Dear Editor,

We agree with Drs. Shekar and Fraser about the importance of studying the effect of extracorporeal circuitry on the pharmacokinetics of medications commonly used in critically ill patients receiving extracorporeal membrane oxygenation (ECMO). The great majority of such studies currently in the literature were conducted in neonates or with outdated extracorporeal technology. It is problematic to apply the results of these studies to adults on ECMO contemporaneously because of physiological differences between the populations and the recent advances in ECMO circuit materials. The studies proposed by the authors could have far-reaching impact on the management of patients receiving ECMO, and we look forward to the results of their ongoing research.