Physiological and biochemical effects of medetomidine-butorphanolpropofol anaesthesia in dogs undergoing orthopaedic surgery

In 12 dogs undergoing orthopaedic surgery, atropine (0.04 mg/kg b.wt i.m.) was administered followed 5 min later by medetomidine (10 ìg/kg b.wt i.v.) and butorphanol (0.02 mg/kg b.wt i.v.) as premedicants. After 5 min of premedication, surgical anaesthesia was induced with propofol administered i.v. to effect. Maintenance was done by continuous i.v. infusion of propofol. Animals were divided into 2 groups M1 and M2 of 6 each. Meloxicam (0.2 mg/kg i.m.) and ketoprofen (2 mg/kg i.m.) were administered pre- and post-operatively for five days, in M1 and M2 group, respectively. Administration of medetomidine and butorphanol nonsignificantly (P>0.05) decreased heart rate and respiratory rate, whereas propofol caused tachycardia, depression in respiratory rate and SpO₂. MAP increased significantly (P<0.05) after the administration of preanaesthetics, whereas after the administration of propofol hypotension was observed. Significantly high base values of glucose and cortisol were observed that further increased significantly (P<0.05) after the administration of drugs. Plasma urea nitrogen decreased, whereas creatinine values increased nonsignificantly (P>0.05). Total Intravenous Anaesthesia was successfully induced with propofol at 3.1±0.29 and 1.76±0.42 mg/kg and maintained with propofol at 0.28±0.06 and 0.26±0.08 mg/kg/min in group M1 and M2, respectively. Both ketoprofen and meloxicam were effective in controlling postoperative analgesia, but ketoprofen was slightly better.