Evaluation of the effects of dexmedetomidine on perioperative hemodynamic changes, analgesic requirements, and recovery profile during laparoscopic cholecystectomy

Background Dexmedetomidine is a highly selective a-2 adrenergic agonist with analgesic, sedative,and sympatholytic effects. We designed this prospective, randomized, double-blind study to examine the effects of dexmedetomidine on the hemodynamic changes, analgesic needs, and recovery profile during and after laparoscopic cholecystectomy (LC). Methods After obtaining written informed consent, 60 ASA I and II patients undergoing LC were recruited and divided equally and randomly into two equal groups. Group D (n=30 patients) received a loading dose of dexmedetomidine 0.5 µg/kg, followed by an intraoperative dexmedetomidine infusion at a rate of 0.5 µg/kg/h. Group C (n=30 patients) received a loading dose of normal saline, followed by saline infusion. The infusions were stopped at the end of surgery at the time of abdominal deflation. The method of administration of the loading doses, volume of infusions, and the rate of infusions were standardized and were identical in both groups. The mean arterial pressure and heart rate were recorded at specific time intervals intraoperatively and during recovery. During recovery, the following data were recorded: the level of sedation, time to eye opening, time to tracheal extubation, incidence of nausea andvomiting, pain scores, time for the first analgesic requirement, and intraoperative and postoperative analgesic requirements in both groups. Results The intraoperative mean arterial pressure and heart rate were significantly lower in group D compared with group C at all measurement points, except the baseline. However, there were no significant differences between both groups in the recovery.Also, the intraoperative fentanyl requirements were significantly less in group D, median 2 µg/kg [interquartile range (IR) 2–2], versus median 3 µg/kg (IR 3–4) in group C (P value 0.001). During recovery, the postoperative fentanyl requirements were significantly lower in group D, median 0.5 µg/kg (IR 0.5–1), versus median 1 µg/kg (IR 0.8–1) in group C. Times to first analgesic dose request were significantly longer in group D, 19 ± 3 min, versus 12 ±3 min in group C (P value 0.001). Sedation scores were significantly higher in group D immediately postoperatively (at 0 h), beingmedian 2 (IR 2–3) in group D versus median 1.5 (IR 1–2) in group C. After 1 h, the sedation scores were 1.5 (1–2) versus 1 (1–1), respectively, P less than 0.001. There were no significant differences between the two groups after 2 h in the sedation scores. Conclusion An intraoperative infusion of dexmedetomidine attenuated the hemodynamic changes occurring during LC and reduced the analgesic requirements during and immediately after surgery.