Comparison of the efficacy of dexmedetomidine and remifentanil in controlled hypotension

Introduction. Controlled hypotension is frequently used for obtaining better exposure during nasal surgery [1]. The aim was to compare dexmedetomidine with remifen-tanil, regarding their effects in achieving controlled hypotension and improving surgical field exposure and surgeon's satisfaction during nasal surgery. Method. After ethic committee approval and informed consent, 50 ASA I-II patients scheduled for elective functional endoscopic sinus surgery and septorhinoplasty were randomly assigned to receive either dexmedetomidine 0.5 /ng/kg over 10 min before induction followed by 0.5-1 μgkg-1 h-1 infusion during maintenance (Group D, n=25) or remifentanil 0.5 /ng/kg over 1 min before induction followed by 0.2-0.5 / gkg-1 h-1 infusion during maintenance (Group R, n=25). The infusion rates were titrated to maintain MAP of 60 to 80 mmHg. Anaesthesia was maintained with sevoflurane (BIS 40-60). HR and MAP were recorded throughout the study period. Surgical field exposure conditions and satisfaction scores for surgeon were recorded. The surgeon used a category scale (0-3) to assess surgical conditions- a value of 0-1 being ideal. Results. Controlled hypotension was achieved at the target pressure within 18.4±5.1and 15.5±16.7 min for Groups D and R, respectively (P=0.91). Controlled hypotension was sustained in the two groups throughout surgery. Decreases in HR were higher in Group D after administration of study drug, induction and extubation (P=0.004, P=0.003, P=0.042). MAP values were lower in Group D at 10 min after the end of infusion and before extubation (P=0.032, P=0.038). However, MAP and HR values during the surgical procedure were similar for the two groups. Ideal surgical conditions were achieved in all patients. Surgeons' satisfaction scores (8.9±1.1 vs. 9.3± 0.8; P=0.062) were similar. Discussion. Both dexmedetomidine and remifentanil in combination with sevoflurane enabled controlled hypotension and provided ideal surgical conditions for nasal surgery with no need for additional use of a potent hypotensive agent.