Comparison between analgesic effect of bupivacaine thoracic epidural and ketamine infusion plus wound infiltration with local anesthetics in open cholecystectomy

BACKGROUND: Neuraxial blocks result in sympathetic block, sensory analgesia and motor block. Continuous epidural anesthesia through a catheter offers several options for perioperative analgesia. Local anesthetic boluses or infusions can provide profound analgesia. Although the role of low-dose ketamine (<2 mg/kg intramuscular, <1 mg/kg intravenous [IV] or ≤ 20 μg/kg/min by IV infusion) in the treatment of post-operative pain is controversial, perioperative administration of a small dose of ketamine may be valuable to a multimodal analgesic regimen. A local anesthetic can be used for wound infiltration intra-operative to minimized the surgical pain. PATIENTS AND METHODS: A prospective randomized study was performed in which 40 patients scheduled for elective open cholecystectomy under general anesthesia admitted to the Medical Research Institute were included and further subdivided into two groups, group A, received thoracic epidural catheter at T7-8, activation was done 20 min before induction of anesthesia with plain bupivacaine at a concentration of 0.25% at a volume of 1 ml/segment aiming to block sensory supply from T4-L2, then received continuous thoracic epidural infusion intra and postoperatively with plain bupivacaine at a concentration of 0.125% at a rate of 5 ml/h for 24 h, group B received 0.3 mg/kg bolus of ketamine at the time of induction then 0.1 mg/kg/h ketamine IV infusion during surgery followed by wound infiltration with 15 ml of plain bupivacaine 0.5% at the time of skin closure. RESULTS: Bupivacaine thoracic epidural analgesia had better control on heart rate and mean arterial blood pressure than ketamine infusion plus wound infiltration with local anesthetic in patients undergoing open cholecystectomy. CONCLUSION: Thoracic epidural analgesia had better control on hemodynamic changes intra-and postoperatively than ketamine infusion with local wound infiltration in open cholecystectomy.