Evaluation of Tramadol, Pentazocine Lactate and Meloxicam as Pre-emptive Analgesics for Pain Management in Canine Ovariohysterectomy

Abstract

Background: It is usually accepted that some degree of post-surgical pain will be commonly present. There are different pain scales adopted in veterinary practice to assess these behavioural signs to measure pain. VAS had been used in human medicine for many years to measure pain and was found equally satisfactory in dogs. Pre-emptive analgesia (PEA) is grasping popularity in recent days, the concept of which originated during the time of growing appreciation of dynamic characteristics of pain pathway for obtaining effective analgesia prior to the surgical trauma. Methods: The present study was conducted to evaluate the effects of tramadol, pentazocine lactate and meloxicam as pre-emptive analgesics in dogs premedicated with glycopyrrolate, induction and maintenance with propofol continuous rate infusion (CRI) for certain clinical and physiological parameters. The animals were randomly divided into three equal groups viz. Group-T, Group-P and Group-M comprising six animals in each group and all were premedicated with glycopyrrolate, I/M. After 10 minutes of pre-anaesthetic administration, pre-emptive analgesia was given (Tramadol in Group-T, Pentazocine lactate in Group-P and Meloxicam in Group-M intravenously). After 10 minutes of pre-emptive analgesic administration, induction was achieved with propofol I/V and also maintained by CRI method up to 1 hour. Clinical and physiological parameters were recorded at 0 (baseline) minute before premedication, thereafter at 10 min, 30 min, 1 hr, 2 hr and 3 hr after pre-emptive analgesic administration. Result: There was no sedation observed within 10 min following pre-emptive analgesia and quality of sedation was recorded as score-0 in all the groups. Time for induction was significantly higher in group-M as compared to group-T and P. Quality of induction in all the groups ranged from score-0 to score1, assessment of peri-operative analgesia was recorded as score-0 in group-T and group-P, whereas in group-M it ranged from score-0 to score-1. Depth of anaesthesia was recorded as score-0 to score-1 in all the groups and quality of recovery was recorded as score-0 to score-1 in group-T and group-P and score-1 to score-2 in group-M. Assessment of post-operative analgesia by VAS was significantly lower in group-T as compared to group-P and M. In all the three groups, the heart rate increased significantly at 30 min interval and thereafter it decreased significantly till the end of the study. Respiratory rate also decreased significantly till 1 hr and thereafter it gradually increased till the end of study in all the groups. Rectal temperature, SpO2, systolic pressure and diastolic pressure decreased significantly at 30 min and thereafter increased gradually and approached base values in all the groups.