Extracorporeal membrane oxygenation (ECMO) in patients with H1N1 influenza infection: a systematic review and meta-analysis including 8 studies and 266 patients receiving ECMO

CENTRAL, Google Scholar, MEDLINE/PubMed, and Scopus (updated January 2, 2012) were systematically searched. Studies reporting on 10 or more patients with H1N1 infection treated with ECMO were included. Baseline, procedural, outcome and validity data were systematically appraised and pooled, when appropriate, with random-effect methods.From 1196 initial citations, 8 studies were selected, including 1357 patients with confirmed/suspected H1N1 infection requiring intensive care unit admission, 266 (20%) of whom were treated with ECMO. Patients had a median SOFA score of 9, and had received mechanical ventilation before ECMO implementation for a median of 2 days. ECMO was implanted before inter-hospital patient transfer in 72% of cases and in most patients (94%) the veno-venous configuration was used. ECMO was maintained for a median of 10 days. Outcomes were highly variable among the included studies, with in-hospital or short-term mortality ranging between 8% and 65%, mainly depending on baseline patient features. Random-effect pooled estimates suggested an overall in-hospital mortality of 28% (95% confidence interval 18%-37%; I2=64%).ECMO is feasible and effective in patients with ALI due to H1N1 infection. Despite this, prolonged support (>1 week) is required in most cases, and subjects with severe comorbidities or multiorgan failure remain at high risk of in-hospital death.