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

https://doi.org/10.1016/j.ijnurstu.2021.103924Get rights and content

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.

Section snippets

What is already known

  • •

    Supplemental oxygen administered liberally to acutely ill adults may result in hyperoxia.

  • •

    A previous meta-analysis found that a conservative approach decreased mortality.

  • •

    Recent large randomized controlled trials have failed to replicate the benefits that the previous meta-analysis found.

What this paper adds

  • •

    Conservative oxygen therapy, compared with liberal oxygen therapy, was not associated with decreased mortality.

  • •

    Conservative oxygen therapy was not associated with decreased incidence of disability.

Protocol and guidance

This systematic review and meta-analysis was conducted according to the Cochrane Handbook for Systematic Reviews. The protocol of this study was registered in Open Science Framework (https://osf.io/y6jk4).

Selection criteria

Trials were considered eligible if they (1) enrolled adults (age≥18) with an acutely ill condition; (2) compared a high-target (liberal) or a low-target (conservative) oxygenation strategy; which was measured by any one of the following: fraction of inspired oxygen, arterial partial pressure

Results

After excluding duplicates, we screened 3890 publications, of which 83 underwent full-text review. We identified 33 trials (including three unpublished trials: NCT 00414726, NCT 02687217, and NCT02378545) (Ali et al., 2014; Asfar et al., 2017; Baekgaard et al., 2019; Barrot et al., 2020; Bickel et al., 2011; Butler et al., 1987; Girardis et al., 2016; He et al., 2019; Heidari et al., 2017; Hofmann et al., 2017; Mackle et al., 2020; Jakkula et al., 2018; Khoshnood et al., 2015; Kuisma et al.,

Discussion

In this meta-analysis of 33 randomized controlled trials(NCT 00414726, NCT 02687217, and NCT02378545) (Ali et al., 2014; Asfar et al., 2017; Baekgaard et al., 2019; Barrot et al., 2020; Bickel et al., 2011; Butler et al., 1987; Girardis et al., 2016; He et al., 2019; Heidari et al., 2017; Hofmann et al., 2017; Mackle et al., 2020; Jakkula et al., 2018; Khoshnood et al., 2015; Kuisma et al., 2006; Lång et al., 2018; Mazdeh et al., 2015; Padma et al., 2010; Panwar et al., 2016; Ranchord et al.,

Conclusions

Compared with liberal oxygen therapy, conservative oxygen therapy was not associated with reduced all-cause mortality.

CRediT authorship contribution statement

Linjie Li: Validation, Investigation, Visualization, Writing - original draft, Writing - review & editing. Yu Zhang: Methodology, Software, Writing - review & editing. Peng Wang: Investigation, Data curation. Weelic Chong: Writing - review & editing. Yang Hai: Investigation, Data curation. Ping Xu: Investigation, Data curation. Fang Fang: Conceptualization, Supervision, Project administration.

Declaration of Competing Interest

None.

Funding

None.

Acknowledgments

None.

Ethical approval

Not required.

Financial Disclosure Statement

None.

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    Both the authors contributed equally to this work.

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