The Potentiation of the Analgesic Effect of Intrathecally Coadministered Magnesium Sulphate and Bupivacaine in Duration of Sensory Blockade in Rats.
10.4097/kjae.2001.41.6.S33
- Author:
Jae Chan CHOI
1
;
Kyung Bong YOON
;
Jin Soo KIM
;
Soon Yul KIM
;
Kwang Ho LEE
;
Young Bok LEE
;
Hyun Kyo LIM
;
Eun Sung JUN
Author Information
1. Department of Anesthesiology, Yonsei University Wonju College of Medicine, Korea. hklim@wonju.yonsei.ac.kr
- Publication Type:Original Article
- Keywords:
Anesthetic techniques: intrathecal;
Pharmacology: bupivacaine;
magnesium sulphate
- MeSH:
Analgesia;
Anesthesia;
Animals;
Bupivacaine*;
Hindlimb;
Humans;
Magnesium*;
Male;
Paralysis;
Rats*;
Rats, Sprague-Dawley;
Sodium Chloride
- From:Korean Journal of Anesthesiology
2001;41(6):S33-S38
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Based on previously reported articles, magnesium sulphate seemed to cause a motor paralysis, but not complete analgesia when administered intrathecally alone, but is likely to have a partial analgesic effect. Accordingly, we tested a hypothesis that magnesium sulphate might potentiate the analgesic effect when coadministered intrathecally with bupivacaine. METHODS: Eighteen male Sprague-Dawley rats were allocated into three groups of six animals each. The duration of sensory blockade was determined by observing the period when the animal did not vocalize and/or withdraw (struggle) while forceps-pinch tests were applied to a hindlimb paw. The six animals in each of the following three groups were injected intrathecally with 0.03 ml of the different test substances: (group 1) 16.7% magnesium sulphate {50% magnesium sulphate (0.01 ml) + 0.9% sodium chloride (0.02 ml)}; (group 2) 50% magnesium sulphate (0.01 ml) + 0.5% bupivacaine (0.02 ml); (group 3) 0.33% bupivacaine {0.5% bupivacaine (0.02 ml) + 0.9% sodium chloride (0.01 ml)}. RESULTS: Sensory blockade in the hindlimbs was observed only in group 2 and lasted for 12 to 14 minutes, while there were no sensory blockades in group 1 and group 3. CONCLUSIONS: Magnesium sulphate potentiated the analgesic effect of bupivacaine when coadministered intrathecally with bupivacaine in rats. These results suggest that intrathecal administration of magnesium sulphate may be a useful adjunct to spinal bupivacaine anesthesia.
