Effect of paracetamol injection on the analgesic effect of tramadol in ketamine-xylazine-diazepam anaesthetized dogs undergoing experimental arthrotomy

Abstract

Five dogs each were randomly treated with 30mg/kg paracetamol (treatment KXDTA) intravenously or equal volume of normal saline (treatment KXDTS) to evaluate if paracetamol potentiate the analgesic effects of tramadol during the intra-operative period. Thirty minutes later, both groups were treated with 3mg/kg tramadol intramuscularly and 15 minutes later with intramuscular injections of 0.5mg/kg xylazine and 0.04mg/kg atropine. Anaesthesia was induced with intravenous ketamine (10mg/kg) and diazepam (0.5mg/kg). Time to loss of righting reflex (TLRR), duration of intubation (DET), duration of analgesia (DAN), duration of recumbency (DRC) and recovery time (RCT) were determined. Heart rates, mean arterial pressure, respiratory rates, saturated oxygen tension and rectal temperatures were recorded for seventy minutes. Anti-nociception was assessed by dogs’ responses to surgical stimulation and artery forceps applied at the digits. Data was compared with students’ t-test, while physiological variables were compared with ANOVA. The quality of anaesthesia did not differ significantly between treatments KXDTA and KXDTS. Duration of endo-tracheal intubation was significantly (P<0.05) longer in treatment KXDTS (59.2±8.7 minutes) than treatment KXDTA (45.4±4.8 minutes). There was no significant difference in TLRR, DAN, DRC and RCT between the two treatments. Also, there were no significant changes in the measured physiological variables. It was therefore concluded that pre-medication with paracetamol injection did not improve tramadol analgesic effect during the intra-operative period in ketamine-xylazine-diazepam anaesthetized dogs.

Keywords: Paracetamol, Ketamine, Tramadol, Arthrotomy, Dogs