Table 1 Patient characteristics, outcomes, and ventilation characteristics
Characteristics | All | Survivors | Non–survivors | P value |
|---|---|---|---|---|
N = 839 | N = 489 | N = 350 | ||
Age (years) | 61 [50 to 70] | 58 [47 to 68] | 63 [53 to 73] | < 0.001 |
Gender (male) | 555 (66%) | 314 (64%) | 241 (69%) | 0.23 |
Ethnicity, no. (%) | 0.09 | |||
African | 12 (1%) | 5 (1%) | 7 (2%) | |
Asian | 9 (1%) | 4 (1%) | 5 (1%) | |
Caucasian | 733 (87%) | 428 (88%) | 305 (87%) | |
Latin American | 16 (2%) | 8 (2%) | 8 (2%) | |
Other | 69 (8%) | 44 (9%) | 25 (7%) | |
BMI (kg/m2) | 25 [23 to 29] | 25 [23 to 29] | 25 [23 to 28] | 0.61 |
PBW (kg) | 71 [62 to 75] | 71 [62 to 75] | 71 [62 to 75] | 0.66 |
ARDS, N (%) | 223 (22%) | 130 (21%) | 93 (22%) | 0.96 |
Mild | 118 (14%) | 67 (14%) | 51 (14%) | |
Moderate | 97 (12%) | 60 (13%) | 37 (10%) | |
Severe | 8 (1%) | 3 (1%) | 5 (1%) | |
Reason for ICU admission, no. (%) | 0.25 | |||
Planned surgery | 116 (14%) | 75 (15%) | 41 (12%) | |
Emergency surgery | 207 (25%) | 122 (25%) | 85 (24%) | |
Medical | 513 (61%) | 289 (59%) | 224 (64%) | |
Risk of death (%)a | 32 [14 to 59] | 23 [10 to 47] | 48 [23 to 74] | < 0.001 |
Reason for intubation, no. (%) | 0.06 | |||
Cardiac arrest | 134 (16%) | 58 (12%) | 76 (22%) | |
Post–surgery | 207 (25%) | 130 (27%) | 77 (22%) | |
Depressed level of consciousness | 77 (9%) | 45 (9%) | 32 (9%) | |
Respiratory failure | 312 (37%) | 187 (38%) | 125 (36%) | |
Other | 109 (13%) | 69 (14%) | 40 (11%) | |
Chronic comorbidity, no. (%) | ||||
Hypertension | 231 (28%) | 137 (28%) | 94 (27%) | 0.73 |
Diabetes mellitus | 127 (15%) | 69 (14%) | 58 (17%) | 0.40 |
Heart failure | 69 (8%) | 44 (9%) | 25 (5%) | 0.39 |
Chronic kidney failure | 60 (7%) | 19 (4%) | 41 (12%) | < 0.001 |
Cirrhosis | 9 (1%) | 1 (0%) | 8 (2%) | 0.01 |
COPD | 89 (11%) | 43 (9%) | 46 (13%) | 0.06 |
Oxygen at home | 5 (1%) | 2 (0%) | 3 (1%) | 0.72 |
Cancer | 46 (5%) | 19 (4%) | 27 (8%) | 0.43 |
Immunodeficiency | 88 (10%) | 47 (10%) | 41 (12%) | 0.40 |
Ventilation at home | 10 (1%) | 6 (1%) | 4 (1%) | 1.00 |
Vital signs | ||||
SpO2 (%) | 98 [96 to 100] | 98 [96 to 100] | 98 [96 to 100] | 0.79 |
Heart rate (bpm) | 101 [83 to 120] | 100 [83 to 118] | 102 [83 to 121] | 0.39 |
MAP (mm Hg) | 57 [52 to 62] | 58 [53 to 63] | 56 [50 to 60] | < 0.001 |
Temperature (C) | 36.7 [35.9 to 37.3] | 36.8 [36.0 to 37.4] | 36.6 [35.7 to 37.2] | 0.03 |
Severity of illness, SOFA score | ||||
Total | 5 [4 to 8] | 4 [3 to 7] | 6 [4 to 9] | < 0.001 |
Non–pulmonary SOFA | 4 [4 to 7] | 4 [3 to 6] | 5 [4 to 8] | < 0.001 |
Pulmonary | 0 [0 to 1] | 0 [0 to 1] | 0 [0 to 1] | 0.07 |
Hematologic | 0 [0 to 1] | 0 [0 to 1] | 0 [0 to 2] | 0.12 |
Liver | 0 [0 to 0] | 0 [0 to 0] | 0 [0 to 0] | 0.12 |
Circulation | 4 [3 to 4] | 3 [2 to 4] | 4 [3 to 4] | < 0.001 |
Neurology | 0 [0 to 1] | 0 [0 to 1] | 0 [0 to 3] | 0.01 |
Renal | 0 [0 to 0] | 0 [0 to 0] | 0 [0 to 1] | < 0.001 |
Outcomes | ||||
ICU mortality, no. (%) | 220 (26%) | 0 (0%) | 220 (63%) | < 0.001 |
Hospital mortality, no. (%) | 305 (36%) | 3 (1%) | 301 (86%) | < 0.001 |
ICU LOS, days | 7 [4 to 12] | 7 [4 to 13] | 7 [4 to 12] | 0.12 |
Hospital LOS, days | 22 [11 to 42] | 31 [17 to 50] | 13 [6 to 27] | < 0.001 |
Duration of mechanical ventilation, days | 5 [3 to 10] | 5 [3 to 10] | 6 [3 to 10] | 0.60 |
VFD–28, days | 17 [0 to 24] | 23 [18 to 25] | 0 [0 to 0] | < 0.001 |
Ventilatory variables, median [IQR] | ||||
Tidal volume (ml) | 471 [410 to 540] | 476 [ 417 to 546] | 461 [405 to 531] | 0.04 |
Tidal volume (ml/kg PBW) | 6.8 [6.0 to 8.0] | 6.9 [6.1 to 7.9] | 6.8 [5.8 to 7.9] | 0.09 |
Respiratory rate (bpm) | 20 [16 to 26] | 20 [15 to 25] | 22 [17 to 28] | 0.003 |
FiO2 (%) | 40 [40 to 48] | 40 [40 to 45] | 40 [40 to 50] | 0.27 |
Pmax (cm H2O) | 23 [18 to 28] | 22 [18 to 27] | 24 [19 to 30] | < 0.001 |
PEEP (cm H2O) | 7 [5 to 10] | 7 [5 to 10] | 8 [5 to 10] | 0.22 |
Dynamic compliance (ml/cm H2O) | 31 [23 to 41] | 32 [25 to 43] | 29 [22 to 37] | < 0.001 |
ΔP (cm H2O) | 15 [12 to 19] | 15 [12 to 18] | 16 [13 to 20] | < 0.001 |
MP (10−3 J/min/kg PBW) | 206 [145 to 298] | 194 [136 to 280] | 218 [156 to 339] | < 0.001 |
Blood gas analysis results, median [IQR] | ||||
PaO2 (mm Hg) | 91 [77 to 110] | 91 [77 to 109] | 92 [78 to 112] | 0.68 |
PaCO2 (mm Hg) | 37 [41 to 43] | 38 [32 to 43] | 37 [31 to 43] | 0.53 |
pHa | 7.38 [7.33 to 7.44] | 7.39 [7.35 to 7.44] | 7.38 [7.32 to 7.43] | < 0.001 |
Bicarbonate (mmol/l) | 23 [20 to 27] | 24 [21 to 27] | 22 [19 to 26] | < 0.001 |