Table 1.
Patient characteristics
| Non-COVID ARDS | COVID ARDS | p value | COVID ARDS, matched cohort | p value* | |
|---|---|---|---|---|---|
| Number of patients | 91 | 276 | 91 | ||
| Age, years | 69 [59, 77] | 68 [60, 73] | 0.30 | 67 [63, 73] | 0.40 |
| Male sex | 61 (67) | 207 (75) | 0.18 | 71 (78) | 0.14 |
| Respiratory rate, breaths·minute−1 | 21 [18, 25] | 22 [20, 25] | 0.16 | 22 [20, 24] | 0.47 |
| PEEP, cmH2O | 8 [6, 10] | 10 [8, 14] | < 0.001 | 10 [8, 12] | < 0.001 |
| pH | 7.34 [7.26, 7.43] | 7.32 [7.23, 7.39] | 0.02 | 7.34 [7.23, 7.39] | 0.13 |
| PaCO2, mmHg | 44 [36, 53] | 51 [44, 62] | < 0.001 | 49 [44, 60] | < 0.001 |
| BMI, kg/m2 | 26 [22, 29] | 28 [26, 32] | < 0.001 | 27 [25, 31] | 0.005 |
| VT, ml·kg IBW | 6.4 [5.8, 7.1] | 6.0 [5.4, 6.5] | < 0.001 | 5.9 [5.4, 6.3] | < 0.001 |
| PaO2/FiO2 | 117 [89, 172] | 103 [77, 138] | 0.017 | 108 [80, 144] | 0.12 |
| Predicted FRC, liters | 3.1 [2.7, 3.6] | 3.1 [2.6, 3.4] | 0.07 | 3.10 [2.7, 3.6] | 0.71 |
| Ventilatory Ratio | 1.7 [1.3, 1.9] | 1.9 [1.5, 2.2] | 0.001 | 1.8 [1.5, 2.1] | 0.027 |
| Best Crs, ml/cmH2O | 38 [29, 50] | 40 [30, 48] | 0.98 | 40 [30, 49] | 0.82 |
| Best minimum PEEP, cmH2O | 6 [4, 8] | 6 [2, 10] | 0.64 | 4 [2, 8] | 0.012 |
Data are shown as median [interquartile range], or count (percentage)
The last column (*) shows the comparison between non-COVID ARDS and COVID ARDS patients matched for predicted FRC. Best compliance is the highest Crs obtained at the tested PEEP levels
Best minimum PEEP is the lowest PEEP level associated with the highest Crs
PEEP positive end expiratory pressure, BMI body mass index, VT tidal volume, IBW ideal body weight, FRC functional residual capacity, Crs respiratory system compliance, ARDS acute respiratory distress syndrome