Evaluation of postoperative analgesic efficacy and perioperative hemodynamic changes with low dose intravenous dexmedetomidine infusion in patients undergoing laparoscopic cholecystectomy - A randomised, double-blinded, placebo-controlled trial

Background and Aim: Dexmedetomidine is a alpha 2-agonist with sedative, sympatholytic and analgesic properties and hence, it can be a very useful adjuvant in anesthesia as stress response buster, sedative and analgesic. We aimed to evaluate the effects of low dose dexmedetomidine infusion (0.5 mcg/kg/h) on postoperative analgesic efficacy along with the perioperative hemodynamic changes in patients undergoing laparoscopic cholecystectomy. Material and Methods: Eighty patients of American Society of Anesthesiologists (ASA) physical grades I and II undergoing laparoscopic cholecystectomy were randomly allocated into two groups of 40 patients each. Group I (Normal Saline group) patients received normal saline and group II (Dexmedetomidine group) patients received dexmedetomidine infusion at 0.5 mcg/kg/h respectively, starting 15 min before induction and continued till the end of surgery. Parameters noted were heart rate, mean arterial pressure, oxygen saturation, post-operative pain was evaluated using VAS and analgesic requirement. Statistical tests such as ANOVA test for continuous variables, post-hoc test for intergroup comparison, and Chi-square test for discrete values were applied. Results: Post-operative efficacy was found to be limited in the dexmedetomidine group in terms of VAS score. The analgesic requirement in 24-hour was observed to be reduced in dexmedetomidine group when compared to the NS group; however, not statistically significant. In group NS, significant hemodynamic stress response was seen following laryngoscopy, tracheal intubation, creation of pneumoperitoneum and extubation. On intergroup comparison, the hemodynamic response was significantly attenuated in the dexmedetomidine group when compared to the NS group. No significant side effects were noted. Conclusion: Dexmedetomidine IV in an infusion dose of 0.5 mu g/kg/hr is effective in providing postoperative analgesia in terms of significant reduction in analgesic consumption in 24 hours and in addition to the effective obtundation of the pneumoperitoneum-induced hemodynamic changes.