Regional analgesic effect of epidural morphine--its evaluation using pain sensation produced by electrical stimulation
Taguchi, H.; Tachibana, K.; Uchida, M.
Masui. Japanese Journal of Anesthesiology 36(6): 836-840
1987
ISSN/ISBN: 0021-4892 PMID: 3656652 Document Number: 288619
Analgesic effect of epidural morphine, with special reference to the onset time and segmental effect, was studied in 45 patients who underwent gynecologic surgery. The patients were divided into following five groups of 9 patients each; 5 mg morphine in 14 ml saline (Group I), 5 mg morphine in 7 ml saline (Group II), 2.5 mg morphine in 14 ml saline (Group III), 2.5 mg morphine in 7 ml saline (Group IV) and 2% lidocaine 14 ml (Group V). Morphine was administered through the lumbar epidural catheters. In order to evaluate the epidural morphine analgesia, pain sensation evoked by the transcutaneous electrical stimulation was used. Two electrodes were placed at the level of Th7 and Th10 respectively, and the intensity of the electrical stimulation was so adjusted that it could be produced in the same degree in the respective locations. After epidural morphine injection, diminishing pain sensation was observed in 8 subjects in Group I, and 6 subjects in Group II within 30 min at Th10. At Th7, the hypalgesia developed in one in Group I and three in Group II. In both groups, the number of the subject with hypalgesia at Th7 was small and hypalgesia occurred a litter later than that at Th10. The onset time of hypalgesia at Th10 was 11.0 .+-. 3.5 min in Group I and 13.7 .+-. 5.0 min in Group II. Hypalgesia was seldom observed in groups III and IV.