Continuous intravenous infusion anaesthesia with ketamine in medetomidine, midazolam, butorphanol premedicated and thiopental induced buffaloes

Abstract

The study was conducted with an objective to standardise and evaluate the continuous intravenous anaesthesia using ketamine in buffaloes and to compare it after 2 different preanaesthetic regimens. Continuous intravenous infusion (CII) anaesthesia in 6 male adult buffaloes was used in K-1 and K–2 groups. In K1 medetomidine (2.5 μg / kg) + butorphanol (0.05 mg/kg) and in K2 midazolam (0.25 mg/ kg) + butorphanol (0.05 mg/kg) intravenously were used. Induction by 5% thiopental sodium and maintenance by 1% ketamine was done. Clinicophysiological, haematobiochemical and haemodynamic parameters were recorded. Group K-1 produced better sedation and analgesia. Muscular relaxation was excellent in both groups. Depression of palpebral reflex was better in K-2, depression of corneal reflex was comparable and depression of pedal and pinprick reflexes was higher in K-1. Lesser dose of thiopental was required in K-1 (2.87±0.44 mg/kg) than K2 group (7.14±0.36 mg/kg). The infusion rates of ketamine were 0.13±0.01 and 0.16±0.01 mg/kg/min in K-1 and K-2. Weak time was comparable. Recovery time, resumption of sternal recumbency and standing time were higher in K-2. Bradycardia in K-1 and tachycardia in K-2 was recorded.
Respiratory rate decreased in K-1. Rectal temperature decreased in both groups. MAP decreased in K-1 and increased in K-2. CVP increased after premedication, decreased after induction and maintenance in both groups.
Medetomidine - butorphanol provides better quality sedation, analgesia and muscle relaxation, has more dose sparing effect on induction and maintenance agents and maintains cardiopulmonary dynamics better than midazolam-ketamine in buffaloes. Additionally continuous intravenous infusion of ketamine (0.13–0.16 mg/kg/min) can be used safely and effectively for maintenance of anaesthesia in buffaloes premedicated with proposed drugs.