Table 2.
Ventilator settings averaged on day 1–3, arterial blood gas, and fluid overload in patients with and without acute kidney injury
| Ventilator settings | No AKI (113) | AKI (244) | p | Missing (%) |
|---|---|---|---|---|
| VT, median (IQR), mL | 451 (401–502) | 487 (422–551) | 0.01a | 35 (9.8) |
| VT, median (IQR), (mL/kg PBW) | 7.4 (6.7–8.6) | 7.5 (6.8–8.5) | 0.89 | 35 (9.8) |
| PEEP, median (IQR), cm H2O | 10.7 (8–13.3) | 10 (8–14) | 0.57 | 32 (9.0) |
| FiO2, median (IQR) | 0.67 (0.54–0.8) | 0.7 (0.57–0.87) | 0.23 | 29 (8.1) |
| Pplat, median (IQR), cm H2O | 27 (23–31) | 27.2 (22.9–33.1) | 0.38 | 158 (44.3) |
| Pplat > 30 cm H2O (%) | 18 (30.5) | 51 (36.4) | 0.42 | 158 (44.3) |
| DP, median (IQR), cm H2O | 15 (11.3–18.5) | 14.8 (12–19) | 0.82 | 158 (44.3) |
| Mean airway pressure, median (IQR), cm H2O | 17.3 (14.3–20.7) | 18 (14.7–21.5) | 0.16 | 66 (18.5) |
| Ppeak, mean (SD), cm H2O | 29.6 (6.5) | 31.2 (7.3) | 0.08 | 62 (17.4) |
| Minute ventilation, median (IQR), L/min | 10.7 (8.5–11.9) | 11.4 (9.7–13.1) | 0.01a | 63 (17.6) |
| Lung protective ventilation, n (%)b | 26 (35.1) | 64 (36.2) | 0.88 | 106 (29.7) |
| Arterial blood gases | ||||
| Arterial pH, median (IQR) | 7.39 (7.34–7.43) | 7.35 (7.3–7.41) | < 0.001a | 28 (7.8) |
| Arterial pH on day 1 | 7.38 (7.32–7.42) | 7.34 (7.27–7.4) | 0.005a | 47 (13.2) |
| Serum HCO3, median (IQR), mEq/L | 25 (22.5–28) | 22 (18.3–25.3) | < 0.001a | 25 (7.0) |
| Serum HCO3 on day 1 | 25 (22–29) | 21 (18–26) | < 0.001a | 46 (12.9) |
| Serum lactate, median (IQR), mmol/L | 1.8 (1.3–2.3) | 2.2 (1.5–3.8) | < 0.001a | 53 (14.8) |
| Serum lactate on day 1 | 1.8 (1.4–2.6) | 2.6 (1.5–5.0) | < 0.001a | 90 (25.2) |
| PaCO2, median (IQR), mm Hg | 45 (39–50.4) | 42 (36–48.9) | 0.02a | 28 (7.8) |
| PaO2, median (IQR), mm Hg | 87 (76–104) | 88 (76–111) | 0.68 | 28 (7.8) |
| PaO2:FiO2, median (IQR) | 139 (107–180) | 138 (99–187) | 0.72 | 31 (8.7) |
| Oxygenation index, median (IQR) | 13.8 (7.9–19.5) | 14.3 (9.1–23.8) | 0.11 | 68 (19.0) |
| Fluid overload, median (IQR), % | ||||
| Day 1 | 0.2 (− 0.5 to 2.8) | 1 (− 0.3 to 3.1) | 0.17 | 117 (32.8) |
| Day 2 | 1.5 (− 0.2 to 3.9) | 3.4 (0.8–7.1) | < 0.001 | 111 (31.1) |
| Day 3 | 1.8 (− 0.5 to 5.2) | 4.9 (1.8–9.2) | < 0.001 | 115 (32.2) |
AKI acute kidney injury, DP driving pressure, FiO2 fraction of inspired oxygen, HCO3 bicarbonate, IQR interquartile range, PaCO2 partial pressure of carbon dioxide in arterial blood, PaO2 partial pressure of oxygen in arterial blood, PBW predicted body weight, PEEP positive end-expiratory pressure, Ppeak peak inspiratory pressure, Pplat plateau pressure, SD standard deviation, VT tidal volume
ap < 0.05
bTidal volume ≤ 8 mL/kg PBW and inspiratory plateau pressure ≤ 30 cm H2O