碳酸利多卡因在硬膜外麻醉中的药动学-药效学与硬膜外输注给药方案设计

Pharmacokinetics-Pharmacodynamics and Design of Administration Schedule on Continued Epidural Infusion of Lidocaine Carbonate in Patients during Epidural Anesthesia

人中的药物动力学及药效学进行研究。采用荧光们振免疫分析方法测定血清利多卡因浓度；结果：根据药动学－药效学研究结果，提出维持有效麻醉血药浓度为２．５～５．０μｇ/ｍｌ；利用药动学参数清除率，计算出硬膜外持续输注给药速率为２０～４０μｇ／ｍｉｎ．ｋｇ。应用先给予初始剂量，后根据病人情况，选择合适的给药速率实施硬膜外持续给药。对５１例病人采用硬膜外持续输注给药后的１４５份血药浓度进行监测，同时对所有病人在手术全过程中的麻醉效果、血压及心牵进行连续监测。结果表明，初始给药剂量为（３．７５±０．６２）ｍｇ/ｋｇ（２．１～６．２）ｍｇ／ｋｇ（ｎ＝５１）；硬膜外持续输注速率为（３５．９９±５．３０）μｇ／ｍｉｎ．ｋｇ；平均血药浓度为（３．３２±ｌ．５２）μｇ／ｍｌ（ｎ＝１４５）。手术过程中麻醉效果满意，病人的血压及心率正常。结论：采用先给予初始剂量．后持续硬膜外输注给药的方案，即可获得满意的麻醉效果，又克服了在硬膜外麻醉中，由于重复给药所引起的血药浓度的较大波动，这种血药浓度的波动，可能引起浓度过低的麻醉效果不够，或浓度过高的药物中毒。

Objective: Pharmacokinetics and pharmacodynamics of lidocaine carbonate in 15 patients dur-ing epidural anaesthesia were studied in order to design the dosage schedul on continued epidural infusion of lidocaine carbonate. Method: Serum concentrations of lidocaine were measured by fluorescence polarization immunoassay method. Results: Range of serum concentrations for the maintaining of effective anaesthesia was obtained, i.e. 2. 5-5. 0μg/mi,according to the results getting from pharmacokinetics and pharmacodynamics of lidocaine carbonate in 15 patients. The epidural infusing rate of lidocaine carbonate was calculated approximately by using the clearance of lidocaine and the results of pharmacokinetics-pharmacodynamics, it ranged from 20μg/min. kg to 40 μg/min. kg. The serum level of lidocaine, anaesthetic effect, blood pressure and heart rate in 51 patients were monitored during surgical operation by epidural anaesthesia, these patients were given a routing dose at first, then administered by epidural infusion in the rate of 20~40 μg/mm. kg. The results showed that the mean routing dose was (3. 75±0. 62) mg/kg, the mean rate of epidural infusion was (35. 99±5. 304)μg/min. kg, the mean serum levels of lidocaine in 145 monitored samples were (3. 32±1. 52) μg/ml, the values of blood pressure and heart rate of all patients were normal. The effect of anaesthesia was satisfied during the surgical operation. Conclusion: The schedule on administration of routing dose plus continued epidural infusion was beneficial to both getting satisfied anaesthetic effect and avoiding obvious fluctuation of serum lidocaine concentrations caused by repeated-drug administration, the obvious fluctuation of serum lidocaine concentrations may lead to lack of anaesthetic effect if the serum level of lidocaine was too low or toxicosis if the serum level of the drug was too high.