Permissive Hypoxemia Versus Normoxemia for Critically Ill Patients Receiving Mechanical Ventilation

Does permissive hypoxemia in critically ill patients receiving mechanical ventilation affect patient morbidity and mortality?

The specific range of “normal” oxygen partial pressure (PaO₂) and oxygen hemogloblin saturation (SaO₂), as measured in an arterial blood gas sample, may vary slightly; however, there are variations in how clinicians interpret a patient’s response to hypoxemia. Hypoxemia is a common finding among critically ill patients and is treated with a combination of interventions aimed at normalizing arterial oxygenation to reduce morbidity and mortality. Unfortunately, these interventions are not without risk. For example, oxygen toxicity due to release of oxygen free radicals is associated with high or prolonged exposure to high inspired concentrations of oxygen (FIO₂) therapy, and this has been associated with patient harm.

Permissive hypoxemia is the concept of allowing lower than normal PaO₂ and SaO₂ levels in order to avoid the risk associated...