Plasma Lidocaine Concentrations After Caudal, Lumbar Epidural, Axillary Block, and Intravenous Regional Anesthesia

Abstract

Chromatographic analysis of lidocaine in plasma was carried out in 15 patients having intravenous regional anesthesia and in 15 patients having axillary block, lumbar epidural, or caudal anesthesia. Plasma lidocaine concentration was lower with intravenous regional anesthesia (1. 5 [plus or minus] 0. 2 [mu]g/ml) than with axillary block (2. 5 [plus or minus] 0. 5[mu]g/ml), or lumbar epidural anesthesia (3. 1 [plus or minus] 0. 7 [mu]g. /ml. ). Pulse rate, blood pressure and ECG [electrocardiogram] changes were absent in those patients having intravenous regional anesthesia. Intravenous lidocaine, 3 mg/kg of a 0. 5% solution, provides safe, effective anesthesia when injected into an exsanguinated extremity.