Table 1.
Baseline characteristics for all patients. Baseline characteristics for the trial cohort stratified by oxygenation target allocation. Numerical values are presented as medians with inter-quartile ranges (IQRs) and categorical variables as numbers (n) and percentages (%). FiO2, fraction of inspired oxygen; PaO2, partial pressure of arterial oxygen; SaO2, saturation of arterial oxygen; SOFA, Sequential Organ Failure Assessment. Additional baseline characteristics are available in the primary trial publication.5∗The PaO2:FiO2 ratio was missing in five patients in the lower oxygenation group and in seven patients in the higher oxygenation group. †Plasma lactate concentration was missing in eight patients in the lower oxygenation group and in 11 patients in the higher oxygenation group. ‡The aggregated SOFA score ranges from 0 to 24, with sub-score from 0 to 4 for six organ systems (respiration, coagulation, liver, cardiovascular, CNS, and renal), with higher scores indicating higher degrees of organ failure. The SOFA score was missing in 44 patients in the lower oxygenation group and in 45 patients in the higher oxygenation group because of one or more missing sub-scores of the SOFA score.
| Variable | Lower target, n=1441 | Higher target, n=1447 |
|---|---|---|
| Median age (IQR, yr) | 70 (61–77) | 70 (60–77) |
| Male sex, n (%) | 916 (63.6) | 939 (64.9) |
| Type of admission, n (%) | ||
| Medical | 1238 (85.9) | 1233 (85.2) |
| Elective surgical | 18 (1.3) | 21 (1.5) |
| Emergency surgical | 185 (12.8) | 193 (13.3) |
| Chronic obstructive pulmonary disease | 277 (19.2) | 285 (19.7) |
| Active haematological cancer | 81 (5.6) | 86 (5.9) |
| Oxygen supplementation in a closed system, n (%) | 1024 (71.1) | 1038 (71.7) |
| Invasive mechanical ventilation, n (%) | 826 (57.3) | 863 (59.6) |
| Noninvasive ventilation or CPAP, n (%) | 198 (13.7) | 175 (12.1) |
| Oxygen supplementation in an open system, n (%) | 417 (28.9) | 409 (28.3) |
| Median PaO2 (IQR, kPa) | 10.3 (8.7–12.6) | 10.3 (8.7–12.3) |
| Median FiO2 (IQR) | 0.70 (0.55–0.90) | 0.70 (0.58–0.85) |
| Median PaO2:FiO2 ratio (IQR)∗ | ||
| In all systems | 15.8 (11.8–21.0) | 15.7 (12.0–20.5) |
| In closed systems | 16.5 (12.2–21.7) | 16.5 (12.6–21.4) |
| In open systems | 14.1 (10.9–18.4) | 13.9 (10.7–18.0) |
| Median lactate concentration (IQR, mM)† | 1.8 (1.1–3.2) | 1.7 (1.1–3.1) |
| Any use of vasopressors, n (%) | 793 (55.0) | 785 (54.3) |
| Median highest dose of norepinephrine (IQR, μg kg−1 min−1) | 0.20 (0.10–0.40) | 0.21 (0.10–0.40) |
| Median SOFA score (IQR)‡ | 8 (5–10) | 8 (5–10) |