Table 1.
Baseline characteristics, therapeutic interventions, and outcomes of patients, according to respiratory compliance
| Overall (N = 36), no. (%) of patientsa | High respiratory compliance (N = 17), no. (%) of patientsa | Low respiratory compliance (N = 19), no. (%) of patientsa | P value between groups | |
|---|---|---|---|---|
| Baseline characteristics | ||||
| Age, mean ± SD, years | 53.4 ± 10.2 | 56.1 ± 7.1 | 50.9 ± 12.1 | 0.12 |
| Male sex | 30 (83.3) | 16 (94.1) | 14 (73.7) | 0.18 |
| Obesityb | 14 (38.9) | 3 (17.7) | 11 (57.9) | 0.02 |
| Diabetes mellitus | 11 (30.6) | 5 (29.4) | 6 (31.6) | 1.0 |
| Arterial hypertension | 16 (44.4) | 11 (64.7) | 5 (26.3) | 0.19 |
| SAPS 2 score, median [IQR] | 31 [27–36] | 31 [29–36] | 29 [22–39] | 0.51 |
| SOFA score, median [IQR] | 5 [4–7] | 6 [4–7] | 4 [3–6] | 0.04 |
| Tidal volume, mean ± SD, mL/kg | 6.1 ± 0.6 | 6.2 ± 0.3 | 6.0 ± 0.7 | 0.02 |
| Respiratory frequency, median [IQR], breaths/min | 25 [24–27] | 25 [24–26] | 26 [24–28] | 0.64 |
| FiO2, median [IQR], % | 65 [50–100] | 60 [40–80] | 70 [60–100] | 0.07 |
| PaO2/FiO2 ratio, median [IQR] | 152 [112–240] | 209 [150–256] | 117 [83–201] | 0.02 |
| PEEP, mean ± SD, cmH2O | 13.4 ± 3.2 | 13.4 ± 3.6 | 13.4 ± 3.1 | 0.92 |
| Respiratory compliance, mean ± SD, mL/cmH2Oc | 39.4 ± 16.9 | 51.8 ± 16.4 | 28.3 ± 6.1 | |
| Therapeutic interventions | ||||
| Prone positioning | 29 (80.6) | 12 (70.6) | 17 (89.5) | 0.22 |
| Number of sessions, median [IQR] | 4.0 [2.0–6.0] | 4.0 [2.5–5.0] | 5.0 [1.7–6.0] | 0.91 |
| Inhaled nitric oxide | 9 (25.0) | 2 (11.8) | 7 (36.8) | 0.13 |
| Venovenous ECMO | 7 (19.4) | 0 (0.0) | 7 (36.8) | 0.008 |
| Vasopressors | 31 (86.1) | 17 (100.0) | 14 (73.7) | 0.048 |
| Renal replacement therapy | 7 (19.4) | 3 (17.7) | 4 (21.1) | 1.0 |
| Hydroxychloroquine | 32 (88.9) | 16 (94.1) | 16 (84.2) | 0.6 |
| Steroïds | 11 (30.6) | 5 (29.4) | 6 (31.6) | 1.0 |
| Outcomes | ||||
| Ventilator-free days, median [IQR] | 3.0 [0.0–14.5] | 10.0 [0.0–17.2] | 0.0 [0.0–8.0] | 0.04 |
| Mortality at day 28 | 4 (11.1) | 1 (5.9) | 3 (15.8) | 0.61 |
Abbreviations: ECMO extracorporeal membrane oxygenation, FiO2 fraction of inspired oxygen, PEEP positive end-expiratory pressure
aUnless otherwise indicated
bObesity is defined by a body mass index above 30 kg/m2. The formula for body mass index is weight in kilograms divided by height in meters squared
cNo statistical comparison performed