Lidocaine and fentany1 are frequently used as analgesic agents or blockers of pathway. To evaluate the influence of lidocaine and/or fentany1 to nerve conduction, we divided 29 wistar rats(200~300gm) into four groups such as 4% lidocaine(2mg/100g) dripping, mixed solution(4% lidocaine and fentany1) dripping, fentany1(2.5ug/100g) dripping, saline solution dripping. Rats were anesthetized with ether and pentothal sodium(2mg/100g) and their sciatic nerves were surgically exposed and were dripped with experimental solution according to groups. Sensory nerve action potentials(SNAP) were examined according to time sequence such as pre-dripping, post-dripping 2 min., 5 min., 10 min., 20 min., 30 min respectively.

The results were as follows:

1) Significantly prolonged latencies and decreased amplitudes were noted in 2 min., 5 min., 10 min., and 20 min. after dripping of lidocaine as compared to that of pre-dripping, respectively (p>0.05)

2) Significantly prolonged latencies were noted in 2 min., 5 min., 10 min., 20 min., and significantly decreased amplitudes were noted in 5 min., 10 min., after dripping of mixed solution as compared to that of pre-dripping, respectively (p<0.05)

3) There was no significant change between pre-and post-dripping of fentany1 or saline solution, respectively (p>0.05).

So we concluded that lidocaine or mixed solution(lidocaine and fentany1) was effective in blocking of nerve conduction, but synergic effects of fentany1 addition was not observed in nerve conduction study.