JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS
AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
A&A International Anesthesia Research Society
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a colleague
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (4)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Nishiyama, T.
Right arrow Articles by Hanaoka, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nishiyama, T.
Right arrow Articles by Hanaoka, K.
Anesth Analg 2000;91:652-656
© 2000 International Anesthesia Research Society

REGIONAL ANESTHESIA AND PAIN MEDICINE

The Effects of Epidural Bupivacaine, Morphine, and Their Combination on Thermal Nociception with Different Stimulus Intensity in Rats

Tomoki Nishiyama, MD, PhD, and Kazuo Hanaoka, MD, PhD

Department of Anesthesiology, The University of Tokyo, Tokyo, Japan

Address correspondence and reprint requests to Tomoki Nishiyama, MD, PhD, 3-2-6-603, Kawaguchi, Kawaguchi-shi, Saitama, 332-0015, Japan. Address e-mail to nishiyamat-ane{at}h.u-tokyo.ac.jp

The analgesic effect of drugs depends on the stimulus intensity as well as the potency of the drugs. We investigated the effects of stimulus intensity on antinociceptive potencies of epidural bupivacaine + morphine. Sprague-Dawley rats implanted with chronic lumbar epidural catheters were tested for paw withdrawal response to thermal stimulation after the epidural injection of bupivacaine, morphine, or bupivacaine + morphine. Two stimulation currents were used, 5.1 and 4.6 A, to provide baseline response latency of approximately 5.0 s (high intensity) and 10.0 s (low intensity), respectively. Increasing the dose of epidural morphine in a dose range that had a maximum effect on low-intensity stimulation was not effective for high-intensity stimulation. Bupivacaine, which alone had no effect, potentiated the antinociceptive effect of epidural morphine at both high- and low-intensity stimuli similarly. We concluded that bupivacaine potentiated the analgesic effect of epidural morphine at both weak and strong nociceptive stimuli similarly, whereas increasing the dose of epidural morphine was not as effective for strong nociceptive stimulation. Therefore, adding bupivacaine might be more effective than increasing the dose of epidural morphine for intense nociception.

Implications: When patients have severe pain even when receiving epidural morphine, adding bupivacaine might be more effective than increasing the dose of epidural morphine.




This article has been cited by other articles:


Home page
 Anesth. Analg.Home page
H. C. Jin, A. J. Keller, J. K. Jung, A. Subieta, and T. J. Brennan
Epidural Tezampanel, an AMPA/Kainate Receptor Antagonist, Produces Postoperative Analgesia in Rats
Anesth. Analg., October 1, 2007; 105(4): 1152 - 1159.
[Abstract] [Full Text] [PDF]


Lippincott, Williams & Wilkins Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999 HighWire Press
Copyright © 2000 by the International Anesthesia Research Society.