Long term anesthesia using a continuous infusion of guaifenesin, ketamine and xylazine in cats

Cats (Felis catus) were anesthetized with a solution containing guaifenesin, ketamine and xylazine (GKX) in 0.9% saline. Anesthesia was induced by intravenous (IV) injection and was maintained for 6 hours by IV infusion. Heart rate, respiratory rate and PvO2 did not change significantly during the 6 hour monitoring period and remained consistently within the published normal ranges for cats. Although the PvCO2 did not change significantly, many values were abnormal. Venous pH decreased to slightly below normal values. Lead II ECG tracings showed no abnormalities. Loss of response to pedal pinch and jaw tone indicates maintenance of a surgical plane of anesthesia and adequate muscle relaxation throughout the 6 hour anesthetic period. Cats exhibited voluntary motor movement and were in sternal recumbency in just over 2 hours and were showing no residual clinical effects of the anesthesia 16 hours later. Although a transient mild acidosis was observed, we conclude that GKX provides a safe, effective and easily administered anesthetic regime for cats for periods up to 6 hours.