Conservative versus liberal oxygen therapy for acutely ill medical patients: A systematic review and meta-analysis

Abstract

Background: The role of conservative versus liberal oxygen therapy for acutely ill patients remains controversial.

Objective: To systematically review the available evidence regarding the efficacy and safety of conservative oxygen therapy compared with liberal oxygen therapy for acutely ill patients.

Methods: A systematic search of Medline, Embase, and the Cochrane Central Register was conducted from their inception until April 5, 2020. Randomized clinical trials evaluating a high-target (liberal) or a low-target (conservative) oxygenation strategy in adults with an acutely ill condition were eligible for inclusion. A meta-analysis using random-effects models was conducted to calculate the risk ratio with corresponding 95% confidence intervals. Heterogeneity and publication bias were evaluated.

Results: The analyses included 33 randomized clinical trials with a total of 17,780 participants. Compared with conservative oxygen therapy, liberal oxygen therapy was not associated with increased mortality at 30 days (risk ratio 1.09, 95% confidence intervals 0.98-1.22; I²=0%), at 90 days (risk ratio 1.00, 95% confidence intervals 0.88-1.13, I²=37%), or at the longest follow-up (risk ratio 1.04, 95% confidence intervals 0.96-1.12, I²=0%). Good functional outcome was similar between groups. Findings were robust to trial sequential, subgroup, and sensitivity analyses.

Conclusions: Compared with liberal oxygen therapy, conservative oxygen therapy was not associated with decreased mortality. Tweetable abstract: Compared with liberal oxygen therapy, conservative oxygen therapy was not associated with decreased mortality.

Keywords: Acute disease; Meta-analysis; Mortality; Oxygen therapy.