Comparison between dexmedetomidine and remifentanil for controlled hypotension during tympanoplasty.

BACKGROUND AND OBJECTIVE: Controlled hypotension is frequently used for obtaining better exposure during tympanoplasty. The aim of this study was to compare dexmedetomidine, a selective, short-acting, central alpha2-adrenergic agonist with remifentanil, an ultra-short-acting opioid with properties similar to other mu-specific agonists, regarding their effects in achieving controlled hypotension and improving surgical field exposure and surgeon's satisfaction during tympanoplasty.

METHODS: In this prospective, double-blind pilot study, 24 consecutive patients scheduled for elective tympanoplasty were randomly assigned to receive either dexmedetomidine 1 microg kg(-1) over 10 min at anaesthesia induction followed by 0.4-0.8 microg kg(-1) h(-1) infusion during maintenance or remifentanil 1 microg kg(-1) over 1 min at anaesthesia induction followed by 0.2-0.4 microg kg(-1) min(-1) infusion during maintenance. Mean arterial pressure and heart rate were recorded before induction, at incision, 30, 60, 90 and 120 min after incision and 10 min after stopping the infusion. Surgical field exposure condition and satisfaction scores were assessed by the surgeon, blinded to the study drugs.

RESULTS: Mean arterial pressure and heart rate were significantly lower in the remifentanil group compared with the dexmedetomidine group at all times (P = 0.03 and 0.036, respectively). Surgical field exposure condition (3 +/- 0.01 vs. 2.3 +/- 0.7; P = 0.039) and surgeons' satisfaction (3 +/- 0.01 vs. 2.25 +/- 0.87; P = 0.039) scores were significant after remifentanil compared with dexmedetomidine.

CONCLUSIONS: Infusion of dexmedetomidine, at the doses used in this study, was less effective than remifentanil in achieving controlled hypotension, good surgical field exposure condition and surgeons' satisfaction during tympanoplasty.