Effects of a Single Dose Dexmedetomidine on Surgical Field Visibility During Middle Ear Microsurgery: A Randomized Study.

Abstract

To investigate whether a single dose of dexmedetomidine (DEX) improves surgical field visibility. Randomized, prospective, double-blind study. Tertiary teaching hospital. ASA I or II patients undergoing tympanoplasty with ossiculoplasty were randomly assigned to receive either 0.8 μg/kg DEX (Group D) or the same volume of saline (Group N) 10 min before anesthesia induction. The primary outcome was the visibility of the surgical field rated by surgeons by Boezaart score. The secondary outcomes were consumption of anesthesia, hemodynamic profiles, and subsequent recovery. Boezaart scores for surgical visibility were lower in Group D than in Group N (1.3 ± 0.8 versus 1.8 ± 0.9, P = 0.014). Minimum alveolar concentrations of sevoflurane (Group D 1 [0.9/1.1] versus Group N 1 [1/1.2], P = 0.018) and remifentanil consumption (Group D 370 [218/504] μg versus Group N 583 [300/1028] μg, P = 0.002) were less in Group D. Except for a transient increase in blood pressure and a decrease in heart rate during DEX infusion, hemodynamic profiles were more stable in Group D than in Group N. More patients needed morphine rescue and presented with postoperative nausea and vomiting in Group N than in Group D (Group D 1 versus Group N 8, P = 0.029). Recovery time was comparable between the two groups (Group D 19 min versus Group N 18 min, P = 0.569). Use of a single dose of DEX resulted in improved surgical visibility, less consumption of anesthesia, and more favorable hemodynamic profile while not delaying recovery time.