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An appraisal of respiratory system compliance in mechanically ventilated covid-19 patients



Heterogeneous respiratory system static compliance (CRS) values and levels of hypoxemia in patients with novel coronavirus disease (COVID-19) requiring mechanical ventilation have been reported in previous small-case series or studies conducted at a national level.


We designed a retrospective observational cohort study with rapid data gathering from the international COVID-19 Critical Care Consortium study to comprehensively describe CRS—calculated as: tidal volume/[airway plateau pressure-positive end-expiratory pressure (PEEP)]—and its association with ventilatory management and outcomes of COVID-19 patients on mechanical ventilation (MV), admitted to intensive care units (ICU) worldwide.


We studied 745 patients from 22 countries, who required admission to the ICU and MV from January 14 to December 31, 2020, and presented at least one value of CRS within the first seven days of MV. Median (IQR) age was 62 (52–71), patients were predominantly males (68%) and from Europe/North and South America (88%). CRS, within 48 h from endotracheal intubation, was available in 649 patients and was neither associated with the duration from onset of symptoms to commencement of MV (p = 0.417) nor with PaO2/FiO2 (p = 0.100). Females presented lower CRS than males (95% CI of CRS difference between females-males: − 11.8 to − 7.4 mL/cmH2O p < 0.001), and although females presented higher body mass index (BMI), association of BMI with CRS was marginal (p = 0.139). Ventilatory management varied across CRS range, resulting in a significant association between CRS and driving pressure (estimated decrease − 0.31 cmH2O/L per mL/cmH20 of CRS, 95% CI − 0.48 to − 0.14, p < 0.001). Overall, 28-day ICU mortality, accounting for the competing risk of being discharged within the period, was 35.6% (SE 1.7). Cox proportional hazard analysis demonstrated that CRS (+ 10 mL/cm H2O) was only associated with being discharge from the ICU within 28 days (HR 1.14, 95% CI 1.02–1.28, p = 0.018).


This multicentre report provides a comprehensive account of CRS in COVID-19 patients on MV. CRS measured within 48 h from commencement of MV has marginal predictive value for 28-day mortality, but was associated with being discharged from ICU within the same period. Trial documentation: Available at

Trial registration: ACTRN12620000421932.


Millions of people have been infected by SARS-CoV-2 worldwide, and many of those have been hospitalized for respiratory complications associated with coronavirus disease-2019 (COVID-19). Many of those COVID-19 hospitalised patients have received mechanical ventilation (MV), due to the development of acute hypoxemic respiratory failure and acute respiratory distress syndrome (ARDS) [1,2,3,4]. To date, several landmark studies [5,6,7,8] have improved our understanding of COVID-19 pulmonary pathophysiology, but pulmonary derangement in COVID-19 and appropriate ventilatory management remains incompletely characterized.

Earlier reports on the pulmonary pathophysiology of COVID-19 patients reported conflicting results and extreme heterogeneity in levels of pulmonary shunting, static respiratory system compliance (CRS), [9,10,11,12] and substantial heterogeneity in lung recruitability [13, 14]. Adding further to the controversy over CRS in COVID-19 patients, Grasselli and collaborators [7] have compared findings from an Italian repository of COVID-19 ARDS with previous ARDS cases of different etiologies. They found statistically significant higher CRS in patients with COVID-19 ARDS. In addition, they found that patients who presented with lower CRS and higher D-dimer values had the greatest mortality risk. In line with these figures, in a small-case series, Chiumello and collaborators found that COVID-19 patients presented higher CRS levels in comparison with patients with ARDS from other etiologies and matched levels of hypoxemia [12]. Regrettably, those previous reports did not provide any information on how CRS progressed beyond a punctual assessment during the period of MV. In contrast, in another landmark study by Ferrando et al. [6], CRS figures from a Spanish database were very similar to previously published cohorts of ARDS patients. The authors also found that intensive care unit (ICU) discharge and mortality were not influenced by the initial levels of CRS.

In a pandemic caused by a novel virus, access to international data is vital, because it may help account for differences in populations, access to medical care, equipment and critical variations in clinical managements among countries. Thus, analysis of international repositories improves the overall understanding of a novel disease and helps establishing best practices to enhance outcome. One example of how single-center or single-country studies can influence medical care early in a pandemic, before being contradicted by subsequent international findings is the issue of CRS. Indeed, as this parameter can be markedly impacted by fine variations in ventilatory management, extrapolations from mono-center or single-country studies may be challenging. In early January 2020, the COVID-19 Critical Care Consortium incorporating the ExtraCorporeal Membrane Oxygenation for 2019 novel Coronavirus Acute Respiratory Disease (COVID-19–CCC/ECMOCARD) group was founded to investigate patients presenting to ICUs worldwide.

Here, we present a comprehensive appraisal of CRS in mechanically ventilated COVID-19 patients enrolled into the COVID-19–CCC/ECMOCARD international study, in order to understand the dynamics of CRS during the first week of mechanical ventilation and its potential impact on patient outcomes.

Materials and methods

Study design and oversight

The COVID-19-CCC/ECMOCARD is an international, multicentre, cohort observational study ongoing in 351 hospitals across 53 countries. The full study protocol is available elsewhere [15]. To summarize, participating hospitals obtained local ethics committee approval and a waiver of informed consent was granted in all cases. ISARIC/SPRINT-SARI data collection began at admission to hospital, while data collection for the COVID-19–CCC observational study commenced at admission to the ICU. De-identified patient data were collected retrospectively and stored via the REDCap electronic data capture tool, hosted at the University of Oxford, United Kingdom or Monash University, Melbourne, Australia.

Study population

We reviewed data of all patients admitted to the ICU at a COVID-19–CCC collaborating site, from January 14 through September 30, 2020, with a clinically suspected or laboratory confirmed diagnosis of SARS-CoV-2 infection, through naso-pharyngeal swab for real-time PCR SARS-CoV-2 detection. Of note, suspicion of SARS-CoV-2 infection was based on symptoms and onset of infection and was confirmed by the clinician when COVID-19 infection was the most likely cause of the symptoms experienced. Patients excluded were those under the age of 15 years or admitted to an ICU for other reasons. We focused our analysis on patients on controlled MV and with a computed CRS value within 48 h of MV commencement.

Definitions and pulmonary mechanics computations

CRS was calculated as: tidal volume (mL)/[(airway plateau pressure-PEEP (cmH2O))]. Of note, we provided to data collectors a detailed data dictionary, with instructions on how to collect airway plateau pressure values, via an inspiratory pause of approximately 3 s. We computed CRS using the first measured tidal volume, airway plateau pressure and PEEP values, within 48 h of MV commencement. In the sub-population of patients on controlled MV, without ECMO support, we analysed key pulmonary variables, such as tidal volume, positive end expiratory pressure (PEEP), static driving pressure, inspiratory fraction of oxygen (FiO2), and gas exchange, recorded during routine clinical practice and only. Tidal volume was reported in mL/kg of predicted body weight (PBW) [16].

Data collection

After enrolment, data on demographics, comorbidities, clinical symptoms and laboratory results were collected by clinical and research staff of the participating ICUs in an electronic case report form [15]. Details of respiratory and hemodynamic support, physiological variables, and laboratory results were collected daily. Of note, the worst daily values were preferentially recorded. The duration of MV and ICU stay, and hospital mortality were recorded. Analysis of daily data was restricted to the first seven days from commencement of MV.

Statistical analyses

Descriptive statistics summarised demographics, clinical signs on ICU admission, ICU management and clinical outcomes for the overall study cohort and subjects with baseline compliance measured within the first 48 h of controlled MV. Statistics were reported as medians (interquartile range) for continuous variables and numbers (percentage) for categorical variables. Linear regression was applied to summarise associations between baseline compliance with body mass index (BMI) (including interaction between BMI and sex), days from symptom onset to MV commencement and PaO2/FiO2, adjusted for BMI. Linear mixed modelling was used to investigate trends in compliance over time and associations with key respiratory parameters during the first 7 days of controlled MV. Models assumed a linear effect for days and a random intercept per subject to account for repeated measures. Consistent with exploratory analyses, BMI was included as a fixed effect to adjust for potential confounding in the clinical characteristics and management of patients with different BMI. Hypothesis testing was applied to all fixed effects, assuming a 5% level of statistical significance. Results were summarised graphically with uncertainty in estimated trends represented by 95% prediction intervals. Expected patient outcomes including length of ICU stay, duration of MV and risk of ICU mortality versus discharge were examined using multi-state modelling [17]. Compared with exploratory analyses of clinical outcomes, the multistate model accounted for ICU discharge and death as competing events and allowed data from all patients to be included, regardless of study follow-up time. The model comprised of four states, to describe patients prior to commencement of MV (non MV), on mechanical ventilation (MV), ICU discharged (Discharge) and mortality (Death). States were presented as percentage and standard error (SE) in the text. Patients extubated before death or discharge were assumed to transition between MV an non-MV states. State transitions were modelled by Cox proportional hazards, with patients censored at last known follow-up, up to 28 days from ICU admission. Follow-up analysis considered Cox proportional hazard regression to examine associations between baseline compliance and competing risks of ICU mortality and discharge, following commencement of MV. Baseline compliance was included as a linear effect, with age, sex, BMI and comorbidities (hypertension, chronic cardiac disease, chronic kidney disease) as additional covariates and adjusted for recruiting centre. A shared frailty term (Gamma distributed) was included to account for residual variation between study sites. Analyses were conducted using R version 3.6.2 or higher (The R Foundation).


We studied 745 patients from 22 countries, who required admission to the ICU and MV from January 14 to December 31, 2020, and presented at least one value of CRS within the first seven days of MV. Among those, 597 (80%) had laboratory-confirmed diagnosis of SARS-CoV2 infection, while in 148 (20%), infection was clinically suspected. Enrolment rate, since January 2020, is reported in Fig. 1. CRS, within 48 h from endotracheal intubation, was available in 649 patients (Fig. 2). No association between CRS and days from onset of symptoms to commencement of MV was found (Fig. 3). Median CRS (IQR), within the first 48 h of mechanical ventilation, was 34.1 mL/cmH2O (26.4–44.0) and PaO2/FiO2 113.0 mmHg (84.0–161.3), without any linear association between these parameters. In particular, 16%, 46% and 38% of the patients presented with mild, moderate or severe hypoxemia, respectively (Fig. 4a). Female sex was associated with a significantly lower CRS than in males (95% CI of difference between genders: − 11.8 to − 7.4 mL/cmH2O p < 0.001) (Fig. 4b). Females also presented higher body mass index (BMI) (95% CI of difference between males and females: − 1.9 to − 5.5, p < 0.001), but as shown in Fig. 5, CRS and BMI were not linearly associated. Our model estimated that CRS was 37.57 cmH2O/mL (95% CI 36.5–38.6) upon commencement of MV (Fig. 6), with further worsening in the first seven days of MV (estimated decrease − 0.31 cmH2O/mL per day, 95% CI − 0.48 to − 0.14, p < 0.001). In addition, as detailed in Fig. 7, PaCO2, tidal volume, PEEP, driving pressure and FiO2 significantly varied across the range of CRS, and a significant association was found between inspiratory plateau pressure and CRS changes (Fig. 8).

Fig. 1
figure 1

Patient enrolment rate from January 14 through December 31, 2020

Fig. 2
figure 2

Patient population flow chart. The analysis of 1505 COVID-19 patients on mechanical ventilation identified 649 patients with static respiratory system compliance within 48 h from commencement of mechanical ventilation

Fig. 3
figure 3

Linear regression analysis of days from onset of symptoms to commencement of mechanical ventilation and static respiratory system compliance, based on the first measurement obtained within 48 h from commencement of mechanical ventilation, adjusted for body mass index. Dark black horizontal bar depicts median value, and upper and lower horizontal light black bars show 90th and 10th percentile. Days of onset of symptoms to commencement of mechanical ventilation was not associated with static respiratory system compliance (estimate 0.92 mL/cmH2O, 95% CI − 0.31–0.31 p = 0.417)

Fig. 4
figure 4

a Linear regression analysis of arterial partial pressure of oxygen (PaO2/FiO2) and respiratory system compliance (CRS), based on the first measurement obtained within 48 h from commencement of mechanical ventilation, with an interaction of gender and adjusted for body mass index (BMI). No statistically significant association was found between PaO2/FiO2 and CRS (estimate 0.49, 95% CI − 0.09–1.07 p = 0.100). Typical acute respiratory distress syndrome stratification groups [35] (severe, moderate and mild based on levels of hypoxemia) are highlighted in dark, medium and light grey, respectively. b Static respiratory system compliance (CRS) distribution by sex, based on the first measurement obtained within 48 h from commencement of mechanical ventilation. Dashed black lines depict median values for females and males

Fig. 5
figure 5

Linear regression analysis of static respiratory system compliance, based on the first measurement obtained within 48 h from commencement of mechanical ventilation, and body mass index with an interaction for sex. Per each graph, fitted line of the model is depicted and the upper and lower lines display the 95% predictive interval. Dark grey dots depict female patients, while light grey dots males. Static respiratory system compliance did not vary according to the body mass index (estimate − 0.12 cmH2O/mL, 95%CI − 0.29 to − 0.04, p = 0.139), but was associated with female sex (estimate − 10.73 cmH2O/mL, 95%CI − 18.54 to − 2.92, p = 0.007)

Fig. 6
figure 6

Static respiratory system compliance dynamics. Evolution of static respiratory system compliance over the first 7 days of mechanical ventilation, adjusted for body mass index. Under each day, the number of analysed patients is reported in parenthesis. Fitted line of the model is depicted, and the upper and lower lines display the 95% predictive interval. Respiratory system compliance varied during the first seven days of mechanical ventilation (estimate − 0.31 cmH2O/mL, 95%CI − 0.48 to 0.14, p < 0.001)

Fig. 7
figure 7

Linear Mixed model analysis of respiratory system compliance vs. crucial pulmonary variables during the first 7 days of mechanical ventilation (grey-scale coded bar for day 1 through 7 is reported on the right section of each graph and in parenthesis is reported the number of analysed patients). Per each graph, fitted line of the model is depicted and the upper and lower lines display the 95% predictive interval. All analyses are adjusted for body mass index. Static compliance of respiratory system was found to be associated with PaCO2 (estimated decrease − 0.11 mmHg, 95% CI − 0.15 to − 0.06, p < 0.001), tidal volume (estimated increase 0.04 mL/Kg of predicted body weight per day, 95% CI 0.03–0.04, p < 0.001), PEEP (estimated increase − 0.03 cmH2O, 95% CI 0.02–0.04, p < 0.001), driving pressure (estimated decrease − 0.31 cmH2O/L, 95% CI − 0.48 to 0.14, p < 0.001) and FiO2 (estimated decrease − 0.15%, 95% CI − 0.23 to − 0.06, p < 0.001). While PaO2/FiO2, was not significantly associated with static compliance of respiratory system (estimated increase 0.29 mmHg, 95% CI − 0.03 to 0.61, p = 072) PaO2/FiO2, ratio between arterial partial pressure of oxygen and inspiratory fraction of oxygen; PaCO2 arterial partial pressure of carbon dioxide; PEEP, positive end-expiratory pressure

Fig. 8
figure 8

Association of airway inspiratory plateau pressure with static respiratory system compliance. Linear Mixed model analysis of the association of respiratory system compliance with airway inspiratory plateau pressure during the first 7 days of mechanical ventilation (grey-scale coded bar for day 1 through 7 is reported on the right section of each graph and in parenthesis is reported the number of analysed patients). Fitted line of the model is depicted, and the upper and lower lines display the 95% predictive interval. Analysis is adjusted for body mass index. The model highlights significant association between respiratory system compliance and airway plateau pressure (estimated decrease − 0.22 cmH2O/L, 95% CI − 0.23 to − 0.21, p < 0.001), but based on the model prediction, airway plateau pressure remained predominantly below 30 cmH2O

Baseline characteristics upon ICU admission, applied interventions and outcomes, are summarized in Table 1. The most common interventions applied to the study population were use of antibiotics (96%), neuromuscular blocking agents (81%) and prone position (61%). The overall hospital mortality of the study population was 40%, and among those patients who died in the hospital or were discharged alive, the median (IQR) duration of MV was 11 days (6–18) and 14 days (8–23), respectively. Overall, 28-day ICU mortality, accounting for competing risks, was 35.6% (SE 1.7) and estimated 28-day mortality from commencement of MV was 37.1% (SE 1.7) (Fig. 9b). Cox proportional hazard analysis (Fig. 9c) demonstrated that age (hazard ratio 1.37, 95% CI 1.19–1.59, p < 0.001) and chronic cardiac diseases (HR 1.62, 95% CI 1.14–2.29, p < 0.001) were the only baseline factors associated with 28-day mortality risk. In addition, age (HR 0.77, 95% CI 0.66–0.83, p < 0.001), male sex (HR 0.59, 95% CI 0.44–0.79, p < 0.001), BMI (HR 0.86, 95% CI 0.79–0.95, p = 0.003) and CRS (+ 10 mL/cm H2O) (HR 1.14, 95% CI 1.02–1.28, p = 0.018) were associated with the chance of being discharge from the ICU within 28 days.

Table 1 Only patients with the following characteristics were included in this analysis: (1) on controlled mechanical ventilation; (2) airway plateau pressure, tidal volume and positive-end-expiratory pressure recorded within 48 h from commencement of mechanical ventilation
Fig. 9
figure 9

Multistate modelling and Cox regression analysis outcomes for patient with static compliance recorded within 48 h of commencing mechanical ventilation. a Multistate model structure for estimating expected outcomes up to 28 days from admission to intensive care unit (ICU). Modelled health states include not on invasive mechanical ventilation (non-MV), on mechanical ventilation (MV), ICU discharge and death. Patients start in the non-MV state if not mechanically ventilated upon or prior to ICU admission, or in the MV state otherwise. b Predicted probabilities of occupying health states up to 28 days from ICU admission. c Results of Cox proportional hazards modelling for risk of death and ICU discharge from commencement of mechanical ventilation. Covariates comprise age, body mass index (BMI), selected comorbidities (hypertension, chronic cardiac disease, chronic kidney disease) and baseline static compliance. Parameter estimates are presented as estimated hazard ratios with 95% confidence intervals (CI). Further details on factors significantly associated with assessed outcomes are available in the results section


This large observational report from intensive care units throughout the world found that initial static respiratory system compliance was only associated with hazard of being discharged from the ICU within 28 days. The duration from onset of symptoms to commencement of MV did not influence CRS, and interestingly lower CRS was found in female patients. In the evaluated population, neuromuscular blocking agents and prone position were commonly applied and ventilatory management across CRS levels varied in terms of tidal volume, PEEP and FiO2, throughout the first 7 days of MV.

In comparison with previous reports on ARDS patients without COVID-19 [18], we similarly found that the majority of patients exhibited moderate hypoxemia, even when presented higher CRS. We also noted a larger range of CRS in line with previous studies [7, 8], but in contrast with values from a larger COVID-19 ARDS series from Spain [6]. Considering that we focused our analysis on static compliance of the respiratory system, without partitioning into the pulmonary and chest wall components [19, 20], it is interesting that CRS was not associated with BMI, suggesting that patients with higher BMI potentially presented also with higher lung compliance. Irrespective, we found lower CRS in female patients, who also presented higher BMIs. To the best of our knowledge, no studies have systematically investigated the effects of gender/BMI on COVID-19 severity; thus, whether obesity might be a crucial risk factor for ICU admission and mechanical ventilation, specifically in female patients, and its effects on lung compliance should be further explored. We also found that throughout the range of CRS values, plateau pressure was within what is typically presumed as lung protective ranges [21], but this resulted in potentially harmful driving pressures, specifically for patients with the lowest CRS values. As many of these patients were obese, this raises the question of whether these modest pressures might have increased the risk of pulmonary derecruitment, or in patients with normal BMI, the resulting driving pressure might have been related to pulmonary overdistention. These factors could have contributed to sustained hypoxemia and impaired lung function throughout the study period. In such circumstances, it is questionable whether MV guided by oesophageal pressure monitoring may have some benefits [22], but more research is needed to corroborate such reasoning.

Phenotypic subsets of COVID-19-associated ARDS have been proposed [9, 13, 23,24,25]. Recent study has also explored whether CRS—related phenotype patterns existed among patients with ARDS before the COVID-19 pandemic [26]. Various investigators [7, 27], who did not find significant CRS variability among COVID-19 patients requiring MV, questioned the overall clinical value of CRS in the COVID-19 population. In a very small case series, Gattinoni et al [9] found an initial CRS of 50 mL/cmH2O, but high levels of shunt fraction that could have explained the resulting severe hypoxemia. In subsequent study, Chiumello and collaborators found higher CRS in patient with COVID-19 ARDS and ARDS caused by other injuries, while matching for similar levels of PaO2/FiO2 [12]. Interestingly, these findings were in line with computed tomography studies results, corroborating higher proportion of normally aerated tissue in COVID-19 ARDS. In similar reports, heterogeneous pathophysiology among patients with different levels of pulmonary compliance has been implied [10, 25]. As corroborated by landmark post-mortem studies [28] and clinical studies [7, 29], SARS-CoV-2 heterogeneously affects pulmonary ventilation and perfusion. Hence, it could be argued that the use of CRS as key pathophysiological parameter to predict clinical evolution might be over simplistic and in-depth characterization of pulmonary pathophysiology should be recommended for COVID-19 patients, specifically when obese. Interestingly, our report is the first that specifically focused on the dynamics of CRS, rather than only baseline CRS. We found that CRS was not related to the duration from the onset of symptoms to commencement of MV, emphasising the need for inclusive data on mechanisms of lung injury in not ventilated COVID-19 patients [30]. The median CRS value found in our population was 34.1 mL/cmH2O, similar to findings by Ferrando et al. [6], not dissimilar to findings by Bellani et al. on patients with non-COVID-19 ARDS [31], but lower than figures recently reported by Grasselli [7] and Grieco [32] in COVID-19 patients. In addition, we found a further decrease in CRS during the first week of MV. This could have been related to the specific ventilatory management in our reported population, but such discrepancy further highlights the need of a comprehensive appraisal of pulmonary and chest wall mechanics in COVID-19 patients [20].

One of the most striking results was the continued use of high PEEP over the first seven days of MV, even in patients with high compliance. This seems counterintuitive, given that current recommendations in ARDS suggest decreasing PEEP, especially in the face of high compliance. As hypoxemia persisted even with high PEEP and high compliance, our results add to the hypothesis that maintaining high PEEP may worsen gas exchange from lung overdistension, resulting in increased dead space and intrapulmonary shunting. Other authors have speculated that using high levels of PEEP in COVID-19 patients with low recruitability may be detrimental, and that lowering PEEP may improve gas exchange and limit ventilator-induced lung injury [33]. Our results in this large cohort of patients from multiple global areas support this theory. Finally, we found that patients required two weeks of MV, and 28-day mortality in the overall population was 35.6%, with hospital mortality up to 40%. These figures are in line with mortality rates reported by Grasselli [7] in the subgroups characterized by low D-dimer, and mortality in severe-moderate COVID-19 ARDS, as corroborated by Ferrando [6]. Nevertheless, we found that CRS was only associated with the discharge from ICU within 28 days. Thus, the marginal clinical value of CRS as a predictor of mortality in COVID-19 patients calls for urgent identification of valuable markers that could inclusively describe pulmonary derangement and guide personalized treatment.

Strengths and limitations

Collaborations between international data collection efforts have the ability to answer many questions related to COVID 19 and to pave the way for future novel diseases to achieve rapid and global data access to help guide best practice. The international COVID-19 Critical Care Consortium study [15], in collaboration with the ISARIC/SPRINT-SARI networks [34], provides inferences not limited by ventilatory management specific to small patient cohort or single-country studies. In addition, in comparison with previous studies, we provided more granular data to inclusively appraise the dynamics of CRS in COVID-19 patients on MV and to study its association with laboratory, and clinical features. A few limitations of our observational study should also be emphasized. First, we centred our analysis on COVID-19 patients, without comparisons against previous repositories of patients with ARDS from different aetiologies. Yet, we provided a wide-ranging discussion of the characteristics of our population in the context of previous analyses in ARDS patients. Second, inferences on pulmonary perfusion disorders in our population can only be speculative, since D-dimer was only available in a small subset of patients (Table 1). Third, as reported by the enrolment rate (Fig. 1 Supplemental Digital Content), patients were mostly enrolled in the early phase of the pandemic, hence extrapolations from our findings should take into account potential biases related to overwhelmed critical care services. Fourthly, it is important to emphasise that we centred our analysis on CRS, but due to the complex respiratory pathophysiology in COVID-19 patients and the high percentage of patients with increased BMI, the use of oesophageal pressure monitoring to fully describe lung and chest wall compliances is advisable and should be prioritised in future investigations. Fifth, the majority of patients were admitted in centers located in North America, Europe and South America. Although these findings are in line with the global distribution of COVID-19 cases, extrapolations of our findings in other regions should be applied cautiously.


Our comprehensive appraisal of COVID-19 patients on MV from a large international observational study implies that expected CRS within 48 h from commencement of MV is not influenced by the duration from onset of symptoms to commencement of MV, but after intubation, a further decrease in CRS might be expected during the first week of ventilation. In addition, baseline CRS is associated with the chance of being discharged from the ICU within 28 days, but it is not a predictive marker of 28-day mortality. Based on potential inferences from our findings, future studies that could provide an in-depth characterization of lungs and chest wall compliance in COVID-19 patients will be critical to guide best practice in ventilatory management.

Availability of data materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.



Acute respiratory distress syndrome


Coronavirus disease-2019


COVID-19 Critical Care Consortium incorporating the ExtraCorporeal Membrane Oxygenation for 2019 novel Coronavirus Acute Respiratory Disease

FiO2 :

Inspiratory fraction of oxygen


Intensive care unit


Interquartile range


Mechanical ventilation


Predicted body weight


Positive end expiratory pressure

C RS :

Static respiratory system compliance


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Download references


We fully acknowledge statistical guidance by Adrian Barnett, Head Statistician of the COVID-19 Critical Care Consortium. We recognize the crucial importance of the ISARIC and SPRINT-SARI networks for the development and expansion of the COVID-19 Critical Care Consortium. We thank the generous support we received from ELSO and ECMOnet. We owe Li Wenliang, MD from the Wuhan Central Hospital an eternal debt of gratitude for reminding the world that doctors should never be censored during a pandemic. Finally, we acknowledge all members of the COVID-19 Critical Care Consortium and various collaborators.


Prefix/First name/Last name

Site name

Tala Al-Dabbous

Al Adan Hospital

Dr Huda Alfoudri

Dr Mohammed Shamsah

Dr Subbarao Elapavaluru

Ashley Berg

Christina Horn

Allegheny General Hospital

Dr Stephan Schroll

Barmherzige Bruder Regansburg

Dr Jorge Velazco

Wanda Fikes

Ludmyla Ploskanych

Baylor Scott & White Health—Temple

Dr Dan Meyer

Maysoon Shalabi-McGuire

Trent Witt

Ashley Ehlers

Baylor University Medical Centre, Dallas

Dr Lorenzo Grazioli

Bergamo Hospital

Dr E. Wilson Grandin

Jose Nunez

Tiago Reyes

Beth Israel Deaconess Medical Centre

Dr Mark Joseph

Dr Brook Mitchell

Martha Tenzer

Carilion Clinic

Dr Ryuzo Abe

Yosuke Hayashi

Chiba University Graduate School of Medicine

Dr Hwa Jin Cho

Dr In Seok Jeong

Chonnam National University Hospital

Dr Nicolas Brozzi

Dr Jaime Hernandez-Montfort

Cleveland Clinic—Florida

Omar Mehkri

Stuart Houltham

Cleveland Clinic—Ohio

Dr Jerónimo Graf

Rodrigo Perez

Clinica Alemana De Santiago

Dr Roderigo Diaz

Camila Delgado

Joyce González

Maria Soledad Sanchez

Clinica Las Condez

Dr Diego Fernando Bautista Rincón

Melissa Bustamante Duque

Dr Angela Maria Marulanda Yanten

Clinica Valle de Lilli

Dr Dan Brodie

Columbia University Medical Centre

Dr Desy Rusmawatiningtyas

Dr Sardjito Hospital (Paediatrics)

Gabrielle Ragazzo

Emory University Healthcare System

Dr Azhari Taufik

Dr Margaretha Gunawan

Dr Vera Irawany

Muhammad Rayhan

Dr Elizabeth Yasmin Wardoyo

Fatmawati Hospital

Dr Mauro Panigada

Dr Chiara Martinet

Dr Sebastiano Colombo

Dr Giacomo Grasselli

Dr Michela Leone

Dr Alberto Zanella

Fondazione IRCCS Policlinico of Milan (Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico)

Prof Massimo Antonelli

Dr Simone Carelli

Domenico L. Grieco

Fondazione Policlinico Universitario Agostino Gemelli IRCCS

Motohiro Asaki

Fujieda Municipal General Hospital

Dr Kota Hoshino

Fukuoka University

Dr Leonardo Salazar

Laura Duarte

Fundación Cardiovascular de Colombia

Dr Joseph McCaffrey

Allison Bone

Geelong Hospital

Dr David Thomson

Dr Christel Arnold-Day

Jerome Cupido

Zainap Fanie

Dr Malcom Miller

Dr Lisa Seymore

Dawid van Straaten

Groote Schuur Hospital

Dr Ibrahim Hassan

Dr Ali Ait Hssain

Jeffrey Aliudin

Al-Reem Alqahtani

Khoulod Mohamed

Ahmed Mohamed

Darwin Tan

Joy Villanueva

Ahmed Zaqout

Hamad General Hospital—Weill Cornell Medical College in Qatar

Dr Ethan Kurtzman

Arben Ademi

Ana Dobrita

Khadija El Aoudi

Juliet Segura

Hartford HealthCare

Dr Gezy Giwangkancana

Hasan Sadikin Hospital (Adult)

Dr Shinichiro Ohshimo

Hiroshima University

Dr Koji Hoshino

Saito Hitoshi

Dr Yuka Uchinami

Hokkaido University Hospital

Dr Javier Osatnik

Hospital Alemán

Dr Anne Joosten

Hospital Civil Marie Curie

Dr Antoni Torres

Ana Motos

Dr Minlan Yang

Hospital Clinic, Barcelona

Carlos Luna

Hospital de Clínicas

Francisco Arancibia

Hospital del Tórax

Virginie Williams

Alexandre Noel

Hospital du Sacre Coeur (Universite de Montreal)

Dr Nestor Luque

Hospital Emergencia Ate Vitarte

Dr Trieu Huynh Trung

Sophie Yacoub

Hospital for Tropical Diseases

Marina Fantini

Hospital Mater Dei

Dr Ruth Noemi Jorge García

Dr Enrique Chicote Alvarez

Hospital Nuestra Señora de Gracia

Dr Anna Greti

Oscar Lomeli

Hospital Puerta de Hierro

Dr Adrian Ceccato

Hospital Universitari Sagrat Cor

Dr Angel Sanchez

Hospital Universitario Sant Joan d’Alacant

Dr Ana Loza Vazquez

Hospital Universitario Virgen de Valme

Dr Ferran Roche-Campo

Hospital Verge de la Cinta de Tortosa

Dr Divina Tuazon

Dr Toni Duculan

Houston Methodist Hospital

Hiroaki Shimizu

Kakogawa Acute Care Medical Center, Hyogo

Marcelo Amato

Luciana Cassimiro

Flavio Pola

Francis Ribeiro

Guilherme Fonseca

INCOR (Universidade de São Paulo)

Dr Heidi Dalton

Dr Mehul Desai

Dr Erik Osborn

Hala Deeb

INOVA Fairfax Hospital

Dr Antonio Arcadipane

Claudia Bianco

Raffaele Cuffaro

Gennaro Martucci

Giovanna Occhipinti

Matteo Rossetti

Chiara Vitiello


Dr Sung-Min Cho

Kate Calligy

Dr Glenn Whitman

Johns Hopkins

Dr Hiroaki Shimizu

Dr Naoki Moriyama

Kakogawa Acute Care Medical Center

Dr Jae-Burm Kim

Keimyung University Dong San Hospital

Dr Nobuya Kitamura

Takashi Shimazui

Kimitsu Chuo Hospital

Dr Abdullah Al-Hudaib

Dr Alyaa Elhazmi

King Faisal Specialist Hospital and Research Center

Dr Johannes Gebauer

Klinikum Passau

Dr Toshiki Yokoyama

Kouritu Tousei Hospital

Dr Abdulrahman Al-Fares

Esam Alamad

Fatma Alawadhi

Kalthoum Alawadi

Dr Sarah Buabbas

Al-Amiri and Jaber Al-Ahmed Hospitals, Kuwait Extracorporeal Life Support Program

Dr Hiro Tanaka

Kyoto Medical Centre

Dr Satoru Hashimoto

Masaki Yamazaki

Kyoto Prefectural University of Medicine

Tak-Hyuck Oh

Kyung Pook National University Chilgok Hospital

Dr Mark Epler

Dr Cathleen Forney

Jared Feister

Katherine Grobengieser

Louise Kruse

Joelle Williamson

Lancaster General Health

Dr Eric Gnall

Dr Mara Caroline

Sasha Golden

Colleen Karaj

Sherry McDermott

Lynn Sher

Dr Timothy Shapiro

Lisa Thome

Mark Vanderland

Mary Welch

Lankenau Institute of Medical Research (Main Line Health)

Prof Luca Brazzi

Le Molinette Hospital (Ospedale Molinette Torino)

Dr Tawnya Ogston

Legacy Emanuel Medical Center

Dr Dave Nagpal

Karlee Fischer

London Health Sciences Centre

Dr Roberto Lorusso

Maria de Piero

Maastricht University Medical Centre

Prof Mariano Esperatti

Mar del Plata Medical Foundation Private Community Hospital

Dr Diarmuid O’Briain

Maroondah Hospital

Dr Edmund G. Carton

Mater Misericordiae University Hospital

Ayan Sen

Amanda Palacios

Deborah Rainey

Mayo Clinic College of Medicine

Cassandra Seefeldt

Dr Lucia Durham

Dr Octavio Falcucci

Amanda Emmrich

Jennifer Guy

Carling Johns

Emily Neumann

Medical College of Wisconsin (Froedtert Hospital)

Dr Nina Buchtele

Dr Michael Schwameis

Medical University of Vienna

Dr Stephanie-Susanne Stecher

Delila Singh

Dr Michaela Barnikel

Lukas Arenz

Medical Department II, LMU Hospital Munich

Dr Akram Zaaqoq

Lan Anh Galloway

Caitlin Merley

MedStar Washington Hospital Centre

Dr Marc Csete

Luisa Quesada

Isabela Saba

Mount Sinai Medical Centre

Dr Daisuke Kasugai

Hiroaki Hiraiwa

Taku Tanaka

Nagoya University Hospital

Dr Eva Marwali

Yoel Purnama

Dr Santi Rahayu Dewayanti

Dr Ardiyan

Dr Debby Siagian

National Cardiovascular Center Harapan Kita

Yih-Sharng Chen

National Taiwan University Hospital

Prof John Laffey

Dr Bairbre McNicholas

Dr David Cosgrave

Galway University Hospitals

Marlice VanDyk

Sarah MacDonald

Netcare Unitas ECMO Centre

Dr Ian Seppelt

Nepean Hospital

Dr Indrek Ratsep

Lauri Enneveer

Kristo Erikson

Dr Getter Oigus

Andra-Maris Post

Piret Sillaots

North Estonia Medical Centre

Frank Manetta

Northwell Health

Mamoru Komats

Obihiro-Kosei General Hospital

Dr S. Veena Satyapriya

Dr Amar Bhatt

Marco Echeverria

Juan Fiorda

Alicia Gonzalez

Dr Nahush A. Mokadam

Johnny McKeown

Joshua Pasek

Haixia Shi

Alberto Uribe

Ohio State University Medical Centre

Dr Rita Moreno

Oklahoma Heart Institute

Bishoy Zakhary

Hannah Johnson

Nolan Pow

Oregon Health and Science University Hospital (OHSU)

Dr Marco Cavana

Dr Alberto Cucino

Ospedale di Arco (Trento hospital)

Prof Giuseppe Foti

Dr Marco Giani

Dr Vincenzo Russotto

Ospedale San Gerardo

Prof Davide Chiumello

Valentina Castagna

Silvia Coppola

Ospedale San Paolo

Dr Andrea Dell’Amore

Padua University Hospital (Policlinico of Padova)

Dr Hoi-Ping Shum

Pamela Youde Nethersole Eastern Hospital

Dr Alain Vuysteke

Papworth Hospitals NHS Foundation Trust

Dr Asad Usman

Andrew Acker

Blake Mergler

Nicolas Rizer

Federico Sertic

Benjamin Smood

Alexandra Sperry

Dr Madhu Subramanian

Penn Medicine (Hospital of the University of Pennsylvania)

Dr Erlina Burhan

Dr Navy Lolong

Dr Ernita Akmal

Prof Menaldi Rasmin

Bhat Naivedh

Dr Faya Sitompu

Persahabatan General Hospital

Dr Peter Barrett

Julia Daugherty

Dr David Dean

Piedmont Atlanta Hospital

Dr Antonio Loforte

Policlinico di S. Orsola, Università di Bologna

Dr Irfan Khan

Olivia DeSantis

Dr Mohammed Abraar Quraishi

Presbyterian Hospital Services, Albuquerque

Dr Gavin Salt

Prince of Wales

Dr Dominic So

Darshana Kandamby

Princess Margaret Hospital

Dr Jose M. Mandei

Hans Natanael

Prof Dr R. D. Kandou General Hospital—Paediatric

Eka YudhaLantang

Anastasia Lantang

Prof Dr R. D. Kandou General Hospital—Adult

Anna Jung

Dr Terese Hammond

Providence Saint John's Health Centre

George Ng

Dr Wing Yiu Ng

Queen Elizabeth Hospital, Hong Kong

Dr Pauline Yeung

Queen Mary Hospital

Dr Shingo Adachi

Rinku general medical center (and Senshu trauma and critical care center)

Dr Pablo Blanco

Ana Prieto

Jesús Sánchez

Rio Hortega University Hospital

Dr Meghan Nicholson

Rochester General Hospital

Dr Michael Farquharson

Royal Adelaide Hospital

Dr Warwick Butt

Alyssa Serratore

Carmel Delzoppo

Royal Children’s Hospital

Dr Pierre Janin

Elizabeth Yarad

Royal North Shore Hospital

Dr Richard Totaro

Jennifer Coles

Royal Prince Alfred Hospital

Robert Balk

Samuel Fox

James Hays

Esha Kapania

Pavel Mishin

Andy Vissing

Garrett Yantosh

Rush University, Chicago

Saptadi Yuliarto

Dr Kohar Hari Santoso

Dr Susanthy Djajalaksana

Saiful Anwar Malang Hospital (Brawijaya University) (Paediatrics)

Dr Arie Zainul Fatoni

Saiful Anwar Malang Hospital (Brawijaya University) (Adult)

Dr Masahiro Fukuda

Saiseikai Senri Hospital

Prof Keibun Liu

Saiseikai Utsunomiya Hospital

Prof Paolo Pelosi

Dr Denise Battaglini

San Martino Hospital

Dr Juan Fernando Masa Jiménez

San Pedro de Alcantara Hospital

Dr Sérgio Gaião

Dr Roberto Roncon-Albuquerque

São João Hospital Centre, Porto

Jessica Buchner

Sentara Norfolk General Hospital

Dr Young-Jae Cho

Dr Sang Min Lee

Seoul National University Hospital

Dr Su Hwan Lee

Severance Hospital

Dr Tatsuya Kawasaki

Shizuoka Children's Hospital

Dr Pranya Sakiyalak

Prompak Nitayavardhana

Siriraj Hospital

Dr Tamara Seitz

Sozialmedizinisches Zentrum Süd—Kaiser-Franz-Josef-Spital

Rakesh Arora

David Kent

St Boniface Hospital (University of Mannitoba)

Dr Swapnil Parwar

Andrew Cheng

Jennene Miller

St George Hospital

Daniel Marino

Jillian E Deacon

St. Christopher's Hospital for Children

Dr Shigeki Fujitani

Dr Naoki Shimizu

St Marianna Medical University hospital

Dr Jai Madhok

Dr Clark Owyang

Stanford University Hospital

Dr Hergen Buscher

Claire Reynolds

St Vincent’s Hospital

Dr Olavi Maasikas

Dr Aleksandr Beljantsev

Vladislav Mihnovits

Tartu University Hospital

Dr Takako Akimoto

Mariko Aizawa

Dr Kanako Horibe

Ryota Onodera

Teine Keijinkai Hospital

Prof Carol Hodgson

Meredith Young

The Alfred Hospital

Timothy Smith

Cheryl Bartone

The Christ Hospital

Dr Timothy George

The Heart Hospital Baylor Plano, Plano

Dr Kiran Shekar

Niki McGuinness

Lacey Irvine

The Prince Charles Hospital

Brigid Flynn

Abigail Houchin

The University of Kansas Medical Centre

Dr Keiki Shimizu

Jun Hamaguchi

Tokyo Metropolitan Medical Center

Leslie Lussier

Grace Kersker

Dr John Adam Reich

Tufts Medical Centre (and Floating Hospital for Children)

Dr Gösta Lotz

Universitätsklinikum Frankfurt (University Hospital Frankfurt)(Uniklinik)

Dr Maximilian Malfertheiner

Esther Dreier

Dr Lars Maier

Universitätsklinikum Regensburg (Klinik für Innere Medizin II)

Dr Neurinda Permata Kusumastuti

University Airlangga Hospital (Paediatric)

Dr Colin McCloskey

Dr Al-Awwab Dabaliz

Dr Tarek B Elshazly

Josiah Smith

University Hospital Cleveland Medical Centre (UH Cleveland hospital)

Dr Konstanty S. Szuldrzynski

Dr Piotr Bielański

University Hospital in Krakow

Dr Yusuff Hakeem

University Hospitals of Leicester NHS Trust (Glenfield Hospital)

Dr Keith Wille

Rebecca Holt

University of Alabama at Birmingham Hospital (UAB)

Dr Ken Kuljit S. Parhar

Dr Kirsten M. Fiest

Cassidy Codan

Anmol Shahid

University of Calgary (Peter Lougheed Centre, Foothills Medical Centre, South Health Campus and Rockyview General Hospital)

Dr Mohamed Fayed

Dr Timothy Evans

Rebekah Garcia

Ashley Gutierrez

Hiroaki Shimizu

University of California, San Francisco-Fresno Clinical Research Centre

Dr Tae Song

Rebecca Rose

University of Chicago

Dr Suzanne Bennett

Denise Richardson

University of Cincinnati Medical Centre

Dr Giles Peek

Dalia Lopez-Colon

University of Florida

Dr Lovkesh Arora

Kristina Rappapport

Kristina Rudolph

Zita Sibenaller

Lori Stout

Alicia Walter

University of Iowa

Dr Daniel Herr

Nazli Vedadi

University of Maryland—Baltimore

Dr Lace Sindt

Cale Ewald

Julie Hoffman

Sean Rajnic

Shaun Thompson

University of Nebraska Medical Centre

Dr Ryan Kennedy

University of Oklahoma Health Sciences Centre (OU)

Dr Matthew Griffee

Dr Anna Ciullo

Yuri Kida

University of Utah Hospital

Dr Ricard Ferrer Roca

Cynthia Alegre

Dr Sofia Contreras

Dr JordI Riera

Vall d'Hebron University Hospital, Barcelona

Dr Christy Kay

Irene Fischer

Elizabeth Renner

Washington University in St. Louis/Barnes Jewish Hospital

Dr Hayato Taniguci

Yokohama City University Medical Center

Gabriella Abbate

Halah Hassan

Dr Silver Heinsar

Varun A Karnik

Dr Katrina Ki

Hollier F. O'Neill

Dr Nchafatso Obonyo

Dr Leticia Pretti Pimenta

Janice D. Reid

Dr Kei Sato

Dr Kiran Shekar

Aapeli Vuorinen

Dr Karin S. Wildi

Emily S. Wood

Dr Stephanie Yerkovich

COVID-19 Critical Care Consortium


Prefix/First name/Last name

Site name

Dr Emma Hartley

Aberdeen Royal Infirmary (Foresterhill Health Campus)

Bastian Lubis

Adam Malik Hospital

Takanari Ikeyama

Aichi Childrens Health and Medical Center

Balu Bhaskar

American Hospital

Dr Jae-Seung Jung

Anam Korea University Hospital

Sandra Rossi Marta

Fabio Guarracino

Azienda Ospedaliero Universitaria Parma

Prof Fabio Guarracino

Azienda Ospedaliero Universitaria Pisana

Stacey Gerle

Banner University Medical Centre

Emily Coxon

Baptist Health Louisville

Dr Bruno Claro

Barts Hospital

Dr. Gonzo Gonzalez-Stawinski

Baylor All Saints Medical Centre, Forth Worth

Daniel Loverde

Billings Clinic

Dr Vieri Parrini

Borgo San Lorenzo Hospital

Dr Diarmuid O’Briain

Stephanie Hunter

Box Hill Hospital

Dr Angela McBride

Brighton and Sussex Medical School

Kathryn Negaard

Dr Phillip Mason

Brooke Army Medical Centre

Dr Angela Ratsch

Bundaberg Hospital

Dr Mahesh Ramanan

Julia Affleck

Caboolture Hospital

Ahmad Abdelaziz

Cairo University Hospital

Dr Sumeet Rai

Josie Russell-Brown

Mary Nourse

Canberra Hospital

Juan David Uribe

Cardio VID

Dr Adriano Peris

Careggi Hospital

Mark Sanders

Cedar Park Regional Medical Center

Dominic Emerson

Cedars-Sinai Medical Centre

Muhammad Kamal

Cengkareng Hospital

Prof Pedro Povoa

Centro Hospitalar de Lisboa

Dr Roland Francis

Charite-Univerrsitatsmedizi n Berlin

Ali Cherif

Charles Nicolle University Hospital

Dr Sunimol Joseph

Children’s Health Ireland (CHI) at Crumlin

Dr Matteo Di Nardo

Children’s Hospital Bambino Gesù

Micheal Heard

Children's Healthcare of Atlanta-Egleston Hospital

Kimberly Kyle

Children's Hospital

Ray A Blackwell

Christiana Care Health System's Centre for Heart and Vascular Health

Dr Michael Piagnerelli

Dr Patrick Biston

CHU de Charleroi

Hye Won Jeong

Chungbuk National University Hospital

Reanna Smith

Cincinnati Children's

Yogi Prawira

Cipto Mangunkusumo Hospital

Dr Giorgia Montrucchio

Dr Gabriele Sales

Città della Salute e della Scienza Hospital—Turin, Italy

Nadeem Rahman

Vivek Kakar

Cleveland Clinic, Abu Dhabi

Dr Michael Piagnerelli

Dr Josefa Valenzuela Sarrazin

Clinica Las Condes

Dr Arturo Huerta Garcia

Clínica Sagrada Família

Dr Bart Meyns

Collaborative Centre Department Cardiac Surgery, UZ Leuven

Marsha Moreno

Dignity Health Medical Group-Dominican

Rajat Walia

Dignity Health St. Joseph's Hospital and Medical Center (SJHMC)

Dr Annette Schweda

Donaustauf hospital

Cenk Kirakli

Dr. Suat Seren Chest Diseases and Surgery Practice and Training Centre

Estefania Giraldo

Fundación Clinica Shaio (Shaio Clinic)

Dr Wojtek Karolak

Gdansk Medical University

Dr Martin Balik

General University Hospital

Elizabeth Pocock

George Washington University Hospital

Evan Gajkowski

Giesinger Medical Centre

Dr James Winearls

Mandy Tallott

Gold Coast University Hospital

Kanamoto Masafumi

Gunma University Graduate School of Medicine

Dr Nicholas Barrett

Guy's and St Thomas NHS Foundation Trust Hospital

Yoshihiro Takeyama

Hakodate City Hospital

Sunghoon Park

Hallym University Sacred Heart Hospital

Faizan Amin

Hamilton General Hospital

Dr Erina Fina

Hasan Sadikin Hospital

Dr Serhii Sudakevych

Heart Institute Ministry of Health of Ukraine

Dr Angela Ratsch

Hervey Bay Hospital

Patrícia Schwarz

Ana Carolina Mardini

Hospital de Clínicas de Porto Alegre

Ary Serpa Neto

Hospital Israelita Albert Einstein

Dr Andrea Villoldo

Hospital Privado de Comunidad

Alexandre Siciliano Colafranceschi

Hospital Pro Cardíaco

Dr Alejandro Ubeda Iglesias

Hospital Punta de Europa

Lívia Maria Garcia Melro

Giovana Fioravante Romualdo

Hospital Samaritano Paulista

Diego Gaia

Hospital Santa Catarina

Helmgton Souza

Hospital Santa Marta

Dr Diego Bastos

Hospital Cura D’ars Fortaleza

Filomena Galas

Hospital Sirio Libanes

Dr Rafael Máñez Mendiluce

Hospital Universitario de Bellvitge

Alejandra Sosa

Hospital Universitario Esperanza (Universidad Francisco Marroquin)

Dr Ignacio Martinez

Hospital Universitario Lucus Augusti

Hiroshi Kurosawa

Hyogo Prefectural Kobe Children's Hospital

Juan Salgado

Indiana University Health

Dr Beate Hugi-Mayr

Inselspital University Hospital

Eric Charbonneau

Institut Universitaire de Cardiologie et de Pneumologie de Quebec—Universite Laval

Vitor Salvatore Barzilai

Instituto de Cardiologia do Distrito Federal—ICDF

Veronica Monteiro

Instituto de Medicina Integral Prof. Fernando Figueira (IMIP)

Rodrigo Ribeiro de Souza

Instituto Goiano de Diagnostico Cardiovascular (IGDC)

Michael Harper

INTEGRIS Baptist Medical Center

Hiroyuki Suzuki

Japan Red Cross Maebashi Hospital

Celina Adams

John C Lincoln Medical Centre

Dr Jorge Brieva

John Hunter Hospital

George Nyale

Kenyatta National Hospital (KNH)

Jihan Fatani

Dr Faisal Saleem Eltatar

King Abdullah Medical City Specialist Hospital

Dr. Husam Baeissa

King Abdullah Medical Complex

Ayman AL Masri

King Salman Hospital NWAF

Yee Hui Mok

KK Women's and Children's Hospital

Masahiro Yamane

KKR Medical Center

Hanna Jung

Kyung Pook National University Hospital

Dr Matthew Brain

Sarah Mineall

Launceston General Hospital

Rhonda Bakken

M Health Fairview

Dr Tim Felton

Manchester University NHS Foundation Trust—Wythenshawe

Lorenzo Berra

Massachusetts General Hospital

Gordan Samoukoviv

Dr Josie Campisi

McGill University Health Centre

Bobby Shah

Medanta Hospital

Arpan Chakraborty

Medica Super speciality Hospital

Monika Cardona

Medical University of South Carolina

Harsh Jain

Mercy Hospital of Buffalo

Dr Asami Ito

Mie University Hospital

Brahim Housni

Mohammed VI University hospital

Sennen Low

National Centre for Infectious Diseases

Dr. Koji Iihara

National Cerebral and Cardiovascular Center

Joselito Chavez

National Kidney and Transplant Institute

Dr Kollengode Ramanathan

National University Hospital, Singapore

Gustavo Zabert

National University of Comahue

Krubin Naidoo

Nelson Mandela Children's Hospital

Singo Ichiba

Nippon Medical School Hospital

Randy McGregor

Northwestern Medicine

Teka Siebenaler

Norton Children's Hospital

Hannah Flynn

Novant Health (NH) Presbyterian Medical Centre

Julia Garcia-Diaz

Catherine Harmon

Ochsner Clinic Foundation

Kristi Lofton

Ochsner LSA Health Shreveport

Toshiyuki Aokage

Okayama University Hospital

Kazuaki Shigemitsu

Osaka City General Hospital

Dr Andrea Moscatelli

Ospedale Gaslini

Dr Giuseppe Fiorentino

Ospedali dei Colli

Dr Matthias Baumgaertel

Paracelsus Medical University Nuremberg

Serge Eddy Mba

Parirenyatwa General Hospital

Jana Assy

Pediatric and Neonatal Cardiac intensive care at the American University

Holly Roush

Penn State Heath S. Hershey Medical Centre

Kay A Sichting

Peyton Manning Children's Hospital

Dr Francesco Alessandri

Policlinico Umberto, Sapienza University of Rome

Debra Burns

Presbyterian Hospital, New York/Weill Cornell Medical Centre

Ahmed Rabie

Prince Mohammed bin Abdulaziz Hospital

Carl P. Garabedian

Providence Sacred Heart Children's Hospital

Dr Jonathan Millar

Dr Malcolm Sim

Queen Elizabeth II University Hospital

Dr Adrian Mattke

Queensland Children’s Hospital

Dr Danny McAuley

Queens University of Belfast

Jawad Tadili

Rabat university hospital

Dr Tim Frenzel

Radboud University Medical Centre

Aaron Blandino Ortiz

Ramón y Cajal University Hospital

Jackie Stone

Rapha Medical Centre

Dr Alexis Tabah

Megan Ratcliffe

Maree Duroux

Redcliffe Hospital

Dr Antony Attokaran

Rockhampton Hospital

Dr Brij Patel

Royal Brompton &Harefield NHS Foundation Trust

Derek Gunning

Royal Columbian Hospital

Dr Kenneth Baillie

Royal Infirmary Edinburgh

Dr Pia Watson

Sahlgrenska University Hospital

Kenji Tamai

Saiseikai Yokohamashi Tobu Hospital

Dr Gede Ketut Sajinadiyasa

Dr Dyah Kanyawati

Sanglah General Hospital

Marcello Salgado

Santa Casa de Misericordia de Juiz de Fora

Assad Sassine

Santa Casa de Misericórdia de Vitoria

Dr Bhirowo Yudo

Sardjito Hospital

Scott McCaul

Scripps Memorial Hospital La Jolla

Bongjin Lee

Seoul National University Children's Hospital

Yoshiaki Iwashita

Shimane University Hospital

Laveena munshi

Sinai Health Systems (Mount Sinai Hospital)

Dr Neurinda Permata Kusumastuti

Soetomo General Hospital (FK UNAIR)

Dr Nicole Van Belle

St. Antonius Hospital

Ignacio Martin-Loeches

St James’s University Hospital

Dr Hergen Buscher

St Vincent’s Hospital, Sydney

Surya Oto Wijaya

Sulianti Saroso Hospital

Dr Lenny Ivatt

Swansea Hospital

Chia Yew Woon

Tan Tock Seng Hospital

Hyun Mi Kang

The Catholic University of Seoul St Mary Hospital

Erskine James

The Medical Centre Navicent Health

Nawar Al-Rawas

Thomas Jefferson University Hospital

Tomoyuki Endo

Tohoku Medical and Pharmaceutical University

Dr Yudai Iwasaki

Tohoku University

Dr Eddy Fan

Kathleen Exconde

Toronto General Hospital

Kenny Chan King-Chung

Tuen Mun Hospital

Dr Vadim Gudzenko

UCLA Medical Centre (Ronald Regan)

Dr Beate Hugi-Mayr

Universitätsspital Bern, Universitätsklinik für Herz- und Gefässchirurgie

Dr Fabio Taccone

Universite Libre de Bruxelles

Dr Fajar Perdhana

University Airlangga Hospital (Adult)

Yoan Lamarche

University de Montreal (Montreal Heart Institute)

Dr Joao Miguel Ribeiro

University Hospital CHLN

Dr Nikola Bradic

University Hospital Dubrava

Dr Klaartje Van den Bossche

University Hospital Leuven

Gurmeet Singh

University of Aberta (Mazankowski Heart Institute)

Dr Gerdy Debeuckelaere

University of Antwerp

Dr Henry T. Stelfox

University of Calgary and Alberta Health Services

Cassia Yi

University of California at San Diego

Jennifer Elia

University of California, Irvine

Shu Fang

University of Hong Kong

Thomas Tribble

University of Kentucky Medical Center

Shyam Shankar

University of Missouri

Dr Paolo Navalesi

University of Padova

Raj Padmanabhan

University of Pittsburgh Medical Centre

Bill Hallinan

University of Rochester Medical Centre (UR Medicine)

Luca Paoletti

University of South Carolina

Yolanda Leyva

University of Texas Medical Branch

Tatuma Fykuda

University of the Ryukus

Jillian Koch

University of Wisconsin & American Family Children's Hospital

Amy Hackman

UT Southwestern

Lisa Janowaik

UTHealth (University of Texas)

Jennifer Osofsky

Vassar Brothers Medical Center (VBMC)

A/Prof Katia Donadello

Verona Integrated University Hospital

Josh Fine

WellSpan Health—York Hospital

Dr Benjamin Davidson

Westmead Hospital

Andres Oswaldo Razo Vazquez

Yale New Haven Hospital


University of Queensland; Wesley Medical Research; The Prince Charles Hospital Foundation; Fisher & Paykel; The Health Research Board of Ireland; Biomedicine international training research programme for excellent clinician-scientists; European Union’s research and innovation programme (Horizon 2020); la Caixa Foundation. Finally, Carol Hodgson is funded by a National Health and Medical Research Council Grant. Sally Schrapnel is funded by the Australian Research Council Centre of Excellence for Engineered Quantum Systems (Project number CE170100009).

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Authors and Affiliations




GLB conceived the study, participated in its design and coordination and helped to draft the manuscript; JYS conceived the study, participated in its design and coordination and helped to draft the manuscript drafted the manuscript; HD participated in the design of the study and helped to draft the manuscript; NW performed the statistical analysis and helped to draft the manuscript; SS participated in the coordination of the study, performed the statistical analysis and helped to draft the manuscript; JPF participated in the design of the study and helped to draft the manuscript; BL performed the statistical analysis and helped to draft the manuscript; SH participated in the coordination of the study performed the statistical analysis and helped to draft the manuscript; AV performed the statistical analysis and helped to draft the manuscript; GB performed the statistical analysis and helped to draft the manuscript; JEM participated in the design of the study and helped to draft the manuscript; SF participated in the design and coordination of the study and helped to draft the manuscript; MP participated in the coordination of the study helped to draft the manuscript; JL participated in the coordination of the study helped to draft the manuscript; DB participated in the coordination of the study helped to draft the manuscript; EF participated in the coordination of the study helped to draft the manuscript; AT participated in the coordination of the study helped to draft the manuscript; DC participated in the coordination of the study helped to draft the manuscript; AC participated in the design of the study and helped to draft the manuscript; AE participated in collection of data and helped to draft the manuscript; CH participated in coordination and collection of data and helped to draft the manuscript; SI participated in collection of data and helped to draft the manuscript; CL participated in coordination and collection of data and helped to draft the manuscript; SM participated in coordination and collection of data and helped to draft the manuscript; AN participated in coordination and collection of data and helped to draft the manuscript; PY participated in coordination and collection of data and helped to draft the manuscript; MO participated in coordination and collection of data and helped to draft the manuscript; AP participated in coordination and collection of data and helped to draft the manuscript; HTT participated in collection of data and helped to draft the manuscript; JFF conceived the study, participated in its design and coordination and helped to draft the manuscript. All authors read and approved the final manuscript.

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Correspondence to Gianluigi Li Bassi.

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Participating hospitals obtained local ethics committee approval, and a waiver of informed consent was granted in all cases.

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Not applicable.

Statistical analysis

Nicole White; Sally Shrapnel; Benoit Liquet; Samuel Hinton; Aapeli Vuorinem; Gareth Booth.

Competing interests

GLB and JF received research funds, through their affiliated institution from Fisher & Paykel. All remaining authors do not have any conflict of interest related to this report.

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Li Bassi, G., Suen, J.Y., Dalton, H.J. et al. An appraisal of respiratory system compliance in mechanically ventilated covid-19 patients. Crit Care 25, 199 (2021).

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