Extracorporeal membrane oxygenation for 2009 influenza A(H1N1) severe respiratory failure in Japan

To evaluate procedures and outcomes of extracorporeal membrane oxygenation (ECMO) therapy applied to 2009 influenza A(H1N1) severe respiratory failure patients in Japan.

This observational study used database information about adults who received ECMO therapy for H1N1-related severe respiratory failure from April 1, 2010 to March 31, 2011.

Fourteen patients from 12 facilities were enrolled. Anti-influenza drugs were used in all cases. Before the start of ECMO, the lowest PaO(2)/FiO(2) was median (interquartile) of 50 (40-55) mmHg, the highest peak inspiratory pressure was 30 (29-35) cmH(2)O, and mechanical ventilation had been applied for at least 7 days in 5 patients. None of the facilities had extensive experience with ECMO for respiratory failure (6 facilities, no previous experience; 5 facilities, one or two cases annually). The blood drainage cannula was smaller than 20 Fr. in 10 patients (71.4 %). The duration of ECMO was 8.5 (4.0-10.8) days. The duration of each circuit was only 4.0 (3.2-5.3) days, and the ECMO circuit had to be renewed 19 times (10 cases). Thirteen patients (92.9 %) developed adverse events associated with ECMO, such as oxygenator failure, massive bleeding, and disseminated intravascular coagulation. The survival rate was 35.7 % (5 patients).

ECMO therapy for H1N1-related severe respiratory failure in Japan has very poor outcomes, and most patients developed adverse events. However, this result does not refute the effectiveness of ECMO. One possible cause of these poor outcomes is the lack of satisfactory equipment, therapeutic guidelines, and systems for patient transfer to central facilities.