[Cerebral extraction of oxygen. A practical model and its clinical applications]

Cerebral extraction of oxygen (CEO2) represents a practical physiologic measure, with multiple clinical applications. This variable is calculated as the arterio-jugular difference in oxyhemoglobin saturation (from arterial blood and from the jugular bulb). Because it involves global measurements, the CEO2 does not allow detection of regional abnormalities in cerebral hemometabolism. However, when dealing with predominantly (not exclusively) global changes, the CEO2 provides accurate information on the balance (or coupling) between cerebral consumption of oxygen and cerebral blood flow.