Dexmedetomidine Premedication Attenuates Ketamine-induced Cardiostimulatory Effects and Postanesthetic Delirium

摘要: BACKGROUND Dexmedetomidine is a new potent and highly selective alpha 2-adrenoceptor agonist with sedative-hypnotic anesthetic sparing properties. Because of its sympathoinhibitory activity, it may prove useful in balancing the cardiostimulatory effects attenuating adverse central nervous system ketamine. METHODS A double-blind, randomized comparative parallel-group study design was employed 40 volunteers ASA physical status 1 who were scheduled for elective superficial surgery under ketamine anesthesia. (2.5 micrograms/kg, n = 20) or midazolam (0.07 mg/kg, administered intramuscularly 45 min before induction Anesthesia induced 2 mg/kg intravenously, muscle relaxation achieved vecuronium. After tracheal intubation, anesthesia maintained nitrous oxide/oxygen (2:1) additional intravenous boluses according to clinical cardiovascular criteria. Hypotension bradycardia treated by increasing infusion rate crystalloids atropine, respectively. Sedative anxiolytic properties, intra- postoperative drug requirements, psychomotor cognitive impairments, compared between two groups. RESULTS proved have equal sedative after intramuscular administration, but dexmedetomidine significantly less preoperative impairment anterograde amnesia than did midazolam. Compared midazolam, decreased need intraoperative more effective reducing ketamine-induced effects. also superior hemodynamic responses intubation general, increased incidence bradycardia. CONCLUSIONS These results suggest that premedication 2.5 micrograms/kg postanesthetic delirium However, because propensity cause bradycardia, routine use an anticholinergic should be considered.