RESUMO
STUDY OBJECTIVE: To compare the sedative, anxiolytic, analgesic, hemodynamic, and respiratory effects of buccal dexmedetomidine with intramuscular (IM) dexmedetomidine for premedication in patients undergoing arthroscopic knee surgery during spinal anesthesia. DESIGN: Randomized, placebo-controlled trial. SETTING: University medical center. PATIENTS: 75 ASA physical status I and II patients undergoing arthroscopic knee surgery with spinal anesthesia. INTERVENTIONS: Patients were randomized to one of three groups for premedication: group B, buccal dexmedetomidine 2.5 microg kg(-1); group IM, IM dexmedetomidine 2.5 microg kg(-1); and group P, buccal 0.9% and NaCl 2 mL. MEASUREMENTS: Noninvasive blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation were recorded. Sedation and anxiety levels were consecutively assessed with Ramsay sedation scores and Visual Analog Scale (VAS) scores of anxiety before premedication, before spinal anesthesia, during surgery, and at the end of surgery. Two, 4, and 8 hours after surgery, sedation levels, postoperative VAS pain scores, and consumption of analgesics (diclofenac sodium) were recorded. MAIN RESULTS: Before spinal anesthesia, during surgery, and at the end of surgery, sedation and anxiety scores of the patients receiving buccal or IM dexmedetomidine were, respectively, higher and lower than in group P. Patients receiving buccal dexmedetomidine (group B) had lower requirement of diclofenac sodium than group P and lower pain scores than groups P and IM. Mild hypotension and bradycardia were observed in the buccal and IM dexmedetomidine patients. CONCLUSIONS: Buccal dexmedetomidine for premedication in arthroscopic knee surgery provided equal levels of sedation and anxiolysis, and more evident analgesia compared with IM dexmedetomidine.