COMPARISON OF INTRAMUSCULAR DEXMEDETOMIDINE AND MIDAZOLAM PREMEDICATION FOR ELECTIVE ABDOMINAL HYSTERECTOMY

The purpose of this study was to compare the perioperative effects of the intramuscular (IM) alpha(2), agonist, dexmedetomidine (DEX), and m idazolam (MID) premedication. The study comprised 192 women (64 per gr oup) scheduled for abdominal hysterectomy. The doses of the study drug s were chosen to obtain equal sedative effects. The three groups were: 1) IM DEX (2.5 mu g/kg) and intravenous (IV) placebo (DexPla group), 2) IM DEX and IV fentanyl (FENT) (1.5 mu g/kg) (DexFent group), and 3) IM MID (0.08 mg/kg) and IV FENT (MidFent group). IM drugs were admini stered 45-90 min before induction of anesthesia. Preoperative sedation and anxiolysis after DEX was comparable to that after MID. The maximu m arterial blood pressure response to endotracheal intubation was blun ted in the DexFent group, while in the two other groups blood pressure increased 30-34 mm Hg after endotracheal intubation. The mean isoflur ane concentration during surgery was 0.14% in the DexFent group, 0.24% in the DexPla group, and 0.34% in the MidFent group (P < 0.001). Duri ng surgery, bradycardia (heart rate < 40 bpm) was observed in 6.2% of DEX patients, and no MID patients, whereas postoperatively 14.1% of DE X patients and 1.6% of MID patients had bradycardia. Fewer patients su ffered from postoperative shivering after DEX (10%) than after MID (52 %). We conclude that DEX has many desirable effects, but side effects such as bradycardia may limit its routine use in ASA physical status I -II patients.