Newly Published
Pain Medicine  |   July 2019
Outcomes of Sympathetic Blocks in the Management of Complex Regional Pain Syndrome: A Retrospective Cohort Study
Author Notes
  • From the Departments of Pain Management (J.C., V.S., M.G., O.T.C., F.Z., R.W.R.), Neurosciences (J.C.), and Quantitative Health Sciences and Outcomes Research (J.Y., D.Y., E.J.M.), Cleveland Clinic, Cleveland, Ohio; Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Palo Alto, California (V.S.).
  • Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).
    Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).×
  • Part of the work presented in this article has been presented at the 9th World Congress of the World Institute of Pain (WIP 2018), May 9–12, 2018, in Dublin, Ireland, the American Academy of Pain Medicine 33rd Annual Meeting, March 16–19, 2017, Orlando, Florida, and the 15th American Society of Regional Anesthesia and Pain Medicine Annual Pain Medicine Meeting, November 17–19, 2016, San Diego, California.
    Part of the work presented in this article has been presented at the 9th World Congress of the World Institute of Pain (WIP 2018), May 9–12, 2018, in Dublin, Ireland, the American Academy of Pain Medicine 33rd Annual Meeting, March 16–19, 2017, Orlando, Florida, and the 15th American Society of Regional Anesthesia and Pain Medicine Annual Pain Medicine Meeting, November 17–19, 2016, San Diego, California.×
  • Submitted for publication November 3, 2017. Accepted for publication May 30, 2019.
    Submitted for publication November 3, 2017. Accepted for publication May 30, 2019.×
  • Correspondence: Address correspondence to Dr. Cheng: Cleveland Clinic Multidisciplinary Pain Medicine Fellowship Program, Departments of Pain Management and Neurosciences, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, Ohio 44195. chengj@ccf.org. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Pain Medicine / Central and Peripheral Nervous Systems / Neuromuscular Diseases and Drugs / Pain Medicine / Regional Anesthesia
Pain Medicine   |   July 2019
Outcomes of Sympathetic Blocks in the Management of Complex Regional Pain Syndrome: A Retrospective Cohort Study
Anesthesiology Newly Published on July 29, 2019. doi:10.1097/ALN.0000000000002899
Anesthesiology Newly Published on July 29, 2019. doi:10.1097/ALN.0000000000002899
Abstract

Editor’s Perspective:

What We Already Know about This Topic:

  • Sympathetic blocks are used in the diagnosis and treatment planning of patients with complex regional pain syndrome

  • It is unclear whether the response to sympathetic blocks is associated with spinal cord stimulation trial success

What This Article Tells Us That Is New:

  • In patients with complex regional pain syndrome, skin temperature change is not associated with sympathetic block pain reduction

  • The short- and long-term effects of sympathetic blocks are not associated with spinal cord stimulation outcomes

Background: Sympathetic dysfunction may be present in complex regional pain syndrome, and sympathetic blocks are routinely performed in practice. To investigate the therapeutic and predictive values of sympathetic blocks, the authors test the hypotheses that sympathetic blocks provide analgesic effects that may be associated with the temperature differences between the two extremities before and after the blocks and that the effects of sympathetic blocks may predict the success (defined as achieving more than 50% pain reduction) of spinal cord stimulation trials.

Methods: The authors performed a retrospective study of 318 patients who underwent sympathetic blocks in a major academic center (2009 to 2016) to assess the association between pain reduction and preprocedure temperature difference between the involved and contralateral limbs. The primary outcome was pain improvement by more than 50%, and the secondary outcome was duration of more than 50% pain reduction per patient report. The authors assessed the association between pain reduction and the success rate of spinal cord stimulation trials.

Results: Among the 318 patients, 255 were diagnosed with complex regional pain syndrome and others with various sympathetically related disorders. Successful pain reduction (more than 50%) was observed in 155 patients with complex regional pain syndrome (155 of 255, 61%). The majority of patients (132 of 155, 85%) experienced more than 50% pain relief for 1 to 4 weeks or longer. The degree and duration of pain relief were not associated with preprocedure temperature parameters with estimated odds ratio of 1.03 (97.5% CI, 0.95–1.11) or 1.01 (97.5% CI, 0.96–1.06) for one degree decrease (P = 0.459 or 0.809). There was no difference in the success rate of spinal cord stimulation trials between patients with or without more than 50% pain relief after sympathetic blocks (35 of 40, 88% vs. 26 of 29, 90%, P > 0.990).

Conclusions: The authors conclude that sympathetic blocks may be therapeutic in patients with complex regional pain syndrome regardless of preprocedure limb temperatures. The effects of sympathetic blocks do not predict the success of spinal cord stimulation.