Sedative, analgesic, cardiopulmonary and haemodynamic effects of medetomidine-butorphanol and midazolam-butorphanol on thiopental-propofol anaesthesia in water buffaloes (Bubalus bubalis)

Abstract

The sedative, dose sparing, cardiopulmonary and haemodynamic effects of medetomidine-butorphanol and midazolam-butorphanol, on thiopental-propofol anaesthesia were evaluated in six healthy male water buffaloes (2 to 3 years; 290 to 325 kg). Group P1 received medetomidine (2.5 µg/kg) + butorphanol (0.05 mg/kg) intravenously, while in group P2 midazolam (0.25 mg/kg) + butorphanol (0.05 mg/kg) were used intravenously at 7 days interval. After 15 min of premedication, anaesthesia was induced by 5% thiopental sodium intravenously. The anaesthesia was maintained with continuous intravenous infusion (CII) of 1% propofol in both groups up to 120 min and the depth was determined by towel clamp method. Cardio-respiratory and haemodynamic parameters were assessed up to 120 min after preanaesthetic administration. Medetomidine-butorphanol produced better sedation in comparison to midazolam-butorphanol. However, this combination produced more depression of cardiovascular system during preanaesthetic period but lesser depression of cardiorespiratory dynamics in post-induction and during maintenance period and quicker recovery was observed. Significantly lesser doses of thiopental sodium were required in the animals of group P1. It can be concluded that medetomidine–butorphanol produced better quality sedation and analgesia and quicker recovery with significantly more reduction in the induction dose of thiopental sodium and propofol and lesser cardiopulmonary effects than midazolam-butorphanol in buffaloes.