[Epidural clonidine or dexmedetomidine for post-cholecystectomy analgesia and sedation.].

BACKGROUND AND OBJECTIVES: Clonidine and dexmedetomidine are alpha2-adrenergic agonists with analgesic proprieties which potentiate local anesthetic effects when epidurally administered. The goal of this study was to evaluate the analgesia and sedation promoted by clonidine or dexmedetomidine associated to epidural ropivacaine, in the postoperative period of subcostal cholecystectomy.

METHODS: Forty patients of both gender participated in this randomized double-blind study , aged 18 to 50 years, weighing 50 to 100 kg, physical status ASA I or II, submitted to subcostal cholecystectomy. The subjects were distributed in two groups: Clonidine (CG), receiving clonidine (1 mL = 150 microg) associated to 0.75% epidural ropivacaine (20 mL); Dexmedetomidine (DG), receiving dexmedetomidine (2 microg.kg-1) associated to 0.75% epidural ropivacaine (20 mL). Analgesia and sedation were evaluated 2, 6 and 24 hours anesthetic recovery.

RESULTS: Both groups present some grade of sedation in the moments 2 and 6 hours , with statistically significant difference between the two moments for the dexmedetomidine group. There has been analgesia in both groups, especially at 2 and 6 hours. There have been statistically significant difference among periods of 2, 6 and 24 hours in the dexmedetomidine group; in the clonidine group, this statistically significant difference was observed between the periods of 2 and 6 hours and between 2 and 24 hours.

CONCLUSIONS: Our results allowed to conclude that the association of clonidine or dexmedetomidine to 0.75% ropivacaine induces analgesia and sedation in 2 and 6 hours after anesthetic recovery in patients submitted to subcostal cholecystectomy and that clonidine promotes more prolonged analgesia.