Pharmacokinetics of intravenous and topical lidocaine in patients undergoing thoracoscopic pulmonary resection: a comparative study.

Abstract

Lidocaine was the commonly used local anesthetic. The present study aimed to compare the pharmacokinetics of intravenous and topical lidocaine in patients undergoing thoracoscopic pulmonary resection. Sixty patients who were scheduled for thoracoscopic pulmonary resection were screened and randomly assigned to the intravenous lidocaine group and topical lidocaine group. After induction, the patient in the intravenous group was given an intravenous bolus of 1.5 mg/kg lidocaine, while the patient in the topical group was given 3.0 mg/kg lidocaine via the "spray-as-you-go" method. Arterial blood was sampled at preset intervals, and plasma concentrations of lidocaine and its metabolites [monoethylglycinexylidide (MEGX) and glycinexylidide (GX)] were measured by ultra-performance liquid chromatography-tandem mass spectrometry. Following intravenous administration, plasma lidocaine concentration reached its peak with a time to reach Cmax (Tmax) of 0.05 h and then decreased in a biphasic manner with a very short half-life time (T1/2) of 1.85 h. After topical administration, lidocaine was well absorbed, with Tmax of 0.21 h and bioavailability of 71.02%. The mean Tmax, Cmax, and area under the curve from the time (AUC0-t) of MEGX and GX were higher in the topical group than in the intravenous group. There were no obvious differences in the Cmax, T1/2, clearance, or apparent volume of distribution of lidocaine between the two groups. No obvious adverse events were observed. Topical administration of 3 mg/kg lidocaine via the "spray-as-you-go" method is an effective and safe technology for patients undergoing thoracoscopic pulmonary resection.