Comparison of post-operative Analgesic Efficacy of Low Dose Dexmedetomidine administered either Intravenous or Intraperitoneal with Bupivacaine in Patients Undergoing Laparoscopic Cholecystectomy: A Randomized, controlled trial

Laparoscopic cholecystectomy is the most commonly used general surgical procedure for symptomatic cholelithiasis. The pain management in the immediate postoperative period is the mainstay of postoperative care in patients undergoing laparoscopic cholecystectomy. In last few years, the use of IV dexmedetomidine (alpha-2 agonist) in patients undergoing laparoscopic cholecystectomy has shown many beneficial effects like reduced anesthetic requirement, reduced inflammatory response, reduced postoperative pain,reduced shivering, better hemodynamic response to pneumoperitoneum, and recently have been found to benefit the cognitive function in elderly patients. All the aforementioned studiesevaluating the postoperative analgesic effect of IV dexmedetomidine have used it in a dose of 1µg/kg bolus, followed by an infusion of 0.5µg/kg /hr. The dose of 1µg/kg is known to cause an initial rise in blood pressure which is followed by hypotension and reflex fall in HR.This ‘’Biphasic response’’ is seen more often in young, healthy patients. Recently, low dose infusion of dexmedetomidine at the rate of 0.4 mcg/kg/h without any bolus dose has been found to be a very useful anaesthesia adjuvant to control haemodynamic stress response to pneumoperitoneum and reduces the postoperative analgesic requirements without any significant adverse effects in patients undergoing laparoscopic cholecystectomy. Intraperitoneal instillation of local anaesthetic agents has become an important method to control post�’operative pain, nausea, vomiting and reduced hospital stay. Various authors have used intraperitoneal administration of dexmedetomidine 1 μg/kg combined with bupivacaine improves the quality and the duration of postoperative analgesia and provides an analgesic sparing effect compared to bupivacaine alone without significant adverse effects in patients undergoing laparoscopic colorectal cancer surgery. With this background, we undertake the present study to evaluate the postoperative analgesic efficacy of low dose dexmedetomidine (0.5µg/kg) either by intravenous or intraperitoneal route with 0.25% bupivacaine in patients undergoing laparoscopic cholecystectomy.The primary outcome being Time to first request of Analgesia and the secondary outcomes include total fdose of diclofenac consumption in 24 hr, VAS score and any adverse effects..