Comparison of the minimum dose to induce seizure for lidocaine administration in the carotid artery and femoral vein

Abstract

Erroneous administration of even a small dose of local anesthetic into the carotid artery may induce generalized seizures resulting from acute lidocaine intoxication. We infused lidocaine continuously with or without epinephrine into the carotid artery or femoral vein of rabbits to compare the lowest cumulative dose that would induce seizures, and recorded blood lidocaine levels and cerebral hemodynamics at the onset of seizures for the two routes of administration. Four groups of rabbits under ventilation received lidocaine with or without epinephrine via the cervical artery or femoral vein, and their electroencephalogram, mean arterial pressure, regional cerebral blood flow, and rectal temperature were monitored. Cumulative dose and the plasma level of lidocaine at the onset of seizures were compared for the four groups.
In rabbits receiving lidocaine alone, plasma lidocaine level at seizure onset was lower with administration via the carotid artery than via the femoral vein, although there was no difference in the cumulative dose at onset. In rabbits receiving lidocaine with epinephrine, the epinephrine increased the lowest intracarotid lidocaine dose that induced seizures, but did not affect plasma lidocaine level at onset for either route of administration.Shika Igaku(J Osaka Odontol Soc) 2003 Sep; 66(3): 220-226.