Comparison between intravenous and intrathecal clonidine for postoperative analgesia of patients submitted to laparoscopic cholecystectomy: randomized clinical trial.

INTRODUCTION AND

OBJECTIVES

Alpha2 adrenergic agonists, such as clonidine, are used as adjuvants during anesthesia due to their analgesic, sedative, and cardiovascular effects. The objective of the present study was to compare the effect of clonidine administered intravenously and intrathecally on the postoperative pain score of patients undergoing laparoscopic cholecystectomy, according to the route of administration and postoperative opioid consumption.

METHODS

This randomized clinical trial, blind to patients and evaluator, assessed 60 patients, candidates for elective laparoscopic cholecystectomy under standardized general anesthesia techniques. Patients were randomly allocated into three groups (20 in each group): Control Group (CG), Intrathecal Clonidine Group (ITCG), and Intravenous Clonidine Group (IVCG). The primary outcome was the comparison of pain, Blood Pressure (BP) and Heart Rate (HR) scores among groups. The secondary outcome was report of adverse effects such as bradycardia, hypotension and sedation, and the need for rescue medication.

RESULTS

The mean age was 37.2 ± 8.2 years, and the mean body mass was 28.3 ± 3.6 kg.m-2. Regarding HR (p = 0.003) and pain (p = 0.027), patients in ITCG and CG showed a different profile over time, with CG showing higher consumption of morphine as rescue medication (p = 0.005).

CONCLUSION

The administration of intrathecal and intravenous clonidine in low doses can reduce hemodynamic parameters and decrease postoperative requirement of analgesics. Further studies should investigate the ideal dose and method.