Dolores, a 25-year-old school teacher, simply tripped while hurrying to her classroom. By early evening, she was limping on a swollen, painful right ankle. By the next morning, despite ice, elevation, and acetaminophen (Tylenol), the pain persisted and her ankle remained swollen, red, and warm to the touch. She stayed out of work to visit her family physician. After normal X-ray findings, Dolores started a course of physical therapy and analgesics. Despite treatment, she still suffered from symptoms of swelling and extreme pain that now extended up her lower leg from the affected area. She was unable to go to school to teach.

After no improvement through the second week, Dolores’ physician sent her to an orthopedist, who diagnosed her with complex regional pain syndrome (CRPS) Type I. A thermogram demonstrated asymmetric color variations consistent with abnormal sympathetic nervous function in her right lower leg and foot. Dolores received a series of nerve blocks with guanethidine, which relieved up to 90% of her pain. She was able to return to work.

Ten weeks after the blocks, Dolores is now able to function well enough to work, but not to play recreational tennis. She has very mild, continuous pain and she favors the affected leg when walking. Her prognosis is guarded, and if her pain or other symptoms flare up, she will need further evaluation and treatment.

In 1993 the International Association for the Study of Pain (IASP) established a special interest group, Pain and the Sympathetic Nervous System, to propose a new taxonomy that would better define and classify manifestations of reflex sympathetic dystrophy syndrome (RSDS) and causalgia. The intent was to facilitate more accurate and timely diagnosis and treatment. This workgroup designed a comprehensive algorithm that focused on a multidisciplinary approach and interventions to be utilized for those diagnosed with RSDS and causalgia. The new taxonomy identified and defined two separate disorders, complex regional pain syndrome — type I and complex regional pain syndrome — type II. Type I has no distinguishable nerve lesion and the pain is localized deep in somatic tissue; Type II has an identifiable nerve lesion.¹

CRPS Type I is a complex, multisymptom, multisystem syndrome characterized by a reflex interaction between sensory nerves and the sympathetic nervous system that causes dystrophy — defective nutrition and metabolism — in the affected tissues. The disorder, which is accompanied by hyperesthesia — an acute sensitivity to pain or other stimuli — and vasomotor and dystrophic changes, is extremely painful.² First recorded by physicians treating soldiers during the Civil War, CRPS has also been known as reflex sympathetic dystrophy syndrome (RSDS), Sudeck’s atrophy, causalgia, algoneurodystrophy, neurovascular dystrophy, and sympathetically maintained pain.

CRPS is difficult to treat and often goes unrecognized. Minor trauma involving an extremity usually precipitates this condition, causing patients to seek out family practitioners or orthopedists for treatment of orthopedic injury and resulting pain. However, many healthcare providers are not familiar with CRPS and its deleterious consequences. Patients may go undiagnosed, shuttled from clinician to clinician, seeking pain relief and being treated with great skepticism and disbelief if the provider is unfamiliar with CRPS. The syndrome can be misdiagnosed as “psychogenic,” until the condition has advanced to irreversible pain and disability. Nurses in all settings, particularly those working with trauma patients, are in key positions to identify these patients early on. Nurses who care for individuals who complain of prolonged, burning pain need to consider the possibility of CRPS and suggest this to other healthcare colleagues to facilitate early diagnosis and treatment. Patients demonstrate wide variability in their presenting complaints and the course of the syndrome which has lead some investigators to speculate about several possible variants or subgroups of CRPS I.

Bizarre symptoms

In the midst of many proposed hypotheses, the pathophysiology of CRPS is not understood. Investigators have suggested theories involving central versus peripheral mechanisms of origin, sympathetic nervous system dysfunction, and an exaggerated inflammatory response.³

Early researchers believed that the problem was created centrally within internuncial neurons of the substantia nigra — a part of the brain associated with other disturbances such as Huntington’s and Parkinson’s disease — that generate a self-perpetuating pain cycle. Later notions were based on beliefs that peripheral mechanisms involving abnormal synapses between efferent sympathetic nerves and afferent sensory nerves were the cause.

Citations can be found that allude to a genetic component or predisposition to CRPS I.^4,5,6 Two experts conclude that one or more genes affecting susceptibility to the onset or progression of CRPS may be present near the MHC region of the short arm of chromosome six.⁶ They theorize that a person’s genetic susceptibility could explain spreading, migration, recurrences, and rare familial occurrences of CRPS; variable treatment outcomes; and the epidemiological differences in gender and ethnic groups.⁶

None of the proposed theories explains the bizarre symptoms and their sequence. Some consider CRPS to be a chronic pain syndrome because persistent, severe, burning pain is a hallmark of the condition. The pain, which does not follow any nerve, dermatomal, or plexus distribution, is exacerbated by psychological and/or physical stress and mobility.^3,7 Investigators Wilfrid Janig, MD, and Ralf Baron, MD, conclude that the nature, extent, and severity of patient manifestations are not related to the type and degree of the precipitating trauma.³

Hyperalgesia — an exquisite, hypersensitive pain experience — and allodynia — when ordinary painless stimulus, such as light touching, is experienced as painful — are also always present. CRPS Type I pain spreads over a period of time. During the early stage of the syndrome, the pain is said to be “sympathetically maintained,” but later “sympathetically independent.”¹ At first, sympathetic nerve blocks may be effective in achieving pain relief for varying periods of time. However, for many patients, repetitive blocks become less and less effective until the pain control is no longer dependent on manipulating the sympathetic nervous system.

A three-stage profile

CRPS Type I affects four times as many females as males. Their average age range is between 35 and 45 years, although the disease may afflict older adults and young children as well.² Children can suffer manifestations as severe and difficult to treat as those found in adults.^2,8 Typically, an individual presents with a history of trauma, mild or severe, accidental or surgical, followed by intense pain at the site of injury. However, as the initial injury heals, the CRPS manifestations get worse. CRPS also may develop postmyocardial infarction or concurrently in patients who have cancer or other medical conditions. In some cases, there is no identifiable precipitating event.

Patients with CRPS pass through three stages characterized by progressive changes in the skin and joints, pain, and edema. Depending on the severity of the pathophysiology and its duration, varying degrees of dysfunction and pain emerge, although individualized manifestations may develop. The syndrome begins as a localized problem that may spread proximally or distally by direct extension, or by migration to a different body site altogether. During the first stage, which lasts approximately one to three months, the affected area is warm from vasodilatation, but then becomes cold and cyanotic from vasoconstriction. Sympathetic stimulation of sweat glands and hair follicles results in profuse perspiration and excessive body hair. Edema in the affected area may be pitting or non-pitting. The patient will complain of stiffness and muscle spasms.

The second stage is marked by skin changes, such as scaling and a shiny, brawny appearance due to the loss of normal fine wrinkling. Nails become brittle and cracked. Muscles develop more severe spasms and atrophy. In the third stage, changes become irreversible and may even spread. If a hand is involved, the part may be transformed into a claw-like extremity.⁵ More recent researchers have identified a fourth stage — total body involvement.

A common, consistent complaint during all stages is constant, intense, burning pain. Severe discomfort causes the patient to possessively guard the affected part and to avoid movement. CRPS patients often demonstrate profound emotional and behavioral manifestations as a result of dealing with chronic pain.⁹ Although some practitioners have alleged that certain personality types are more prone to this kind of pathology, there is little evidence to support this view.⁷

In a 2006 study, Han J. A. Samwel, MD, and his colleagues examined the role of helplessness, fear of pain, and passive pain-coping strategies in chronic pain patients and found them all to be related to the pain level, disability, and depression found among study subjects. After multiple regression analyses, findings indicate that helplessness was the only significant predictor for the study subjects’ pain levels. They further report that helplessness, in addition to the passive behavioral strategy of resting and guarding, significantly predicted disability. Worrying, as a passive cognitive pain-coping strategy, significantly predicted depression.⁹

These findings relate to an earlier 2001 report that proposed that disuse alone could produce CRPS I manifestations in healthy subjects. Twenty-three healthy subjects volunteered to wear fiberglass arm casts for four weeks. Researchers reported CRPS I-like manifestations in participants after four weeks of cast immobilization that indicated involvement of brain centers associated with sensory processing, pain, and motor function.¹⁰

Sympathetic testing

Early diagnosis is usually based on the patient’s history and clinical presentation. However, an accurate assessment of pain and related sympathetic physiological changes experienced by patients is difficult. Also, there are no diagnostic tests specifically for CRPS. Routine lab values in the early stages are normal or only reflect other underlying diseases. Standard X-rays are not useful during early stages because characteristic deossification usually takes from four to six weeks to occur. Even neurodiagnostic studies are normal unless nerve injury or entrapment is present.⁵

Diagnosis may be confirmed with nerve blocks, which relieve early pain if it is sympathetically maintained, and thermography, especially within the first 72 hours.¹¹ Thermography detects variations in the body’s radiant heat emission patterns, reflecting the response of the sympathetic nervous system. Variations in heat emissions between affected and unaffected body parts are converted into electronic signals that can be visualized, computer-analyzed, and recorded. Asymmetric color variations on a thermogram reflect the abnormal sympathetic function of CRPS.

Because sudomotor manifestations — sympathetic autonomic activity that stimulates sweat glands — have been associated with as many as 92% of these patients, tests that measure these functions, such as resting sweat output (RSO) and quantitative sudomotor axon reflex test (QSART), can facilitate diagnosis. One study used capillary microscopy to evaluate degenerative changes relative to impaired nutritive skin blood flow (NSBF) and transcutaneous oximetry to measure oxygenation and temperature of superficial skin. The researchers found changes in the blood flow of CRPS patients that they related to sympathetic dysfunction.¹² More recent research findings document significant changes in the innervation of various target tissues affected and evidence of secondary tissue changes as the pathology progresses. Examples include more notable vasoconstriction with hypoperfusion in nutrition vessels leading to hypoxia, acidosis, and further pain in the affected areas.^3,13,14

Focus on pain

Nurses play an extremely important role in early identification of CRPS Type I patients through comprehensive nursing histories, assessments, and documentation. Because early interruption of the transmission of pain via nerve pathways seems to offer the only hope for remission, prompt recognition and early treatment are vital.

Pain relief remains the cornerstone of treatment. Nurses need to make pain management a priority with these patients. Treatments for CRPS have included everything from analgesics, steroids, nerve blocks, sympathectomies, physical therapy, and morphine pumps to acupuncture, hypnosis, and behavior modification. Most of these approaches offer only temporary symptomatic relief.

Nonsteroidal antiinflammatory agents; narcotic analgesics; topical analgesics such as capsaicin (Zostrix); and transcutaneous electrical nerve stimulators may be added to the patient’s treatment plan. Analgesics, individually titrated for around-the-clock pain relief, need to be used judiciously. Nevertheless, patients in stages 2 and 3 almost never get complete pain relief from analgesics alone.¹ If there is no significant improvement within four weeks, the provider will probably consider the use of steroids or sympatholytic therapy.

Sympathetic nerve blocks early in Stages 1 and 2 seem to be helpful for some, although no one knows why other patients need two, three, or even four blocks to achieve remission of pain. These procedures may include paravertebral or epidural blocks, or the intra-arterial infusion of alpha-adrenergic blocking agents. The value and scientific merit of block therapies is now being questioned.^1,11 Sympathectomies have also been used to interrupt CRPS pain cycles in the past, but over the years they have not proven to be effective.

Physical therapy, usually prescribed for several times a day, enhances circulation to the affected extremity, inhibits the sympathetic nervous system, and stimulates the formation of endorphins, thereby relieving pain.⁴ Therapy is aimed at maintaining mobility, but only after pain relief has been established. The patient and provider need to determine what is sufficient, or realistically attainable pain relief.

Initially, physical therapy needs to be started slowly and gently while the patient learns to trust clinicians. Desensitization to increased sensory stimuli is approached incorporating the use of mild nonnociceptive, controlled interventions such as gentle massage, heat, and very gentle movement. As the patient’s tolerance increases, activities should be advanced to include isometric strengthening and stress-loading exercises. Using a multidisciplinary approach, excellent team communication, and documentation will assist in monitoring and charting the individual’s responses and progress.

Information about passive pain-coping strategies, notably immobility and guarding, and evidence that demonstrates immobility in health subjects causing CRPS manifestations need to be addressed in all patient plans of care. It is difficult to encourage individuals who are hurting to exercise. It does seem evident that physical therapy plays a major role in rehabilitation of the individual with CRPS I.

Although frequent, regular exercise is desirable, safety is equally important. Further trauma, such as venipuncture or blood pressure reading on an affected extremity, needs to be avoided. Gentleness in moving and assisting these patients is important, since bumps or falls can trigger the syndrome in a previously unaffected area. Observe for blistering, ecchymosis, and other skin lesions that could lead to pressure ulcer formation.

Little attention has been given to diet and chronic pain. There are those who believe that chronic pain patients should avoid foods and chemicals that stimulate the formation of catecholamines, such as red meats, cold cuts, chocolate, and alcohol. These substances raise the level of tyrosine, a precursor of dopamine and norepinephrine, which stimulate an already hyperactive sympathetic nervous system. The opposite effect may be obtained from a diet high in tryptophan and fructose — fresh fruits and vegetables, fish, and fowl.

Nurses need to conduct frequent, comprehensive assessments because of the unpredictability of the syndrome. Because the sympathetic nervous system affects all areas of the body, any change in the patient’s baseline assessment needs to be investigated. Some patients have developed seemingly unrelated, bizarre symptomatology, such as frequent fevers, cardiac dysrhythmias, spontaneous purpura, frequent falls, and seizure activity, all with no demonstrable causes. However, as the CRPS Type I data base grows with patient input from all over the country, patterns are emerging from the experiences of large groups of patients that challenge many previous assumptions about the disease. For example, many patients who were thought to be “cured” have had exacerbations after remissions of several years. Other patients have had CRPS symptoms migrate to other distant body parts from the initial site. And researchers found severe CRPS in a large group of children and young adults, in whom previous investigators believed symptoms were less severe.

Psychosocial aspects of care are extremely important. Individual and group psychotherapy are recommended to deal with the chronic pain and disruptions in activities of daily living, sexuality, employment, and relationships. Patients need help in dealing with an uncertain future created by the disease process. Chronic pain patients are often stigmatized, especially when the causative condition is as misunderstood as CRPS Type I. Many patients suffer from periods of disbelief from practitioners, families, and friends because of ignorance and misdiagnosis; these patients can become distrustful and cynical, withdrawing from others.

Rehabilitation is long and difficult. The patient must learn to deal with chronic pain and disability that is disruptive to lifestyle and requires adaptations in daily activities. These individuals may need assistance in setting realistic goals for themselves. Socioeconomic ramifications are also considerable and incapacitating aspects of the syndrome may prohibit patients from attending school or work. Hardships may be compounded when insurers refuse to compensate for extended illnesses that are not understood or properly diagnosed.

Unanswered questions

No one has explained why some people develop mild cases of CRPS that respond to treatment, while others develop severe, intractable cases in which the condition progresses to affect the entire body. While early diagnosis and treatment are needed to provide relief, they do not guarantee a cure. Some patients who were diagnosed and treated early still have CRPS. Others have had remissions that suggest cure, only to have the condition return months or years later. It appears that CRPS patients are rarely cured, and are subject to erratic patterns of remissions and exacerbations.²

Nurses need to teach colleagues and disseminate information about CRPS to other healthcare professionals and the community-at-large. Hopefully, this vigilance and these interventions will contribute to more positive outcomes for those afflicted with this devastating, painful, and disabling syndrome. For further information, contact the Reflex Sympathetic Dystrophy Syndrome Association of America at (877) 662-7737 or www.rsds.org.