From: Hypoxemia in the ICU: prevalence, treatment, and outcome
All hypoxemic patients, n = 859 | Mild hypoxemia P/F 201–300 mmHg, n = 440 | Moderate hypoxemia P/F 101–200 mmHg, n = 345 | Severe hypoxemia P/F ≤ 100 mmHg, n = 74 | p | |
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Respiratory rate (n = 846/432/340/74) | 23 [18–27] | 22 [18–26] | 24 [20–28] | 25 [20–30] | 0.001 |
Arterial blood gases | 749 (87.2) | 368 (83.6) | 311 (90.1) | 70 (94.6) | 0.004 |
pH (n = 745/366/309/70) | 7.41 [7.36–7.46] | 7.42 [7.38–7.45] | 7.41 [7.36–7.46] | 7.38 [7.29–7.45] | 0.007 |
PaCO2 (mmHg) (n = 749/368/311/70) | 41 [36–49] | 40 [35–46] | 43 [38–55] | 45 [39–56] | 0.001 |
PaCO2 > 45 mmHg (n = 749/368/311/70) | 260 (34.7) | 96 (26.1) | 131 (42.1) | 33 (47.1) | < 0.001 |
PaO2 (mmHg) (n = 749/368/311/70) | 78 [66–92] | 84 [73–100] | 74 [64–88] | 65 [56–74] | < 0.001 |
FiO2 (%) (n = 749/368/311/70) | 0.40 [0.33–0.50] | 0.35 [0.30–0.40] | 0.50 [0.40–0.60] | 1 [0.70–1] | < 0.001 |
HCO3-(meq/L) (n = 747/368/309/70) | 26 [23–30] | 26 [22–29] | 27 [23–32] | 26 [23–30] | 0.03 |
Lactates (meq/L) (n = 630/312/257/61) | 1.3 [1.0–1.9] | 1.2 [0.9–1.7] | 1.3 [1.0–1.9] | 1.4 [1.1–2.7] | 0.02 |
Oxygenation modalities, N (%) | < 0.001 | ||||
Ambient air | 14 (1.6) | 11 (2.5) | 3 (0.9) | 0 (0) | |
Low-flow oxygen | 191 (22.2) | 136 (30.9) | 55 (15.9) | 0 (0) | |
High-flow oxygen | 45 (5.2) | 11 (2.5) | 23 (6.7) | 11 (14.9) | |
Non-invasive ventilation | 84 (9.8) | 43 (9.8) | 33 (9.6) | 8 (10.8) | |
Invasive ventilation | 525 (61.2) | 239 (54.3) | 231 (66.9) | 55 (74.3) | |
Ventilator settingsa | |||||
Tidal volume, mL/kg of ideal body weight; median IQR (n = 509/230/225/54) | 6.9 [6.1–7.9] | 7.1 [6.2–8.1] | 6.8 [6.0–7.6] | 6.1 [4.8–6.6] | < 0.001 |
TV ≤ 8 mL/kg of ideal body weight (n = 509/230/225/54) | 393 (77.2) | 165 (71.7) | 178 (79.1) | 50 (92.6) | 0.003 |
PEEP (cmH20) (n = 519/236/229/54) | 6 [5–10] | 5 [5–8] | 7 [5–10] | 10 [8–12] | < 0.001 |
Plateau pressureb (cmH20) (n = 186/66/84/36) | 22.5 [19–27] | 20 [16–24] | 23.5 [20–28] | 25.5 [23–29.5] | < 0.001 |
Driving pressureb (cmH20) (n = 186/66/84/36) | 14 [10–18] | 13 [9–17] | 14 [11–18] | 13 [10–19] | 0.31 |
Adjunctive therapies | |||||
Prone positioning (n = 516/232/230/54) | 22 (4.3) | 3 (1.3) | 13 (5.7) | 6 (11.1) | 0.001 |
Inhaled NO (n = 513/233/226/54) | 19 (3.7) | 3 (1.3) | 9 (4.0) | 7 (13.0) | 0.001 |
Continuous intravenous sedation, N (%) (n = 522/237/231/54) | 321 (61.5) | 121 (51.1) | 159 (68.8) | 41 (75.9) | < 0.001 |
Neuromuscular blocking agents, N (%) (n = 522/237/231/54) | 83 (15.9) | 11 (4.6) | 44 (19.1) | 28 (51.9) | < 0.001 |
Extracorporeal oxygenation, N (%) (n = 522/237/231/54) | 26 (3.0) | 5 (1.1) | 7 (2.0) | 14 (18.9) | < 0.001 |
ICU length of stay (days) (n = 840/431/336/73) | 16 [7–32] | 15 [7–32] | 16 [8–31.5] | 18 [7–37] | 0.89 |
ICU length of stay (days) in ICU survivors (n = 625/342/246/37) | 15 [7–30] | 15 [7–30] | 14 [6.5–30] | 20.5 [9–46.5] | 0.27 |
ICU mortality, N (%) (n = 839/431/335/73) | 225 (26.7) | 92 (21.3) | 96 (28.5) | 37 (50.7) | < 0.001 |