While the use of sympathetic blocks (injections) is controversial, in this study, 20 patients suffering from complex regional pain syndrome (CRPS) were given injections to examine the method's contribution "as prospective predictors of outcome."
The patients, who exhibited allodynia, or pain with light touch, were given an initial "diagnostic" injection after which results were analyzed to determine if further treatments would be advantageous. This treatment consists of injections into the sympathetic nerves that run along the front side of the spinal column.
Those who showed at least a 50% improvement were treated with subsequent blocks. Patients who did show initial improvement were considered to have "sympathetically maintained pain" (SMP) and were also more likely to experience greater long-term improvement as well. Cases in which patients did not have significant improvement were considered to have "sympathetically independent pain" (SIP) and no further treatment was given.
Previous studies by Cepeda et al (1) showed that less than one-third of CRPS patients are likely to respond to this type of procedure.
"Reserving these invasive procedures for patients who will receive the greatest benefit could have significant value by reducing unnecessary risk for adverse events, as well as significant economic benefit by limiting the costs associated with unnecessary procedures," states lead researcher, Dr. Craig T. Hartrick.
Although this study was not randomized and was not placebo-controlled, it "speaks to the rational use of sympathetic block" and suggests that this procedure is especially useful when allodynia is present.
This study is published in Pain Practice. Media wishing to receive a PDF of the article contact medicalnews@bos.blackwellpublishing.net.
About the Author
Craig T. Hartrick, M.D., D.A.B.P.M., F.I.P.P., directs the clinical and basic science laboratory research for the Department of Anesthesiology at the William Beaumont Hospital Research Institute. Hartrick has published over 80 articles, abstracts, chapters, reviews and editorials and serves on the editorial boards for Pain Practice and MD Consult Pain Medicine. His current research involved cytokine mediated nitric oxide release in CRPS and outcomes following interventional pain management techniques. Dr. Hartrick is available for questions and interviews and can be reached at chartrick@beaumont.edu.
About Pain Practice
Pain Practice, the official journal of World Institute of Pain, publishes international multidisciplinary articles on pain that provide its readership with up-to-date knowledge of the research, evaluation methods, and techniques of pain management. The present literature on pain medicine is diverse and published in a variety of basic and clinical specialty journals. For a practitioner to subscribe to all the venues needed to cover the field of pain medicine would be impractical, if not impossible. Likewise, the literature search can be cumbersome, costly, and entirely unavailable in some areas. As a thorough, multidisciplinary journal, Pain Practice is a convenient, cost-effective way to resolve these dilemmas. Published on behalf of the World Institute of Pain. For more information on membership, please visit www.wipain.org.
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