Abstract We were interested to read the article by Faria et al. on the diagnosis of brain death in intensive care patients undergoing extracorporeal membrane oxygenation(ECMO) using an apnea test 1. The authors propose an apnea test based on a low-sweep flow protocol (200ml/minute) to achieve a CO2 partial pressure of >55mmHg, which corresponds to brain death. In cases of severe hypoxemia during the test, it was proposed to increase ECMO blood flow to maintain oxygenation 1. The authors concluded that their physiologically based proposal represents a clinically feasible strategy for managing the complex interplay between gas exchange, oxygenation and CO2 clearance during the apnea test 1. The study is noteworthy, but some points should be discussed.
Finsterer et al. (2025) studied this question.