利多卡因喉上神经阻滞联合环甲膜穿刺气管内给药时的药代动力学

Pharmacokinetics of 2% lidocaine superior laryngeal nerve block combined with 5% lidocaine topical anesthesia to endotracheal mucosa by thyrocricocentesis

目的:研究利多卡因喉上神经阻滞联合环甲膜穿刺气管内给药时的药代动力学。方法:8例择期全麻病人(ASA Ⅰ～Ⅱ级)。用2%利多卡因2mg/kg行双侧喉上神经阻滞,5%利多卡因2mg/kg行环甲膜穿刺气管内给药,操作在1分钟内完成。在给药后1、5、15、20、30、60、120和180分钟采取颈内静脉血,用荧光偏振免疫法(TDxFLx)测定利多卡因血清浓度,用药代动力学计算程序(3p 87)处理。结果:吸收半衰期t_(1/2)Ka 5.0±2.5分钟,达峰浓度Cmax 3.8±0.5μg/ml,达峰时间Tpeak7.5±2.1分钟。结论:2%利多卡因2mg/kg行双侧喉上神经阻滞加5%利多卡因2mg/kg行环甲膜穿刺气管内表面麻醉是安全的。

Objective: To study pharmacokinetics of lidocaine during superior laryngeal nerve block (SLNB) combined with topical anesthesia to endotracheal mucosa by thyrocricocentesis(TCC). Method: Eight patients (ASA Ⅰ-Ⅱ grade)scheduled for general anesthesia and operation were performed bilateral SLNB with 2% lidocaine 2mg/kg and TCC with 5 % lidocaine 2mg/kg within 1 min,The internal jugular venous blood samples were taken at 1,5,10,20,30, 60,120 and 180 minutes after lidocaine administrations to determine lidocaine serum concentrations using a fluoresence polarization immunoassy. Pharmacokinetics were calculated with a procedure (3p87) by computer. Result: The pharmacokinetics could be described as two-compartment model. Absorption rates of lidocaine were fast,values of t_(1/2) Ka and Tpeak were 5.0±2.5 min and 7.5±2.1 min respectively。Maximal concentrations (Cmax) of lidocaine were 3.8±0. 6μg/ml, which were within safety ranges. Conclusion: It may be safe that 2% lidccaine 2mg/kg superior laryngeal nerve block is combined with 5% lidocaine 2mg/kg topical anesthesia to endotracheal mucosa by thyrocricocentesis.