Differential peripheral axon block with lidocaine: unit studies in the cervical vagus nerve
Fink, B.R.; Cairns, A.M.
Anesthesiology 59(3): 182-186
1983
ISSN/ISBN: 0003-3022 PMID: 6881581 Document Number: 205366
The differential susceptibility of large and small axons to lidocaine was studied on units in the rabbit vagus nerve. The results classified the units into 3 groups: myelinated, conduction velocity 37.5-5 m/s, which were blocked by lidocaine 0.4-0.8 mM; slow, unmyelinated axons, conduction velocity 1.2-0.5 m/s, and these axons were not blocked by 0.2, 0.4 or 0.6 mM lidocaine but usually were blocked by 0.8 mM lidocaine; and axons of intermediate conduction velocity, between 1.2 and 4 m/s. The last group of axons was the most sensitive; some were blocked by as little as 0.2 mM lidocaine. No size-related trend was detected within the groups.