Extracorporeal membrane oxygenation for influenza A (H1N1): experience in a regional referral center

Introduction

The novel influenza A H1N1 virus can cause, in a restricted subgroup of infected patients, an acute respiratory failure not responding to conventional treatment. In selected cases, extracorporeal membrane oxygenation (ECMO) has been applied with a 21% mortality rate. Here we report the experience of the ICU of a regional referral center for ECMO (Careggi Teaching Hospital, Florence, Italy).

Methods

An Emergency Medical Service has been established for the novel pandemic influenza to guarantee the possibility of ECMO initiation in the peripheral hospitals by our ECMO Team and the subsequent transport on extracorporeal circulation to our referral center. The ECMO Team is composed of an intensivist, a cardiac surgeon, a cardiologist, a perfusionist and a nurse. All of the different figures were properly trained and formed on ECMO treatment. According to our internal protocol, eligible patients for ECMO treatment are aged 15 to 70 years old with acute respiratory failure with one of the following conditions: a ratio PaO₂/FiO₂ <60 or pH <7.20 under protective ventilation conditions. ECMO insertion was achieved percutaneously and a high-flow approach (5 to 6 l/minute) was initially established according to patient need. ECMO device is a Rotaflow Maquet Centrifugal Pump with a Quadrox-D oxygenator (Maquet, Rastatt, Germany) and biocoated circuits. H1N1 infection was monitored by RT-PCR examination on pharyngeal swab and bronchial aspirate. Antiviral therapy was conducted by oral administration of oseltamivir (75 mg twice daily), and inhaled zanamivir (10 mg twice daily).

Results

From October 2009 to November 2009, six patients with influenza A (H1N1) have been treated with ECMO support. Three patients were cannulated in the district hospital and transported safety to our ICU by our ECMO Team. Median SAPS II at admission, median age and sex were as listed as follows: 46, 35 years old and five males/one female. All patients had an acute respiratory failure accompanied by a multiorgan dysfunction. ECMO was established and maintained for 200 hours. All patients were successfully weaned from ECMO support, extubated and discharged from our ICU. No major procedure-related complications were observed.

Conclusions

Well-timed ECMO use in cases of influenza A H1N1 acute respiratory failure could improve overall the survival rate.