Table 2.
Differences in respiratory mechanics during mechanical ventilation between influenza A- and COVID-19-induced ARDS.
| Day 1 | ||||
| Characteristics |
Total participants (N = 87) |
Influenza A induced ARDS (N = 45) |
COVID-19-induced ARDS (N = 42) |
p-value |
| Pco2 | 38.9 (33.5–43.6) | 37.5 (33.8–44.3) | 40.0 (33.0–43.3) | 0.584 |
| PaO2:FiO2 | 184.7 (135.7–243.6) | 216.1 (134.2–271.3) | 167.9 (137.5–212.7) | 0.009 |
| Mve (L/min) | 8.9 (7.6–10.3) | 8.5 (7.2–10.2) | 9.0 (8.0–10.3) | 0.707 |
| TV/PBW (ml/kg) | 7.2 (6.3–8.4) | 7.0 (6.3–8.3) | 7.2 (6.3–8.5) | 0.763 |
| PIP (cm H2O) | 23.0 (20.0–26.0) | 23.0 (20.5–27.0) | 22.0 (19.0–25.0) | < 0.001 |
| PEEP (cm H2O) | 8.0 (7.0–10.0) | 8.0 (5.0–8.0) | 10.0 (8.0–12.0) | < 0.001 |
| Cdyn (cm H2O) a | 30.0 (23.7–37.9) | 25.7 (21.3–34.4) | 35.8 (28.9–41.6) | 0.001 |
| DP (cm H2O) b | 14.0 (12.0–17.0) | 15.0 (13.5–19.0) | 13.0 (9.8–16.0) | 0.369 |
| Day 3 | ||||
| Characteristics |
Total participants (N = 80) |
Influenza A induced ARDS (N = 39) |
COVID-19-induced ARDS (N = 41) |
p-value |
| Pco2 | 38.8 (33.3–44.2) | 37.7 (30.3–47.1) | 39.8 (35.0–42.8) | 0.763 |
| PaO2:FiO2 | 215.2 (158.2–309.0) | 279.5 (172.0–333.0) | 181.0 (141.0–252.0) | 0.005 |
| Mve (L/min) | 8.4 (7.3–9.8) | 7.9 (6.1–9.3) | 8.4 (7.7–9.9) | 0.072 |
| TV/PBW (ml/kg) | 7.3 (6.5–7.8) | 7.2 (6.4–8.0) | 7.3 (6.6–7.8) | 0.969 |
| PIP (cm H2O) | 23.0 (18.3–25.8) | 22.0 (16.0–25.0) | 24.0 (20.0–26.5) | 0.051 |
| PEEP (cm H2O) | 8.0 (6.0–10.0) | 6.0 (5.0–8.0) | 10.0 (8.0–11.0) | < 0.001 |
| Cdyn (cm H2O) a | 28.4 (22.7–39.0) | 28.2 (21.4–47.9) | 28.6 (23.1–37.9) | 0.935 |
| DP (cm H2O) b | 14.0 (11.0–17.0) | 14.0 (9.0–18.0) | 14.0 (12.0–17.0) | 0.817 |
| Day 7 | ||||
| Characteristics |
Total participants (N = 64) |
Influenza A induced ARDS (N = 27) |
COVID-19-induced ARDS (N = 37) |
p-value |
| Pco2 | 38.2 (34.0–42.5) | 36.9 (31.6–42.6) | 39.1 (35.1–42.6) | 0.799 |
| P/F ratio | 215.0 (146.4–310.7) | 279.1 (143.6–353.3) | 204.2 (147.6–282.5) | 0.170 |
| Mve (L/min) | 8.8 (7.5–10.6) | 8.6 (6.4–10.1) | 8.9 (8.1–10.9) | 0.123 |
| TV/PBW (ml/kg) | 7.4 (6.5–8.5) | 7.4 (6.0–8.7) | 7.4 (6.6–8.4) | 0.838 |
| PIP (cm H2O) | 21.0 (16.3–25.0) | 18.0 (13.0–25.0) | 22.0 (19.0–25.5) | 0.108 |
| PEEP (cm H2O) | 8.0 (5.0–10.0) | 6.0 (5.0–7.0) | 8.0 (8.0–10.0) | < 0.001 |
| Cdyn (cm H2O) a | 31.3 (23.7–45.3) | 32.5 (20.5–62.2) | 31.3 (24.5–37.8) | 0.951 |
| DP (cm H2O) b | 13.5 (9.3–16.8) | 12.0 (8.0–18.0) | 15.0 (11.0–16.0) | 0.643 |
Data are presented as no. (%) or median (IQR)
Pco2, partial pressure of carbon dioxide; P/F ratio, the arterial partial pressure of oxygen (PaO2) divided by the inspired oxygen concentration (FiO2); Mve, Exhaled minute volume; TV, tidal volume; PBW, predicted body weight, PIP, peak inspiratory pressure; PEEP, positive end expiratory pressure; Cdyn, dynamic compliance; DP, dynamic driving pressure
a Cdyn = TV/(PIP-PEEP)
b DP = PIP-PEEP