Recent advances in venovenous extracorporeal membrane oxygenation for severe acute respiratory distress syndrome.

PURPOSE OF REVIEW

To summarize results of the most recent trials on venovenous extracorporeal membrane oxygenation (VV-ECMO) in severe acute respiratory distress syndrome (ARDS) and to elaborate on the unmet needs regarding VV-ECMO management in this setting.

RECENT FINDINGS

Although it was terminated early for futility (i.e., failure to demonstrate a difference in 60-day mortality of 20%), the ECMO to Rescue Lung Injury in Severe ARDS trial of VV-ECMO for severe ARDS reported a nonsignificant, but clinically important, reduction in mortality (35 vs. 46%; relative risk 0.76; 95% confidence interval 0.55-1.04, P = 0.09). Refractory hypoxemia led to rescue ECMO in 28% of controls, who had more severe ARDS at inclusion, were extremely sick at the time of ECMO cannulation and for whom mortality was 57%. Beyond the rescue of patients dying of refractory hypoxemia, ECMO may now be used early in severe ARDS patients to reduce the intensity of mechanical ventilation and to minimize ventilator-induced lung injury. Future research in the field should focus on identification of patients who are more likely to benefit from this technique and the right timing for its initiation, optimization of daily management of patients under ECMO to further reduce complications, and selection of optimal ventilator management on ECMO.

SUMMARY

VV-ECMO is a reasonable therapeutic option for patients with severe ARDS and major hypoxemia or excessive pressures. Future trials should be designed to optimize patients' management while on VV-ECMO support.