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Table 2 Respiratory mechanics

From: Respiratory physiology of COVID-19-induced respiratory failure compared to ARDS of other etiologies

  Low PEEP High PEEP
COVID-19 Non-COVID-19 p COVID-19 Non-COVID-19 p
Set PEEP, cmH2O 5 [5–5]* 5 [5–8]§ 0.031 15 [15–15]* 15 [15–18]§ 0.011
Total PEEP, cmH2O 5 [5–6]* 8 [6–9]§ < 0.001 15 [15–16]* 16 [15–18]§ 0.001
Tidal volume, ml 431 [395–473] 414 [370–443] 0.15 431 [395–473] 417 [357–445] 0.20
Tidal volume/PBW, ml/kg 6.4 [6–6.8] 6 [5.7–6.3] 0.037 6.4 [6–6.8] 6 [5.8–6.3] 0.036
Respiratory rate, breaths/minute 28 [26–30] 26 [24–30] 0.16 28 [26–30] 26 [24–30] 0.11
PaO2/FiO2, mmHg 119 [101–142]* 116 [87–154]§ 0.92 165 [132–196]* 150 [121–192]§ 0.049
pH 7.35 [7.29–7.42] 7.37 [7.33–7.40] 0.63 7.35 [7.32–7.42] 7.36 [7.32–7.40] 0.45
PaCO2, mmHg 43 [37–49] 43 [37–49] 0.76 43 [36–49] 45 [35–49] 0.91
Ventilatory ratio 2.1 [1.7–2.3] 1.6 [1.4–2.1] 0.032 2.1 [1.7–2.4] 1.7 [1.4–2.2] 0.08
Standardized minute ventilation, liters/minute 12.4 [10.7–15.6] 11.1 [9.5–13.3] 0.12 12.4 [10.7–15.9] 11.5 [9.7–14.2] 0.29
Peak pressure, cmH2O 29 [23–32]* 33 [29–39]§ 0.003 39 [36–41]* 41 [39–46]§ 0.043
Plateau pressure, cmH2O 15 [14–17]* 19 [16–22]§ < 0.001 26 [25–29]* 30 [28–33]§ < 0.001
Inspiratory resistance, cmH2O/liters/second 12 [10–14] 14 [11–16]§ 0.09 12 [10–14] 12 [10–14]§ 0.55
Driving pressure, cmH2O 10 [8–12] 11 [9–13]§ 0.09 10 [9–14] 13 [11–17]§ 0.007
Patients with driving pressure ≤ 14 cmH2O, no. (%) 24 (80) 25 (83) 1 24 (80) 21 (70) 0.55
Respiratory system compliance, ml/cmH2O 41 [32–52] 36 [27–42]§ 0.045 39 [27–53] 32 [23–40]§ 0.003
Respiratory system compliance/PBW, ml/cmH2O/kg 0.62 [0.48–0.78] 0.54 [0.46–0.63]§ 0.018 0.57 [0.45–0.75] 0.47 [0.37–0.56]§ < 0.001
Arterial pressure, mmHg
 Systolic 130 [112–140]* 124 [110–131]§ 0.27 118 [110–126]* 116 [104–126]§ 0.71
 Diastolic 70 [57–80] 60 [55–64] 0.017 65 [54–70] 57 [54–62] 0.08
Heart rate, beats per minute 78 [70–93] 82 [74–101] 0.15 80 [70–92] 85 [75–103] 0.15
  1. Data are expressed as medians [interquartile range], if not otherwise specified
  2. *p < 0.05 for the comparison between low and high PEEP within the COVID-19 cohort
  3. §p < 0.05 for the comparison between low and high PEEP within the non-COVID-19 cohort