The Value of Venous Oxygen Levels During General Anesthesia

Abstract

Right atrial and superior vena caval O2 saturations were measured in premedicated adult patients under anesthesia, 5 with ether and 5 with halothane, during surgical treatment of varicose veins. Sampling catheters were positioned by electrocardiographic techniques. Saturations were determined by in vitro reflection oximetry. Average venous O2 levels were higher during ether than during halothane anesthesia. The differences were small, however, and not considered to be of functional import. Average right atrial O2 levels agreed well with mixed-venous O2 levels predicted from previous studies of cardiac output and O2 uptake during ether or halothane anesthesia. Such measurements of right atrial O2 saturation offer advantage in clinical investigations on anesthesia.