神经外科手术异丙酚复合麻醉时芬太尼量效关系的分析

The dose-effect relationship of fentanil in combination with propofol in patients with neurosurgery

目的通过观察电刺激-循环反应的变化,探讨神经外科手术患者复合异丙酚麻醉时芬太尼的量效关系。方法选择15例ASAⅠ~Ⅱ级择期额颞部开颅手术患者,先行靶控输注（TCI输注）异丙酚,设定效应室靶浓度为3μg/ml,必要时面罩辅助通气,待达到异丙酚靶浓度后开始TCI输注芬太尼,设定效应室靶浓度分别为2ng/ml、3ng/ml、4ng/ml、5ng/ml、6ng/ml、7ng/ml、8ng/ml,分别于芬太尼达不同效应室浓度时给予50mA、50Hz、5s强直电刺激,记录电刺激前后血压、心率的变化。结果随着芬太尼效应室浓度的增加,血压及心率逐渐降低,电刺激-循环反应也逐渐减弱。芬太尼效应室浓度达（5.40±0.83）ng/ml时,50mA强直电刺激后平均动脉压（MAP）升高幅度﹤5%,95%置信区间为（3.77~7.02）ng/ml。结论在异丙酚复合麻醉时,随芬太尼效应室浓度的增加,镇痛强度逐渐增强,电刺激-循环反应逐渐减弱;芬太尼效应室浓度﹥（5.40±0.83）ng/ml时,强直电刺激-循环反应变化不再明显。

Objective To evaluate the dose-effect relationship of Fentanil in combination with propofol in patients with neurosurgery by electrical stimulation. Methods Fifteen ASA physical status Ⅰ or Ⅱ patients, scheduled for intracranial surgery, were involved in this study. Anesthesia was performed with propofol and Fentanil using a targetcontrolled infusion device. Constant effect-site concentrations of 3/g/ml propofol were maintained. Constant effect-site concentrations of 2ng/ml, 3ng/ml, 4ng/ml, 5ng/ml, 6ng/ml, 7ng/ml, 8ng/ml Fentanil were administered stepwise. Heart rate and invasive arterial pressure were monitored and recorded before and after the electrical stimulation （50mA, 50Hz, 5s） when propofol and Fentanil reached their each effect-site concentration. Results Heart rate and invasive arterial pressure were decreased significantly, electrical stimulation-circulation response was weaken as increasing effect-site concentration of Fentanil. At a effect-site concentration of Fentanil greater than （5.40±0.83）ng/ml, increases in MAP were less than 5% after electrical stimulation （50mA）, and the 95% confidence limits were 3.77-7.02ng/ml. Conclusions Circulation response electrical stimulation of 50mA induced by is weaken as increasing effect-site concentration of Fentanil. At a effect-site concentration greater than （5.40±0.83）ng/ml, with 95% confidence limits of （3.77-7.02）ng/ml^-1, Fentanil exhibits a ceiling effect.