Why opioids and sedatives may prolong life rather than hasten death after ventilator withdrawal in critically ill patients.

The process of death in patients in whom cardiorespiratory support is withdrawn is related to the occurrence of tissue hypoxia that results from an imbalance between the demand for oxygen and the delivery of oxygen to the organs. Limiting the demand for oxygen may thus delay the occurrence of tissue hypoxia. Because the demand for oxygen increases significantly after ventilator withdrawal and because sedatives and opioids are known to decrease the demand for oxygen in patients with cardiorespiratory distress, these agents might thus actually prolong life rather than hasten death.