Effect of esmolol on bispectral index in patients undergoing orotracheal intubation during induction of anesthesia / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of esmolol on bispectral index (BIS) in patients undergoing orotracheal intubation during induction of anesthesia and to investigate the mechanism of inhibiting the cardiovascular responses to tracheal intubation.Methode Forty patients in physical status of ASA Ⅰ or Ⅱ and aged 20-60 years were randomly divided into 2 groups ( n = 20 each) esmolol group (group E) and control group (group C). Anesthesia was induced with midazolam 0.1 mg/kg, fentanyl 5 μg/kg and vecuronium 0.1 mg/kg. In group E, esmolol 1 mg/kg was given intravenously before anesthesia induction and followed by an infusion of esmolol 250 μg· kg- 1·min-1, while a comparable volume of saline was given for group C. Mean arterial pressure (MAP), heart rate (HR) and BIS were recorded before esmolol administration, before induction of anesthesia, before orotracheal intubation, and at 1, 2 and 5 min after intubation, respectively.Results There were no significant differences in HR, MAP and BIS between the two groups before tracheal intubation. HR and MAP significantly increased after tracheal intubation in both groups, but BIS only in group C significantly increased after intubation.HR, MAP and BIS were significantly lower after intubation in group E than in group C ( P＜ 0.05).Conclusion Esmolol can decrease BIS during tracheal intubation and its antinociceptive property is related to the mechanism of inhibiting cardiovascular responses to tracheal intubation.