Conservative versus liberal oxygen therapy in relation to all-cause mortality among patients in the intensive care unit: a systematic review of randomized controlled trials with meta-analysis and trial sequential analysis

Abstract

Objective: To evaluate the benefits and harmful effects of conservative versus liberal oxygen therapy in patients admitted to the Intensive Care Unit (ICU).

Design: A systematic review and meta-analysis was carried out.

Setting: ICU.

Participants: Adult patients (aged 18 years or older) were randomized to either a lower oxygenation target strategy (conservative oxygen therapy) or a higher oxygenation target strategy (liberal oxygen therapy) in the ICU.

Interventions: Patients received different oxygenation target strategies.

Results: Ten studies involving 5429 adult patients admitted to the ICU were included in the meta-analysis. The pooled results showed no decreased all-cause mortality at 28 days (RR 0.90; 95%CI 0.75-1.09; p = 0.28), 90 days (RR 1.02; 95%CI 0.92-1.13; p = 0.71) or longest follow-up (RR 0.97; 95%CI 0.88-1.08; p = 0.63) among patients administered conservative oxygen therapy. Secondary outcomes were comparable between the two groups. The results of sensitivity analyses and subgroup analyses were consistent with the main analyses.

Conclusion: No beneficial or harmful effects of conservative oxygen therapy were found compared to liberal oxygen therapy in relation to all-cause mortality among adult patients in the ICU. Conservative oxygen therapy did not reduce all-cause mortality at 28 days, 90 days or longest follow-up. Other important clinical outcomes were also comparable between the two groups.

Keywords: Conservador; Conservative; Intensive care unit; Liberal; Meta-analysis; Metanálisis; Oxigenoterapia; Oxygen therapy; Revisión sistemática; Systematic review; Unidad de cuidados intensivos.