Table 4 Differences in respiratory mechanics during mechanical ventilation between influenza A- and COVID-19-induced ARDS survivors

Day 1

Characteristics

Total participants

(N = 55)

Influenza A induced ARDS

(N = 23)

COVID-19-induced ARDS

(N = 32)

p-value

Pco₂

38.0 (35.1–43.6)

37.1 (34.4–40.5)

40.3 (36.8–44.3)

0.096

Pa_O2:Fi_O2

194.4 (149.4–268.3)

268.0 (196.4–304.3)

162.5 (139.4–208.3)

< 0.001

Mve (L/min)

8.7 (7.2–10.3)

7.8 (6.1–8.5)

9.4 (8.0–10.4)

0.005

TV/PBW (ml/kg)

7.2 (6.6–7.8)

7.0 (6.6–8.0)

7.2 (6.4–7.8)

0.824

PIP (cm H₂O)

22.0 (19.0–25.0)

22.0 (19.0–25.0)

22.0 (19.0–25.0)

0.537

PEEP (cm H₂O)

8.0 (7.0–10.0)

7.0 (5.0–8.0)

10.0 (8.0–11.8)

< 0.001

Cdyn (cm H₂O) ^a

33.4 (25.6–40.0)

27.0 (23.5–36.8)

35.7 (28.7–42.9)

0.056

DP (cm H₂O) ^b

14.0 (11.0–16.0)

14.0 (12.0–17.0)

12.5 (9.3–15.8)

0.072

Day 3

Characteristics

Total participants

(N = 53)

Influenza A induced ARDS

(N = 22)

COVID-19-induced ARDS

(N = 31)

p-value

Pco₂

38.9 (33.7–42.6)

36.4 (32.3–41.8)

40.0 (35.1–42.6)

0.136

Pa_O2:Fi_O2

269.3 (171.3–333.0)

308.9 (276.9–379.1)

185.0 (157.0–275.6)

< 0.001

Mve (L/min)

8.3 (7.2–9.8)

7.2 (5.5–9.2)

8.7 (7.7–9.9)

0.012

TV/PBW (ml/kg)

7.3 (6.5–7.8)

7.4 (6.3–8.0)

7.3 (6.5–7.8)

0.691

PIP (cm H₂O)

21.0 (17.5–24.5)

18.5 (14.5–22.0)

23.0 (20.0–25.0)

0.001

PEEP (cm H₂O)

8.0 (6.0–10.0)

6.0 (5.0–8.0)

10.0 (8.0–10.0)

< 0.001

Cdyn (cm H₂O) ^a

30.2 (25.0–41.6)

32.9 (27.3–56.1)

28.6 (22.7–38.9)

0.108

DP (cm H₂O) ^b

13.0 (10.5–16.0)

11.0 (8.0–15.3)

13.1 (12.0–17.0)

0.044

Day 7

Characteristics

Total participants

(N = 42)

Influenza A induced ARDS

(N = 14)

COVID-19-induced ARDS

(N = 28)

p-value

Pco₂

36.7 (33.5–41.6)

35.5 (29.1–39.1)

37.3 (34.0–42.2)

0.196

P/F ratio

260.3 (182.2–336.9)

314.6 (267.9–366.8)

212.9 (174.2–283.9)

0.014

Mve (L/min)

8.6 (6.9–10.7)

6.7 (5.7–8.8)

9.3 (8.3–11.1)

0.001

TV/PBW (ml/kg)

7.6 (6.6–8.6)

7.5 (6.0–9.1)

7.6 (6.8–8.6)

0.626

PIP (cm H₂O)

20.0 (14.8–24.0)

16.5 (12.8–20.0)

21.5 (17.3–24.8)

0.007

PEEP (cm H₂O)

8.0 (5.0–8.3)

6.0 (5.0–7.0)

8.0 (7.0–10.0)

0.005

Cdyn (cm H₂O) ^a

32.1 (27.3–55.3)

35.0 (28.0–81.6)

31.5 (26.1–38.6)

0.348

DP (cm H₂O) ^b

13.0 (8.0–16.0)

10.0 (7.0–13.3)

15.0 (10.3–16.0)

0.048