摘要： 目的   观察长效选择性β受体阻断剂美托洛尔对麻醉诱导气管插管期间血流动力学和熵指数的影响。方法   60 例美国麻醉医师协会分级Ⅰ ~ Ⅱ级颅内动脉瘤患者，分为美托洛尔组和对照组，持续监测围手术期平均动脉压、心率、中心静脉压、反应熵、状态熵，以及反应熵与状态熵之差值。结果   （1）与麻醉诱导前比较，两组患者所有观察时间点反应熵值和状态熵值降低（均P < 0.05）。气管插管后1、3 和5 min，美托洛尔组患者反应熵值、反应熵与状态熵之差值显著降低（P < 0.05）；而状态熵组间差异无统计学意义（P > 0.05）。（2）与麻醉诱导前相比，两组患者气管插管前心率有平均动脉压明显下降（P < 0.05），但气管插管后1、3 和5 min 时，对照组患者心率和平均动脉压显著升高（P < 0.05）。与对照组和同组气管插管前相比，美托洛尔组患者气管插管后1、3 和5 min 心率及平均动脉压平稳（P < 0.05）。结论   美托洛尔可抑制喉镜直视和气管插管应激反应引起的熵指数变化，降低手术应激引起的心率和平均动脉压升高，稳定麻醉诱导期血流动力学状态。

关键词: 美托洛尔, 插管法, 气管内, 血流动力学, 熵

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.

Key words: Metoprolol, Intubation, intratracheal, Hemodynamics, Entropy