ECMO for Severe Acute Respiratory Distress Syndrome

To the Editor: In the trial conducted by Combes et al. (May 24 issue),¹ a large number of patients who had been randomly assigned to the control group later crossed over to receive extracorporeal membrane oxygenation (ECMO). The rate of the key secondary outcome (a composite of death or treatment failure) was significantly lower in the ECMO group than in the control group. The conclusions of this analysis are problematic. First, despite the severity of the acute respiratory distress syndrome (ARDS) and the illness trajectory, the patients in the control group who crossed over were younger than those who did . . .