The Physiology of the Apnea Test for Brain Death Determination in ECMO: Arguments for Blending Carbon Dioxide

The indications for ECMO were respiratory failure (63%), cardiac failure (29%), and as a last resort in cardiopulmonary resuscitation (8%). The rate of extracorporeal cardiopulmonary resuscitation (CPR) is also increasing. Case Report A 45-year-old man suffered a cardiac arrest at home followed by recurrent ventricular fibrillation requiring cumulatively more than 60 min of CPR. During hypothermic cardiopulmonary bypass, an arterial pH of approximately 7.40 and PaCO2 of 40 mmHg is maintained and corrected to the patient’s actual temperature. Because of the alkaline shift in pH during cooling due to increased CO2 solubility, CO2 is added to the sweep gas