异丙酚麻醉期间心率对阿托品的反应

目的观察异丙酚麻醉期间心率对阿托品的反应。方法选择75例ASAⅠ～Ⅱ级患者随机分三组。每组25例。对照组（P0组）不使用异丙酚；控制组2组（P4组、P8组）分别静脉注射异丙酚1．50mg／kg、2．50mg/kg以及万可松0．15mg／kg后行气管插管，麻醉分别以异丙酚4mg·kg^-1·h^-1、8mg·kg^-1·h^-1及50％笑气维持，血流动力学平稳后，每两分钟给予阿托品5μg／kg，观察心率反应并记录数据。结果阿托品累积用量达10μg/kg，三组心率值分别与基础心率值组内比较，差异均有统计学意义（t分别=4．77、3．32、2．58，P均〈0．05）；阿托品累积用量达15μg／kg时，P4、P8组心率值分别与基础心率值组内比较，差异有统计学意义（t分别=6．67、4．07，P均〈0．05）。阿托品累积用量迭10μg／kg时，P4、P8组心率值分别与PO心率值组间比较，差异有统计学意义（t分别=2．59、4．26，P均〈0．05）。阿托品累积用量达15μg／kg时，P4组与P8组两组心率组间比较，相同剂量（15μg／kg）的阿托品对异丙酚不同用量的两组间心率反应的差异有统计学意义（t=3．07，P〈0．05）。结论异丙酚麻醉期间心率对阿托品的反应是减弱的，其原因在于异丙酚引起的付交感神经系统活性的增强。交感神经系统活性和压力感受器反射的抑制。

Atropine-induced heart rate changes during propofol anesthesia

Objective To investigate atropine-induced heart rate changes during propofol anesthesia. Methods Seventy-five patients were randomly assigned to three groups：P0 group did not receive propofol;P4 and P8 received IV propofol 1.50mg/kg,2.50mg/kg respectively and veeuronim 0.15mg/kg.After tracheal intubation, anesthesia was maintained with propofol 4mg·kg^-1·h^-1, 8mg·kg^-1·h^-1 respectively and 50% N2O.When a stable hemodynamie state was obtained,all patients received incremental doses of atropine 5μg/kg at every 2mins,and heart rate response was observed. Results When cumulative atropine was 10μg/kg,HR in three groups were significantly different from baseline values （t=4.77,3.32,2.58, P〈0.05）;when cumulative atropine was 15μg/kg , atropine-induced heart rate changes of P4 and P8 were significantly different from baseline values respectively （t= 6.67,4.07, P〈0.05）; when cumulative atropine was 10μg/kg, the changes of HR in group P4 and P8 were significantly different from those in group P0 respectively （t=2.59,4.26, P〈0.05）; when cumulative atropine was 15μg/kg, atropine-induced heart rate changes between P4 and P8 were significantly different （t=3.07, P〈0.05） . Conclusions The HR response to IV atropine is attenuated during propofol anesthesia,which is attributable to propofol-induced dominance of parasympathetic nervous system,suppression of the sympathetic nervous system and baroreflex.