Evaluation of cardiovascular effects of total intravenous anesthesia with propofol or a combination of ketamine-medetomidine-propofol in horses

Objective—To evaluate the cardiovascular effects of total IV anesthesia with propofol (P-TIVA) or ketamine-medetomidine-propofol (KMP-TIVA) in horses. Animals—5 Thoroughbreds. Procedures—Horses were anesthetized twice for 4 hours, once with P-TIVA and once with KMP-TIVA. Horses were medicated with medetomidine (0.005 mg/kg, IV) and anesthetized with ketamine (2.5 mg/kg, IV) and midazolam (0.04 mg/kg, IV). After receiving a loading dose of propofol (0.5 mg/kg, IV), anesthesia was maintained with a constant rate infusion of propofol (0.22 mg/kg/min) for P-TIVA or with a constant rate infusion of propofol (0.14 mg/kg/min), ketamine (1 mg/kg/h), and medetomidine (0.00125 mg/kg/h) for KMP-TIVA. Ventilation was artificially controlled throughout anesthesia. Cardiovascular measurements were determined before medication and every 30 minutes during anesthesia, and recovery from anesthesia was scored. Results—Cardiovascular function was maintained within acceptable limits during P-TIVA and KMP-TIVA. Heart rate rang...