Complex Regional Pain Syndrome in Emergency Medicine Treatment & Management

Updated: Sep 07, 2023
  • Author: Marcella L Ruffo, MD; Chief Editor: Andrew K Chang, MD, MS  more...
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Approach Considerations

It is in the best interest of patients with complex regional pain syndrome (CRPS) to have a physician knowledgeable about this entity orchestrate all care. Appropriate referral is important.


Prehospital Care

There is nothing for prehospital providers to do in cases of complex regional pain syndrome (CRPS) except transport. Most state guidelines do not include chronic pain syndromes as an indication for narcotic administration.


Emergency Department Care

Definitive care for complex regional pain syndrome (CRPS) is really beyond the purview of the ED physician. An emergency physician's primary role with patients who have CPRS is to recognize the possibility of the diagnosis and refer such patients to clinical services utilizing treatment modalities listed below. Early breaking of the pain cycle increases the likelihood of a better outcome.

The 3 basic modes of therapy include pain management, rehabilitation (including physical therapy), and psychological therapy. [40]

Once the diagnosis is established, a number of treatment modalities are available. The most effective treatment involves differential neural blockade. Children may also benefit from neural blockade. [39]

CRPS experts and researchers have looked at many treatment possibilities. Some have proven beneficial, others less so. The list below includes most of the possibilities that have been considered. Some of the oral medications may be prescribed in the ED after discussion with the primary care physician or pain specialist. Neural blockade may be an option for ED providers, based on location of pain. Although none of the other modalities will be used in the ED, the clinician should have an overview of the available options.

  • The anesthesia literature provides good evidence that spinal stimulation is effective. [41, 42]

  • Most patients, especially children, can benefit from physical therapy. [21, 43, 44, 45] A new physical modality—graded motor imagery—has recently received a great deal of attention. [46, 47]

  • Tricyclic antidepressants have been used to decrease burning. Gabapentin (Neurontin) and systemic steroids have also been used with varying degrees of success. Other agents include the alpha-1 adrenoreceptor antagonists terazosin and phenoxybenzamine; the alpha-2 adrenoreceptor agonist clonidine; and the NDMA receptor antagonists ketamine, dextromethorphan, and calcitonin. When treatment reaches a plateau, invasive interventions to be considered include tunneled epidural catheters and neuroaugmentation.

  • Dadure et al recently described a series of pediatric patients with recurrent CRPS who benefited from continuous peripheral nerve blocks given at home. [39]

  • Sympathetic nerve block as well as ketamine infusions have become widely used in CRPS. Cohen et al conducted a multi-center retrospective study that found improved effects of ketamine infusion after successful use of sympathetic nerve block. [48]  

  • Acupuncture has been reported to have some value, especially in children. [49]

  • Topical and intravenous lidocaine have been reported to be effective in some cases. [50] Most of the literature appeared several years ago, but the group at Drexel University College of Medicine in Philadelphia reported favorable results for a 5-day lidocaine infusion. [51]

  • Eckmann et al performed a randomized, controlled trial that looked at several parameters with the use of IV regional block with ketorolac and lidocaine for treating CRPS. This small study of10 patients with lower extremity CPRS type I showed short-term (1 week) pain relief. No improvement was shown in the primary outcome of overall pain numeric rating scale or secondary outcomes of pain in motion, allodynia, joint pain score, edema, range of ankle motion, and skin temperature. [52]

  • A Turkish group performed a randomized controlled trial using a Bier block containing methylprednisolone and lidocaine in patients with CRPS type I patients. The group concluded that the therapy did not provide long-term benefit, and the short-term benefit was no better than with placebo. [53]

  • Case reports and small number studies have reported good efficacy for topical and IV infusion of ketamine. As a dissociative anesthetic, the logic is to try to "erase the memory" of the pain stimulation. [54, 55, 56] Several more recent studies also discuss the value of this therapy. [57, 58, 59]

  • A group in the Netherlands reported significant pain decrease in 8 patients treated with an IV infusion of magnesium. [60]

  • Work that is looking at the efficacy of bisphosphonates has begun. [11, 61]

  • Intravenous immunoglobulin has been studied. [8]

  • Case reports describe some promise for the injection of botulinum toxin. [62, 63]

  • The use of hyperbaric oxygen chambers has been evaluated and found to decrease edema when compared to regular air, however, this treatment option requires further investigations to become a true treatment strategy. [64]  

  • For patients who cannot be seen in the ED or cannot be treated in an expeditious fashion with neural blockade, the primary care physician who knows the patient best should arrange for narcotic analgesia, recognizing that neuropathic pain may be very resistant to standard analgesics, even potent ones. Patients who fail neural blockade very well may have disease that has progressed to the sympathetic-independent stage, and they are likely to have a lifelong problem. In this group, treatment by specialists in pain management, who have access to more sophisticated and experimental therapies, is mandatory.

  • In the ED, narcotics often are required to provide temporary relief while waiting for definitive treatment to begin. Patients with refractory disease may present to the ED with flare-ups that require narcotics. Although distinguishing between those who are truly in pain and those who are malingering is very difficult, the clinician must not assume that all who present without an obvious painful problem are drug seekers. Those with CRPS/RSDS may have a paucity of objective findings. Many are under the care of a knowledgeable pain expert and do not allow themselves to run out of analgesia.



Consultations with the following in cases of complex regional pain syndrome (CRPS) may include the following:

  • anesthesiologist or other qualified pain management specialist
  • physical medicine personnel regarding rehabilitation

  • occupational, physical, and vocational rehabilitation specialists

  • hand surgeon

  • psychiatry for coping mechanisms as well as secondary psychological problems from the disease course 


Medical Care

Although not FDA approved in the United States, in some countries, patients with complex regional pain syndrome (CRPS) are hospitalized and placed on continuous intravenous infusions of medications such as lidocaine or ketamine. As a dissociative anesthetic, the latter is intended to "erase" the memory of dysfunctioning neurons. Results have been variable.



Unfortunately, the syndrome cannot be prevented entirely, given the variety of injuries and inciting events that may result in CRPS.

It has been well documented that those with CRPS who are diagnosed earliest do the best. Once the disease is well established, it probably cannot be reversed.