The Effect of Adrenaline on the Blockade of Compound Action Potential by Local Anesthetics in Rat Sciatic Nerves.
10.4097/kjae.1999.37.4.675
- Author:
Yoon CHOI
1
;
Joog Woo LEEM
;
Hyun Cheol YANG
;
Jong Seok YANG
;
Sung Min HAN
;
Jae Young YU
;
Seung Woon LIM
;
Dong Myung LEE
Author Information
1. Department of Anesthesiology, College of Medicine, University of Ulsan.
- Publication Type:In Vitro ; Original Article
- Keywords:
Animals, rats;
Local anesthetics, lidocaine;
Monitoring, compound action potential;
Nerve, sciatic;
Pharmacology, adrenaline
- MeSH:
Action Potentials*;
Adrenergic Agonists;
Adult;
Anesthetics;
Anesthetics, Local*;
Animals;
Clonidine;
Depression;
Epinephrine*;
Humans;
Lidocaine;
Male;
Nerve Block;
Neural Conduction;
Peripheral Nerves;
Rats*;
Rats, Sprague-Dawley;
Receptors, Adrenergic;
Sciatic Nerve*;
Vasoconstriction
- From:Korean Journal of Anesthesiology
1999;37(4):675-684
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Adrenaline has often been used to prolong the local anesthetic effect during surgical procedures. As a possible explanation for this, a local vasoconstriction caused by adrenaline has been proposed. However, in a recent study, clonidine, an alpha2 adrenergic receptor agonist, was reported to block the conduction of mammalian nerves in vitro. Thus, there is a possibility that adrenaline may block nerve conduction by acting on the adrenergic receptor. The present study is performed to see : (1) If adrenaline directly affects nerve conduction ; (2) If adrenaline affects conduction blockade caused by local anesthetic. METHODS: Recordings of compound action potentials (CAPs) of A- and C-components were obtained from isolated sciatic nerves of adult male Sprague-Dawley rats. Dose-response curves of lidocaine and adrenaline regarding depression of CAPs were determined. Effects of adrenaline on the lidocaine-induced nerve block was assessed by comparing the effect of lidocaine (3.5x 10 5) with a lidocaine-epinephrine mixture (Lido-Epi, 3.5 x10 5 lidocaine with 1:100,000 epinephrine). RESULTS: Adrenaline, near the clinical concentrations, had no effect on the size of either A- or C-component of CAPs. The ED50 of lidocaine was 3.5x 10 5. Lidocaine depressed A-CAP 45.9+/- 7.0 when compared with baseline value, and the Lido-Epi solution depressed A-CAP to 41.7+/- 5.0 (P > 0.05). Lidocaine depressed C-CAP 59.8 +/- 3.4 when compared with the baseline value, and the Lido-Epi solution depressed C-CAP to 60.5 8.1 (P > 0.05). Consequently, adrenaline did not augment lidocaine induced nerve blockade. CONCLUSION: This study confirmed that adrenaline applied to the peripheral nerve has no effect either on nerve conduction itself or on conduction block produced by lidocaine.
