序贯法测定持续输注米库氯铵用于甲状腺手术神经监测的最大剂量

Sequential method for determining the maximum dose of mivacurium continuously infused for intraoperative neuromonitoring in thyroid surgery

目的利用序贯法探讨持续输注米库氯铵用于不影响甲状腺手术术中神经功能监测的最大输注剂量,并观察其不良反应。方法纳入28例行甲状腺手术术中神经功能监测的患者序贯地进行试验。术中以七氟烷复合瑞芬太尼维持麻醉深度。手术中当TOF值升至75%以上时开始持续输注米库氯铵,以5.43μg·kg-1·min-1为起始剂量,根据前一例患者对神经功能监测仪的反应来上调或者下调下一例患者的米库氯铵输注剂量。通过Brownlee上下序贯法来计算求得米库氯铵的LD50及95%CI。结果持续输注米库氯铵且不影响甲状腺手术术中神经功能监测的LD50为8.94μg·kg-1·min-1,95%置信区间为8.89～8.99μg·kg-1·min-1。9例(32.1%)患者诱导后出现一过性胸前皮肤发红,所有患者均未出现插管困难及术中体动。结论在采用静吸复合麻醉维持的甲状腺手术中,持续输注米库氯铵且不影响甲状腺手术术中神经功能监测的LD50为8.94μg·kg-1·min-1,95%置信区间为8.89～8.99μg·kg-1·min-1。术中未见严重不良反应。

Objective To determine the maximum dose of continuously infused mivacurium for intraoperative neuromonitoring and observe its adverse effects in thyroid surgery. Methods Twenty-eight patients undergoing thyroid surgery with intraoperative neuromonitoring received continuous infusion of mivacurium at the initial rate of 5.43 μg·kg^-1·min^-1, and the infusion rate for the next patient was adjusted based on the response of the previous patient according to the results of neurological monitoring. The depth of anesthesia was maintained with sevoflurane and remifentanil during the surgery. The LD50 and 95% CI of mivacurium were calculated using Brownlee’s up-and-down sequential method. Results The LD50 of continuously infused mivacurium was 8.94 μg·kg^-1·min^-1(95% CI: 8.89-8.99 μg·kg^-1·min^-1) during thyroid surgery, which did not affect neurological function monitoring. Transient chest skin redness occurred after induction in 9 patients(32.1%). None of the patients experienced intubation difficulties or showed intraoperative body motions during the surgery. Conclusion In patients undergoing thyroid surgery under anesthesia maintained by inhalation and intravenous infusion, the LD50 of mivacurium was 8.94 μg · kg^-1·min^-1(95% CI: 8.89-8.99 μg · kg^-1·min^-1) for continuous infusion, which does not cause serious adverse effects during the operation.