Residual effects of ether anesthesia on whole-body hemodynamics and organ blood flows in the rat

This study was designed to determine the short-term residual effects of ether anesthesia on hemodynamics and blood flow distribution in the rat. Eighteen male Sprague Dawley rats were instrumented and allowed to recover for at least 2 days before beginning the experiment. Using microspheres, cardiac output, and blood flow distribution were determined at five different periods: before ether anesthesia; at a surgical level of ether anesthesia; and 20 min, 1 hr, or 3 hr after cessation of anesthesia. Ether anesthesia initially decreased arterial pressure, increased cardiac index, and decreased total peripheral resistance. The residual effects of ether included progressive increases in arterial blood pressure and an increase in total peripheral resistance index. Cardiac index was returned to normal 1 hr after termination of anesthesia. Blood flow to the brain and heart increased during anesthesia and was significantly elevated 1 hr later. Other organs, including kidney, spleen, and intestine showed a decrease in blood flow during anesthesia, which persisted for at least 20 min. Thus, ether anesthesia produced acute and residual disturbances in hemodynamics and blood flow distribution, which may have an untoward influence on concomitant experimental observations.