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Table 1 Characteristics of the study population

From: Clinical impact of ventilator-associated pneumonia in patients with the acute respiratory distress syndrome: a retrospective cohort study

Characteristics All patients with ARDS
(n = 336)
Patients with COVID-19-related ARDS
(n = 101)
Patients with ARDS from other causes
(n = 235)
P value
Male sex 247 (73.5) 73 (72.3) 174 (74.0) 0.79
Age, years 67 (57–74) 67 (58–72) 66 (55–74) 0.73
BMI, kg.m−2 28.5 (25.0–32.6) 29.4 (26.1–32.1) 27.8 (24.1–32.9) 0.13
Immune deficiency 53 (15.8) 11 (10.9) 42 (17.9) 0.14
SAPS 2 at ICU admission 50 (38–67) 40 (33–49) 56 (43–71)  < 0.0001
SOFA score at ICU admission 8 (5–11) 5 (3–8) 9 (7–12)  < 0.0001
ARDS aetiology     
 COVID-19a 101 (30.0) 101 (100) NA
 Bacterial or non-SARS-CoV-2 viral pneumonia 106 (31.6) 106 (45.1)  
 Aspiration 60 (17.9) 60 (25.5)  
 Extra-pulmonary sepsis 45 (13.4) 45 (19.1)  
 Miscellaneous 24 (7.1) 24 (10.2)  
ARDS and MV characteristicsb     
 Lowest Vt, mL kg−1 (PBW)
 Highest PEEP, cmH2O
 Highest plateau pressure, cmH2O
 Highest driving pressure, cmH2O
 Lowest PaO2/FiO2 ratio, mmHg
 Highest PaCO2, mmHg
 Lowest pH
6.1 (5.8–6.6)
10 (7–13)
24 (20–27)
13 (10–16)
100 (74–163)
44 (40–52)
7.36 (7.25–7.4)
6.0 (5.8–6.3)
12 (11–14)
26 (24–28)
13 (11–15)
91 (76–138)
43 (38–49)
7.36 (7.30–7.42)
6.1 (5.7–6.8)
8 (6–12)
23 (18–26)
13 (10–16)
105 (74–172)
46 (40–55)
7.35 (7.22–7.39)
0.02
 < 0.0001
 < 0.0001
0.91
0.17
0.0005
 < 0.0001
ARDS classification (Berlin definition)b
 Mild
50 (14.9) 11 (10.9) 39 (16.6) 0.09
 Moderate
 Severe
116 (34.5)
170 (50.6)
30 (29.7)
60 (59.4)
86 (36.6)
110 (46.8)
 
ARDS-targeted therapies     
 Prone positioning
 Number of days
 Nitric oxide inhalation
 Neuromuscular blocking agents
127 (37.8)
5 (2–11)
90 (26.8)
209 (62.2)
75 (74.3)
8 (3–16)
46 (45.5)
86 (85.1)
52 (22.1)
2 (1–5)
44 (19.1)
123 (52.3)
 < 0.0001
 < 0.0001
 < 0.0001
 < 0.0001
Organ support during the ICU stay     
 Invasive MV duration, overall, days Vasopressors
 Renal replacement therapy
 VV-ECMO
 VA-ECMO
11 (7–20)
280 (83.3)
85 (25.3)
15 (4.5)
7 (2.1)
17 (10–26)
82 (81.2)
23 (22.8)
7 (6.9)
0
9 (6–16)
198 (84.2)
62 (26.4)
8 (3.4)
7 (3.0)
 < 0.0001
0.52
0.58
0.16
0.11
Ventilator-associated pneumonia     
 First episode
 Prior MV duration, days
 More than one episode
176 (52.4)
7 (4–11)
59 (17.6)
69 (68.3)
9 (8–13)
35 (34.6)
107 (45.5)
6 (4–10)
24 (10.2)
0.0001
0.01
 < 0.0001
  1. Data are expressed as number (%) or median (interquartile range)
  2. ARDS acute respiratory distress syndrome, COVID-19 coronavirus disease 2019, BMI body mass index, COPD chronic obstructive pulmonary disease, ICU intensive care unit, LOS length of stay, SAPS 2 simplified acute physiology score 2, SOFA sepsis-related organ failure assessment, MV mechanical ventilation, Vt tidal volume, PBW predicted body weight, PEEP positive end-expiratory pressure, VV/VA-ECMO veno-venous/veno-arterial extracorporeal membrane oxygenation
  3. aIncluding 8 cases (7.9%) with bacterial and/or viral co-infection
  4. bFirst day with ARDS criteria
  5. Full characteristics of the study population are provided in Additional file 1: Table S1