. Kulkarni AP, et al. Indian J Crit Care Med 12: 1–9, 2008

3. Spoletini G, et al. Chest 148:253–61, 2015

4. Hernández G, et al. JAMA 315:1354–61, 2016

5. Monro-Somerville T, et al. Crit Care Med. 2016 Sep 8. [Epub ahead of print]

Ramón y Cajal University Hospital, Madrid, Spain

Introduction: The goal of the study is to analyze the impact and the results of the application of high flow nasal cannula in an intensive care unit of a tertiary, university hospital.

Methods: We perform a retrospective study with all patients who have been treated with high flow nasal cannula (HFNC) for their respiratory failure between May 2013 and April 2016.

Results: 174 patients were included. Average age: 57.81 ± 15.5 (18–88), male (58.6%). Severity index: SOFA 8.17 ± 4.29 (1–19), APACHE II 19.43 ± 8.3 (3–44) and SAPS II 48.66, average stay 14 days and mortality rate of 22.4%

For a better categorization of patients, diagnostics were tabulated in the following groups. Respiratory 52.3% Haematological 20.7%, Septic 16.1%, Neurological 4.6%, Cardiologic 3.4%, Digestive 0.6%, Oncologic 0.6%

The origin of respiratory failure was primarily: Respiratory (72.4%), Septic (21.3%), and miscellaneous (6.3%)

Patients required high flow nasal cannula therapy for hypoxemic decompensation in 77.6% of the cases. In the 1.7% of the cases the cause were mixed and was hypercapnia in the 20.1% of the cases.

56.9% (99/174) of the patients, required mechanical ventilation. 43.1% of the patients (75/174) didn’t require mechanical ventilation. In 31 up to the 99 patients who require mechanical ventilation, HFNC was used as a support for the scheduled extubation. In 68 up to 99 patients, mechanical ventilation was required after HFNC failure.

The group of patients which needed mechanical ventilation had higher mortality (p < 0.0001).

The mortality rate is considerable higher due to retardation of the intubation, after the high flow oxygen therapy has failed. The patients intubated the first 48 hours after the high flow oxygen therapy failure have a mortality of 44% vs the 61% after 72 hours.

There are significant differences in the mortality rate regarding the type of patient. Is very probable that the most benefit group by HFNC is the one with severe respiratory failure with exclusive respiratory cause and hypoxic decompensation.

Conclusions: The use of high flow oxygen therapy has changed the attitude towards the patients with insufficiency respiratory failure and may avoid in some cases the use of mechanical ventilation. The delay in the orotracheal intubation after high flow therapy has failed, increases the rate of mortality. Further controlled studies are needed to display which other patients can be beneficed by the high flow oxygen therapy.

Sinai Health System, Toronto, Canada

Introduction: Our study objectives were to evaluate the impact of high flow nasal cannula (HFNC) in immunocompromised (IC) patients with acute hypoxemia respiratory failure. The role of HFNC compared to conventional oxygen therapy remains controversial in this population.

Methods: We performed a systematic review and meta-analysis to evaluate the application of HFNC in an adult IC patients with acute respiratory failure (to August 2016). We included any randomized controlled trials (RCTs) or observational studies and meta-analyzed results where HFNC was compared to face mask oxygen or non-invasive ventilation (NIV). Our primary outcome was the need for mechanical ventilation. A series of secondary outcomes were analyzed.

Results: Of 3099 citations screened, 6 fulfilled our inclusion criteria (3 RCTs, 3 observational studies). Across 428 patients, the definition of IC included patients with pharmacologic IC states or IC due to one’s underlying disease. Of the two trials evaluating the application of HFNC vs face mask, there was no decrease in the rates of mechanical ventilation (RR 1.03, 95% confidence interval (CI) 0.41–2.61, p = 0.95) Fig. 18. Contrary to this, HFNC vs NIV was associated with a decrease in need for invasive mechanical (RR 0.58, 95% CI 0.41–0.83, p = 0.003).

Conclusions: Evidence to date is limited on the application of HFNC in this population; therefore, a larger number of high quality studies are needed to corroborate these preliminary findings.

¹University of Milan, Milan, Italy; ²University of Ferrara, Ferrara, Italy; ³Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy

Introduction: High-flow nasal cannula (HFNC) is a non-invasive respiratory support associated to several physiologic advantages in acute hypoxemic respiratory failure (AHRF) patients [1]. Previous studies showed that these effects depend on set flow. Aim of the study was to identify the flow at which gas exchange, end-expiratory lung volume (ΔEELV), respiratory rate (RR), inspiratory effort and corrected minute ventilation (MVcorr = MV*PaCO[sub]2[/sub]/40) result in highest improvement.

Methods: We performed a prospective, randomized, cross-over study, divided in 4 phases, on AHRF patients (PaO[sub]2[/sub]/FiO[sub]2[/sub] < =300) admitted to intensive care unit. We randomly applied standard facial mask (12 l/min) vs HFNC set at 30, 45 and 60 l/min, each step lasting 20 minutes. Clinical FiO[sub]2[/sub] was left unchanged. We collected gas exchange, lung volumes by electrical impedance tomography, patient’s inspiratory effort by esophageal pressure (Pes) and respiratory rate.

Results: We enrolled 17 patients (9 females), aged 62 ± 10 year-old. At enrolment the PaO[sub]2[/sub]/FiO[sub]2[/sub] was 151 ± 60 mmHg. The highest PaO2 value in 71% of patients was reached at HFNC 60 l/min (p = 0.0047). The highest lung volume was obtained for 59% of patients at HFNC 60 l/min (p = 0.0094). The lowest respiratory rate (bpm) in 77% of patients was at HFNC 60 l/min (p = 0.0007) and the lowest value in ΔPes was obtained for 57% of patients at HFNC 60 l/min (p = 0.0464). On the contrary, the percentage of patients with minimum value of MVcorr was equally distributed among the 3 HFNC flows (p = 0.662). Figure 19 shows flows distribution.

Conclusions: Our results show that HFNC 60 l/min might be regarded as the optimal flow for most parameters. However, 30–40% of patients obtained best results at lower flows and with absence of “optimum” flow for corrected minute ventilation.

References

1. Roca O. et al. Crit Care 28;20:109, 2016

Ramón y Cajal University Hospital, Madrid, Spain

Introduction: Our goal is to analyze the impact and the results of the application of high flow oxygen therapy (HFNC) in hematological patients with respiratory failure

Methods: We performed a retrospective study.

All hematological patients who were treated with HFNC between May 2013 and April 2016 were included (n = 36)

Results: Average age: 51. 67 ± 15. 77 (23–80); 50% male; mean SOFA: 9. 09 ± 5. 15 (2–19), and APACHE II: 22. 61 ± 8. 86 (3–40). The etiology of respiratory failure was hypoxemic in 91. 66% (n = 33) and mixed in 8. 33% (n = 3) of cases.

HFNC avoided intubation and therefore mechanical ventilation (MV) in 38. 9% (n = 14) of the patients. 19 patients required MV after HFNC failure and in the other 3 HFNC was used after extubation. (Fig. 20)

The mortality rate in the study was 44.4% (n = 16). In the group of patients who avoided MV was 14.28% (2/14). In the ones who required mechanical ventilation after HFNC failure the mortality rate was 68.42% (13/19). 3 Patients required HFNC after extubation, 1/3 died. (Fig. 21)

The group of patients, who need mechanical ventilation, had higher mortality. (p <0.0001) However, the mortality rate was higher in this group due to delay of intubation. The average delay in the patients who died (n = 13) was 2.28 days vs. 1.83 days in the survivors group (n = 6)

Conclusions: HFNC oxygen therapy appears to be a safety therapeutic option for the treatment of severe respiratory failure in patients with haematological malignancies. Intubation was avoided in a substantial proportion of patients. Also was related a lower mortality rate in this subgroup of patients. However, the delayed of intubation due to HFNC failure was related to higher mortality.

Careggi Teaching Hospital, Florence, Italy

Introduction: The study aims to compare endotracheal tube (ETT) and extraglottic devices (EGD) in the out-of-hospital setting, in terms of consequences and outcome. Secondary endpoints were evaluation of parameters that could correlate with survival and neurological outcome and evaluation of the influence of a mechanical ventilation (MV) vs bag valve mask ventilation (BVM) during the transport from the field to the hospital.

Methods: This retrospective study examined 404 patients with a out-of-hospital airway management between January 2013 and June 2016. 187 of them were transferred to the Intensive Care Unit (154 managed with ETT and 33 with EGD); they were analyzed for demographic, infective, radiologic and neurologic parameters. Patients with ETT were subsequently divided in 2 subgroups, the ones who received a MV during the transport to the hospital and the ones who were manually ventilated.

Results: Our results show that there was no correlation between the use of ETT or EGD and mortality rates 48 hours after the admittance to ICU, but there was a significant difference in survival after 7 days. There was no significant difference between ETT and EGD in terms of neurological and pulmonary outcome when patients were dismissed from ICU. The ventilation technique during the transport revealed to be an accurate parameter of survival after 48 hours, as the MV reduced patients’ mortality when compared to the BVM.

¹Medical Univesity, Lublin, Poland; ²Wroclaw University of Technology, Wroclaw, Poland; ³Medical University, Lublin, Poland; ⁴SPSK No4, Lublin, Poland

Introduction: Recruitment maneuvers have been advocated recently, however their routine use is still under debate [1]. This study attempts to evaluate the impact of extrathoracic negative pressure (eNP) on arterial oxygenation and hemodynamics in pigs with acute lung injury.

Methods: The study involved 10 adult Large White pigs weighting 48–60 kg. Under general anaesthesia animals were intubated and ventilated in a volume-controlled mode (Puritan-Bennett 840) with F[sub]I[/sub]O[sub]2[/sub]-1.0, I:E ratio-1:2. Vt −8–10 ml/kg and RR-14–18/min were used to maintain PaCO[sub]2[/sub]- 35–45 mmHg. An infusion of lactate Ringers solution was given iv at a rate of 5–8 ml/kg/h.

Lung injury was induced with bronchoalveolar lavage by warm 0.9% NaCl (30 ml/kg) until PaO[sub]2[/sub]/F[sub]I[/sub]O[sub]2[/sub] remain below 100. Thereafter, using a whole body close-chamber, the eNP was commenced in combination with IPPV.

Heart rate (HR), mean arterial pressure (MAP), mean pulmonary arterial (MPAP) and pulmonary capillary wedge (PCWP) pressures, cardiac output (CO) (Swan-Ganz catheter) as well as arterial oxygen tension (PaO[sub]2[/sub]) were recorded before and after lung injury: at 0 (baseline), −4, −8, −12, −16 cmH[sub]2[/sub]O.

Results: Significant improvement in PaO[sub]2[/sub] was observed during the eNP when compared with baseline. There were no significant changes in hemodynamic parameters when the negative pressures of −4, −8 and −12 cmH[sub]2[/sub]O were applied (fig. 22).

Conclusions: This study demonstrates effectiveness of extrathoracic negative pressure during recruitment of injured lung tissue in terms of arterial oxygenation and hemodynamic stability.

References

1. Lovas A. et al.: Biomed Res Int 2015; 2015: 478970.

¹Medical University, Lublin, Poland; ²Wroc³aw University of Technology, Wroclaw, Poland; ³SPSK No4, Lublin, Poland

Introduction: Respiratory mechanics are regularly impaired when atelectasis occurs. There are many different procedures that can be used in order to reopen collapsed lung tissue. The aim of our study was to determine the effects of extrathoracic negative pressure (eNP) on respiratory mechanics of atelectatic lungs.

Methods: Ten Large White pigs weighting 52 ± 5 kg were included in the study. Under general anaesthesia all animals were tracheotomized (tube size 8.5–9 mm) and ventilated in a volume-controlled mode (P-B 840) at RR–18/min, with VT– 8–10 ml/kg, I:E ratio −1:2 and F[sub]I[/sub]O[sub]2[/sub]–1.0. Lungs injury was induced by repetitive lavages with 1.5–1.8 l warm 0.9% NaCl until PaO[sub]2[/sub]/F[sub]I[/sub]O[sub]2[/sub] remain stable below 100. After lungs injury was produced, the eNP, using a whole body size-box, was commenced in combination with IPPV. Peak airway pressure (P[sub]a[/sub][sub]w[/sub]peak), airway resistance (R) and dynamic compliance (Cdyn) were recorded, using ventilator software, before lungs injury and after – at 0 (baseline), −4, −8, −12 and −16 cmH[sub]2[/sub]O negative pressures.

Results: There were significant differences in P[sub]a[/sub][sub]w[/sub]peak and R but no in Cdyn at negative pressure −8, −12, and −16 cmH[sub]2[/sub]O compared to baseline (tab).

¹Epicura, Hornu, Belgium; ²Condorcet, Tournai, Belgium; ³UCL, Bruxelles, Belgium

Introduction: In emergency care, oxygen therapy can be administered directly with bag valve mask (BVM). In some cases, this method is applied to patient with a spontaneous breathing. The purpose of this study was to evaluate inspiratory negative pressure (INP) during spontaneous breathing through three different bag valve masks.

Methods: Three BVM (Ambu®Oval, MR100®, Ambu® Mark IV; without oxygen reservoir bag) were analyzed. Spontaneous breathing was simulated on a bench study. A two-compartment model of adult test lung (Dual Test Lung® DTL, Michigan Instrument) was connected to a Servo i® ventilator. One compartment of DTL was moved by Servo i®, the other as the driving compartment which simulated breathe. Servo i® was set in volume-controlled mode. Three-minute ventilation (MV) (Respiratory frequency (Rf): 10,20,30 cpm with tidal volume (Vt) of .45 L were analyzed. The peep was equal to 0 cm H2O and the Ti/Ttot was equal to 0.33. The compliance of DTL was set to .06 L/cm H2O and the initial resistance set to 5 cm H2O/L/sec. The change in inspiratory pressure was measured by an analog IWorx station/digital IWx/214 LabScribe II ® software. Three consecutive measurements were performed for each MV. Parameters were compared over time using ANOVA for each MV (p < .001).

Results: For all MV, no significant statistical differences were raised between Ambu®Oval and Ambu® Mark IV (ANOVA: p < .001).

Conclusions: For a same BVM, when MV increases, INP increases. For all MV, MR100® is the BVM is one who offers the lower resistance. This is most likely due to the type of patient valve of the BVMs, because patient valve of AMBUs® is a mushroom valve conception, while patient valve of MR100® is a duckbill valve conception. This last type of valve seems to offer less resistance than mushroom valve.

¹Epicura, Hornu, Belgium; ²Condorcet, Tournai, Belgium; ³UCL, Bruxelles, Belgium

Introduction: Bag valve masks (BVM) are frequently used in emergency unit or with intubated patients breathing spontaneously. The mask and the tube of intubation are thought to increase resistances and thus inspiratory resistance. The purpose of the present study is to evaluate:

1) The impact of BVM on the inspiratory negative pressure (INP) during simulated spontaneous breathing with intubate tube.

2) The additional effects of the intubation tube size and minute ventilation on the INP.

Methods: In a bench study, a bag valve mask (Ambu® Mark 4, without oxygen reservoir bag) was tested with three intubations tube (Internal Diameter 7,8,9 mm). Spontaneous breathing was simulated with a two-compartment model of adult test lung (Dual Test Lung® DTL, Michigan Instrument). DTL was connected to a Servo i® ventilator in volume-controlled mode. One compartment of DTL was moved by Servo i®, the other as the driving compartment which simulated breathing. Three-minute ventilations (MV) (Respiratory frequency: 10,20,30 cpm with volume tidal = .5 L) were analyzed. The peep was equal to 0 cm H2O and the Ti/Ttot was equal to 0.33. The compliance of DTL was set to 0.06 L/cm H2O and the initial resistance set to 5 cm H2O/L/sec. The change in inspiratory pressure was measured at entry of DTL, by an analog IWorx station/digital IWx/214 LabScribe II ® software. Three consecutive measurements were performed for each MV. Parameters were compared using ANOVA for each MV.

Results: For MV (10 × 500 ml): NO Statistical differences were found between A2 and A4, A5 and A1, A6 and A4, A3 and A1, A5 and A3. - For MV (20 × 500) and (30 × 500): Statistical differences were found between all groups ANOVA (p < .001).

Conclusions: With a bag valve mask, in spontaneous breathing, when MV increase, INP increase. Moreover, when intubation tube size decrease, the INP increase. For the same intubation tube size, when MV increase, INP increase. For the same MV and same intubation tube size, the addition of a BVM increase INP.

References

1) Abdo Khoury. From Mouth-to-Mouth to Bag-Valve-Mask Ventilation: Evolution and Characteristics of Actual Devices—A Review of the Literature. Biomed Res Int. 2014; 2014: 762053.

Institute of Postgraduate Education Bogomolets National Medical University, Kyiv, Ukraine

Introduction: The safe level of endotracheal tube (ETT) cuff pressure during anesthesia is between 20 to 30 cm H2O. The over-inflated cuffs may cause different complications, e.g. sore throat, cough, aspiration and trachea injuries, including rupture. The use of cuff pressure manometer was recommended in several studies (1), hovewer it is still not a routine during anesthesia in many hospitals allover the world (2). Often skilled anesthesiologists are sure that they could evaluate normal and high pressure in the cuff by palpating it after intubation.

The aim of this prospestive onservational study was to estimate whether anesthesiologists could evaluate a safe (20–30 cm H2O), high (30–60 cm H2O) and very high cuff pressure (more than 60 cm H2O) by palpation of the external cuff ballon on an ETT.

Methods: The study was conducted in two Kyiv city hospitals at the department of anesthesiology and intensive care in 2015–2016. Anesthesiologists were asked to inflate an ETT cuff after intubation using their usual inflation technique and estimate by palpation if the cuff pressure is at the safe level, high level or very high level. After that the actual pressure in the cuff was validated with manometer measurements.

Results: ETT cuff pressure were measured in 146 patients by 24 anesthesiologists. The majority self-evaluate ETT cuff pressure as safe (86%), other as high (14%). The actual pressure in the cuff was safe in 26 (18%) of cases, high in 100 (68%) and very high in 20 (14%) of cases. There were no statistical difference between accuracy of ETT cuff pressure self-evaluation from one anesthesiologist to another.

Conclusions: Findings from this study shows that only in 18% of cases anesthesiologists could evaluate safe level of ETT cuff pressure by palpation of the ballon after intubation. Most of anesthesiologists underestimated the ETT cuff pressure. So, pressure manometer measurement of ETT cuff pressure should be implemented for safe medical practice.

References

1. Harm F, Zuercher M, Bassi M, Ummenhofer W. Prospective observational study on tracheal tube cuff pressures in emergency patients: is neglecting the problem the problem? Scand J Trauma Resusc Emerg Med. 2013;21:83. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4235018/. Accessed March 26, 2014.

2. Chan S-M, Wong C-S, Cherng C-H. Determining an optimal tracheal tube cuff pressure by the feel of the pilot balloon: a training course for trainees providing airway care. Acta Anaesthesiol Taiwan. 2009;47(2):79–83.

¹Plymouth hospitals NHS Trust, Plymouth, UK; ²Royal Devon and Exeter Hospital, Exeter, UK

Introduction: Despite the use of endotracheal tubes (ETT) with high volume, low pressure cuffs, concerns about tracheal mucosal damage and long term tracheal stenosis following intubation in ICU remain. Estimates of the incidence of laryngeal injury range from 15–94%. It is generally accepted that pressure exerted by the ETT cuff impairs mucosal blood flow and causes ischaemia. [1] We hypothesised that the lack of agreed ‘safe’ cuff pressure or relationship between cuff pressure and complications may be because cuff pressure is not a surrogate for mucosal pressure.

Methods: The study was performed using a cadaveric pig trachea. Sheridan endotracheal tubes in sizes 6,7,8 and 9 were used to intubate the trachea. The ETT cuff pressure was measured using a hand held manometer. A strain gauge was inserted under direct vision in a retrograde manor to align with the midpoint of the ETT cuff. The cuff was inflated in 1 ml increments and cuff pressure and applied pressure were recorded.

Results: We found no correlation between ETT cuff pressure and applied tracheal mucosa pressure for a size 6 or 7 ETT.

For size 8 and 9 ETT the graph of cuff pressure and applied pressure had an inflection point. Below the inflection point applied pressure remained low. Above the inflection point there was a linear relationship between applied pressure and cuff pressure.

Conclusions: We presume that for the smaller ETT, over the volumes tested, there is no circumferential contact between the cuff and trachea. The applied pressure remains independent of the cuff pressure. For size 8 and 9 ETT above the inflection point the cuff becomes in circumferential contact with the tracheal mucosa. The rise in cuff pressure is directly proportional to the applied mucosal pressure.

References

[1] Sultan et al. Endotracheal tube cuff pressure monitoring: a review of the evidence. J Perioper Pract. 2011 Nov;21(11):379–86.

Pusan National University Hospital, Busan, South Korea

Introduction: The most likely cause of tracheal tube displacement is the increased pretracheal soft tissue thickness related to obesity. If postural change of pretracheal tissue depth increase, it may reduce the intratracheal length of the tube and induce tube displacement. Our purpose was to analyze relationship between difference of pretracheal tissue depth as postural change and risk of tracheal tube displacement.

Methods: We performed a prospective clinical trial from June 2014 to September 2015. Patients enrolled in the present study had been admitted to the Department of emergency medicine. We use a linear probe(Sonosite, M-Turbo) to measure each pretracheal tissue depth in neutral and extended neck. Neck extension is accomplished by placing the pillow under patient’s back.

Results: Seventy patients (male 49, female 21, mean age 53.9 18 [SD] years) were enrolled in this study. Pretracheal tissue depth difference was positively correlated with neutral depth(rho 0.629) and and BMI(rho 0.326).

Conclusions: Because Accidental decannulation is the most common serious complication associated tracheostomy, it is important to predict probability of tube displacement and use extended-length tube for risky patients. Pretracheal tissue depth difference as postural change measured by ultrasound was correlated well with risk factor of tubal displacement, pretracheal tissue depth and BMI. Pretracheal tissue depth difference as neck posture is helpful to predict risk of tracheostomy tube displacement.

References

1. Goldenberg D, Bhatti N. Management of the impaired airway in the adult. In: Cummings CW, ed. Otolaryngology Head and Neck Surgery. 4th ed. Philadelphia: Mosby; 2005:2441–53.

2. De Leyn P, Bedert L, Delcroix M, et al. Tracheotomy: clinical review and guidelines. Eur J Cardiothorac Surg 2007;32:412–21. Epub 2007 Jun 27.

3. Kost K. Percutaneous tracheotomy: a prospective evaluation of 500 consecutive cases. Laryngoscope 2005;115:1–.30.

4. McCormick T, Venn R. Recently published papers: Tracheostomy: why rather than when? Obesity: does it matter? And stroke: diagnosis, thrombosis and prognosis. Crit Care 2007;11:127.

5. El Solh AA, Jaafar W. A comparative study of the complications of surgical tracheostomy in morbidly obese critically ill patients. Crit Care 2007;11:R3.

6. Byhahn C, Lischke V, Meininger D, et al. Peri-operative complications during percutaneous tracheostomy in obese patients. Anaesthesia 2005;60:12–5.

7. Darrat I, Yaremchuk K. Early mortality rate of morbidly obese patients after tracheostomy. Laryngoscope 2008;118:2125–8.

8. Szeto C, Kost K, Hanley JA, et al. A simple method to predict pretracheal tissue thickness to prevent accidental decannulation in the obese. Otolaryngol Head Neck Surg 2010;143:223–29.

9. Walker RN, Alexander IJ et al. Anthropometric measurements: Effect of CT depth of pretracheal soft tissue on tracheostomy tube selection. Am J Neuroradiol 2012;33:449–52.

Tata Memorial Hospital, Mumbai, India

Introduction: Tracheostomy has been used traditionally to provide secure airway in patients undergoing radical resections for head and neck cancer. However, recent studies have questioned these practices, emphasizing endotracheal intubations to be equally safe. We planned a study to determine the safety and efficacy of overnight intubation followed by extubation the next morning (ETT group) as compared to tracheostomy (TT group) for postoperative airway management and to audit our airway management practices for major head and neck cancer surgeries.

Methods: A prospective observational audit was conducted over one year at Tata Memorial Hospital from August 2015 to July2016. Adult patients undergoing intraoral surgeries were included. Patients undergoing emergency surgery and having a tracheostomy prior to enrolment were excluded. Extent of the disease, type of surgery, demographic details of the patient, anaesthesia details and airway management details were recorded. These patients were followed up in the post-operative period until discharge. Time to extubation was recorded in the ETT group. Time to oral intake, speech, complications until discharge and length of hospital stay were recorded in both groups.

Results: We screened 4477 patients and included 720. There were 417 patients in ETT group and 303 patients in TT group. As compared to TT group, ETT group had shorter stay in hospital (7.2 ± 3.7 versus 11.5 ± 7.2 days, p = 0.00), less time to oral intake (5.1 ± 1.6 versus 7.2 ± 2.8 days, p = 0.00), and less time to speech (3.6 ± 1.6 versus 6.1 ± 2.7 days p = 0.00). The overall complications (4.3% versus 22.4%, p = 0.00) and airway related complications (1.68% versus 8.58%, p = 0.00) were lower in the ETT group compared to the TT group.

Conclusions: The airway in intra-oral major head and neck cancer surgery can be managed safely with overnight intubation with faster return to oral feeding and speech. Tracheostomy should be performed only in select patients.

References

1. Scher, N., Dobleman, T. J. and Panje, W. R. (1989), Endotracheal intubation as an alternative to tracheostomy after intraoral or oropharyngeal surgery. Head Neck, 11: 500–504. doi: 10.1002/hed.2880110605

2. Agnew J(1), Hains D, Rounsfell B, Aust N Z J Surg. 1992 Aug;62(8):652–3. Management of the airway in oral and oropharyngeal resections

3. Randell T, Söderholm AL, Lindqvist C Is nasotracheal intubation safe in surgery for mandibular cancer?Arch Otolaryngol Head Neck Surg. 1992 Jul; 118(7):725–8

¹Hospital General “Norberto Treviño”, CD. Victoria, Mexico; ²Hospital Infantil de Tamaulipas, Cd. Victoria, Mexico

Introduction: Treatment of neurocritical patients is complex due to their different types of brain injury, however the realization of early tracheostomy shown to have lower incidence of pneumonia associated with mechanical ventilation (VAP), reduced hospital stay, lower mortality and lower costs hospital.

Methods: Prospective observational study corresponding to patients with TCEs admitted to the Intensive Care Unit (ICU) of the General Hospital of Cd. Victoria “Norberto Trevino” over two years (2014–2015). Patients over 18 years were grouped into two groups; “Early” or “late” using as a cutoff 7 days. Tracheostomy We analyzed: age, sex, APACHE II, VM days, incidence of pneumonia associated with VM, days in ICU, ICU mortality. Continuous variables were expressed as mean and standard deviation, categorical variables as absolute value and percentage, test Students were used for independent samples to compare numerical variables and Chi-square test for categorical whether ordinal or nominal, measures of association with OR. SPSS v.23.

Results: Early vs late tracheotomy tracheostomy: 62 patients (68% male) with severe head injury, divided into 2 groups they were included. Trach average age <7 days 27.7 ± 5.4 (22–35) vs Trach > 7 days 23.9 ± 10.1 (18–50) p = 0.672, VM days in Trach <7 days 8.5 ± 4.1 (4–13) vs Trach > 7 days 14.0 ± 3.0 (9–21) p <0.05, sedation days Trach <7 days vs 5.0 ± 2.3 Trach > 6.9 ± 3.0 7 days p = 0.21, APACHE in Trach <7-day 16.5 ± 7.4 (10–25) Trach vs > 7-day 15.0 ± 3.2 (10–22) p = 0.53, ICU days in Trach <7 days 10 ± 4.83 (4–14) vs Trach > 7 days 14.9 ± 4.00 (10–26) p <0.04, complications Trach <7-day 27.3% (12n) vs Trach > 7 days 72.7% (32n) p <0.001, mortality Trach <7 days 28.6% (4 N) vs Trach > 7 days 71.4% (10n) p = 0.34. Trach prevalence of VAP with <46% vs 7-day Trach > 7 days 84%. Pneumonias in Trach <7 days OR 0.160 (0.100–0.890).

Conclusions: In this study in the Intensive Care Service General Hospital “Norberto Trevino” We conclude that the effectiveness of conducting early days of VM decreases tracheostomy, ICU stay and ventilator associated pneumonia (VAP).

Lithuanian University of Health Sciences, Kaunas, Lithuania

Introduction: One third of all patients undergo open standard tracheostomy (ST) or bedside percutaneous dilatational tracheostomy (PDT) in our 18 bed neurosurgery ICU (NICU). The aim of our study was to evaluate the incidence rate of stoma infection after tracheostomy according to the type of procedure (PDT vs ST) in NICU patients.

Methods: We performed a retrospective chart review of 240 patients who underwent tracheostomy during their stay in the NICU at our 2200 bed university teaching hospital Kaunas Clinics from October 2012 to December 2015. The data from 202 patients (140 males) with median age 58.4 (18–80) who met the inclusion criteria were used for further analysis. There were 84 patients in PDT group and 118 patients in ST group.

Results: There was no significant difference between two groups in terms of age, sex, timing of tracheostomy, duration of ICU stay, mortality and infectious status before the procedure. The incidence rate of stoma infection was significantly lower in PDT group vs ST group (16.7% vs 65.3%, p < 0.001). We performed the logistic regression adjusting for age, sex, the cause of hospitalization, tracheostomy strategy and timing of the procedure. The use of ST was associated with an increase in the risk of stoma infection (OR = 8.83 95% 4.40–17.71).

Conclusions: The incidence rate of stoma infection was significantly higher in ST group compared to PDT group in NICU patients.

¹University of Sassari, Sassari, Italy; ²Città della Salute e della Scienza Torino, Torino, Italy; ³Sapienza University of Rome Policlinico Umberto I Hospital, Roma, Italy

Introduction: Ventilator-Associated Pneumonia (VAP) represents a cause of morbidity and mortality in critically ill patients who require mechanical ventilation. Subglottic secretions above the endotracheal cuff are associated with bacteria colonization of lower respiratory tract, causing VAP. A preventive strategy to avoid subglottic secretions progression is to remove it by drainage with the use of special tracheal tubes effective in preventing both early onset and late onset VAP.[1] The purpose of this study is to measure VAP incidence in tracheostomized patients with suction above the cuff.

Methods: Study design: matched cohort study with historical control in 3 academic italian ICUs.

Procedures and measurements: upon admission to ICU, patients requiring mechanical ventilation were submitted to tracheostomy with a tracheal tube allowing drainage of subglottic secretions (treatment group) to reduce the incidence of VAP. A control group of tracheostomized patients without the ability of suctioning above the cuff was created applying the propensity score matching technique on a dataset including patients enrolled in the previous ELT study [2].

Primary endpoint: occurrence of post-tracheostomy VAP incidence (as determined by clinical pulmonary infection score) at 28-days from intubation. Secondary endpoints: 28-days mortality after tracheostomy; number of ventilator-free days and ICU-free days at 28-days from intubation; time of decannulation, total number of days of inpatient hospital stay; assessment of SOFA score.

Results: 125 patients were enrolled in the treatment group from July 2014 to April 2016; 232 patients without suctioning were selected as a control group. Overall incidence of VAP was 10 patients (8%) in treatment group and 45 patients (19.4%) in the control group (p value = 0.004) with OR: 0.361 and CI (0.175; 0.745). In order to balance the two groups for timing of tracheostomy, gender, age, SAPS and SOFA covariates, a propensity score matching was performed: VAP incidence (120 patients) was 8.3% and 21.7% in treatment and control groups respectively (p value = 0.0408) with OR: 0.329 and CI (0.109; 0.990).

Conclusions: Subglottic secretions drainage reduces incidence of VAP in critically ill patients requiring ongoing mechanical ventilation via tracheostomy.

References

1. Lacherade JC, et al.: Am J Resp Crit Care Med 2010;182:910–7.

2. Terragni PP, et al.: JAMA 2010;303:1483–9.

ICU, 1st Department of Pulmonary Medicine, “Sotiria” Hospital, Athens Medical School, Athens, Greece

Introduction: Spontaneous breathing trial (SBT), a routine procedure during ventilator weaning, entails cardiopulmonary stress for the ventilated patient, which is higher in the patients failing the trial. SBT has been shown to activate an intense inflammatory response, with an increase of cytokines in plasma such as TNF-a, IL-6, IL-1b, and IL-18, a pro-inflammatory cytokine which is being considered as a potential sepsis biomarker. Sepsis has been associated with severe muscle wasting and/or ICU-aquired weakness. Aim of this study was to investigate the effect of sepsis on weaning outcome in critically ill patients.

Methods: A total of 55 intubated and mechanically ventilated patients were included in the study (29 with a septic condition, 26 non septic, intubated for other reasons). Patients were assessed during a 30 minute SBT trial SBT. Blood samples were collected at baseline and at the end of the 30 minute trial. IL-18, caspase-3, TLR-2, IL-6, and TNF-á were measured by ELISA and were correlated with markers of inflammation and the weaning outcome.

Results: In these preliminary data we included 29 mechanically ventilated patients (53%) with a septic condition and 27 (47%) patients with other than sepsis conditions. Septic patients had a higher percentage of weaning failure compared to non septic ones (38% vs 27%), and this was associated with statistically significantly lower levels of serum albumin (p = 0.026) and CRP (p = 0.05). No statistically significant differences were observed in the cytokine levels between the failure/success groups in septic and non-septic patients, as well as, at the two measurement time points. However, IL-18 levels were higher in septic patients that failed SBT at 30 mins compared to the success group [192 (75–583) vs 147 (12.5–581), median (range)]. In both septic and non-septic patients that failed SBT the stress during the trial led to an increase of IL-18 levels (although, non statistically significant). Finally, IL-18 was correlated at both time points with serum albumine (p = 0.012 and p = 0.011, respectively, and r = −0.344 and r = −0.347, respectively), PCT (p < 0.001, r = 989), and APACHE II score (p = 0.05, r = 0.383)

Conclusions: Although the number of patients per group is small in these preliminary data, our results indicate that SBT failure in septic patients was associated with a higher inflammatory profile of the patients. Among all the measured cytokines, IL-18 seems to reflect the severity of sepsis associated with weaning failure.

¹Gelre Hospitals Apeldoorn, Apeldoorn, Netherlands; ²Catharina Hospital Eindhoven, Eindhoven, Netherlands

Introduction: Dysphagia is a common problem in the intensive care unit (ICU), and has been associated with prolonged ICU length of stay and increased risk of pneumonia, reintubation and death. However, no national guidelines on dysphagia prevention, screening and management exist for ICU patients. Therefore, we performed a national survey to learn what strategies are being used in Dutch ICUs.

Methods: A survey was developed based on current literature and experts’ opinions. It comprised both open and multiple choice questions regarding hospital and intensive care characteristics, perceived prevalence and importance of dysphagia, screening strategies including the use of certain diagnostic tests and specialist consultation, modalities used to prevent complications such as aspiration, and interventions used to improve swallowing function and follow-up. It was sent to all 90 non-pediatric ICUs in The Netherlands with two reminders by telephone and e-mail.

Results: 67 of 90 addressed ICUs (74%) replied to our survey. A median relevance score of 4 (IQR 4–5) out of 5 was given to the topic of dysphagia. In 22% of ICUs, patients were always screened for dysphagia after extubation, in 45% of ICUs screening was always performed after tracheotomy. The water swallow test was always part of the work-up in 88% of ICUs. Fiberoptic endoscopic evaluation of swallowing (FEES) was used as the gold standard in 60% of ICUs, versus videofluoroscopic swallowing study (VFSS) in 25%. In 49% of ICUs no standardized active rehabilitation protocol for dysphagia existed. In the remaining 51% swallowing exercises supervised by the speech language pathologist were part of standard rehabilitation, occasionally supplemented by electrical stimulation or sEMG biofeedback training in 6% and 10%, respectively.

Conclusions: Despite the known possible consequences of dysphagia and it being considered relevant by the majority of respondents, most Dutch ICUs do not regularly screen for dysphagia after extubation or tracheotomy and almost half do not have a treatment or rehabilitation protocol. The diagnostic tests and therapies used vary between hospitals, including some of unproven validity. A well-defined screening and treatment algorithm based on an evidence-based guideline could provide more standardized approach to this problem, thus improving quality of care.

¹Fiona Stanley Hospital, Perth, Australia; ²SCGH, Perth, Australia; ³The Alfred Hospital, Melbourne, Australia; ⁴Hadassah University Hospital, Jerusalem, Israel

Introduction: Intra-abdominal hypertension can increase airway pressures and impair ventilation. Little is known about the relationship between increasing intra-abdominal volume (IAV) and airway pressures. We asseseds the effect of increasing IAV on airway and intra-abdominal pressures (IAP) in a porcine model

Methods: Seven pigs (41.4 +/−8.5 kg) received standardized anesthesia and mech. ventilation. A latex balloon in the abdomen was inflated in one liter steps until IAP exceeded 40 cmH2O. At each step, we measured peak airway pressure (pPAW) and IAP.

Results: Raising IAV led to an exponential increase of pPAW and IAP while decreasing both abdominal and respiratory system compliance. pPAW increased by approx. 40% of the increase of IAP.

Conclusions: The exponential nature of IAV on pPAW and IAP implies that small reductions in IAV may lead to significant reductions in airway and abdominal pressures in the presence of high grades of intra-abdominal hypertension. Treatment to reduce IAP may be more effective at high grades of IAH.

¹University of Milano Bicocca, Monza, Italy; ²San Gerardo Hospital, Monza, Italy

Introduction: Lung donation occurs in a limited number of potential donors due to the deterioration of lung function after brain death and the strict eligibility criteria. “Protective” ventilator strategy markedly increased lung donation rate [1]. However, to our knowledge no studies have investigated individualization of PEEP and recruitment maneuvers in this setting. Thus, we explored the use of electrical impedance tomography (EIT) in a hypothesis-generating study.

Methods: Single center observational study. Potential lung donors underwent a 10 minutes evaluation by EIT (PulmoVista 500 Dräger Medical) after neurologic determination of death. Potential donors were ventilated with a “protective” protocol. Gas analysis and respiratory system compliance (Crs) were assessed. Two regions of interest were defined: non-dependent lung zones (ROIn-dep) and dependent lung zones (ROIdep). We measure the Vt distending each region (VtROIn-dep, VtROIdep); the heterogeneity of Vt distribution (VtH) and regional values of compliance (CrsROInon-dep, CrsROIdep). Results are expressed as median (Q1; Q3).

Results: 5 subjects were enrolled. Vt was 7.4 (7.1; 7.7) ml/Kg IBW and PEEP was 8 (8; 8) cmH20. PF ratio was 358 (47; 560) and Crs was 43 (35; 76) ml/cmH2O. Vt was preferentially distributed in non-dependent lung zones because of higher CrsROInon-dep 26 (20; 43) ml/cmH2O vs. CrsROIdep 18 (13; 32). For clarity, VtROInon-dep was 252 (196; 285) ml while VtROIdep was 166 (143; 197) ml and VtH was 1.35 (1.09; 2.02).

Conclusions: EIT monitoring showed that ventilation is preferentially distributed in ventral lung zones when the protective ventilator strategy is employed in potential organ donors. Next step will be to verify whether PEEP titration and recruitment maneuver based on EIT findings contribute to enhance respiratory performance and suitability for lung transplantation.

References

[1] Mascia, 2010 JAMA 304:2620–7

¹University of Ferrara, Ferrara, Italy; ²Swisstom AG, Landquart, Switzerland

Introduction: Recruitment Maneuvers (RM) typically consist of high airway pressures for prolonged periods of time to open closed lung units. Despite potentially positive effects, RM can cause hypotension, desaturation, or pneumothorax. Different methods have been proposed to identify patients who can benefit from a RM but conclusive recommendations are still lacking. We hypothesized that the shape of a pixel-level pressure-volume curve (PVpx) could predict recruitability defined as Recruited Volume (RV) after a RM at rising PEEP levels.

Methods: 12 ARF patients (P/F < 300 mmHg) were mechanically ventilated with TV of 6–8 ml/kg. A 5-step PEEP trial - increasing (5,10,15 cmH[sub]2[/sub]O) and decreasing (10,5 cmH[sub]2[/sub]O) limb - was performed with a RM (inspiratory hold,40 cmH2O CPAP for 40s) between PEEP10 and PEEP15. At each step, lung mechanics and EIT data were recorded during a quasi-static pressure-volume curve (PV) maneuver. The PV before the RM was adapted to an isogravitational pixel level plotting the variation of impedance in each pixel row and the variation of pressure in the respiratory system (fig. 28); 19 pixel-level PV curves (PVpx) were obtained [1] and fitted in the equation V = a + b•Pao + c•Pao²[2]. The “c” factor derived from the fitting (C) indicates the shape of the curve: positive C is related to a compliance increase during the inflation, while negative C to its reduction. We correlated the RV after the RM with the C before the RM at each pixel level, from non-dependent (pixel 1) to dependent lung (pixel 19).

Results: The C had a significant positive correlation with RV (ml/kg/PBW) for pixel levels 13–17,19 (dependent lung); positive PVpx values predicted recruitability of the dependent lung. In the central lung, no correlation was founded. A negative (non-significant) correlation was founded in non-dependent lung indicating that a preexisting non-dependent overinflation could be inversely correlated with the effects of the RM.

Conclusions: The C factor from PVpx predicts lung recruitability at the bedside and could help to identify patients who might benefit from lung RM.

References

1. Kunst PW et al.: Crit Care Med 2000 Jan;28(1):178–83

2. Ranieri MV et al.: Am J Respir Crit Care Med. 1994 Jan; 149(1):19–27

University Hospital Maastricht, Maastricht, Netherlands

Introduction: Aim: determine the effect of PEEP on alveolar collapse (CL) and overdistension (OD) in ARDS.

Lung recruitment decreases CL but may induce regional OD. PEEP may be optimal when the balance between CL and OD is optimal. The distribution of this balance and changes in local ventilation distribution at varying PEEP levels throughout different lung fields in ARDS is unknown. Regional OD, CL and centre of ventilation (COV, a measure of homogeneity of ventilation distribution) can be visualized using Electrical Impedance Tomography (EIT).

Methods: Ten ARDS patients (P/F-ratio 170, SD 53) were studied. Ventral and dorsal OD and CL (% overdistended or collapsed alveoli) and COV were measured by EIT during an incremental and decremental PEEP trial (8–20 cmH2O). COV was expressed as dorsal to ventral ventilation distribution. A COV of 50% indicates an equal distribution between ventral and dorsal lung fields. COV >50% indicates a shift of ventilation distribution towards ventral. We estimated the balance between overdistended and collapsed alveoli by subtracting CL from OD (ODCL). An ODCL of 0% indicates an optimal balance between CL and OD. Data are expressed as mean ± SEM. 1 or 2-way ANOVA was used as appropriate.

Results: At 8 cmH2O, dorsal ODCL (−30% ±6) was significantly lower than ventral ODCL (−6% ±3) (p < 0.001). During the increment in PEEP, ODCL significantly increased to +20% ±2 dorsally and +49% ±2 ventrally (p < 0.001), the magnitude of this increase was similar in both lung fields (p = 0.6, Fig. 29a). The COV shifted dorsally from 57% ±1 to 50% ±1 (p < 0.001, Fig. 29b).

Conclusions: The balance between CL and OD at varying PEEP levels differs between ventral and dorsal lung fields. Lung recruitment reduces CL and increases ventilation in dorsal lung fields and a dorsal shift of the centre of ventilation. However simultaneously ventral OD occurs. When determining optimal PEEP settings, variations in the balance between CL and OD between lung fields should be taken into account. Visualization of local ventilation by EIT appears to be a useful tool for this.

University of Milano Bicocca, Milan, Italy

Introduction: Electrical Impedance Tomography (EIT) is a bedside monitoring technique of regional ventilation that measures the changes in the impedance within the thorax. The tight correlation between variation of impedance (ΔZ) and variation of lung volumes (Vt) is known. Unless the Vt is measured by an external reference (e.g. spirometry) its absolute value (in ml) cannot be determined, however measurement of Vt would be useful in non intubated subjects.

Methods: We performed a prospective study on thirteen healthy volunteers (>18 years) without obesity, pregnancy, chest circumference <75 cm and history of pulmonary or medical disorders. The subjects were connected to the EIT monitor.

Calibration phase: the subjects breathed 10 times, from functional residual capacity, fully distending a non-elastic bag with a volume of 1680 ml. In this way the conversion factor between Vt and ΔZ (K[sub]Vt/ΔZ[/sub]) was found for each subject.

Validation phase: tidal volumes were estimated (estVt = ΔZ* K[sub]Vt/ΔZ[/sub]) from impedance variations; the accuracy was assessed measuring tidal volumes (Vt) with a ventilator through which the subjects breathed by a mouthpiece. Four different ventilator settings were used changing pressure support ventilation (PSV) and positive end expiratory pressure (PEEP).

Results: The correlation between Vt and estVt was tight (r² = 0.89) with a within-subject mean r² of 0.91 ± 0.07. The fit equation was estVt = 0.9 * Vt + 10.1 (Fig. 30). The highest correlation was found at PEEP 0 (mean: estVt = 0.93 * Vt) vs PEEP 8 (mean: estVt = 0.8 * Vt), p = 0.01. No differences were found between PSV 0 (mean: estVt = 0.97) and PSV 8 (mean: estVt = 0.93 * Vt), p = 0.50. The Bland-Altman plot showed a systematic bias of −95,5 ml (−10%) and 95% CI of -396 ml (−40%); 205 ml (20%).

Conclusions: A simple and fast technique of calibration of the EIT can allow a reliable and non-invasive measure of Vt in non intubated subjects.

¹Wroclaw University of Science and Technology, Wrocław, Poland; ²Lublin Medical Univesity, Lublin, Poland

Introduction: The recruitment maneuver (RM) is a part of clinical strategy of respiration supporting, The subject of the research was to monitor the phenomena occurring during RM when the artificial ventilation is applied at the mouth of animal ARDS model, using modified low frequency forced oscillation technique (FOT).

Methods: The phenomenon of the opening alveoli was modelled according to the estimations made in the complex mathematical model of respiratory system. The complex model structure was reduced into its simpler, identifiable analog of nonlinear resistance and capacitance of the lung.

A Large White pig weighing 50 ± 5 kg were included into the study. Under general anaesthesia the animal was tracheostomised, intubated and ventilated in a volume-controlled mode (Puritan Bennett 840) at RR–18/min, with VT– 8–10 ml/kg, I:E ratio −1:2 and FIO2–1.0. Lungs injury was induced by repetitive lavages with 1.5–1.8 l warm 0.9% NaCl.

The low frequency (0,5Hz) sinusoidal flow oscillations were induced at the intubation tube by means of mechanically controlled syringe. The flow and pressure changes were monitored by pneumotachograph (Hans Rudolph) while the external negative pressure (eNP) in the whole body size-box was changing. For the estimation of time-varying mechanical parameters (Rest and Cest) of the lung the Kalman filter method of data analysis was used.

Results: Application of the proposed method of the identification of the parameters of lung during the vacuum changes in the chamber results as in the example figure (Fig. 31). There were significant differences in Rest and in Cest at the body size-box negative pressure 0, −4, −8, −12, and −16 cmH2O.

Conclusions: The modified low frequency forced oscillation technique allows observation of changes in the parameters typical for recruited lungs and assess the possibility of monitoring of changes of physiological parameter values when the RM is applied in artificially ventilated lungs.

¹Pirogov Russian National Research Medical University, Moscow, Russia; ²City Hospital#67, Moscow, Russia; ³Federal research and clinical center for special methods of healthcare and medical technology of FMBA, Moscow, Russia

Introduction: There is limited data on safe tidal volume and pressure setting in pressure support ventilation (PSV).

Methods: We included 59 mechanically ventilated patients in SICU with PSV mode. We used monitoring of airway pressure, tracheal pressure, and esophageal pressure, plotted dynamic «tracheal pressure-volume» (Ptr-Vt) and «esophageal pressure-volume» (Pes-Vt) loops. We measured tidal volume (Vt), patient’s work of breathing (WOBp), delta esophageal pressure (ΔPes), plateau pressure (Pplat), transpulmonary plateau pressure (Ptp plat), transpulmonary pressure at PEEP (Ptp PEEP), dynamic compliance of respiratory system (Cdyn), dynamic lung compliance (Clung dyn), dynamic chest wall compliance (Ccw dyn), delta transpulmonary pressure (ΔPtp = Ptp plat - Ptp PEEP), tracheal pressure at PEEP level (PEEPtr), minimal tracheal pressure during triggering (Ptrig tr), and calculated difference between PEEP tr and Ptrig tr. After that we plotted loops and estimated its shape. We collected data at 6 steps: (1) at baseline PS and PEEP level, (2) at PS + 4 mbar level and baseline PEEP, (3) at PS-4 mbar level and baseline PEEP, (4) at PEEP + 4 mbar level and baseline PS, (5) at PEEP set by end-expiratory transpulmonary pressure level (PEEPtp0) and baseline PS, and then (6) at PEEP-4 mbar level and baseline PS.

Results: We discovered 3 typical shapes of inspiratory part of «tracheal pressure–time» (Ptr-t) curve: triangle, square and S-shape. We found significant differences between different shapes of inspiratory part of «Ptr-t» curve in WOBp (p < 0.0001), ΔPes (p < 0.0001), PEEPtr-Ptrig tr (p < 0.0001), and PS-ΔPtp (p = 0.002). We discovered 4 types of dynamic «Ptr/Vt» loops: inverted (n = 41), classical (n = 7), linear (n = 7), and S-shaped (n = 4). We found significant differences between different shapes of dynamic «Ptr/Vt» loops in ΔPtp (p = 0.05) и Clung dyn (p = 0.020), which allowed to estimate delta transpulmonary pressure without esophageal pressure monitoring. We found significant differences between different shapes (v-,u-,w- and v + −shaped) of inspiratory part of «Pes-t» curve in WOBp (p = 0.002), PEEPtr-Ptrig tr (p = 0.05), PS-ΔPtp (p = 0.034), and Ccw dyn (p = 0.014). Vt was more than 6 ml/kg of ideal body weight (IBW)(7.8 (6.9–9.1)ml/kg) in 88.1% of patients at baseline while ΔPtp was 16.3 (12.1–19.7) mbar, and «safe» Vt (in which ΔPtp <15 mbar) had 46.2% of patients.

Conclusions: Monitoring of «Ptr-t» curve and dynamic «Ptr/Vt» loop allow for estimation of the lung injury and WOBp without Pes an Ptp monitoring.

Eskisehir Osmangazi Uni. Faculty of Medicine, Eskisehir, Turkey

Introduction: Evaqua technology allows the humidity in the expiratory limb to diffuse through the permeable membrane of the expiratory limb wall before it has an opportunity to condense into liquid water within the circuit limb. As the membrane is not permeable to pathogens it seems to reduce the risk of pathogen transfer to the patient. With conventional circuits, condensate can form inside the expiratory limb when humidity in the expiratory gas flow touches cooler surfaces along the gas path. In this study, we aimed to evaluate the effect of respiratory circuit systems on the development of ventilator associated pneumonia (VAP).

Methods: We evaluated 41 patients retrospectively who were admitted to intensive care unit (ICU) and mechanically ventilated using 2 different circuit systems between May, 2013-August, 2015 (Group 1: Adult dual heated wire ventilator circuit, Group 2: Adult ventilator circuit dual heated with Evaqua technology).

Results: Patients’ characteristics are showed in Fig. 32. There was statistically difference only in gender status between two groups. Respiratory failure (28.6 vs 30%), Postresuscitation Syndrome (PRS) (23.8 vs 30%) and multiple traumas (28.6 vs 20%) were the main reasons for admission to ICU. Mean duration of hospitalization in ICU and duration of mechanical ventilation were similar in two groups (53.5 (9–174) vs 37 (11–102) days, 45 (9–152) vs 32.5 (4–102) days, respectively). Positive result in tracheal culture was obtained 100% and 85% in Group 1 and 2. Acinetobacter Baumannii, Pseudomonas Aeruginosa and Klebsiella Pneumoniae were the most detected agents in the weekly tracheal culture results. Mean duration time to positive tracheal culture was similar in two groups (10.1 ± 5.9 vs 13.6 ± 9.1 day).

Conclusions: We could not find any significant advantage on development of VAP in favor of Evaqua technology. Well-designed prospective studies with more patients are necessary for better understanding of the effect of respiratory circuit system on development of VAP.

¹Cleveland Clinic Foundation, Cleveland, OH, USA; ²Respiratory Motion, Inc, Waltham, MA, USA

Introduction: Opioids are commonly used for postoperative pain management but often decrease respiratory drive and can cause opioid-induced respiratory depression. Current respiratory monitoring in non-intubated patients relies on late indicators of respiratory depression, such as pulse oximetry or point of care measurements of RR [1,2]. Here, we assess the effectiveness of respiratory rate (RR) alone to detect respiratory depression by using a non-invasive respiratory volume monitor (RVM) which accurately measures minute ventilation (MV), tidal volume (TV), and RR [3].

Methods: Impedance-based RVM (ExSpiron, Respiratory Motion, Waltham MA) was used to non-invasively collect MV, TV and RR measurements from 104 patients (55 males, BMI: 27.2 ± 5.0 kg/m2) recovering from elective major abdominal surgery. MV, TV and RR were calculated from 30-second respiratory segments for up to 48 hours following surgery. Predicted MV (MVPRED) was calculated for each patient based on body surface area. LowMV was defined as MV < 40% MVPRED and LowRR was defined as RR < 6 breaths/min. RR rate values were compared to MV measurements and sensitivity and specificity of LowRR as a predictor of LowMV were calculated.

Results: Patients were monitored for an average of 34.5 ± 14.7 hours in the PACU and general hospital ward. Analysis of all 417,850 paired MV and RR measurements revealed that although MV is a function of RR (MV = TV*RR), there was poor correlation between a given MV measurements and its corresponding RR measurements (r = 0.35). 56.4% of MV recordings were below 80% MVPRED and 19.1% were below 40% MVPRED while only 4.0% were below 6 breaths/min. A variety of RR alarm conditions (4–8 breaths/min (bpm)) were explored which showed that a substantial fraction of low MV measurements remain undetected. Specifically, with a RR cutoff of 8 bpm, 74% of all MV measurements < 40% MVPRED would be missed. Decreasing the RR cutoff to 4 bpm misses 93% of MV measurements <40% MVPRED. Overall, LowRR was a poor predictor of LowMV with a sensitivity of 15.0% and specificity of 98.6%. Furthermore, 29% of all low RR events were associated with adequate MV, indicating that patients were adequately ventilated even in the presence of LowRR.

Conclusions: Our data suggest that LowRR alone does not accurately reflect episodes of LowMV, and is not sufficient for accurate assessment of respiratory status. The tidal volume of each breath is at least equally critical to ensure respiratory sufficiency.

References

1. British Journal of Anaesthesia, 108:872–875, 2012.

2. Anesthesia & Analgesia, 117:69–75, 2013.

3. Anesthesia & Analgesia, 117:91–100, 2013.

Military Hospital of Tunis, Tunis, Tunisia

Introduction: Weaning failure of cardiac origin can be diagnosed by the elevation of the left ventricular (LV) filling pressure. This hydrostatic pulmonary edema is associated with hemoconcentration du to hypooncotic fluid movement from the vascular compartiment to the interstitium. The aim of this study was to search for a correlation between the protidemia and the hemoglobin elevation during the weaning test and the presence of LV filling pressure elevation.

Methods: This prospective observational study was conducted during two years (between January 2014 and January 2016). Every patient with weaning failure was included. The variation of the biological and ultrasound criteria between the periods before and after the ventilator weaning was analysed.

Results: We included 56 patients which failed during the first weaning test. 20 patients (35,7%) had an elevation of the LV filling pressure during the second weaning test with E/A > 0.95 and E/Ea > 8.5 at the end of the test period and within these 20 patients, 12 (60%) failed this second weaning test. When compared to the 36 patients who didn’t present a pulmonary edema, these 12 patients required additional delay for the weaning: 2.5 + 3.7 days versus 0.75 + 2.4 days (P = 0.023). the unique predictive factor associated with the occurrence of pulmonary edema was positive body weight difference between the admission in the ICU and the inclusion in the study (4.6 + 5.6 versus 3.5 + 7.3, p = 0.004). the was no significant variation of the hemoglobin and protidemia during the weaning for the patients who presented a pulmonary edema.

Conclusions: During this study we didn’t find a correlation between the hemoglobin or the protidemia variation during the weaning period and the ultrasound criteria of th LV filling pressure elevation. The difference of body weight between the admission in the ICU and the inclusion, which reflect a positive fluid balance, was the unique factor associated with weaning failure of cardiac origin. Its control could allow a more frequent weaning success and the diminution of the morbidity and mortality due to the diminution of the mechanical ventilation duration

¹University-Hospital, Udine, Italy; ²University-Hospital of Pisa, Pisa Italy

Introduction: The prevalence of diaphragmatic dysfunction (DD) in patients admitted to Intensive Care Units (ICUs) has often been underestimated, even though it occurs quite frequently.1,2 The first aim of our study is to estimate its prevalence in patients with acute respiratory failure admitted to our ICU; the second aim is to show if Non Invasive Ventilation (NIV) can be helpful in these court.

Methods: We enrolled patients with acute respiratory failure admitted to our ICU, scheduled to perform NIV. To measure the diaphragm excursion, a trans-thoracic ultrasound (US) examination was performed before (T0) and after 30 minutes of NIV (T1).3 NIV was performed through a full-face mask with a pressure support ventilation of 6 to 10 cmH2O and a Positive End Expiratory Pressure (PEEP) of 5 cmH2O. Inspired oxygen fraction was set to obtain an SpO2 > = 92–93%.

Results: In our general ICU, the overall prevalence of DD was 55% (11 over 20 pts). A subgroup analysis revealed that 90% (9 over 10 pts) of the post-operative patients had DD, compared to only 20% (2 over 10 pts) of medical origin. All patients with normal diaphragmatic functionality were NIV responder. The sensitivity and specificity of DD in predicting NIV failure was, respectively, 100% and 60%; negative predictive value was 100% while positive predictive value was 46%.

Conclusions: The main finding of this study is that DD showed a high prevalence: 55% of our mixed population (surgical and medical). The presence of a normal diaphragmatic functionality seems to be an indicator of good response to NIV.

References

1. Kim SH et a. Anesth Analg. 2010; 110(5):1349–54

2. Kim WY et al. Crit Care Med 2011; 39: 2627–30

3. Boussuges A et al. Chest 2009; 135: 391–400

¹Radboudumc, Nijmegen, Netherlands; ²VU Medical Center, Amsterdam, Netherlands

Introduction: Mechanical ventilation unloads the respiratory muscles in order to prevent development of muscle injury and patient discomfort. On the other hand, over-assist may lead to diaphragm inactivity associated with disuse atrophy and patient-ventilator asynchrony. Clinicians are often unable to recognize diaphragm inactivity based on pressure and flow signals on the ventilator. In recent studies an index was described, the neuromuscular efficiency (NME), in which the electrical activity of the diaphragm (EAdi) was used to determine the respiratory muscle effort. However, conversion of EAdi (in microvolt) into pressure has not been very well validated today. The aim of the current study was to assess the repeatability coefficient (RC) of the NME (dynamic and during occlusion).

Methods: We included 31 mechanically ventilated adult ICU patients with a dedicated naso-gastric feeding tube for assessing diaphragmatic EMG activity. NMEoccl was calculated by measuring the change in airway pressure (delta Paw) divided by the EAdi during an end expiratory occlusion; repeated 5 times with a 1-minute interval at inclusion and 12, 24, 72 hours respectively. NMEdyn was calculated by dividing the peak inspiratory effort of the diaphragm (Pmus = chestwall compliance + esophageal pressure) by the corresponding EAdi during regular tidal ventilation.

Results: The repeatability coefficient of NMEoccl was 81.7%, which means that the difference between two repeated measurements lies between this ratio with a 95% confidence interval. For example, with a calculated NME of 0.93cmH2O/μV and a repeatability coefficient of 81.7% it is expected that 95% of the subsequent measurements will be between 0.17–1.69 cmH2O/μV. Both the Eadi peak as the Paw peak showed a wide variation in which just a moderate correlation was found (p = 0.44). Also after additional analysis, the RC did not improve. The repeatability coefficient of NMEdyn was 125,7%.

Conclusions: The measurements of the NME is feasible in daily practice, but the repeatability coefficient of both NMEoccl and NMEdyn seems too high for clinical use.

¹Milano Niguarda, Milano, Italy; ²Ospedale San Gerardo, Monza, Italy

Introduction: A preserved respiratory muscle function is essential for the liberation of patients from mechanical ventilation. Evidence suggests that a prolonged time of ventilation leads to diaphragm atrophy and dysfunction. Bedside diaphragmatic function monitoring may allow for a more complete evaluation of the patient’s respiratory effort. Surface Electromyography (sEMG) is a non-invasive technique for the assessment of diaphragmatic electrical activity.[1] Diaphragm Ultrasound (US) provides a reliable evaluation of its motion.[2] Aim of the present study was to assess, through US, the motility corresponding to sEMG-derived electrical activity signals of the healthy diaphragm.

Methods: 12 healthy volunteers underwent a standard breathing protocol including three different respiratory patterns: Quiet Breathing (QB), Deep Breathing and Voluntary Sniffing (VS). Analysis of sEMG recordings was performed to assess baseline and maximum electrical activity (sEMG max, sEMG delta), and the Area Under the Curve (sEMG AUC). Simultaneously we assessed baseline (Tmin) and maximum muscle thickening (Tmax) with a linear 10 Mhz probe positioned at the 9th intercostal space in the mid-axillary line. We calculated Thickening Fraction (TF) as: 100(Tmax-Tmin)/Tmin. We then assessed Diaphragm Excursion (DE) with a convex 7.5 Mhz probe placed below the right costal margin.

Results: In healthy volunteers the simulation of different respiratory patterns led to statistically significant differences in terms of both sEMG and US parameters. TF differed among QB (24,8 ± 11,4%), DB (154 ± 40,8%), and VS (96,9 ± 33,3%, p < 0.0001). As well, differences in sEMG delta could be measured (QB: 0.99 ± 0.5 μV; DB: 16.8 ± 9.43 μV; VS: 13.03 ± 5.87 μV, p < 0.0001). A significant correlation could be identified between several parameters obtained by the two techniques. Particularly, sEMG max vs. Tmax (r = 0.81, 95%CI: 0.73–0.87, p < 0.0001, Fig. 35A), and sEMG AUC vs. DE (r = 0.79, 95%CI: 0.71–0.85, p < 0.0001, Fig. 35B).

Conclusions: SEMG provides reliable and reproducible information about the electrical activity of diaphragm, showing a direct relationship with the resulting muscle motility, as assessed by ultrasonography.

References

[1] Bellani et al. Submitted data

[2] Goligher AJRCCM Nov1;192(9):1080–8,2015

¹University of Milano-Bicocca, Milano, Italy; ²Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milano, Italy; ³San Gerardo Hospital, Monza, Italy; ⁴Hospital San Gerardo, Monza, Italy; ⁵University of Milano-Bicocca, San Gerardo Hospital, Monza, Italy

Introduction: In ICU the dysfunction of respiratory muscles, during mechanical ventilation is a relevant problem which may lead to prolonged ventilation and difficult weaning. Some data suggest that ventilator induced diaphragmatic dysfunction (VIDD) can be aggravated by neuromuscular blockers and high doses corticosteroids. Aims of this study are to evaluate the coherence between ultrasound (US) and computed tomography (CT) measurements of diaphragmatic thickness in mechanically ventilated patients, and their relationship with clinical features and outcomes.

Methods: We enrolled intubated or tracheotomized patients undergoing mechanical ventilation for at least 48 hours undergoing chest CT scan for clinical reasons. Patients under the age of 18 years, with neuromuscular diseases, phrenic nerve lesions or air leakage were excluded. In enrolled patients thickness of the right hemidiaphragm was evaluated with US as described by Goligher [1] (within 12 hours prior to or after CT scan), while thickness of right and left diaphragm (anterior, posterior pillars, domes) was evaluated with CT scan. At the time of enrollment clinical data were collected.

Results: We enrolled 24 patients in whom 35 CT and US were performed. US evaluation of the right hemidiaphragm was feasible in all patients, and with CT scan in all patient except one. CT measurements of thickness in different portions were tightly related (r = 0,631 ± 0,142). Consistency between US and CT is supported by significant correlations between measurements, in particular posterior diaphragmatic pillars evaluated with CT scan showed the highest correlation coefficient with US, r = 0,439;p-value = 0,009 and r = 0,573;p-value < 0,001 respectively for right and left. Finally we found significant correlations between thickness of posterior pillars and duration of controlled mechanical ventilation (Fig. 36 - r = −0,433;p-value = 0,01), of neuromuscular blocking (r = −0,434;p-value = 0,010) and fraction of total time spent on assisted ventilation on (r = 0,351;p-value = 0,045) before enrollment.

Conclusions: Evaluation of diaphragmatic thickness is feasible with both US and CT scan. These techniques may be both useful to evaluate effects of mechanical ventilation and administration of neuromuscular blockers on diaphragmatic structure.

References

[1] Goligher et al. Am J Respir Crit Care Med 192(9): 1080–1088, 2015

Cairo University, Giza, Egypt

Introduction: Ventilator induced diaphragmatic dysfunction (VIDD leads to difficulties in weaning.

We aimed to evaluate the presence of VIDD during spontaneous breathing trials (SBT) of patients who required mechanical ventilation > =72 hrs and monitor its impact on weaning.

Methods: The study was conducted in the Critical Care department Cairo university hospital between march 2014 and march 2015. All consecutive patients who required mechanical ventilation > =72 hrs and were ready for SBT were prospectively recruited. Exclusion criteria: Any history of aminoglycosides, paralyzing agent, central or neuromuscular disease, chemotherapy, cachexia, severe electrolytes imbalance and Intra-abdominal pressure (IAP) > 7

At the start of a 1-hr SBT, each hemidiaphragm was evaluated by M-mode Sonography with the patient in the supine position. Six measurements were recorded and averaged for each side. Ultrasonographic Diaphragmatic Dysfunction (DD) was diagnosed if Diaphragmatic Excursion (DE) was <10 mm or negative paradoxical movement. Patients were classified into two groups: Non Diaphragmatic Dysfunction (NDD Group) and Diaphragmatic Dysfunction (DD Group). Patients were monitored for Rapid shallow breath index (RSBI), Spontaneous minute volume (Spont MV), Airway Occlusion pressure (PO.1), weaning time and outcome.

Results: Fifty patients (100%) were studied. DD group included 24 (48%) while NDD group included 26 (52%) patients. There was no statistically significant difference regarding Age, Sex, weight and comorbidities between the two groups (p > 0.05).DE median, was higher [14.4(1.9–40) vs. 9.2 (6.6–35.1), p 0.01] in successfully weaned vs. failed weaning patients.

Successful weaning was higher [18/26(69%) vs.13/24(54.2%), p 0.02)], Weaning time was shorter [29 (11–72) hrs vs 43 (10–192) hrs, p = 0.02], RSBI was lower (58.6 ± 29.9 vs. 72.5 ± 30.5, p = 0.02), PO.1 was lower (1.3 ± 0.8 vs 1.7 ± 0.88, p 0.05) and Spont MV was higher (12.35 L/min ±4.22 vs. 9.45 L/min ±2.28, p 0.017) in NDD Group vs. DD Group respectively.

There was no differences between application of RT. DE <14 mm and the famous RSBI <105 as a cut off in predicting weaning outcome (p > 0.05), ROC was 0.84 of DE < =14 mm and 0.71 of RSBI <105.

Conclusions: DD is present in nearly half of our ICU patients on MV > =72 hrs. DE as a morphometric index is as good as traditional volumetric respiratory indices in predicting weaning outcome.

¹Complejo hospitalario de Jaen, Jaen, Spain; ²Hospital Reina Sofía, Cordoba, Spain

Introduction: Tidal volume and respiratory rate are the usual variables to follow the weaning from mechanical ventilation. Although different studies show controversies; because these parameters are influenced by several factors on critically ill patients, and could do not reflect with accurately the work of breathing. Our objective was to study the relationship between respiratory pattern and variables related with the work of breathing.

Methods: We studied 11 patients ready to maintain spontaneous breathing after recovering form acute respiratory failure from different causes. Respiratory flow (V’), airways and esophageal pressure (Paw, Pes) were registered for ulterior analysis of these signals. Respiratory rate (RR), delta Pes and pressure time product (PTP) were measured from Pes. The respiratory mechanics during control mechanical ventilation, dynamic elastance (Ers) and total resistances (Rrs), were calculated by multiple linear regression techniques.

Results: Age 44 ± 18 y, ventilated since 1 to 70 days (23 ± 22). Ers 26 ± 9 cmH2O/l, Ecw 10 ± 6 cmH2O/l, Rrs13 ± 7 cmH2O/l/s, PEEPi 4 ± 6 cmH2O. On CPAP (5 ± 4 cmH2O), tidal volume 0.350 ± 0.185 l, Inspiratory V’ 0.68 ± 0.16 l/s, RR 24 ± 14 bpm. Variables related with respiratory effort were: PTP 7 ± 4 cmH2O/l•s, PTPm 189 ± 108 cmH2O/l•s/min, delta Pes 10 ± 5 cmH2O. These variables were related with tidal volume (r 0.8;0.5;0.7), however respiratory rate was unrelated (0.05;0.5;0.3).

Conclusions: The respiratory effort may not be reflected in the global ventilatory pattern during trial of spontaneous breathing, with risk of respiratory muscle injury and fatigue. Therefore it is necessary to analyze other breathe components by additional monitoring.

Unicamp, Campinas, Brazil

Introduction: Lung ultrasound (LUS) is useful to assess lung edema in many clinical situations. We hypothesized that LUS might be a good tool to assess gas exchange defect (GED) in patients with the Acute Respiratory Distress Syndrome(ARDS).

Methods: This was a prospective observational study at an academic intensive care unit. We Included adult septic patients with ARDS. A simplified lung edema scoring system (SLESS) was used, and 6 thoracic regions were evaluated. Four LUS patterns were considered, from normal aeration to consolidation. To evaluate the GED, the SLESS was compared with the PaO2/fraction of inspired oxygen ratio (PaO2/FiO2) and the partial pressure of carbon dioxide (PCO2).

Results: Fifty-seven patients were enrolled. Clinical characteristics are presented in Table 11. Figure 37.a shows correlation between SLESS and PaO2/FiO2; Figure 37.b shows the correlation between the SLESS and PCO2 levels. Figure 38 shows a stepwise increase in SLESS among ARDS stages (mean SLESS = 12.21; 14.32 and 16.22, respectively, for mild, moderate and severe ARDS; p < .05 for * and **).

Conclusions: The SLESS seems to be useful to assess the gas exchange deffect in patients with ARDS. It also seems to correlate with ARDS severity stages.

	Survivors (n = 27)	Non-survivors (n = 30)	Total (N = 57)
Age	41.9 ± 16.6	51.3 ± 15.6	46.8 ± 16.6
Female	12	9	21
Male	15	21	36
ARDS severity
Mild	7	7	14
Moderate	16	18	34
Severe	3	6	9
Clinical data
Respiratory Rate (bpm)	17.8 ± 5.0	17.7 ± 4.2	17.7 ± 4.5
Mean blood pressure (mmHg)	86.3 ± 10.5	85.3 ± 15.6	85.8 ± 13.3
PCO2	47.3 ± 18.6	46.2 ± 16.3	46.7 ± 17.3
Plasma lactate	1.9 ± 1.5	2.8 ± 3.9	2.4 ± 3.0
Severity scores
SOFA	8.26 ± 3.31	9.7 ± 3.7
SAPS3	62.9 ± 13.7	71.97 ± 14.51

Legend Table 11 Clinical characteristics of study population

¹Papa Giovanni XXIII Hospital, Bergamo, Italy; ²University of Milano-Bicocca, Milano, Italy; ³San Gerardo Hospital, Monza, Italy; ⁴Università degli studi Milano Bicocca, San Gerardo Hospital, Monza, Italy

Introduction: In critically ill patients ultrasonography has gained widespread acceptance for lung monitoring of ventilated patients [1]. Lung Ultrasound Score (LUS) has been demonstrated to be a valid tool to monitor semi-quantitatively lung aeration using four patterns corresponding to increasing loss of air content [2]. Computed tomography (CT) scan remains the reference method, nonetheless X-ray exposure is a relevant concern, particularly in children. We developed a modified pediatric lung ultrasound score (pLUS) to assess aeration in infants. Aim of this study was to compare pLUS with CT scan.

Methods: Mechanically ventilated children < = 1 years old who underwent CT-scan for clinical purposes received a lung ultrasound examination. Each hemithorax was divided in six regions according a systematic protocol examination [1]. For each explored region, the worst finding was scored as follows: normal: 1, single B-lines: 2; multiple non-coalescent B-lines: 3; coalescent B-lines: 4; white lung: 5; consolidation: 6. A cumulative pLUS was calculated as the sum of each examined region in order to obtain a comprehensive picture of the lung. CT scans were analyzed determining, for each lung region the median density and percentage of aerated lung (fraction of voxels with a density < −500 Hounsfield Units).

Results: Nine infants (median age 86 days [36–242]) were enrolled between September 2015 and September 2016 (18 lungs, 108 regions). Regional pLUS and cumulative pLUS of each lung showed a good correlation with median CT-density (R = 0.83; p < 0.05 and R = 0.71; p < 0.01, respectively). Moreover, regional pLUS had a closed correlation with fraction of aerated lung (R = 0.99; p < 0.01) (Fig. 39). Cumulative pLUS showed a significant correlation with fraction of aerated lung (R = 0.54; p < 0.05).

Conclusions: According to these preliminary data, pLUS seems to be a reliable method to assess lung aeration in infants showing a close correlation with aeration lung determined by CT scan.

References

[1] Bouhemad B, et al. Anesthesiology 122(2):437–47, 2015

[2] Bouhemad B, et al. Am J Respir Crit Care Med. 183(3):341–7, 2011

¹Fondazione IRCCS Policlinico S. Matteo, University of Pavia, Pavia, Italy; ²CHU Dijon, Dijon, France

Introduction: Lung ultrasound (LUS) is a useful tool for lung diseases’ assessment and monitoring [1]. A lung aeration score can be computed on the basis of type and number of visualized artefacts per scan [2]; this allows semiquantification of lung aeration. LUS score is affected by the length of visualized pleura, significantly different in different scans (longitudinal (Long) vs. transversal (Transv)) [3]. The choice of the probe may also affect the length of visualized pleura, and therefore type and number of artefacts useful for lung assessment and LUS score computation. No clear indications on the most appropriate probe are reported in recommendations [4] and different kinds of probe (microconvex-Mi, linear-Li, phased-array-Pa, convex-Co) can be found in literature [5–8], limiting the possibility to standardize the exam. We prospectively compared 4 probes.

Methods: Prospective observational monocenter study. In each patient, we scanned 6 standard areas per lung (anterior, lateral, posterior, each divided in superior and inferior) with 4 probes (Pa 2.5 MHz, Co 4 MHz, Li 10 MHz, Mi 10 MHz), in Long (craniocaudal orientation) and Transv (aligned with intercostal space) scan. The length of visualized pleura was measured by a caliper.

Results: We enrolled 6 patients (2 males, age 63 ± 23 yrs, BMI 24.7 ± 2.0 kg/m2), corresponding to 72 areas and 288 scans. In all probes, Long has poorer performances than Transv scan: it visualizes significantly shorter pleura with higher pleural length variance (Table 12). In Transv, the length of visualized pleura shows significant differences among different probes. Co visualizes the longest pleura, but also has the highest pleural length variance.

Conclusions: Transv visualizes longer and more constant pleura with any probe; it’s confirmed to be a better approach to assess the lung. The length of visualized pleura and its variance differ among probes; linear probe seems to offer the best combination of high visualized pleura and low pleural length variance.

References

1. Bouhemad B et al., Anesthesiology 2015,122(2):437–47

2. Bouhemad B et al., Crit Care Medicine 2008;38(1),84–92

3. Mongodi S et al., Eur J Ultrasound 2016; In press

4. Volpicelli et al., Intensive Care Med 2012;38:577–91

5. Soummer A et al., Crit Care Med 2012, 40(7):2064–72

6. Bouhemad B et al., Am J Resp Crit Care Med 2011;1;183(3):341–7

7. Corradi F et al., Chest 2016;150(3):640–51

¹Univesity Hosptial, Pisa, Italy; ²Univesity anesthesia and intensive care unit, University of Pisa, PISA, Italy; ³Azienda Ospedaliero Universitaria di Udine, Udine, Italy

Introduction: Chest ultrasonography is commonly performed in the ICU to identify pleural fluid and to guide thoracic drainage. Aim of this study was to compare the accuracy of two ultrasound methods of estimating the volume of pleural effusions(PEV) with sonography in intubated ICU patients

Methods: The first method used to measure PEV was V = 20xSep [1]. Sep was the maximal distance between parietal and visceral pleura, recorded in end-expiration at the posterior axillary line in supine position with trunk elevation at 15°. The compared method multiplied PE paravertebral length (LUS), assessed between the apical and the caudal limits in supine patients, by its cross-sectional area at mid length (AUS) [2]. Moreover the estimated PEV was compared to the volume drained. Patients with incomplete drainage, suspect of empyema, high bleeding risk or interpleural distance less than 10 mm were excluded. T-test, Bland-Altman were used to compare the results.

Results: 10 patients (average age 63,2 ± 12,5) were recruited. Bland-Altman analysis showed no differences between the two methods, which can therefore be regarded as interchangeable (fig. 40). Both ultrasound approaches resulted highly correlated with drained PEV (respectively R0,75 R20,56 P0,012, and R0,92 R20,86 P0,001), and so accurate in estimating it. Coefficients of correlation were totally similar to those reported in previous publications. Ultrasound was performed after a 5-h professional training. These results underlined the simplicity of execution and learning of the ultrasound methods. The time necessary to measure ultrasound parameters was less than 4 min. No patients developed complications after thoracentesis

Conclusions: Ultrasound quantification of pleural effusion volume was found to be equally rapid, easy and precise using both methods, and could become a fundamental part of the clinical decision to perform thoracentesis.

References

1. Balik, M., et al., Intensive Care Med, 2006. 32(2): p. 318–21.

2. Remerand, F., et al., Intensive Care Med, 2010. 36(4): p. 656–64.

¹Karolinska Institutet, Stockholm, Sweden; ²Linköping University, Linköping, Sweden; ³Uppsala University, Uppsala, Sweden

Introduction: The aims of this study were to evaluate if:

1) Arterial oxygen saturation can be determined using Photo Plethysmography (PPG) recordings obtained from a probe placed on the sternum.

2) Only the DC-component of the PPG-signal can be used to calculate arterial oxygen saturation.

3) A change in arterial oxygen saturation can be detected faster when monitored centrally over the sternum as compared to other standard non-invasive monitoring sites.

Peripheral vasoconstriction markedly increases the time to detect hypoxia with pulse oximetry [1]. The sternum bone has a central anatomical location and is highly vascularized. Monitoring arterial oxygen saturation in the sternum could circumvent effects of peripheral vasoconstriction and shorten time for detecting hypoxia.

Methods: A hypoxia study was conducted with healthy male volunteers (n = 16) that breathed different gas mixtures with gradually decreasing oxygen content to successively lower their arterial oxygen saturation to approximately 60%. A research prototype PPG-probe (RespiHeart) using reflection mode was used to monitor the arterial oxygen saturation in the sternum. Simultaneous sampling of arterial blood gases and recordings of pulse oximetry from an earlobe and a finger were performed. Arterial oxygen saturation from the probe (S[sub]RH[/sub]O[sub]2[/sub]%) was calculated via the quotient of DC-components from infrared (810 nm) and red (660 nm) lights.

Results: The observed association between S[sub]RH[/sub]O[sub]2[/sub]% and arterial oxygen saturation measured in blood gases were found to be significant (r² 0.9736, p < 0.05) for every gas mixture used. The sternum probe was in average 28.7 s (95% CI 20.0–37.4 s) faster than the finger probe and 6.6 s (95% CI 5.3–7.8 s) faster than the ear probe to detect desaturation defined as the lowest observed oxygen saturation.

Conclusions: Based on the results in the current study we conclude that:

1) It is possible to accurately detect arterial oxygen saturation changes with reflection PPG-recordings based on sternal blood flow on an individual level.

2) Arterial oxygen saturation can be calculated using only the DC-component of the PPG-signal from infrared and red lights.

3) Arterial oxygen saturation changes are detected markedly faster on the sternum compared to more distal sites of measurement.

References

1. Mannheimer et al. Minerva Anestesiol 68:236–9,2002

¹Brigham & Women’s Hospital, Boston, MA, USA; ²Respiratory Motion, Inc, Waltham, MA, USA

Introduction: Capnography (EtCO2) is the current standard of care for monitoring ventilation in patients under moderate & deep sedation. It assists in making decisions regarding airway interventions. In non-intubated patients, EtCO2 monitoring is often challenging or impossible. Thus, clinicians often rely on pulse oximetry, a late indicator of respiratory depression, or subjective assessments. A recently developed non-invasive respiratory volume monitor (RVM) provides accurate & continuous monitoring of minute ventilation (MV), tidal volume (TV) & respiratory rate (RR) [1–2]. Here we compared RVM & EtCO2 monitoring in patients receiving propofol-based sedation.

Methods: Continuous RVM (ExSpiron, Respiratory Motion, Inc.) & capnography data (Capnostream 20, SmartCapnoLine, Covidien) were collected from 17 patients undergoing colonoscopies (6 males; age: 53.1 ± 14.4 yrs; BMI: 27.2 ± 4.9 kg/m2). Baseline MV was established during normal breathing pre-sedation. Monitored anesthesia care was provided using a combination of propofol with midazolam and/or fentanyl. Clinicians were blinded to RVM data. MV, TV, RR, & EtCO2 measurements were compared before & after a cumulative dose of 100 mg of propofol using paired t-tests.

Results: After administration of propofol, MV & TV decreased significantly (p < 0.05) while EtCO2 remained unchanged (p > 0.5). RR, measured by the RVM, & EtCO2 were similar & not significantly affected by propofol. Figure 41 shows a typical course where MV decreases due to propofol, while EtCO2 shows little change.

Conclusions: In non-intubated patients, the RVM reflects expected changes in ventilation with propofol & demonstrates reduction in TV & MV during obstruction & hypoventilation. The RVM provides reliable measurements when capnography is unavailable & is not subject to the EtCO2 limitations of nasal cannula placement, dilution with O2, mouth breathing, & during upper endoscopies. The RVM shows expected decreases in respiratory status in response to anesthetics, while there is little change EtCO2. The RVM provides useful data similar to that provided by capnography & may be a useful alternative.

References

1. Voscopoulos C et al.: Anesth Analg 2013; 117: 91–100 2. Voscopoulos C et al.: J Clin Monit Comput 2015; 29: 223–30

¹Lithuanian university of health sciences, Kaunas, Lithuania; ²Lithuanian Sports University, Kaunas, Lithuania, Kaunas, Lithuania

Introduction: Marathon race transiently elevates the probability of sudden death. Also during long-distance run may occur various gastrointestinal symptoms with range from mild nausea to hemorrhagic stool. However microcirculatory nature of this disturbances is not clear. Microcirculation of sublingual mucosa is part of interest, because it is easy and noninvasively accessible, changes have relation with mortality and it is part of the upper digestive tract. Here, we evaluate changes in sublingual microcirculation induced by a marathon race.

Methods: Thirteen healthy male controls and 13 male marathon runners volunteered for the study. We performed sublingual microcirculation, using a Cytocam-IDF device (Braedius Medical, Huizen, The Netherlands), and systemic hemodynamic measurements four times on the marathon runners: 24 hours prior to their participation in the Kaunas Marathon (distance: 41.2 km), directly after finishing the marathon, 24 hours after the marathon and one week after the marathon.

Results: The marathon runners exhibited a higher functional capillary density (FCD) and total vascular density of small vessels at the first visit compared with the controls. Overall, we did not find any changes in sublingual microcirculation in the marathon runners at any of the visits. However, in a subgroup of marathon runners with a decreased FCD after finishing the marathon race compared to increased FCD had shorter running time (190.37 ± 30.2 vs. 221.80 ± 23.4 min, p = 0.045), ingested less fluids (907 ± 615 vs. 1950 ± 488 ml, p = 0.007) during the race and lost much more weight (−2.4 ± 1.3 vs. -1.0 ± 0.8 kg, p = 0.041).

Conclusions: Recreational marathon running is not associated with an alteration of sublingual microcirculation. However, faster running and dehydration may be crucial for further impairing microcirculation.

¹University of Pittsburgh, Pittsburgh, PA, USA; ²Oslo University Hospital, Oslo, Norway; ³Staten Island University Hospital, New York, NY, USA; ⁴Bronx-Lebanon Hospital, New York, NY, USA

Introduction: We hypothesized that that sublingual (SL) microcirculatory parameters 1. Can predict microvascular response to resuscitation during sepsis; and 2. Are associated with tissue level lactate, lactate/pyruvate ratio (L/P) and tissue to blood lactate gradient (T-BLac).

Methods: Lipopolysaccharide (LPS) was administered to 23 anesthetized Yorkshire-Durock pigs for 45 minutes. Thirteen animals received late (90 min after LPS) and 10 early (immediately after LPS) resuscitation. Five animals per group had available data for this opportunistic study. Sublingual microcirculatory parameters (microvascular flow index (MFI) and perfused vessel density (PVD)) were collected. Tissue level lactate and pyruvate were measured using microdialysis catheters inserted in the liver, kidney and tongue at baseline and pre-/post-resuscitation (PreR, PostR). Resuscitation was driven by MAP and SvO2 as targets and using SVV for fluid responsiveness. Data are shown in median (interquartile range). Non parametric statistics were used whenever appropriate.

Results: Pre-R MFI correlated with Post-R MFI (r2 = 0.562, p = 0.008). Microvascular ‘responsive’ animals (i.e. increase in MFI > 50% or any increase in PVD) had lower Pre-R MFI and PVD (Fig. 42A). Pre-R PVD correlated with Pre-R SL lactate (r2 = 0.4, p = 0.08). A higher Pre-R MFI (>2.5) was associated with lower SLT-BLac (−0.42 (0.74) vs. 3.49 (0.34), p = 0.008). At the Post-R time point, PVD was associated with liver L/P (Fig. 41B), and MFI with renal L/P (r2 = 0.31, p = 0.09). Animals with increased Post-R renal T-BLac had lower Pre-R MFI (1.25 (0.25) vs. 1.75 (0.75), p = 0.07).

Conclusions: Pre-resuscitation MFI and PVD may predict post-resuscitation microvascular responsiveness. Importantly, pre- and post-resuscitation MFI and PVD were associated with local metabolic changes in the tongue as well as in vital organs, particularly the kidney and the liver.

East Sussex Healthcare, East Sussex, UK

Introduction: The definition of sepsis has changed recently, pushing us to redefine and examine how we screen for sepsis [1] [2].

The bedside clinical score termed quickSOFA (qSOFA) has been introduced as an additional tool to identify patients with suspected sepsis who are likely to have a prolonged ICU stay or to die in hospital. The trigger score for qSOFA correlates with a NEWS of either 4 or 5 depending on which qSOFA parameters are abnormal. We have recently updated the sepsis screening tool at our institution, amending that published by the UK Sepsis Trust with their permission. We decided to use a NEWS score of 5 as a trigger by local ‘sepsis steering group’ consensus. Whilst reaching this consensus decision, however, we also wanted to look at NEWS for our local population admitted to critical care with sepsis.

Methods: Our Trust is a District General Hospital comprising 19 medical and surgical critical care beds across two separate sites. All patients admitted to critical care with a diagnosis of sepsis as per ICNARC coding method from April 2015 until March 2016 were identified using ‘Wardwatcher software’ (Critical Care Audit Ltd, West Yorkshire, UK). This period was before the introduction of the updated sepsis screening tool. We then looked retrospectively at highest NEWS prior to admission to critical care using early warning score electronic records (VitalPac, The Learning clinic, London, UK). Admissions to critical care were from the emergency department, general medical and surgical wards.

Results: 200 patients were admitted to critical care with a diagnosis of sepsis during the study period. 47 patients were excluded as NEWS data was not available for these patients. Overall mortality was 34%. 17.6% had a NEWS between 0 and 4. This cohort consisted mainly of young patients with single organ dysfunction who had the lowest mortality (6% of all deaths).

The majority of patients fell into the middle category – 47.8% scored NEWs 5–9 The remaining score a NEWS of greater or equal to 10, this accounted for 34.6% of selected patients. The mortality in this group was high as was the length and complexity of the stay.

Conclusions: In our local population NEWS score of 5 is a reasonably sensitive screening trigger for identifying the septic patient at risk of significant deterioration. The patients with a NEWS less than 5 and admitted to ICU with sepsis had a lower morbidity and mortality than those with a NEWS score over 5.

References

[1] Singer M et al.; JAMA. 2016;315(8):801–810

[2] Churpek et al.; Am J Respir Crit Care Med. 2016 Sep 20.

Università Politecnica delle Marche, Ancona, Italy

Introduction: Microvascular alteration is associated with organ dysfunction and adverse outcome in several subsets of critically ill patients. We performed a daily monitoring of sublingual microcirculation to evaluate the association between microcirculatory alterations and the development of organ dysfunction in polytraumatic patients.

Methods: This is a subgroup analysis of a perspective observational study on a mixed Intensive Care Unit (ICU) population. 36 polytraumatic patients. Sublingual microcirculation was monitored with Sidestream Dark Field (SDF) imaging daily from admission to discharge/death. Parameters of vessel density and flow quality were calculated with a dedicated software. Organ function was observed and SOFA score was recorded daily.

Results: Patients who had a SOFA ad day 4 < 6.5 showed a higher Total Vessel Density (TVD) at day 1 and 2 (Fig. 43). TVD at day one was also a good predictor of SOFA > = 6.5 at day 4 (Area Under the Receiver Operating Characteristic Curve 0.826; p = 0.002; 95%CI = 0.681–0.970) (Fig. 44). Analogue results were obtained for the Perfused Vessel Density (AUC 0.p99773; p = 0.009; 95%CI = 0.604–0.942). Microvascular Flow Index did not show any predictive value towards development of organ dysfunction.

Conclusions: The presence of altered microcirculatory vessel density and perfusion in the first 48 hours from the ICU admission resulted to be associated with the development of organ dysfunction in polytraumatic patients.

¹Hospital of Traumatology and Orthopaedics, Riga, Latvia; ²University of Latvia, Riga, Latvia

Introduction: Skin mottling is extreme manifestation of microcirculatory changes in septic shock. Skin discolouration is thought to be due to heterogenous changes in oxygen saturation and volume of microcirculatory blood which results in alterations in the amount of reflected light in various parts of the spectrum. These alterations can be captured using hyperspectral imaging. We aim to describe mottled knee skin relative total hemoglobin concentration and microcirculatory saturation values in survivors and non survivors of septic shock and assess their prognostic information.

Methods: Hyperspectral imaging was performed in 62 intensive care patients with septic shock enrolled within 24 hours of admission in single centre observational study to obtain relative oxy/deoxyhemoglobin concentration maps and numerical values from mottled area around the knee. Images were processed to identify areas with purple blue discolouration. Nonlinear fitting of optical density spectra was used to calculate relative oxy/deoxy haemoglobin concentration and obtain total hemoglobin concentration (a.u.) and microcirculatory oxygen saturation values (%). In addition, demographic (age, sex, primary site of infection), hemodynamic (mean arterial pressure, dose of vasopressor agents) and disease severity (SAPS II, SOFA score) data were collected.

Results: It was possible to obtain analysable images in 55 patients, 26 survivors and 29 non survivors. There was no statistical difference in terms of age (60 (53–73) vs 70 (62.5–82)yrs), gender (42.3 vs 55.2% male), severity of disease (SAPS II 44.5 (32.0–50.0) vs 44.0 (36.0–57.5)) and dose of noradrenaline (0.02 (0–0.09) vs 0.08 (0–0.12 mcg/kg/min) between those who survived the episode of septic shock and those who died. In non survivors relative total hemoglobin concentration in mottled areas was significantly higher (267.6 ± 249.7 a.u. vs 72.3 ± 36.7 a.u.; P < 0.001) and skin microcirculatory oxygen saturation values were significantly lower (29.7 ± 36.1% vs 76.3 ± 30.7%;P < 0.001). Skin microcirculatory oxygen saturation of more than 22% provided 72% specificity and 69% sensitivity for predicting survival. Increase of relative skin total haemoglobin concentration (RR 1.11 (1.05–1.20)) and decrease of skin oxygen saturation by 5 units (RR 1.19 (1.09–1.30)) was associated with increase in hospital mortality.

Conclusions: We used a non contact hyperspectral imaging system to quantify total haemoglobin and oxygen saturation in dermal microcirculation of septic shock patients. Increase in total dermal hemoglobin and decrease in oxygen saturation was strongly predictive of 28 day mortality.

MUMC, Netherlands, Netherlands

Introduction: There is a growing interest in the state of the microcirculation during critical illness. Sidestream Dark Field Imaging (SDFI) is widely used to study microcirculation in vivo. One such SDFI device is the Glycocheck®, which estimates the thickness of the endothelial glycocalyx by measuring the thickness of the Perfused Boundary Region (PBR). Though single measurements are current clinical practice, intra observer variability is unknown.

Methods: Microcirculation was assessed in a pilot study of 49 mechanically ventilated mixed ICU patients using SDFI (Glycocheck®). Each patient was assessed three times consecutively within 30 minutes by the same experienced operator. The operator was unaware of the results of the measurements until all three measurements were completed. The Glycocheck® calculated a PBR for each of the measurements. The intra-observer agreement was calculated using an intra-class correlation coefficient (ICC) using SPSS.

Results: The mean (SD) PBR was 2,02 (0,26) μm. The ICC for single measures was 0,362, indicating a poor intraobserver agreement for single measures. ICC for average measures was 0,630 indicating reasonable reliability of the averaged value of 3 consecutive measurements.

Conclusions: Intraobserver variability in this pilot study was higher than expected. Averaging the results of three consecutive measurements improved data quality. Whether intraobserver agreement was limited by patient factors such as hemodynamic instability or whether it is inherent to the method itself remains unclear. Reliability of measurement of PBR by SDFI should be increased by averaging (at least three) multiple consecutive measurements. A single measurement is insufficient to yield reliable data on PBR diameter assessed by glycocheck.

Hôpitaux universitaires Paris-Sud, Hôpital de Bicêtre, Inserm UMR S_999, Univ Paris-Sud, Le Kremlin-Bicêtre, France

Introduction: To compare the microcirculatory reserve at two levels of mean arterial pressure (MAP) in septic shock patients.

Methods: In 22 septic shock patients receiving norepinephrine with a MAP > 75 mmHg (so-called “high MAP”) within the first six hours of resuscitation, we decreased the norepinephrine dose in order to target MAP to 65–70 mmHg (so-called “low MAP”). We measured muscle tissue oxygen saturation (StO2) at the thenar eminence by using near-infrared spectroscopy and the StO2 recovery slope after a vascular occlusion test at “high MAP” and “low MAP”. Transpulmonary thermodilution cardiac index was also measured at the both MAP levels.

Results: On average, MAP was decreased from 81 ± 3 to 67 ± 3 mmHg. Cardiac index did not change (3.26 ± 1.09 vs. 3.12 ± 1.05 L/min/m², respectively). The decrease in MAP was associated with a decrease in mean StO2 recovery slope (3.00 ± 1.40 vs. 2.61 ± 1.46 units/sec, respectively, p < 0.05). StO2 recovery slope decreased by more than 5% in 16 patients and increased by more than 5% in 5 patients. Decreasing MAP from “high” to “low” values was not associated with any changes in mean StO2 (81 ± 8 vs. 81 ± 9%, respectively). StO2 decreased by more than 1% in 11 patients and increased by more than 1% in 8 patients. There was no difference in baseline cardiac index between patients with a decrease or an increase in StO2 or in StO2 recovery slope. Changes in StO2 or in StO2 recovery slope were not different between patients with (n = 17) and without (n = 5) a past medical history of arterial hypertension. There was no correlation between changes in StO2 and changes in StO2 recovery slope.

Conclusions: Decreasing MAP from “high” to “low” values in septic shock patients was associated with a decrease in the mean StO2 recovery slope without any changes in mean StO2. Nevertheless, there was a large interindividual variability with two opposite behaviours: the StO2 recovery slope seems to be greater at the high MAP level in the majority of patients but greater at the low MAP level in a smaller group of patients. Thus, it could make sense to monitor the microvascular reserve in septic shock patients in order to individualize the MAP level to target above 65 mmHg.

¹Hôpitaux universitaires Paris-Sud, Hôpital de Bicêtre, Inserm UMR S_999, Univ Paris-Sud, Le Kremlin-Bicêtre, France; ²zouheir bitar, Fahahil, Kuwait

Introduction: We investigated the relationship between the ultrasonic B profiles and Spectral tissue Doppler echocardiography (E/E’ ratio), a non-invasive surrogate for left ventricular diastolic pressures, in patients presenting with suspicion of acute pulmonary edema

Methods: This is a prospective observational study of 61 consecutive patients presenting with acute pulmonary edema and B - profile detected by echocardiography with a 5 MHz curvilinear probe. The Filling pressure of the left ventricle considered high when E/E’ is equal or > 15 or when value between 9 and 14 with ultrasound chest B pattern. The filling pressure is considered normal if E/E’ is equal or below 8 or the value between 9 and 14 with A-line pattern (1).

Results: Sixty-one participants were included (49.2% male, with a mean age 66.8). The mean E/E’ level in the patients with B-profile was (20.8), compared with the mean level in the patients with an A-profile of (8.2) (p = 0.003). Based on the value of E/E’, the sensitivity and specificity (including the 95% confidence interval) were determined and are shown in Table 13. The systolic function in the subjects with a B-profile was below 50% in 74.3% of the subjects. All the subjects with B profile and systolic function > 50% had elevated NT-proBNP and E/E’ > 15.

Conclusions: Detecting the B-profile in lung ultrasound is highly sensitive and specific for elevated left ventricular diastolic pressures in patients with acute pulmonary oedema.

References

¹Klinikum rechts der Isar; Technical University of Munich, Munich, Germany; ²University Hospital, Ghent, Belgium; ³Centre Hospitalier, Lens, France; ⁴Nagayama Hospital, Tokyo, Japan; ⁵Charité, Campus Virchow-Klinikum, Berlin, Germany

Introduction: EVLW is a marker of pulmonary oedema associated to morbidity and mortality. To adjust for individual patients, EVLW is indexed to biometric data (EVLWI). Several studies suggest that predicted bodyweight BW_pred is superior to actual bodyweight BW_act for indexation, in particular in obese patients. However, BW_pred is an unspecific formula based on height and gender. BW_act has been introduced to define a gender-adjusted normal weight, but not to specifically adjust haemodynamic parameters.

Therefore, we analyzed the original data of 9 databases of 6 centers regarding the association of EVLW to age, height, gender and BW_act.

Methods: Spearman correlation and multivariate regression analysis regarding the association of unindexed EVLW to biometric data. Analyses were performed for all measurements, the first measurements and the individual means Statistics: IBM SPSS 23. ELWI-STAR: EVLW-Study and Research-group

Results: 20226 thermodilutions in 1760 adult ICU or peri-operative patients (1049 male and 711 female).

In all measurements, EVLW was univariately associated to male gender (r = 0.264; p < 0.001), height (r = 0.249; p < 0.001), BW_act (r = 0.172;p < 0.001), but not to age (r = −0.013; p = 0.068). In multivariate analysis (R² = 0.047) EVLW was independently associated to male gender (t = 13.919), height (t = 7.169), BW_act (t = 8.471) and age (t = 5.823) with p < 0.001 for all variables.

First measurements of EVLW were univariately associated to male gender (r = 0.261; p < 0.001), height (r = 0.112; p < 0.001), age (r = 0.064; p = 0.009), but not to BW_act (r = 0.034; p = 0.181). In multivariate analysis (R² = 0.054), EVLW was independently associated to male gender (t = 9.205; p < 0.001) and age (t = 2.188; p = 0.029), but neither to height nor to BW_act.

Individual means of EVLW were univariately associated to male gender (r = 0.272; p < 0.001) height (r = 0.146; p < 0.001), BW_act (r = 0.068; p = 0.006), but not to age (r = −0.031; p = 0.193). In multivariate analysis (R² = 0.057) EVLW_mean was only associated to male gender (p < 0.001).

Conclusions: EVLW is predominatly associated to height and male gender, whereas BW_act and age have at best limited impact on EVLW. The small amount of R² of about 0.06 suggests that in adult critically ill patients EVLW is mainly driven by pathology (i.e. pulmonary oedema), whereas the impact of biometrics seems to be low, resulting in a high “signal to noise ratio” of EVLW.

Klinikum rechts der Isar; Technical University of Munich, Munich, Germany

Introduction: Haemodynamic parameters are measured as unindexed “raw values” and in part adjusted to unspecific biometric data. We hypothesized that 1.) Indexation to unspecific biometrics is inappropriate. 2.) Haemodynamic parameters might be associated not only to biometrics, but also to “contexts” such as mechanical ventilation MV, position of the CVC used for transpulmonary thermodilution TPTD and (patho)physiological contexts (e.g. heart rate HR, heart rhythm Rh).

Methods: Database analysis (10936 TPTDs; 608 patients). Multivariate regression regarding independent association of GEDV, stroke volume SV, SVV, EVLW and CVP to age A, gender G, weight W, height H, HR, Rh, MV and CVC.

Results: 1.) All haemodynamic parameters were independently associated to biometrics and contexts (Table 14).

2.) R²-values for the combined models between 0.074 and 0.444 suggest that up 44.4% of the unindexed values can be explained by biometrics and contexts.

¹St Georges Hospital, London, UK; ²GSTT, London, UK

Introduction: We aimed to run a training day focused on practical use of haemodynamic monitoring (HM). Methods of HM have rapidly expanded, trainees’ knowledge of, and exposure to, all of them is likely to be variable. HM is of increasing importance which has been mirrored with an increasing array of devices. Trainees undergo assessment of their knowledge of these devices during examinations. Practical application however is learnt by apprenticeship. To encourage a wider and more detailed practical understanding we undertook a HM training day.

Methods: We conducted a training day consisting of didactic lectures followed by small group practical sessions. We conducted pre and post course surveys assessing subjective confidence of setting up and interpreting data, and objective assessment via multiple choice questions.

Results: There was an increase in confidence across all four monitoring techniques in both setting up and interpreting (fig. 45 and 46). The MCQ showed a pre and post course mean of 74% and 78% respectively.

Conclusions: The survey has demonstrated inconsistent knowledge of and exposure to the many haemodynamic monitors available. The course has improved both subjective and objective measures. There was a proportionately greater increase in confidence with ECHO and PAC, which may be indicative of the lower overall prior exposure. The MCQ showed minimal increase, and this may reflect the aims of the course were to focus on hands on experience and understanding rather the exam based knowledge.

¹Carnegie Mellon University, Pittsburgh, PA, USA; ²University of Pittsburgh, Pittsburgh, PA, USA

Introduction: Tachycardia events observed in the Intensive Care Unit (ICU) could lead to cardiorespiratory instabilities and significant morbidity and mortality [1]. We apply machine learning to predict whether and how soon tachycardia will occur based on continuous hemodynamic monitoring data.

Methods: An episode of tachycardia is defined as heart rate over 130 for at least 10% of a 5 minute interval. Based on heart rate, respiratory rate, blood pressure and plethysmography from data in MIMIC-II [2], we extracted 42 statistical features over 30-minute time windows right before the onset of tachycardia. We trained two random forest classification models. The first used the first occurrences of tachycardia during patient stay as cases, and randomly selected controls from patients without tachycardia. The second model used the same cases as above but controls were sampled from tachycardia patients data way ahead of its onset.

Results: We evaluated the models using 10-fold cross validation, and tracked predictions made over the entire stays of test patients. Fig. 47 summarizes predicted risk scores and 95% confidence intervals for cases (solid) and controls (dashed) over 3.5 hours leading to tachycardia. Fig. 48 depicts the ratio of risk scores (lift) for cases during 3.5 hours leading to the onset (solid) vs. the risk computed for the same patient during the first few hours of their ICU stay (dashed).

Conclusions: Estimated risks scores for cases and controls differ significantly throughout the test period suggesting potential utility of the first proposed model in triage as it helps identify who is going to develop tachycardia with high confidence, and could inform monitoring and care resource allocation in the ICUs. The second model applied to patients at risk reliably signals the upcoming episode more than 1 hour ahead of its onset, allowing preemptive treatment. The results suggest improvements of quality of care and patient outcomes, and mitigation of costs.

References

1. Park S et al. Journal of critical care, 2011

2. MIMIC-II. physionet.org/mimic2/

Zainab Al Duhailib, Riyadh, Saudi Arabia

Introduction: Several predictive models and scores were developed to predict critical care disease severity and prognosis. QT dispersion, one of the proposed measures of heterogeneity of ventricular repolarization. It was studied extensively in cardiology and there was a trend toward increased cardiac adverse outcome as well as mortality in normal subjects with a prolonged QTd. We aimed to clarify the relationship between QTd and serum lactate clearance along with ICU mortality and vasopressors requirements in critically ill patients.

Methods: A prospective, observational study was performed on inpatients that required a Rapid Response Team (RRT) consultation. 12 lead EKG and serial measurements of physiological and biochemical data were made. QT dispersion was measured as the difference between maximum QT interval and minimum QT interval on the baseline EKG. The study was performed as a nested cohort study within a larger study (Research Ethics Committee approval No. 2151069).

Results: Seventy patients were evaluated with a mean age 49.9 ± 22.3 years; mean APACHE II score 23.5 ± 7.3 and a mean SOFA score 9.1 ± 4.9, 64% patients had presumed sepsis. The mean QT dispersion was 68.1 ± 26.5. Significant negative correlations were observed between QT dispersion and mean arterial blood pressure, p =0.03 and serum lactate, p =0.04. QT dispersion was also significantly associated with changes in serum lactate, i.e.: delta lactate at 4 hours, p = 0.04 and at 6 hours, p =0.015. No associations were observed with ICU mortality, 28-day mortality, vasopressor requirement, and QT dispersion.

Conclusions: Increased QT dispersion appears to reflect perfusion in patients with critical illness.

East Surrey Hospital, Redhill, UK

Introduction: It is recognised that both a prolonged tachycardia and a high daily mean heart rate are associated with an increase in Intensive Care patient mortality [1]. This study aimed to look at the highest recorded heart rates during Intensive Care Unit (ICU) admission and the associated rate of survival to discharge from hospital.

Methods: A retrospective analysis looking at a total patient population of 11,685 which included consecutive patients admitted to a mixed medical and surgical ICU over a 22-year period. We assessed the highest heart rate recorded during the first 24 hours of ICU admission. Patients were grouped in incremental sets depending on highest heart rate. The defined outcome was survival to discharge from hospital. Fischer’s exact test was applied to determine two-tailed p values for the dataset.

Results: Of those patients with a highest recorded heart rate of 90 beats per minute (bpm), or less, 77.4% survived to discharge from hospital. This decreased to 70.6% in patients with a high heart rate of between 101 and 110 bpm (p value < 0.0001) and to 50% or less in patients with a high heart rate of more than 170 bpm (p value < 0.0001) (see Fig. 49). The difference in mortality between those with a maximum heart rate of 90 bpm (77.4%) and those with a maximum heart rate of 100 bpm (75.5%) was not statistically significant (p = 0.172).

Conclusions: The occurrence of tachycardia of greater than 100 bpm during an ICU admission is associated with a reduced rate of survival to discharge when compared with those patients with a high heart rate of 90 bpm or less.

References

1. Park S et al.: J Crit Care. 2011 Oct; 26 (5): 534

Hopital Bichat, Paris, France

Introduction: Adult cardiac surgery and perioperative care underwent continuous improvement, with decline in mortality and morbidity. We present data from a prospective, observational study, regarding current clinical practice in cardiac surgery.

Methods: With approval from the Ethics and Research Committee, 32 centres in France included cardiac surgery patients from 2 November to 20 December 2015, excluding transcatheter aortic valve replacement, extracorporeal life support, congenital cardiac surgery, wound infections or pericardial drainage.

Results: Comparative results in Table 15 present data collected globally and from our centre.

Populations are similar in preoperative risk and comorbidities. Significant differences concern the type of surgery, mean extracorporeal circulation (ECC) and cross clamping (CC) time.

All centres rely on less invasive monitoring, our centre showing remarkable preference for minimally invasive monitoring. While no patient had invasive intraoperative CO monitoring, this was used for 2% of patients in ICU. 36% of patients were monitored intraoperatively by transesophageal echocardiography (TEE), with all patients being monitored by TEE or transthoracic echocardiography (TTE) in the ICU.

All centres used preferentially norepinephrine and dobutamine, while milrinone and levosimendan remain peripheral in clinical practice.

Mortality is low, with no significant differences in postoperative complications or ICU stay.

¹Vanderbilt University Medical Center, Nashville, TN, USA; ²UCL, London, UK; ³Brigham and Womens Hospital, Boston, MA, USA; ⁴Boston Strategic Partners, Boston, MA, USA

Introduction: The utility of the PAC has been called into question over recent years as studies have demonstrated varying outcomes in different patient populations. Despite this, sales of PACs have remained robust, suggesting that users of the device derive value from it. To investigate this apparent paradox, we used propensity score methodology to control for observable bias in a retrospective study of adult cardiac surgical patients who were managed with and without a PAC, and whose data were recorded in a North American electronic health record (EHR) database (Cerner Health Facts). The study protocol and analysis plan were approved by the VUMC IRB prior to data abstraction and the study was registered in ClinicalTrials.gov (NCT02964026).

Methods: From the Cerner Healthfacts database we identified a study cohort of 6,844 adult cardiac surgery patients: 3,422 PAC patients matched 1:1 with 3,422 non PAC patients via propensity score (PS), developed from patient and hospital demographics, operation, EuroSCORE II, and Elixhauser algorithm. For each patient the APS was calculated on ICU admission and used to control for severity of illness in the outcomes models. Primary outcomes included hospital mortality, Major Adverse Cardiac Events (MACE), Length-of-stay (LOS) and unplanned readmissions. Secondary outcomes included individual organ function outcomes.

Results: There was no statistically significant difference in the primary endpoint; although 60 and 90 day all-cause readmission rates were significantly lower in PAC patients. Patients who were managed with a PAC experienced significantly fewer complications due to new onset heart failure (index visit OR [95%CI] 0.70 [0.59–0.84], respiratory failure (index visit OR [95%CI] 0.66 [0.53–0.84] and hemorrhage through 30 days post-discharge OR [95%CI] 0.62 [0.39–0.97] (Fig. 50). Patients managed with a PAC experienced some increased infections and abnormal coagulation labs.

Conclusions: Use of a PAC in adults undergoing cardiac surgery is associated with fewer cardiopulmonary and bleeding complications, more infections but no increased length of hospital stay, readmissions, or mortality.