Oxygen Targets After Cardiac Arrest: A Meta-analysis of Randomized Controlled Trials

Abstract

Background: Optimal oxygen saturation target in patients resuscitated after cardiac arrest is unknown. Previous randomized controlled trials (RCTs) comparing restrictive oxygen therapy with liberal therapy have shown conflicting results. Study Question: We performed a meta-analysis of available RCTs to consolidate the contrasting findings regarding the oxygen targets after cardiac arrest. Data Sources: We searched electronic databases for RCTs comparing restrictive versus liberal oxygen targets in patients resuscitated after cardiac arrest. Study Design: End points of interest were mortality, unfavorable neurological outcomes, and rearrests. Random-effects meta-analysis was performed to estimate the risk ratio (RR) with a 95% confidence interval (CI). Results: Eight RCTs with 1641 patients (restrictive n = 833, liberal n = 808) were included in the analysis. The oxygen targets were defined by either saturation, partial pressure (PaO2), or supplementation rates. The mean age and male percentage were 63 years and 80%, respectively. There was no significant difference observed in the 2 groups for overall mortality (RR = 0.91, 95% CI = 0.75–1.10, P = 0.33), unfavorable neurological outcomes (RR = 0.93, 95% CI = 0.74–1.18, P = 0.56), and rearrests (RR = 0.67, 95% CI = 0.22–1.98, P = 0.47). Conclusions: Overall, this meta-analysis shows no significant difference in mortality, unfavorable neurological outcomes, and rearrests when using restrictive or liberal oxygen targets in patients after cardiac arrest. The limitations in the newer trials should be kept in mind while interpreting the overall results.