[Effect of dexmedetomidine alone for postoperative analgesia after laparoscopic cholecystectomy].

Objective: To investigate the effect of dexmedetomidine alone for postoperative analgesia after laparoscopic cholecystectomy. Methods: Forty patients scheduled for elective laparoscopic cholecystectomy in First Hospital of Ninghai County, American Society of Anesthesiologists (ASA) gradeⅠor Ⅱ, were randomly divided into dexmedetomidine group (Group D, n=20) and fentanyl group (Group F, n=20). The patient controlled analgesia (PCA) pumps were used after the operation. In the group D, the intravenous PCA protocol was dexmedetomidine 0.2 µg·kg(-1)·h(-1) diluted to 100 ml in 0.9% saline. In the group F, the PCA protocol was fentanyl 20 µg /kg diluted to 100 ml in 0.9% saline. Mean arterial pressure (MAP) and heart rate (HR) were recorded at the following time points: before induction of anaesthesia, end of operation and 4, 6, 8, 24, 48 hours after the operation. The pain score on a visual analogue scale (VAS) and the Ramsay sedation score were recorded at 4, 6, 8, 24, 48 hours after the operation. The incidences of postoperative nausea and vomiting (PONV), respiratory depression, dizziness, time to recovery of gastrointestinal function (time to first passage of flatus) and satisfaction with pain control were also recorded. Results: There were no significant difference in the general data of patients, duration of surgery, total dose of intraoperative propofol, fentanyl and sevoflurane, and total fluids during the operation (P>0.05). No patients received rescue analgesic. The MAP and HR values at different time points showed no significant difference between the groups (P>0.05). Similarly, the VAS scores and Ramsay sedation scale at 4, 6, 8, 24, 48 hours after the operation were not significantly different between the groups (P>0.05). The incidence of PONV was significantly reduced in group D, rating as 5%, comparing with 40% in Group F (P<0.05). Patients of Group D experienced a faster gastrointestinal function recovery, and the time to the first passage of flatus were (41.3±10.1) h in Group D and (55.6±11.4) h in Group F (t=-4.195, P<0.05), respectively. The pain treatment satisfactory score (PTSS) in Group D was (8.1±1.3) points, higher than that in Group F (6.1±1.5) points (t=4.426, P<0.05). Meanwhile, there was no statistic difference in the incidence of respiratory depression and dizziness in both groups (P>0.05). Conclusion: Intravenous infusion of dexmedetomidine alone at 0.2 µg·kg(-1)·h(-1) after laparoscopic cholecystectomy not only reduces postoperative pain, but also enhances satisfaction with pain control and improves the recovery of gastrointestinal function.