[Extracorporeal membrane oxygenation for severe acute respiratory distress syndrome caused by novel 2009 influenza A (H1N1) virus]

Abstract

Objective: To summarize the clinical experiences and indications of extracorporeal membrane oxygenation (ECMO) for severe ARDS caused by novel 2009 influenza A (H1N1) virus.

Methods: All ECMO cases with severe ARDS associated with novel 2009 influenza A (H1N1) virus were analyzed in 5 intensive care units (ICUs) from 5 different hospitals in Beijing and Tianjin. A physician experienced in ECMO handling collected the relevant data, including general conditions pre and post-EMCO, efficacy and complication parameters, ventilator settings of mechanical ventilation and clinical outcomes. The statistical software of SPSS (version 11.5) was used for data analysis.

Results: 18 cases of novel H1N1 influenza with severe ARDS received ECMO. There were 9 males and 9 females (all pregnant). The mean age was (33 ± 11) years old. Eight were complicated with pulmonary barotraumas (6 of pneumothorax). Prior to ECMO, the patients underwent noninvasive and invasive positive pressure ventilation for 1 day and 60 hours respectively. Physiological parameters 2-6 hours prior to ECMO use were: (53 ± 14) mm Hg of PaO2/FiO2, (17 ± 5) cm H2O of positive end expiratory pressure (PEEP), 3.80 ± 0.29 of Murray lung injury score, (7.38 ± 0.10) of arterial pH, (3.3 ± 2.3) mmol/L of serum lactate, 16 ± 8 of APACHE II score. All patients treated venous-venous ECMO (VV-ECMO) for a mean duration of 8 days (range: 2 - 168). Settings of mechanical ventilation (prior to ECMO vs 2 hours post-ECMO) were: peak airway pressure (31 ± 7) vs (25 ± 6) cm H2O, respiratory rate (15 ± 4) vs (22 ± 6) breaths/min, FiO2 0.8 - 1.0 vs 0.35 - 0.50, PEEP (16 ± 5) vs (12 ± 4) cm H2O. Arterial blood gas (pH, PaO2 and PaCO2) post-ECMO of 2 hours and 24-hour significantly improved (P < 0.05). Seven patients died during ECMO, 11 patients were successfully weaned from ECMO. And 8 of them survived and were discharged. One patient stayed in ICU and 2 died in ICU.

Conclusions: As an effective measure of respiratory supports, ECMO may provide pulmonary rest and improve gas exchanges in severe ARDS induced by novel H1N1 Influenza.