title: Effects of repeated anaesthesia with ketamine/medetomidine and of pre-anaesthetic administration of buprenorphine in rats.
abstract: Two groups of rats were anaesthetized at weekly intervals for 6 weeks with either ketamine/medetomidine alone (60 mg/0.4 mg/kg i.p.) or ketamine/medetomidine (45 mg/0.3 mg/kg i.p.) one hour following buprenorphine (0.05 mg/kg s.c.). Animals that received buprenorphine had longer periods of surgical anaesthesia (P = 0.04) and a greater depression of both mean pedal withdrawal score (P < 0.01) and mean respiratory rate (P = 0.014). Mean total duration of anaesthesia was also greater in the buprenorphine group on day 1. Sleep times reduced with successive doses of anaesthetic in the buprenorphine group (P = 0.024). Two animals in the buprenorphine group died. Repeated anaesthesia with ketamine/medetomidine alone was not associated with anaesthetic mortality. These results indicate that although buprenorphine has a clear anaesthetic-sparing effect, its use with ketamine/medetomidine may be associated with an increased risk of anaesthetic-related mortality.
authors.affiliation: Karolinska Institute, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Hedenqvist
authors.forename: J V
authors.initials: JV
authors.lastname: Roughan
authors.forename: P A
authors.initials: PA
authors.lastname: Flecknell
mesh_terms: D000758:Anesthesia / Q000662:veterinary*; D000818:Animals; D002047:Buprenorphine / Q000008:administration & dosage* / Q000009:adverse effects*; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D020926:Medetomidine / Q000008:administration & dosage*; D011229:Preanesthetic Medication; D051381:Rats; D017208:Rats, Wistar; D012119:Respiration; D012890:Sleep
chemical_list: D002047:Buprenorphine; D007649:Ketamine; D020926:Medetomidine