Esmolol for control of increases in heart rate and blood pressure during tracheal intubation after thiopentone and succinylcholine.

Abstract

Esmolol, an ultra-short-acting cardioselective beta-adrenergic blocker, was investigated in a double-blind prospective protocol for its ability to control haemodynamic responses associated with tracheal intubation after thiopentone and succinylcholine. Thirty ASA physical status I patients received a 12-minute infusion of esmolol (500 micrograms X kg-1 X min-1 for four minutes, then 300 micrograms X kg-1 X min-1 for 8 minutes) or saline. Five minutes after the start of the drug/placebo infusion, anaesthesia was induced with 4 mg X kg-1 thiopentone followed by succinylcholine for tracheal intubation. Prior to induction esmolol produced significant decreases in heart rate (HR) (9.3 +/- 1.8 per cent) and rate-pressure product (RPP) (13.1 +/- 1.8 per cent), systolic blood pressure (SAP) (4.3 +/- 1.5 per cent) and mean arterial blood pressure (MAP) (1.7 +/- 2.0 per cent). Increases in HR, SAP and RPP after intubation were approximately 50 per cent less in patients given esmolol compared to patients given placebo. There were highly significant differences in HR (p less than 0.0001), and RPP (p less than 0.0005) and significant differences in SAP (p less than 0.05) when the maximal esmolol post-intubation response was compared to the maximal placebo response. Infusion of esmolol in the dose utilized in this study significantly attenuated but did not completely eliminate cardiovascular responses to intubation.