Table 3.
Primary outcome and key secondary outcomes
| Conservative oxygen (n = 87) | Usual oxygen (n = 79) | Estimatea (95% CI) | ||||
|---|---|---|---|---|---|---|
| Odds ratio | ||||||
| Unadjusted | P value | Adjustedb | P value | |||
| Unfavourable neurological outcome at day 180—n/N (%) | 43/78 (55.1%) | 49/72 (68.1%) | 0.58 (0.3–1.12) | 0.10 | 0.54 (0.23–1.26) | 0.15 |
| Day 180 mortality—n/N (%) | 37/86 (43%) | 46/78 (59%) | 0.53 (0.28–0.98) | 0.04 | 0.56 (0.25–1.23) | 0.15 |
| Died in ICU—n (%) | 31 (35.6%) | 37 (46.8%) | 0.63 (0.34–1.17) | 0.14 | 0.68 (0.31–1.48) | 0.33 |
| Died in hospital—n (%) | 37 (42.5%) | 43 (54.4%) | 0.62 (0.34–1.14); | 0.13 | 0.65 (0.3–1.42) | 0.28 |
| Difference in medians (95% CI) | P value | |||||
|---|---|---|---|---|---|---|
| ICU length of stay (days)—median [IQR] | 3.01 [2.03–5.91] | 3 [1.75–5.67] | 0.01 (− 1.21 to 1.23) | 0.99 | ||
| Hospital length of stay (days)—median [IQR] | 8.72 [3.89–17.6] | 6.49 [2.31–14.2] | 2.23 (− 1.04 to 5.5) | 0.18 | ||
| Vasopressor-free days—median [IQR] | 23 [0–26] | 0 [0–25] | 23 (12.43–33.57) | < 0.001 | ||
| Duration of vasopressors (days, survivors to day 28)—median [IQR] | 3 [1–4], N = 51 | 2.5 [1.5–4]; N = 36 | 1 (0.03–1.97) | 0.04 | ||
| Ventilator-free days—median [IQR] | 21.1 [0–26.1] | 0 [0–26] | 21.08 (10.43–31.73) | < 0.001 | ||
| Duration of ventilation (hours, survivors to day 28 only)—median [IQR] | 51 [27–92]; N = 51 | 45.5 [23–114]; N = 36 | 5.0 (− 27.3 to 37.3) | 0.52 | ||
| Cause-specific mortality—n/N (%) | P valued = 0.87 | |||||
| Arrhythmia | 8/37 (21.6%) | 7/46 (15.2%) | ||||
| Brain death | 3/37 (8.1%) | 2/46 (4.3%) | ||||
| Brain damage (not brain death) | 15/37 (40.5%) | 20/46 (43.5%) | ||||
| Cardiogenic shock | 9/37 (24.3%) | 12/46 (26.1%) | ||||
| Distributive shock | 1/37 (2.7%) | 1/46 (2.2%) | ||||
| Hypoxic respiratory failure | 1/37 (2.7%) | 3/46 (6.5%) | ||||
| Metabolic | 0/37 (0%) | 1/46 (2.2%) | ||||
IQR interquartile range, CI confidence interval
aThe widths of the confidence intervals for secondary analyses have not been adjusted for multiplicity and the intervals should not be used to infer definite differences between the groups
bAdjusted for age, cardiac arrest location outside the hospital, shockable first monitored rhythm, time to ROSC, whether there was a medical cause for arrest, and whether the patient had a STEMI. These analyses were undertaken with patients nested in site and site treated as a random variable
cAll differences in medians [95% CI] were calculated using quantile regression
dP value for cause-specific mortality calculated using Chi-square test