Comparative Evaluation of the Isoflurane-sparing Effects of Butorphanol and Pentazocine in Buffaloes Undergoing Diaphragmatic Herniorrhaphy

Background: Isoflurane is commonly used as an inhalant anaesthesia in animals. Foreign body syndrome ultimately results into diaphragmatic hernia which is common in buffaloes. Diaphragmatic herniorrhaphy is generally performed under isoflurane anaesthesia. But there are adverse effects of isoflurane like respiratory depression, hypotension, reduced cardiac output and its metabolites cause atmospheric pollution. So, the present study was planned with the hypothesis that inclusion of opioid analgesic in the balanced anaesthesia might have isoflurane sparing effect. Methods: The present study was conducted in 15 female buffaloes which were suffering from diaphragmatic hernia which was diagnosed by radiography and later confirmed on rumenotomy. Animals were randomly divided in three groups - group I (Atropine (0.04 mg/kg) - xylazine (0.05 mg/kg) - propofol (till effect) - isoflurane; AXPI), group II (Atropine - xylazine - butorphanol (0.03 mg/kg) - propofol - isoflurane; AXBPI) and group III (Atropine - xylazine - pentazocine (0.75 mg/kg) - propofol - isoflurane; AXPPI) having five animals in each. Group I was taken as control as no analgesic was used in anaesthetic combination for animals of this group. The total isoflurane vapour delivered (mL) for the total duration of anaesthesia was calculated and the values so obtained were equated to 400 kg body weight and 40 minute duration for each animal for statistical comparison. Result: The Mean volume of isoflurane (ml) utilized for group I (65.58±8.8) was significantly higher than in Group II (38.54±5.7) and Group III (41.01±4.8). There were no significant changes in the haematological and biochemical profile of these buffaloes among three groups.