CARDIOVASCULAR AND PULMONARY EFFECTS OF SEVOFLURANE ANESTHESIA IN HORSES

The effects of 1.0, 1.5, and 2.0 minimum alveolar concentration (MAC) of sevoflurane on hemodynamic, pulmonary and blood chemistry variables were measured during spontaneous and controlled ventilation in health y horses. Sevoflurane was the only anesthetic drug administered to the horses. In a dose-dependent manner, sevoflurane significantly decreas ed(P < .05) mean arterial blood pressure, cardiac output, and stroke v olume. There was a progressive decrease in peripheral vascular resista nce and an increase in heart rate as the concentration of sevoflurane was increased, but the differences were not significant. During sponta neous ventilation there was a dose-dependent decrease in respiratory r ate that caused a decrease in the minute volume. As the dose of sevofl urane increased, the arterial carbon dioxide tension also increased (P < .05). All blood chemistries remained within normal limits. Recovery from anesthesia was without incident. In conclusion, sevoflurane indu ces a dose-dependent decrease in hemodynamic variables and pulmonary f unction in horses that is not greatly different from that of other app roved inhalant anesthetics. (C) Copyright 1996 by The American College of Veterinary Surgeons