Cardiopulmonary function, anesthetic effects, quality of arousal, hematology, and blood biochemistry during continuous intravenous infusion of a combination solution of xylazine, butorphanol, and propofol in calves.

General anesthesia in calves is easier to perform under field conditions, total intravenous anesthesia (TIVA) than using inhalation anesthesia. In the present study, cardiopulmonary function, anesthetic effects, quality of arousal, hematology, and blood biochemistry were assessed during continuous infusion of a combination solution of 0.01% xylazine, 0.001% butorphanol, and 0.2% propofol (XBP) at doses of 6 (G6; 10 μg/kg/min xylazine, 1 μg/kg/min butorphanol, 200 μg/kg/min propofol) and 9 mL/kg/h (G9; 15 μg/kg/min xylazine, 1.5 μg/kg/min butorphanol 300 μg/kg/min propofol). For both groups, five castrated Holstein calves received intravenous injections of xylazine (0.2 mg/kg) and propofol (2 mg/kg), followed by a continuous infusion of XBP for 60 min to maintain anesthesia. Respiratory management consisted of tracheal intubation followed by spontaneous inhalation of pure oxygen. Cardiopulmonary, anesthesia, hematology, and blood biochemistry variables were assessed at rest (baseline) and every 5 or 15 min after the start of the XBP infusion. Quality of arousal was assessed based on the swallowing reflex recovery time from the stop of XBP infusion, and the sternal position time and standing time after atipamezole administration. XBP produced adequate sedation, analgesia, and muscle relaxation in all calves and maintained stable anesthesia for 60 min. As XBP infusion time passed, rectal temperature and heart rate became lower, and mean arterial blood pressure increased. In both groups, hematologic and blood biochemical effects were mild. The quality of arousal was not different, and all calves were standing. The results of the present study suggested that XBP is useful for TIVA in calves.