Effect of Perioperative Perineural Injection of Dexamethasone and Bupivacaine on a Rat Spared Nerve Injury Model.
10.3344/kjp.2010.23.3.166
- Author:
Jeong Beom LEE
1
;
Seong Soo CHOI
;
Eun Hye AHN
;
Kyung Don HAHM
;
Jeong Hun SUH
;
Jung Gil LEEM
;
Jin Woo SHIN
Author Information
1. Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. sjinwoo@hotmail.com
- Publication Type:Original Article
- Keywords:
bupivacaine;
dexamethasone;
perineural injection;
preemptive analgesia;
spared nerve injury model
- MeSH:
Animals;
Bupivacaine;
Dexamethasone;
Hair;
Hyperalgesia;
Neuralgia;
Rats
- From:The Korean Journal of Pain
2010;23(3):166-171
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Neuropathic pain resulting from diverse causes is a chronic condition for which effective treatment is lacking. The goal of this study was to test whether dexamethasone exerts a preemptive analgesic effect with bupivacaine when injected perineurally in the spared nerve injury model. METHODS: Fifty rats were randomly divided into five groups. Group 1 (control) was ligated but received no drugs. Group 2 was perineurally infiltrated (tibial and common peroneal nerves) with 0.4% bupivacaine (0.2 ml) and dexamethasone (0.8 mg) 10 minutes before surgery. Group 3 was infiltrated with 0.4% bupivacaine (0.2 ml) and dexamethasone (0.8 mg) after surgery. Group 4 was infiltrated with normal saline (0.2 ml) and dexamethasone (0.8 mg) 10 minutes before surgery. Group 5 was infiltrated with only 0.4% bupivacaine (0.2 ml) before surgery. Rat paw withdrawal thresholds were measured using the von Frey hair test before surgery as a baseline measurement and on postoperative days 3, 6, 9, 12, 15, 18 and 21. RESULTS: In the group injected preoperatively with dexamethasone and bupivacaine, mechanical allodynia did not develop and mechanical threshold forces were significantly different compared with other groups, especially between postoperative days 3 and 9 (P < 0.05). CONCLUSIONS: In conclusion, preoperative infiltration of both dexamethasone and bupivacaine showed a significantly better analgesic effect than did infiltration of bupivacaine or dexamethasone alone in the spared nerve injury model, especially early on after surgery.
