COMPARISON OF DEXMEDETOMIDINE AND MIDAZOLAM SEDATION AND ANTAGONISM OF DEXMEDETOMIDINE WITH ATIPAMEZOLE

Study Objective: To evaluate the effects of dexmedetomidine, an alpha- 2 agonist, as an intravenous sedative drug and the effects of atipamez ole, an alpha-2 antagonist, on recovery. Design: Randomized, double-bl ind study with three parallel groups. An open dose-finding study prece ded it to optimize the atipamezole dose. Setting: Outpatient operating room at the gynecologic and obstetric university hospital in Helsinki , Finland. Patients: Seventy-two healthy women scheduled for legal ter mination of pregnancy. Interventions: Patients were assigned to one of three groups of 24 patients each to receive either dexmedetomidine 2 mug/kg and atipamezole 50 mug/kg; dexmedetomidine 2 mug/kg and saline; or midazolam 0.15 mg/kg and saline. In addition to paracervical block , each patient received two different study drugs: study drug 1 was a sedative agent (either dexmedetomidine or midazolam), administered bef ore the procedure. If the sedation was not deep enough and the patient reacted to the procedure, a low dose of propofol was administered. St udy drug 2 was a reversing agent or a placebo, administered following the procedure. Measurements and Main Results: The mean time to regain consciousness was shorter in the dexmedetomidine-atipamezole and the d exmedetomidine-saline groups compared with the midazolam group. Postop erative sedation, tested both by subjective and objective assessments, decreased more quickly in the dexmedetomidine-atipamezole group compa red with the dexmedetomidine-saline and the midazolam groups. Conclusi on: Atipamezole is an effective antagonist for reversing psychomotor i mpairment following dexmedetomidine sedation.