Effects of metoprolol on hemodynamics and entropy during endotracheal intubation

Abstract

Objective To investigate the effects of metoprolol, a selective long ⁃ termed β ⁃ adrenoreceptor antagonist, on hemodynamics and entropy indices during endotracheal intubation in anesthesia induction. Methods Sixty patients, American Society of Anesthesiologists (ASA) class Ⅰ -Ⅱ, undergoing elective clipping of intracranial aneurysm were randomly assigned into one of 2 groups to receive metoprolol (group M, n = 30) and saline (group S, n = 30), respectively. In group M, metoprolol (50 μg/kg) was administrated before anesthesia induction. In group S, patients were given saline with the same volume. Anesthesia was induced by propofol effect⁃site concentration target⁃controlled infusion (TCI, 3 μg/ml) and remifentanil target ⁃ controlled infusion (4 ng/ml) with rocuronium bromide (1 mg/kg). Mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), reaction entropy (RE), state entropy (SE) and the difference between RE and SE (RE - SE) were continuously recorded perioperatively. Results RE and SE in both 2 groups decreased significantly compared with before anesthesia induction (P < 0.05, for all). RE in group S increased significantly comparing with that in group M at 1, 3 and 5 min after intubation (P < 0.05, for all). No significant difference was observed in SE (P > 0.05). Meanwhile, RE - SE decreased more significantly in group M than that in group S (P < 0.05). MAP and HR in group S increased significantly at 1, 3 and 5 min after endotracheal intubation compared with before anesthsia induction (P < 0.05, for all). MAP and HR in group M were suppressed obviously compared with before intubation and group S (P < 0.05, for all). Conclusion Metoprolol suppresses hemodynamic response and entropy indices response to endotracheal intubation, and provides a stable hemodynamic state during anesthesia induction.

DOI：10.3969/j.issn.1672-6731.2010.04.011