A systematic review to inform institutional decisions about the use of extracorporeal membrane oxygenation during the H1N1 influenza pandemic.

Abstract

To systematically evaluate the effect of extracorporeal membrane oxygenation on survival in adults with acute respiratory failure and to help inform institutional decisions about implementing an extracorporeal membrane oxygenation program or transferring patients to experienced extracorporeal membrane oxygenation centers during the H1N1 influenza pandemic. National Guideline Clearinghouse, MEDLINE, EMBASE, Agency for Healthcare Research and Quality Evidence-based Practice reports, National Institute for Health and Clinical Excellence, Cochrane Library, International Network of Agencies for Health Technology Assessment, and citation review. Studies of extracorporeal membrane oxygenation in adult acute respiratory failure, reporting mortality rates for at least 10 patients in extracorporeal membrane oxygenation and nonextracorporeal membrane oxygenation groups. Mortality rates were abstracted for all patients and for patients with influenza. Risk ratios were meta-analyzed using random-effects methods and assessed for heterogeneity. There are no evidence-based clinical guidelines on the use of extracorporeal membrane oxygenation in patients with influenza. Three randomized controlled trials and three cohort studies evaluated extracorporeal membrane oxygenation in patients with acute respiratory failure; none reported specifically on patients with influenza. Meta-analysis of the randomized controlled trials revealed significant heterogeneity in risk of mortality. The summary risk ratio found by the meta-analysis was 0.93 (95% confidence interval, 0.71 to 1.22). The most recent trial found a reduction in mortality and severe disability at 6 months among patients in whom extracorporeal membrane oxygenation was considered. Observational studies suggest that extracorporeal membrane oxygenation for acute respiratory failure resulting from viral pneumonia is associated with improved mortality compared with other etiologies of acute respiratory failure. The best evidence to guide decisions regarding the use of extracorporeal membrane oxygenation for patients with influenza stems from trials of extracorporeal membrane oxygenation for acute respiratory failure of all etiologies, among which significant heterogeneity exists, and from case series describing outcomes of extracorporeal membrane oxygenation in patients with influenza. Thus, there is insufficient evidence to provide a recommendation for extracorporeal membrane oxygenation use among patients with respiratory failure resulting from influenza. However, clinicians should consider extracorporeal membrane oxygenation within the context of other salvage therapies for acute respiratory failure.