Extracorporeal membrane oxygenation for severe influenza A (H1N1) acute respiratory distress syndrome: a prospective observational comparative study.

PURPOSE: To compare characteristics, clinical evolution and outcome in adult patients with influenza A (H1N1) acute respiratory distress syndrome (ARDS) treated with or without extracorporeal membrane oxygenation (ECMO).
METHODS: A prospective observational study of patients treated in Marseille South Hospital from October 2009 to January 2010 for confirmed influenza A (H1N1)-related ARDS. Clinical features, pulmonary dysfunction and mortality were compared between patients treated with and without ECMO.
RESULTS: Of 18 patients admitted, 6 were treated with veno-venous and 3 with veno-arterial ECMO after median (interquartile, IQR) duration of mechanical ventilation of 10 (6-96) h. Six ECMO were initiated in a referral hospital by a mobile team, a median (IQR) of 3 (2-4) h after phone contact. Before ECMO, patients had severe respiratory failure with median (IQR) PaO₂ to FiO₂ ratio of 52 (50-60) mmHg and PaCO₂ of 85 (69-91) mmHg. Patients treated with or without ECMO had the same hospital mortality rate (56%, 5/9). Duration of ECMO therapy was 9 (4-14) days in survivors and 5 (2-25) days in non-survivors. Early improvement of PaO(2) to FiO₂ ratio was greater in ECMO survivors than non-survivors after ECMO initiation [295 (151-439) versus 131 (106-144) mmHg, p < 0.05]. Haemorrhagic complications occurred in four patients under ECMO, but none required surgical treatment.
CONCLUSIONS: ECMO may be an effective salvage treatment for patients with influenza A (H1N1)-related ARDS presenting rapid refractory respiratory failure, particularly when provided by a mobile team allowing early cannulation prior to transfer to a reference centre.