Dynamic hyperinflation and intrinsic positive end-expiratory pressure in ARDS patients

Table 1 Baseline characteristics of the study population in relation to the presence of intrinsic PEEP

	Total population (n = 217)	Patients with intrinsic PEEP (n = 87)	Patients without intrinsic PEEP (n = 130)	p
Age (yr)	61 [48–73]	60 [48–61]	62 [48–73]	0.69
Female % (n)	32 (69)	28 (24)	35 (45)	0.30
Height (cm)	170 [162–177]	170 [163–180]	170 [162–175]	0.34
BMI (kg/m²)	25 [22–29]	27 [23–29]	24 [22–28]	*0.004*
Intensive care unit stay (days)	18 [18–26]	19 [10–28]	17 [10–25]	0.58
SAPS II score	40 [32–53]	41 [33–50]	40 [32–53]	0.82
Hospital mortality % (n)	46 (99)	46 (47)	40 (52)	*0.05*
PaO₂/FiO₂	173 [132–224]	159 [119–193]	188 [142–225]	*0.008*
PaCO₂ (mmHg)	42 [37–49]	44 [39–51	41 [36–48]	*0.005*
ARDS category % (n)				0.09
• Mild	18 (40)	16 (14)	15 (20)
• Moderate	62 (135)	58 (50)	65 (85)
• Severe	20 (42)	26 (23)	20 (25)
Cause of ARDS % (n)				0.78
• Pulmonary	57 (123)	55 (48)	58 (75)
• Extrapulmonary	43 (94)	45 (39)	42 (55)
Respiratory rate (breath/min)	16 [14–20]	18 [16–21]	15 [12–20]	*< 0.0001*
Tidal volume (mL)	500 [430–586]	480 [420–550]	500 [450–600]	*0.03*
Tidal volume/body weight (mL/kg)	7.8 [6.8–8.8]	7.6 [6.7–8.3]	7.9 [6.9–9.4]	*0.0095*
Clinical PEEP (cmH₂O)	10 [10–12]	10 [10–12]	10 [10–12]	0.24
Minute ventilation (L min⁻¹)	8.5 [7.2–10.2]	9.0 [7.6–11-6]	8.2 [6.8–9.7]	*0.001*
Respiratory system compliance (mL cmH₂O⁻¹)	38 [32–50]	37 [30–45]	41 [33–51]	0.11

Student’s t test or Mann-Whitney rank sum test, as appropriate, were used to analyze continuous variables and the chi-square or Fisher’s exact test, as appropriate, for non-continuous variables. Data are expressed as mean (standard deviation) or median [I.Q. range] as appropriate
N sample size, yr years, BMI body mass index, ARDS acute respiratory distress syndrome, SAPS Simplified Acute Physiology Score
Italics: for all the statistical data
Bold italics: for statistical significant data

ISSN: 1364-8535