INTRAMUSCULAR DEXMEDETOMIDINE PREMEDICATION - AN ALTERNATIVE TO MIDAZOLAM-FENTANYL-COMBINATION IN ELECTIVE HYSTERECTOMY

Sedation, anxiolysis, intubation responses and fentanyl anaesthetic re quirements were investigated in a double-blind, randomized study in tw enty ASA I-II elective hysterectomy patients. Ten patients received de xmedetomidine 2.5 mu g kg(-1) i.m. 60 min before induction and saline placebo i.v. 2 min prior to induction (= DP group). Ten patients recei ved midazolam 0.08 mg kg(-1) i.m. 60 min and fentanyl 1.5 mu g kg(-1) i.v. (= MF group) 2 min before induction of anaesthesia with thiopento ne 4 mg kg(-1). Anaesthesia was maintained with 70% nitrous oxide in o xygen and with fentanyl 2 mu g kg(-1) i.v. increments according to pre determined criteria. Both premedications induced sedation (P < 0.01 in both groups) and anxiolysis (P < 0.01 in DP vs P < 0.05 in MF group) without any differences between the groups. Haemodynamic changes follo wing tracheal intubation did not significantly differ between the grou ps. Intraoperatively systolic and diastolic arterial pressure were 15% and 13% lower in DP group (P < 0.01 and P < 0.05 for drug effect), th e mean heart rate was approximately 9 beats min(-1) lower in DP group (n.s.). Fentanyl was required more often in MF group: median 3.5 (QD 1 .5) vs. 2.5 (QD 0.5) times in DP group (P < 0.05), the total amount be ing 57% smaller in DP group: 0.03 (QD 0.01) vs. 0.07 (QD 0.02) mu g kg (-1) min(-1) (P < 0.05). Postoperative course and analgesic requiremen ts were similar in both groups. Dexmedetomidine premedication may offe r an alternative to current anaesthesia practice in elective hysterect omy.