Work-Related Complex Regional Pain Syndrome




Complex regional pain syndrome can be a debilitating disorder, which, in its earliest stages, can be prevented by aggressive rehabilitation based on reactivation. It is critical to follow international criteria on making the diagnosis; overdiagnosis can lead to inappropriate interventions and further disability. When present, early recognition with reactivation is the cornerstone of treatment. This article presents a phased approach to treatment that suggests movements of nonresponders quickly to more integrated levels of care. Some commonly used invasive interventions, such as sympathectomy and spinal cord stimulation, have not been proved effective; these unproven and potentially harmful therapies should be avoided.


Key points








  • Prevention and early identification of complex regional pain syndrome (CRPS) are critical in regard to optimizing outcomes. Use of vitamin C can be helpful in preventing CRPS in cases of distal extremity injury.



  • Risk factors include injury or immobilization of a distal extremity, female sex, fear of movement, and tobacco use. Failure to follow a normal course of return to function should warrant closer attention by the physician.



  • The diagnosis of CRPS requires the presence of a specific set of symptoms and findings in addition to pain.



  • A phased approach to treatment is presented. CRPS should be identified early and the patient moved quickly to more integrated and experienced levels of care aimed at reactivation if not improving.






Introduction


This guideline is to be used by physicians, claim managers, occupational nurses, all other providers, and utilization review staff. The emphasis is on accurate diagnosis and treatment that is curative or rehabilitative (see Washington Administrative Code [WAC] 296-20-01,002 for definitions).


This guideline was developed between 2010 and 2011 by the Industrial Insurance Medical Advisory Committee (IIMAC) and its subcommittee on chronic noncancer pain. The subcommittee presented its work to the full IIMAC, and the IIMAC voted with full consensus advising the Washington State Department of Labor & Industries to adopt the guideline. This guideline is based on the best available clinical and scientific evidence from a systematic review of the literature and a consensus of expert opinion. One of the committee’s primary goals is to provide standards that ensure high quality of care for injured workers in Washington State.


Complex regional pain syndrome (CRPS), sometimes referred to as reflex sympathetic dystrophy or causalgia, is an uncommon chronic condition with clinical features that include pain, sensory, sudomotor and vasomotor disturbances, trophic changes, and impaired motor function. This condition may involve the upper or lower extremities and can affect men or women of any age, race, or ethnicity. Most people with onset of CRPS are females and adults. Females are affected as least 3 times more than males. The pathophysiology of CRPS is not fully understood. When CRPS occurs it typically follows an injury, such as a fracture, sprain, crush injury, or surgery. Immobilization, particularly after fracture or surgery, is a well-described risk factor.


Two types of CRPS have been described: CRPS I and CRPS II. For the most part, the clinical characteristics of both types are the same. The difference is based on the presence or absence of nerve damage. CRPS I (also known as reflex sympathetic dystrophy) is not associated with nerve damage, whereas CRPS II (also known as causalgia) is associated with objective evidence of nerve damage. Treatment for either form of CRPS should follow the recommendations in this guideline, although if there is objective evidence for CRPS II, other references and treatment guidelines for the particular nerve injury may also apply.




Introduction


This guideline is to be used by physicians, claim managers, occupational nurses, all other providers, and utilization review staff. The emphasis is on accurate diagnosis and treatment that is curative or rehabilitative (see Washington Administrative Code [WAC] 296-20-01,002 for definitions).


This guideline was developed between 2010 and 2011 by the Industrial Insurance Medical Advisory Committee (IIMAC) and its subcommittee on chronic noncancer pain. The subcommittee presented its work to the full IIMAC, and the IIMAC voted with full consensus advising the Washington State Department of Labor & Industries to adopt the guideline. This guideline is based on the best available clinical and scientific evidence from a systematic review of the literature and a consensus of expert opinion. One of the committee’s primary goals is to provide standards that ensure high quality of care for injured workers in Washington State.


Complex regional pain syndrome (CRPS), sometimes referred to as reflex sympathetic dystrophy or causalgia, is an uncommon chronic condition with clinical features that include pain, sensory, sudomotor and vasomotor disturbances, trophic changes, and impaired motor function. This condition may involve the upper or lower extremities and can affect men or women of any age, race, or ethnicity. Most people with onset of CRPS are females and adults. Females are affected as least 3 times more than males. The pathophysiology of CRPS is not fully understood. When CRPS occurs it typically follows an injury, such as a fracture, sprain, crush injury, or surgery. Immobilization, particularly after fracture or surgery, is a well-described risk factor.


Two types of CRPS have been described: CRPS I and CRPS II. For the most part, the clinical characteristics of both types are the same. The difference is based on the presence or absence of nerve damage. CRPS I (also known as reflex sympathetic dystrophy) is not associated with nerve damage, whereas CRPS II (also known as causalgia) is associated with objective evidence of nerve damage. Treatment for either form of CRPS should follow the recommendations in this guideline, although if there is objective evidence for CRPS II, other references and treatment guidelines for the particular nerve injury may also apply.




Establishing work relatedness


CRPS may occur as a delayed complication of a work-related condition or its treatment. Usually, CRPS occurs following an injury. In rare situations, CRPS may occur following an occupational disease. An injury is defined as a sudden and tangible happening of a traumatic nature producing an immediate or prompt result and occurring from without. The only requirement for establishing work-relatedness for an injury is that it occurs in the course of employment.


For an occupational disease, establishing work relatedness requires a more critical analysis that demonstrates more than a simple association between the disease and workplace activities. Establishing work relatedness for an occupational disease requires



  • 1.

    Exposure: workplace activities that contribute to or cause the condition


  • 2.

    Outcome: a medical condition that meets certain diagnostic criteria


  • 3.

    Relationship: generally accepted scientific evidence that establishes on a more probable than not basis (greater than 50%) that the workplace activity (exposure) in an individual case was a proximate cause of the development or worsening of the condition (outcome)



Establishing CRPS as a work-related condition requires documentation of



  • 1.

    Another work-related condition has been previously accepted


  • 2.

    A diagnosis of CRPS that meets the criteria in further section


  • 3.

    CRPS involves the same body part as the accepted, work-related condition





Prevention


CRPS is believed to be incited by trauma or immobilization following trauma. It is most likely to occur in the setting of bone fracture, especially of the distal extremity. The greatest risk for CRPS appears to be certain types of fractures such as distal radial, tibial, and ankle, as well as limited movement of the affected limb.


CRPS may be preventable if the alert clinician is on the lookout for CRPS. Therefore, in addition to the usual protocols for a particular injury, close surveillance of patients at risk for CRPS is recommended. For such patients, extra office visits may be appropriate, especially if the clinician suspects a patient may not follow the expected course of recovery within the expected length of time. The use of vitamin C (500 mg by mouth every day for 50 days) has been shown to reduce the incidence of CRPS following radial, foot, and ankle fractures (based on Level I and Level II Evidence).


CRPS may be prevented or arrested by early identification of risk factors and taking prompt action when they are present. The emphasis should be on pain control, mobilization, and monitoring from onset of acute injury through the normally expected treatment time, typically a few weeks to a few months.


To help prevent CRPS, one should know the risk factors and identify cases early and take action.


Know the Risk Factors


Risk factors include



  • 1.

    Prolonged immobilization (eg, due to bone fractures or soft tissue injury, especially in upper or lower distal extremities)


  • 2.

    Longer than normal healing times


  • 3.

    Delays in reactivation after immobility (eg, due to inadequate control of acute pain)


  • 4.

    Lack of weight bearing on lower extremities


  • 5.

    Tobacco use, which can delay fracture healing


  • 6.

    Reluctance to move or reactivate because of fear of pain or injury (fear avoidance)


  • 7.

    Nerve damage



Identify Cases Early and Take Action


One should take the following steps



  • 1.

    Intentionally solicit symptoms and watch for signs


  • 2.

    Educate the patient to immediately report any CRPS symptoms


  • 3.

    Give clear and specific instructions to patients about mobilization and use of the injured part


  • 4.

    Manage patients’ expectations about pain relief


  • 5.

    Use vitamin C at recommended doses in cases of fracture



Encourage Active Participation in Rehabilitation


One should take the following actions



  • 1.

    Have patient keep a recovery diary, logging pain level, symptoms, and activities


  • 2.

    Provide or facilitate activity coaching


  • 3.

    Set recovery goals with specified time frames (eg, next office or physical therapy visit)


  • 4.

    Use medications or interventional procedures in concert with rehabilitative strategies





Making the diagnosis


Most patients with pain in an extremity do not have CRPS. Avoid the mistake of diagnosing CRPS primarily because a patient has widespread extremity pain that does not fit an obvious anatomic pattern. In many instances, there is no diagnostic label that adequately describes the patient’s symptoms. It is often more appropriate to describe the condition as regional pain of undetermined origin than to diagnose CRPS. However, it is equally important to identify CRPS when it does occur, so that appropriate treatment can be instituted.


Symptoms and Signs


CRPS is an uncommon syndrome based on a particular pattern of symptoms and signs in addition to pain. Symptoms and signs may be present at rest or elicited by exercise or activity involving the affected limb. The primary symptom associated with CRPS is continuous pain that is disproportionate to the inciting event. Pain is often described as burning or sharp and may be associated with changes in skin sensation such as hyperalgesia (increased sensitivity) or allodynia (pain perception to stimuli that are normally not painful). Other symptoms and signs in the affected area may include



  • 1.

    Skin temperature dysregulation


  • 2.

    Skin color variability


  • 3.

    Sweat dysregulation


  • 4.

    Swelling or edema


  • 5.

    Changes to the texture or growth pattern of hair, nails, or skin


  • 6.

    Motor weakness, decreased range of motion (ROM), tremors, or dystonia



Three-Phase Bone Scintigraphy


Three-phase bone scintigraphy can be a useful supplement to making the clinical diagnosis of CRPS (Based on Level II and Level IV evidence). Abnormalities related to CRPS that may be seen in a 3-phase bone scan include increased blood flow and increased blood pool uptake to the region of interest, with delayed images showing increased uptake in a periarticular pattern. Including the bone scan as a criterion is intended to increase diagnostic sensitivity. A normal bone scan neither increases nor decreases the likelihood of the diagnosis of CRPS. An abnormal bone scan is not required for a CRPS diagnosis.


Diagnostic Criteria


Diagnostic criteria for CRPS, known as the Budapest criteria, were adopted by the subcommittee, with slight modification, after careful consideration of existing criteria and available scientific evidence. Information about the sensitivity and specificity of the diagnostic signs and symptoms can be found in the literature ( Box 1 ).


Apr 17, 2017 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Work-Related Complex Regional Pain Syndrome

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