Effects of ketamine/xylazine and pentobarbital anesthesia on cerebral tissue oxygen tension, blood pressure, and arterial blood gas in rats.

General anesthesia is needed in many animal experiments in order to carry the studies out in an effective and appropriate manner. The concentration of oxygen in tissues is often a critical variable in many of these studies. Anesthesia, however, can affect tissue oxygenation because it can alter many physiological parameters, especially cardiopulmonary and metabolic parameters. While these physiological parameters can be measured, the relationship between them and tissue oxygenation may not be straightforward and further, the effects of anesthetics on these parameters vary with the type of anesthetic, the route of administration, and the method of administration. Therefore, it seems very desirable to directly measure the effects of anesthesia on tissue oxygenation.