Table 4 Mechanisms/causes of hypoxemia and radiological findings according to oxygenation modalities
From: Hypoxemia in the ICU: prevalence, treatment, and outcome
Ambient air, n = 14 | Low-flow oxygen, n = 191 | High-flow oxygen, n = 45 | Non-invasive ventilation, n = 84 | Invasive ventilation, n = 525 | p | |
|---|---|---|---|---|---|---|
Pneumonia, N (%) (n = 852/14/189/45/83/521) | 3 (21.4) | 62 (32.8) | 34 (75.6) | 37 (44.6) | 317 (60.8) | < 0.001 |
Aspiration (n = 852/14/190/45/83/520) | 0 (0) | 11 (5.8) | 0 (0) | 3 (3.6) | 60 (11.5) | 0.003 |
Acute on chronic respiratory failure (n = 853/14/190/45/83/521) | 0 (0) | 32 (16.8) | 4 (8.9) | 41 (49.4) | 89 (17.1) | < 0.001 |
Cardiogenic pulmonary edema (n = 853/14/190/45/83/521) | 2 (14.3) | 28 (14.7) | 4 (8.9) | 15 (18.1) | 78 (15.0) | 0.75 |
Pulmonary embolism (n = 853/14/190/45/83/521) | 0 (0) | 5 (2.6) | 2 (4.4) | 2 (2.4) | 17 (3.3) | 0.93 |
Thoracic trauma (n = 852/14/190/45/83/520) | 0 (0) | 5 (2.6) | 2 (4.4) | 0 (0) | 14 (2.7) | 0.46 |
Pleural effusion (n = 852/14/189/45/83/521) | 2 (14.3) | 34 (18.0) | 11 (24.4) | 24 (28.9) | 121 (23.2) | 0.3 |
Atelectasis (n = 853/14/190/45/83/521) | 2 (14.3) | 30 (15.8) | 10 (22.2) | 22 (26.5) | 112 (21.5) | 0.27 |
Pneumothorax (n = 853/14/190/45/83/521) | 0 (0) | 4 (2.1) | 0 (0) | 0 (0) | 11 (2.1) | 0.72 |
Fluid overload (n = 853/14/190/45/83/521) | 2 (14.3) | 47 (24.7) | 12 (26.7) | 28 (33.7) | 191 (36.7) | 0.02 |
Acute pancreatitis (n = 852/14/190/45/83/520) | 0 (0) | 6 (3.2) | 0 (0) | 1 (1.2) | 15 (2.9) | 0.81 |
Shock, low PvO2 (n = 853/14/190/45/83/521) | 0 (0) | 6 (3.2) | 3 (6.7) | 6 (7.2) | 95 (18.2) | < 0.001 |
Smoke/toxic inhalation (n = 852/14/190/45/83/520) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 5 (1.0) | 0.63 |
Transfusion-related acute lung injury (n = 852/14/190/45/83/520) | 1 (7.1) | 10 (5.3) | 2 (4.4) | 3 (3.6) | 28 (5.4) | 0.92 |
Pulmonary vasculitis (n = 852/14/190/45/83/520) | 0 (0) | 1 (0.5) | 0 (0) | 0 (0) | 5 (1.0) | 1 |
Drowning (n = 851/14/190/45/82/520) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 1 (0.2) | 1 |
Other (n = 851/14/190/45/83/519) | 0 (0) | 21 (11.1) | 11 (24.4) | 9 (10.8) | 49 (9.4) | 0.04 |
Number of causes of hypoxemia (n = 853/14/190/45/83/521) | 1 [0–1] | 1 [1, 2] | 2 [1, 2] | 2 [1–3] | 2 [1–3] | < 0.001 |
Number of causes of hypoxemia (n = 853/14/190/45/83/521) | < 0.001 | |||||
None | 6 (42.9) | 41 (21.6) | 0 (0) | 6 (7.2) | 54 (10.4) | |
1 | 5 (35.7) | 63 (33.1) | 16 (35.6) | 24 (28.9) | 122 (23.4) | |
2 | 2 (14.3) | 45 (23.7) | 18 (40.0) | 23 (27.7) | 133 (25.5) | |
3 or more | 1 (7.1) | 41 (21.6) | 11 (24.4) | 30 (36.2) | 212 (40.7) | |
Radiological infiltrates (n = 845/14/189/45/82/515) | 4 (28.6) | 101 (53.4) | 37 (82.2) | 57 (69.5) | 384 (74.6) | < 0.001 |
Unilateral c (n = 583/4/101/37/56/385) | 1 (25.0) | 36 (35.6) | 9 (24.3) | 19 (33.9) | 111 (28.8) | 0.58 |
Bilateral c (n = 581/4/100/37/56/384) | 3 (75.0) | 65 (65.0) | 28 (75.7) | 37 (66.1) | 273 (71.1) | 0.65 |
ARDS | 0 (0) | 0 (0) | 0 (0) | 9 (10.7) | 169 (32.2) | < 0.001 |
Hypoxemia class | < 0.001 | |||||
Mild | 11 (78.6) | 136 (71.2) | 11 (24.4) | 43 (51.2) | 239 (45.5) | |
Moderate | 3 (21.4) | 55 (28.8) | 23 (51.2) | 33 (39.3) | 231 (44.0) | |
Severe | 0 (0) | 0 (0) | 11 (24.4) | 8 (9.5) | 55 (10.5) | |
ICU length of stay (days) (n = 840/14/190/45/83/508) | 11 [4–21] | 8 [4–17] | 14 [8–23] | 9 [4–18] | 21 [12–40] | < 0.001 |
ICU length of stay (days) in ICU survivors (n = 625/11/170/37/70/337) | 11 [4–16] | 7.5 [4–15] | 13 [8–22] | 9 [4–18] | 24 [12–43] | < 0.001 |
ICU mortality, N (%) (n = 839/14/190/44/83/508) | 3 (21.4) | 20 (10.5) | 7 (15.9) | 13 (15.7) | 168 (33.1) | < 0.001 |