Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Complex Regional Pain Syndrome


Related Terms

  • Algodystrophy
  • Causalgia
  • CRPS
  • CRPS I
  • CRPS II
  • Neurodystrophy
  • Reflex Sympathetic Dystrophy Syndrome
  • RSD
  • RSDS
  • Shoulder-hand Syndrome
  • Sudeck's Atrophy
  • Sympathalgia

Specialists

  • Anesthesiologist
  • Clinical Psychologist
  • Ergonomist
  • Hand Surgeon
  • Neurologist
  • Occupational Therapist
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Psychiatrist

Factors Influencing Duration

The factors influencing duration of disability in CRPS have not been precisely determined. Remission is common for periods of time (weeks, months, years); however, the duration of disability is influenced by the severity of the condition, the individual's response to treatment, and the development of complications or the presence of a comorbid condition.

Medical Codes

ICD-9-CM:
355.9 - Causalgia; Mononeuritis, Unspecified Site; Complex regional pain syndrome NOS

Overview

Complex regional pain syndrome (CRPS) is a complicated chronic pain condition that produces significant disability and dysfunction. In a majority of cases, CRPS follows acute trauma or major injury to an arm or leg (e.g., gunshot wound or fracture). Surgery, such as carpal tunnel decompression, can also trigger CRPS. It may also be triggered by a minor injury, such as a strain, sprain or laceration, just as it may be triggered by a clinical condition, such as stroke, heart attack, burns, cancer, arthritis, polymyalgia, spinal cord injury, or infection. Finally, it can develop in the absence of a remembered inciting event or illness.

The cause of CRPS is not entirely understood, although in some cases is thought to stem from dysfunction of the sympathetic nervous system that controls blood flow and sweat gland activity. While it is normal for the sympathetic nervous system to respond to injury, the response normally quiets down as healing occurs; however, in individuals with CRPS, it can remain active despite a lack of ongoing trauma.

CRPS usually affects the upper or lower extremities, although it can affect other areas of the body as well. The main symptom is constant pain, intensely burning and often out of proportion to the severity of the initial injury. Other symptoms may include dramatic changes in the color and temperature of the skin over the affected limb or body part, skin sensitivity and tenderness to touch (also called allodynia), sweating, changes in skin texture (from dry and scaly to thin and shiny), changes in hair and nail growth, swelling and stiffness in joints, and decreased motor ability, especially in the affected body part. Tremor and muscle spasm may develop, and edema of the affected limb can be marked. Muscle atrophy and joint contracture may occur, and bones of the limb can become osteoporotic.

CRPS is often divided into two types. CRPS I, formerly known as reflex sympathetic dystrophy syndrome (RSD), generally follows an illness or injury that has not directly affected the nerves in the painful extremity. CRPS II, formerly known as causalgia, presents the same symptoms but occurs after specific nerve injury. Symptoms of both types of CRPS usually develop within a month after the inciting event and often first appear near the area of injury.

The syndrome can be described as having three general stages although these may not apply to the disease pattern of all individuals. Stage I is acute, usually lasting from 1 to 3 months. It is characterized by intense, burning pain accompanied by muscle spasm, joint stiffness, rapid hair growth, and alterations in the blood vessels that cause the skin to redden and become warm. Stage II is subacute, lasting from 3 to 6 months. It is characterized by increasing pain; stiff joints; swelling; cracked, brittle or pitted nails; decreased hair growth; and weak muscle tone. Stage III is chronic, starting typically after 6 months and becoming progressively atrophic, resulting in irreversible damage to the skin and bones. Pain intensifies and can be continuous, involving the entire limb or affected area of the body. Muscle atrophy may occur along with contraction of joints, resulting in contortion of the affected limb, severely limited range of motion, inability to initiate movement, and involuntary contractions of the muscles or tremors. Some affected individuals do not progress beyond stage I, and only a relatively small number of individuals progress to stage III.

Early diagnosis of CRPS is considered essential for effective management of the syndrome before the development of any permanent disability. Because symptoms may vary dramatically among individuals, and also vary from day to day within individuals, the combination of the individual’s medical record, self-reported symptoms, clinical observation, and supportive testing and diagnostic imaging will be needed to confirm a diagnosis of CRPS. Positive findings may support a diagnosis of CRPS but the absence of positive findings (e.g., negative results of x-ray, bone scan or sympathetic nerve block) does not necessarily rule out the condition.

Incidence and Prevalence: CRPS occurs in about 1% to15% of all cases of peripheral nerve injury in conjunction with various fractures, sprains, and soft tissue injury; incidence ranges from 10% to 30% after fractures and contusions (Parillo). About 90% of individuals with CRPS have type I. Upper extremities are affected more than lower.

Source: Medical Disability Advisor



Causation and Known Risk Factors

Complex regional pain syndrome occurs in both sexes and all ages but is reported to be more common in women (60% to 80% of cases) (Stanton-Hicks). It occurs most often among young to middle-aged adults, though is also reported to develop in children and senior adults. Risk may be somewhat greater for individuals with an existing neurological impairment such as carpal tunnel syndrome or for immobilized or chronically ill individuals.

Source: Medical Disability Advisor



Diagnosis

History: The approach to diagnosing CRPS begins with a detailed medical history, with an emphasis on any recent injury, as well as prior illnesses and injuries. The individual may report intense, constant, burning pain that occurs without stimulation or movement, and beyond the territory of a single peripheral nerve, often with spreading of pain away from the original site (distally) or next to it (proximally). The pain is often disproportionate to the inciting event. Physical signs and symptoms may be described by the individual as coming and going. A limb may be normal temperature one moment and cold the next, making the patient's self-reported history an important diagnostic tool.

Physical exam: Clinical signs of CRPS found on physical examination should satisfy diagnostic criteria for CRPS adopted by the International Association for the Study of Pain (IASP) in 1994 (Merskey), stated as follows: (1) the presence of an inciting noxious event (or nerve injury for type II) or a cause of immobilization (although not required for diagnosis since 5% to 10% of patients will not have this); (2) continuing pain, allodynia, or hyperalgesia in which pain is disproportionate to any known inciting event; (3) evidence at some time of edema, changes in skin blood flow, or abnormal sudomotor activity in the region of pain (sign or symptom); and (4) the recognition that this diagnosis is excluded by the existence of other conditions that would otherwise account for the degree of pain and dysfunction. The IASP advises further that if the condition is seen without major nerve damage, it should be diagnosed as CRPS I, whereas if it is seen with major nerve damage, it should be diagnosed as CRPS II.

New, empirically validated, statistically derived revisions of the current IASP diagnostic criteria have been proposed by an international consensus group and submitted to the IASP for approval and codification. The proposed criteria are intended to be descriptive, general and without implying etiology of CRPS, including a direct role of the sympathetic nervous system (Harden). However, CRPS remains a controversial diagnosis. Other criteria are sometimes employed with the observance of other factors, such as characteristic hand or arm positioning, signs of carpal tunnel syndrome, dystrophic skin changes, and muscle weakness suggestive of a neurologic cause. Psychological or emotional factors may also be observed. To aid in diagnosis, a stimulus test (with touch, pinprick, heat, or cold) may be employed to gauge the pain level at the affected site.

Tests: No single test is available to confirm CRPS, and specific test results may vary widely from individual to individual. A triple-phase bone scan may be used to reveal osteoporosis or increased circulation to the joints in the affected areas, providing radiographic evidence of CRPS and ruling out other conditions. An x-ray may demonstrate a loss of bone minerals, which can occur in progressive CRPS. As mentioned earlier, positive tests or scans can be definitive for CRPS, but negative tests or scans do not necessarily rule out CRPS.

Source: Medical Disability Advisor



Treatment

Treatment for CRPS includes use of oral medications such as corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs), anticonvulsants, antispasmodics, antidepressants, anti-hypertensives, and vasodilators, among others. Opioid analgesics may be prescribed for pain, but their long-term efficacy has not been established. In selected cases, implantation of an intrathecal opioid pump may be considered after more conservative therapies have failed. Topical medications may also be employed to relieve pain in the affected limb or area.

Invasive procedures used to treat CRPS include various nerve and sympathetic blocks (spinal cord and peripheral nerve stimulation), as well as acupuncture.

Rehabilitation and functional restoration approaches include physical therapy and psychological services such as psychotherapy, as well as pain control measures that may include biofeedback, stress reduction, meditation, relaxation training, and hypnosis.

While medications can be helpful, there is no single proven treatment for CRPS. The most important intervention appears to be appropriate, aggressive, active and passive physical therapy with cognitive behavioral therapy as part of the treatment plan. Other modalities may be used, but a coordinated functional restoration approach is critical.

Source: Medical Disability Advisor



ACOEM

ACOEM's Practice Guidelines, the gold standard in effective medical treatment of occupational injuries and illnesses, are provided in this section to complement the disability duration guidelines.*
 
Chronic Pain
 
* The relationship between the MDGuidelines (MDA) content and ACOEM's guidelines is approximate and does not always link identical diagnoses. The user should consult the diagnostic codes in both guidelines, as well as the clinical descriptions, before assuming an equivalence.

Source: ACOEM Practice Guidelines



Prognosis

The prognosis for persons with CRPS varies. Remission from symptoms occurs in certain individuals; others have unyielding pain and irreversible damage in spite of treatment. About 30% of individuals will have spreading of symptoms to other extremities and ongoing musculoskeletal discomfort due to changes that occur with dysfunction of one limb. Research suggests that prognosis improves with early treatment.

Source: Medical Disability Advisor



Rehabilitation

The focus of rehabilitation in individuals with CRPS is to decrease symptoms and to promote function. Treatment depends on the location, the severity, and the stage of the syndrome. Although individuals may benefit from a multidisciplinary rehabilitation program, to date no evidence exists to substantiate this (Forouzanfar). Based on common clinical practice, numerous treatment options may be explored.

The duration and intensity of rehabilitation varies among individuals. CRPS may take up to 1 to 2 years to resolve, and it is not uncommon for residual deficits to persist.

The first goal of rehabilitation during the inflammatory stage is to decrease pain and swelling of the affected body part. In combination with pharmacological management, thermal modalities can be used to relieve symptoms (Bryant). During this stage, some common findings associated with CRPS may include local discoloration, sweating, and changes in hair distribution.

Once pain and swelling have decreased, the second goal is to prevent any loss of functional ability and possibly to improve function. Rehabilitation should include gentle range of motion and strengthening exercises, progressed according to the individual's tolerance (Stanton-Hicks). Efforts should be made to promote full range of motion and prevent contractures. In addition to supervised rehabilitation, individuals should be instructed in an independent home exercise program to be performed daily.

If a functional deficit is evident, the individual may be evaluated for assistive devices. A home assessment may be beneficial to determine the need for modifications. An ergonomic evaluation may help to maintain the individual's employment status.

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistComplex Regional Pain Syndrome
Occupational / Hand / Physical TherapistUp to 52 visits within 26 weeks
The table above represents a range of the usual acceptable number of visits for uncomplicated cases. It provides a framework based on the duration of tissue healing time and standard clinical practice.

Source: Medical Disability Advisor



Complications

Complications are often related to the inciting event (i.e., fracture, infection, crush injury), and to the person's psychosocial behavior (i.e., self-limitation of activities of daily living). The treatment itself as it pertains to medications and invasive interventions may potentially result in complications.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Categorical statements regarding work restrictions and accommodations are not possible due to the wide range of clinical presentations in individuals with CRPS. Work restrictions and accommodations are based upon the interaction between a person's medical impairment (if any) and the job requirements.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Were alternative diagnoses investigated?
  • Were concurrent or comorbid diagnoses investigated?
  • Was diagnosis based solely on the individual's self-report?
  • Was diagnosis based on objective diagnostic criteria identified during a standard examination and by standard clinical and radiologic techniques?

Regarding treatment:

  • Was appropriate, aggressive, active, and passive physical therapy performed?
  • Have unproven treatments resulted in unwanted side effects?
  • Have treatment methods reinforced counterproductive behaviors?

Regarding prognosis:

  • Were psychosocial factors such as family and workplace dynamics considered?
  • Were mental and behavioral disorders (depression, somatoform disorders, factitious disorders) considered?
  • Were inappropriate illness behaviors (symptom exaggeration, malingering) considered?

Source: Medical Disability Advisor



References

Cited

"Complex Regional Pain Syndrome." MayoClinic.com. 9 Jul. 2003. Mayo Foundation for Medical Education and Research. 21 Jul. 2008 <http://www.mayoclinic.com/invoke.cfm?objectid=8F3237C2-D7C0-4063-AE87DC86D78085FE>.

Bryant, P. R., C. T. Kim, and R. Millan. "The Rehabilitation of Causalgia (Complex Regional Pain Syndrome-Type II)." Physical Medicine and Rehabilitation Clinics of North America 13 1 (2002): 137-157. National Center for Biotechnology Information. National Library of Medicine. 21 Jul. 2008 <PMID: 11878079>.

Forouzanfar, T., et al. "Treatment of Complex Regional Pain Syndrome Type I." European Journal of Pain 6 2 (2002): 105-122. National Center for Biotechnology Information. National Library of Medicine. 22 Jan. 2009 <PMID: 11900471>.

Harden, R. N. "Proposed New Diagnostic Criteria for Complex Regional Pain Syndrome." Pain Medicine 8 4 (2007): 326-331.

Merskey, H., and N. Bogduk. Classification of Chronic Pain: Descriptions of Chronic Pain Syndromes and Definitions of Pain Terms. Seattle: IASP Press, 1994.

Parrillo, Steven J. "Complex Regional Pain Syndrome." eMedicine. Eds. Joseph A. Salomone, et al. 3 Apr. 2008. Medscape. 22 Jan. 2009 <emedicine.com/emerg/topic497.htm>.

Stanton-Hicks, M. "Complex Regional Pain Syndrome." Anesthesiology Clinics Of North America 21 4 (2003): 733-744. National Center for Biotechnology Information. National Library of Medicine. 21 Jul. 2008 <PMID: 14719716>.

Source: Medical Disability Advisor






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