Intraoperative use of bolus doses of esmolol to treat tachycardia

Abstract

A randomized, double-blind, parallel, placebo-controlled study was conducted to determine the safety and efficacy of intravenous (IV) bolus administration of esmolol in treating intraoperative tachycardia in patients undergoing noncardiac general surgery. Forty-eight ASA II-IV patients were randomized into three equal groups to receive either placebo, esmolol 50 mg, or esmolol 100 mg. Premedication (lorazepam) and anesthetic induction techniques (thiopental sodium and succinylcholine) were identical between groups. Approximately 20 minutes after intubation, during isoflurane/N2O/O2 maintenance anesthesia, patients with systolic pressure (SBP) greater than or equal to 110 mmHg were advanced into a 10-minute study drug period if one of two conditions were met: (1) heart rate (HR) was greater than or equal to 95 beats/minute, or (2) an increase in HR of greater than 20% above preinduction baseline occurred. After two consecutive recordings of HR and blood pressure (BP), the study drug (or placebo) was injected. HR was recorded every 30 seconds and BP was recorded every minute during the ensuing 10-minute period. Compared to placebo responses, HR was significantly reduced with both doses of esmolol within 1 minute of bolus injection and remained below placebo levels for 5 minutes after 50 mg of esmolol and for 9.5 minutes after 100 mg of esmolol. There were, however, only minor differences among groups with respect to SBP, diastolic blood pressure (DBP), and mean blood pressure (MBP) changes.

Conclusion: Bolus administration of esmolol can produce a rapid reduction of HR with relatively few adverse effects in an unhealthy surgical population.(ABSTRACT TRUNCATED AT 250 WORDS)