Reduction of pain by neuraxial blockade with bupivacaine

The efficacy of pre-traumatic and post-traumatic neuraxial blockade with bupivacaine in controlling the post traumatic pain and morbidity was studied in 12 non-descript adult goats of either sex randomnly divided into groups A, B and C of 4 animals each. In all the animals, acute pain was induced by injecting turpentine (0.15 nil) in left hock joint. In animals of group A, bupivacaine @ I mg/kg was injected at lumbosacral epidural space 30 min before the injection of turpentine. whereas, in animals of group B, bupivacaine at the same dose rate and site as in group A was injected 2 hr after the injection of turpentine, In animals of group C (control) normal saline was administered at lumbosacral space 30 min before and 2 hr after turpentine injection. In adition to the epidural injection, diclofenac sodium tot I mg/kg was also administered for 5 Jays in all the animals. the post traumatic pain and morbidity was assessed in all the groups up to 7 days by recording, HR, RR, RT, post traumatic swelling. joint warmth, hyperalgesia, extension and flexion angles of affected joints and movement associated pain. A significant (P<0.01) increase in HR, RR and RT in animals of groups B and C and only mild rise in animals of group A v as seen. Similarly, maximum increase in swelling,joint warmth, hyperalgesia and pain scores was recored in animals of group C followed by group B. Least changes were observed in animals of group A indicating minimum discomfort in these animals, It is revealed that epidural blockade with bupivacaine if achieved before trauma is able to preempt the post operative pain and morbidity up to a great extent and may be used in clinical cases with or without general anaesthesia. Use of post-operative epidural blockade seems to have only limited beneficial effect.