Influence of Bolus Injection of Thiopental Sodium on Respiratory and Cardiovascular Function under General Anesthesia in the Horse

Abstract

We conducted this study to determine the influence of bolus injection of thiopental sodium on cardiovascular function under general anesthesia in the horse. Thiopental sodium was administered to three horses as a bolus injection at the dose of 1 or 2 mg/kg, while anesthesia was maintained by continuous infusion of a mixture of guaifenesin, xylazine and ketamine. One minute after bolus administration of the drug at 2 mg/kg decrease in the respiratory frequency and mild decrease in mean arterial pressure was noted, although no change of tidal volume, the heart rate, stroke volume and cardiac output were present. These results indicate that bolus injection of thiopental sodium does not produce any serious cardiovascular changes for clinical use under general anesthesia in the horse.