Assessment of the efficacy of esmolol on the haemodynamic changes induced by laryngoscopy and tracheal intubation: A meta-analysis

Background: Adrenergic stress response induced by laryngoscopy and tracheal intubation (LTI) appears to be attenuated by esmolol, but its potential cl inical benefits have not been fully weighed against possible adverse effect s. Methods: A systematic search up to May 2000 was performed using MEDLINE, EM BASE, LILACS, Cochrane library, manual searching and bibliographies in all languages. All randomised comparisons of esmolol with placebo on the haemod ynamic changes elicited by LTI were obtained. Trials were included in the p resent meta-analysis if they recorded heart rate (HR), systolic pressure (S BP), mean arterial pressure (MAP) or diastolic pressure (DBP) at three diff erent stages: pre-induction, immediately prior to intubation, and in the po st-intubation period. Weighted mean differences (WMD) and 95% confidence in tervals (CI) of the changes in the haemodynamic variables between treatment and placebo groups were calculated. Results: Of 72 publications identified, 38 randomised controlled trials con taining a total of 2009 patients were finally included. Eleven different re gimens and doses of esmolol demonstrated effectiveness in the attenuation o f HR and BP after LTI in a dose-dependent manner. The most effective regime n was a loading dose of 500 mug . kg(-1) . min(-1) over 4 min followed by c ontinuous infusion dose of 200-300 mug . kg(-1) . min(-1) [WMD: 20.2 bpm (9 5% CI: 15.6 to 24.7)]. High bolus dose (200 mg) of esmolol produced a consi derable decrease in DBP [WMD 10.1 mmHg (95% CI: 7.3 to 12.8)]. Conclusion: Esmolol is effective, in a dose-dependent manner, in the attenu ation of the adrenergic response to LTI. To minimise its adverse effects it should be administered, when considered clinically appropriate, as a conti nuous infusion regimen.