Cardiopulmonary responses of swine to intravenous infusion of guaifenesin, ketamine, and xylazine.

Swine were anesthetized with a 5% solution of dextrose in water containing 50 mg of guaifenesin, 1 mg of ketamine, and 1 mg of xylazine X ml-1 (G-K-X) infused IV at a rate of 2.2 ml X kg-1 X hr-1. Mean arterial blood pressure and systemic vascular resistance were significantly increased from base-line values throughout the 2 hours of G-K-X infusion. Cardiac index decreased significantly initially, but returned to near base line at 30 minutes. Fifteen minutes after G-K-X infusion was discontinued, cardiac index was not significantly different from base line. Heart rate decreased significantly from base line 90 minutes after infusion of G-K-X began and remained so throughout the study. However, the mean heart rate remained within the acceptable range for swine. Rate-pressure product was not significantly altered. The PaCO2 decreased, and arterial pH increased significantly from base line, supporting our clinical impression that pigs breathe well when anesthetized with G-K-X. We conclude that G-K-X is a satisfactory combination of drugs for induction and maintenance of surgical anesthesia in healthy swine for a period of 2 hours.