Skip to main content

Table 1 Baseline characteristics of patients with ARDS meeting ARDS criteria within 48 h of acute hypoxemic respiratory failure onset (n = 2813)

From: Etiologies, diagnostic work-up and outcomes of acute respiratory distress syndrome with no common risk factor: a prospective multicenter study

Parameters ARDS patients with ≥1 risk factor identified (n = 2579) ARDS patients with no risk factor identified (n = 234) p valuea
Age (years) 61 ± 17 65 ± 15 <0.01
Chronic disease    
 COPD 527 (20.4) 80 (34.2) <0.01
 Diabetes 548 (21.2) 65 (27.8) 0.025
 Immunoincompetence 544 (21.9) 40 (17.9) 0.17
 Chronic cardiac failure 252 (9.8) 38 (16.2) <0.01
 Chronic renal failure 248 (9.6) 38 (16.2) <0.01
 Active neoplasm 210 (8.1) 22 (9.4) 0.58
 Hematological malignancy 134 (5.2) 4 (1.7) 0.03
 Chronic liver failure 106 (4.1) 6 (2.6) 0.33
Type of admission    <0.001
 Medical 1979 (76.7) 179 (76.5)  
 Postoperative 127 (4.9) 26 (11.1)  
 Surgical 365 (14.1) 28 (12.0)  
 Trauma 108 (4.2) 1 (0.4)  
ARDS severity    <0.001
 Mild 651 (25.2) 63 (26.9)  
 Moderate 1026 (39.8) 80 (34.2)  
 Severe 524 (20.3) 33 (14.1)  
 ARDS receiving only NIV 378 (14.7) 58 (24.8)  
Day 1 SOFA scoreb 9.5 ± 4.1 8.5 ± 3.7 <0.01
Day 1 non-pulmonary SOFA scorec 6.3 ± 4.1 5.3 ± 3.7 <0.01
Worst SOFA score 11.2 ± 4.4 9.8 ± 4.1 <0.01
Worst non-pulmonary SOFA score 8.1 ± 4.2 6.8 ± 4.1 <0.01
FiO2 0.60 [0.45–0.80] 0.50 [0.40–0.80] 0.03
Total respiratory rate (1/min) 21.8 ± 8.9 21.3 ± 6.5 0.42
Tidal volume (mL/kg PBW) 7.7 ± 2.0 7.9 ± 2.3 0.20
 In intubated patients 7.6 ± 1.9 7.7 ± 1.9 0.59
 In NIV patients 8.3 ± 2.7 8.7 ± 3.2 0.52
Set PEEP (cmH2O) 8.2 ± 3.2 7.5 ± 2.4 <0.01
Peak pressure (cmH2O) 25.6 ± 8.8 23.5 ± 8.0 <0.01
Plateau pressure (cmH2O)d 23.2 ± 6.1 22.8 ± 5.4 0.65
Respiratory system compliance (mL/cmH2O)d 36.8 ± 22.1 33.5 ± 15.2 0.16
Driving pressure (cmH2O)d 14.7 ± 5.4 11.8 ± 6.0 0.67
Standardized minute ventilation (L/min)e 11.3 ± 5.4 11.9 ± 6.0 0.42
PaO2/FiO2 ratio (mmHg) 159 ± 67 169 ± 68 0.03
SpO2 (%) 96 [93−98] 96 [94–98] 0.18
PaCO2 (mmHg) 45.6 ± 15.3 48.8 ± 18.0 0.01
pH 7.33 ± 0.12 7.33 ± 0.12 0.90
  1. Categorical variables are shown as n (%); Continuos variables are shown as median [1st-3rd quartiles] or mean ± standard deviation, as appropriate; ARDS: acute respiratory distress syndrome; COPD, chronic obstructive pulmonary disease
  2. NIV, non-invasive ventilation; SOFA: Sequential Organ Failure Assessment; FiO2, inspired fraction of oxygen; PBW: Predicted Body Weight; PEEP: Positive End-Expiratory Pressure; SpO2: peripheral arterial oxygen saturation
  3. a p value represents comparisons across ARDS with or without known risk factor; Parametric or nonparametric tests were used according to the distribution of variables
  4. bFor all SOFA scores, where data points were missing, this value was omitted and the denominator adjusted accordingly
  5. cFor computing the non-pulmonary SOFA score, the pulmonary component of the score was omitted and the denominator adjusted accordingly
  6. dPlateau pressure values are limited to patients in whom this value was reported (n = 732), and in whom either an assist control mode was used or, where a mode permitting spontaneous ventilation was used, the set and total respiratory rates were equal. Patients receiving high frequency oscillatory ventilation (HFOV) or extracorporeal membrane oxygenation (ECMO) were also excluded
  7. eStandardized minute ventilation = minute ventilation * PaCO2/40 mmHg