Esmolol for hypotensive anesthesia in middle ear surgery.

Abstract This study was performed to investigate the efficacy of esmolol, an agent used in hypotensive anesthesia for middle ear surgery. We compared 20 ASA I-II patients to 20 controls in whom we administered routine anesthesia. All patients were premedicated with intramuscular 0.05 mg/kg atropine, 1 mg/kg pethidine and 25 mg promethazine. Anesthesia was induced with 0.004 mg/kg fentanyl and 5 mg/kg thiopental sodium. Succinylcholine 1.5 mg/kg was administered to facilitate intubation. Isoflurane, nitrous oxide, oxygen, 0.08 mg/kg vecuronium bromide and controlled ventilation were used for anesthetic maintenance. Before the controlled hypotensive period, nitrous oxide was discontinued and an esmolol infusion started. We registered hemodynamic values (via noninvasive and invasive radial artery cannulation), central venous pressure, electrocardiography, body temperature, end-tidal carbon dioxide levels, periferal oxygen saturation, and arterial blood gas analysis. Mean infusion rate of esmolol was 330 +/- 10 micrograms/kg/min. We found significant decreases in systolic blood pressure (28.7%), mean blood pressure (26.5%) and diastolic blood pressure (33.4%). The operative field was virtually bloodless. Hemodynamic values recovered to normal or to within -12.45% of normal at the end of intravenous esmolol infusion. During the postoperative period, no side effects were observed. In conclusion, esmolol is an appropriate hypotensive agent for patients undergoing middle ear surgery under hypotensive anesthesia because it yields no side effects, it is easy to control administration and it provides the desired degree of hypotension without complications.