Objectives: During 2009, pandemic influenza A (H1N1) affected France and several patients developed influenza A (H1N1)-associated acute respiratory distress syndrome. The use of extracorporeal membrane oxygenation (ECMO) could be advocated as therapeutic solution. We present our experience with ECMO utilized in patients with influenza A (H1N1)-associated respiratory failure.
Methods: We conducted a retrospective observational analysis of our experience with veno-venous ECMO for 2009 influenza A (H1N1)-associated respiratory failure. We have excluded from our study all not confirmed cases of influenza A (H1N1). Veno-venous ECMO was always instituted using a percutaneous cannulation technique. Mechanical circulatory support was maintained until respiratory function recovery.
Results: Between October 2009 and February 2010, we performed veno-venous ECMO support in 12 patients with influenza A (H1N1)-associated respiratory failure. Mean age was 33 ± 12 years (14-63 years) and there was a prevalence of female sex. Median time from influenza A (H1N1) onset to mechanical ventilation (MV) initiation was 6 days (1-17 days); median time from MV to veno-venous ECMO support was 3 days (1-20 days). Six patients (50%) suffered ventilator-associated pneumonia during ECMO support. Eight patients (66.6%) suffered significant haemorrhage requiring transfusion of more than 2 packed red cells. In two patients (16.6%), there was a thrombosis of the inferior vena cava and one of them experienced pulmonary embolism. Mean duration of ECMO support was 23 ± 14 days (3-47 days); mean duration of mechanical ventilatory support was 24 ± 21 days (6-70 days). ECMO was weaned in 10 patients (83.3%) and all these patients are still alive after a period of follow-up of 13.8 ± 1.12 months (11.03-14.83 months). Two patients (in-hospital mortality of 16.6%) died under ECMO support for refractory septic shock.
Conclusions: Veno-venous ECMO for 2009 H1N1-associated respiratory failure gives good results with a very low mortality rate. The use of a mobile unit is a safe procedure and may improve survival of patients who might not be otherwise eligible for transfer to our institution. Larger studies are however required in order to optimize and refine the best treatment strategy in this subgroup of patients.