Esmolol — just another beta blocker?

Intravenous esmolol infusion improves surgical fields during sevoflurane-anesthetized endoscopic sinus surgery: a double-blind, randomized, placebo-controlled trial

BACKGROUND

There is increasing evidence to support the use of anesthetics to affect operative fields during endoscopic sinus surgery and thus the speed, thoroughness, and safety of the surgery itself. Previous research has suggested preoperative beta-blockers improve surgical fields (SFs); our study is novel in showing the impact of a beta-blocker infusion on SFs during sinus surgery.

METHODS

A prospective, randomized, double-blind, placebo-controlled trial was conducted in 40 patients. Patients undergoing endoscopic sinus surgery for chronic rhinosinusitis received a constant infusion of i.v. esmolol or saline in addition to a standard inhaled anesthetic protocol. At regular 15-minutes intervals, the quality of SF, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were assessed. Total blood loss was also recorded.

RESULTS

Average vital sign parameters (HR/SBP/DBP) were significantly lower in the esmolol group (69.1/90.2/55.1 versus 77.2/99.5/63.5; p < 0.01). The esmolol infusion improved SFs relative to control (2.3 versus 2.6; p = 0.045). Esmolol infusion resulted in good SFs (grades 1 and 2) more often than poor fields (grades 3 and 4); on the contrary, the control group showed more poor than good SFs (chi-square; p = 0.04). A correlation between increasing HR and worsening SFs was identified (r = 0.259; p = 0.002). The control group had significantly higher average blood loss (1.3 versus 0.8 mL/min; p = 0.037).

CONCLUSION

Esmolol-induced relative hypotension and bradycardia during endoscopic sinus surgery achieves significantly improved SFs relative to saline control.

Effects of anesthetic technique on the hemodynamic response to microlaryngeal surgery

Our aim was to study the attenuation of the hemodynamic response to microlaryngeal surgery by beta-blocking agents used as support drugs to the anesthetic technique. The study was carried out in 30 patients randomly allocated to one of three groups. The control group received only anesthetic drugs. The second group received labetalol hydrochloride 0.3 mg/kg 3 minutes before induction and 0.15 mg/ kg 2 minutes prior to the start of suspension of the larynx. The third group received esmolol hydrochloride 500 micrograms/kg 3 minutes prior to induction and a continuous infusion of 300 micrograms/kg during the surgical procedure. Hemodynamic data in the three groups were compared by analysis of variance. A statistically significant difference (p < .05) was found in hemodynamic data among the two groups treated with blocking agents and the control group. The addition of beta-blocking agents to the anesthetic technique attenuates the hemodynamic response to suspension laryngoscopy.