Pharmacokinetics of 2% lidocaine superior laryngeal nerve block combined with 5% lidocaine topical anesthesia to endotracheal mucosa by thyrocricocentesis / 中华麻醉学杂志

ABSTRACT

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. 6?g/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.