BACKGROUND

Respiratory failure and acute respiratory distress syndrome secondary to H1N1 influenza infection is a source of substantial morbidity and mortality, having caused over 265,000 hospitalizations in the United States in 2009. During the H1N1 pandemic, up to 31% of the H1N1 patients required intensive care unit admission, and many were refractory to maximal conventional therapies. These most critically ill patients may require extracorporeal membrane oxygenation (ECMO) for survival.

METHODS

We retrospectively reviewed the medical records of the 7 patients with refractory hypoxemia due to H1N1 influenza who were treated with ECMO in our pediatric intensive care unit.

RESULTS

Five of the 7 patients survived to hospital discharge. The cohort's mean age was 21 years, and 4 were female. At admission to the pediatric intensive care unit, 6 had at least one comorbid condition, 6 were mechanically ventilated, and one was in shock. All 7 patients were treated with oral oseltamivir, high-frequency oscillatory ventilation, and inhaled nitric oxide prior to ECMO. Five received intravenous steroids, and 2 were treated with compassionate-use intravenous zanamivir. The mean duration of pre-ECMO ventilation was 8.7 days (range 14 h to 25 d). Mean oxygenation index was 50 (range 26-73) at ECMO cannulation. Six received venovenous ECMO, and one received venoarterial ECMO. The mean duration of ECMO was 432 hours (range 192-890 h).

CONCLUSIONS

This series suggests that ECMO is a viable treatment for refractory hypoxemia secondary to H1N1 influenza infection in both pediatric and adult patients.