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PAIN IS A BLIND GUIDE IN INJURY MANAGEMENT

©1995,Kelly Patrick Flannigan, MD, FRCP(C)

Bibliography

INTRODUCTION

Definitions

Pain is the primary symptom that prompts individuals to seek medical attention and entrust part of their adult autonomy to physicians and other health care providers. It is the main reason for voluntary or physician-advised restriction of activity and occupation of the "sick" role.

The International Association for the Study of Pain has defined Pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage..."  

DSM-IV provides diagnostic classification. Pain Disorders are found under Somatoform Disorders, and recognize three subtypes of pain disorder, as follows:

307.8 Pain Disorder Associated with Psychological Factors

Psychological factors are judged to have the major role in the onset, severity, exacerbation, or maintenance of the pain. In this condition, general medical conditions play either no role or minimal role in pain onset or maintenance.

307.89 Pain Disorder Associated with Both Psychological Factors and a General Medical Condition

Both psychological factors and a general medical condition are judged to have important roles in the onset, severity, exacerbation, or maintenance of the pain.

Pain Disorder Associated with a General Medical Condition

This is not considered a mental disorder. Pain results from a medical condition, and psychological factors are judged to play either no or minimal role in pain onset or maintenance. 

Under this classification, it is further specified whether Pain Disorders are acute (duration less than 6 months) or chronic.  

"Chronic Pain is a self-sustaining, self-reinforcing, and self-regenerating process. It is not a symptom of an underlying acute somatic injury but rather, a destructive illness in its own right. It is an illness of the whole person and not a disease caused by the pathological state of an organ system. Chronic pain is persistent, long-lived, and progressive. Pain perception is markedly enhanced. Pain related behaviour becomes maladaptive and grossly disproportional to any underlying noxious stimulus, which usually has healed and no longer serves as an underlying pain generator..."

The above definition of chronic pain by the American Medical Association implies the progression over time from the DSM-IV Pain Disorder Pain Disorder Associated with a General Medical Condition to one of the more malignant Pain Disorders 307.8 Pain Disorder Associated with Psychological Factors or 307.89 Pain Disorder Associated with Both Psychological Factors and a General Medical Condition. It also implies the assumption that pre-existing psychological or subsequent environmental factors are necessary for sustained pain.

It is a major theme of this discussion, that pain which persists beyond 3-6 months, regardless of initial diagnostic catagory, will not be effectively managed on the basis of the "classical" biomedical model.

Chronic pain and disability is a problem of steadily growing concern to health care providers, insurers, employers, and governments in industrialized society. A person’s chances of never returning to an autonomous adult social role (work) increase steadily with prolonged functional impairment following an injury. Treatment for chronic pain and disability is expensive and has uniformly poor outcomes, with most programs unable to claim more than a 30-50 % success rate at one year post treatment.

The "epidemic" of chronic pain and disability has fueled an increasing research effort into the factors associated with the development of chronic pain. In the course of this research over the last decade, several concepts have emerged, and the reliability of pain as a guide to physical rehabilitation has been intensely questioned. When pain has persisted beyond the expected soft tissue healing time, and signs of tissue pathology cannot be demonstrated, the biomedical model of disease no longer provides an effective basis for patient management. There is also a growing recognition of the importance of early "functional restoration" ,even in spite of persisting pain, as a therapeutic goal crucial to the prevention of chronic pain and disability. There are an increasing number of clinical tools being developed to allow early identification of individuals at risk for delayed recovery from injury and chronic pain. Individuals identified at risk for the development of chronic pain or poor rehabilitation outcomes should be managed in a multidisciplinary treatment environment from the earliest stage of injury.

The purpose of this discussion is to present an approach to the prevention of chronic pain and disability, and to provide the clinician with potentially useful tools for the recognition of individuals at risk for chronic illness for whom multidisciplinary treatment is indicated.  

Most of the following discussion is based on literature relating to back injuries, but many of the issues that pertain to the management of back injuries and the development of chronic pain are also applicable to the management of soft tissue injury in general.

BACKGROUND

Illness as a Social Role

The doctor-patient relationship is not generally formed because the patient wishes to foster wellness, but rather because the patient perceives that he or she has an illness or an injury. "Illness" is a social role, with both privileges and obligations, as initially analyzed by Parsons:

THE "SICK" ROLE

In a busy clinical setting, however, it can be difficult to recognize illness as a social role. It is assumed that behavioral changes, the most dramatic and compelling of which is pain behaviour, are directly relatable to the physical basis of the illness. But these behavioral changes are presumably the manifestation of all the unobservable cognitive, affective, and social aspects of the person’s illness. Clinical assessment and management would therefore ideally include observation of the patient’s behaviour in an attempt to assess the psychosocial context in which a "physical" illness occurs. Otherwise, there is the danger that the physician will not recognize those cases in which the physical disorder provides an incomplete explanation for the individual’s occupation of the sick role, and therapy may then be misdirected and ineffective. This is particularly true when the person seems unable or unwilling to "get well".

Physicians, while rigourously trained in the formalized process of physical diagnosis, are generally much less rigourously trained in the recognition of psychosocial aspects of illness. On the basis of history, physical examination, and ancilliary testing, the complaint (symptom), is tentatively related to a condition of a specific organ system of the patient’s body. On the basis of the diagnosis thus established, the physician can then consult his or her knowledge base and the medical literature to provide the patient with both a "standard" medical treatment plan and a likely outcome (prognosis) based on what is known about the effect of the proposed treatment on that illness (diagnosis).

"...The physical approach to disease depends on the illness being due to a physical pathology, symptoms and disability being directly related...and proportionate to that physical pathology, and any psychological element being relatively unimportant or secondary to the physical disorder. Clinical recognition and diagnosis of the underlying pathology then provides the basis for rational physical treatment of the illness..."

The validity of this approach is questionable when the clinical situation is that of chronic pain, particularly when pain is accompanied by significant disability. This clinical situation can be extremely difficult to rationally manage on the basis solely of the above biomedical model, because almost invariably the disabilty (eg inability to work because of chronic back pain) is a symptomatic condition and not an objectively verifiable biomedical diagnosis. That is, the person is regarded as "disabled" because activity is painful and therefore not performed.

Pain, however, is only one facet of illness. Pain experience and illness behaviour are inseparable, and the understanding and explanation of pain needs to include all the biological, psychological, and sociocultural aspects of the illness. Often the beginning of difficulty for patient and physician is a continued reliance on pain symptomatology as the sole guide to rehabilitation beyond the acute injury phase.  

While pain, disability, and objective physical impairment are clearly interrelated, they can and should be clinically distinguished. Disability can be described by the person clearly and reliably in terms of restriction of activities of daily living, and may provide a more practical, comprehensive and socially relevant measure of illness than pain alone. There is increasing clinical support for treatment focused on functional restoration ("healing" disability and suffering) as much as on relieving pain At least in the situation of chronic back disability, physical reconditioning, combined with direct psychological management, continues to gain increasing recognition and support. Psychological treatment is aimed primarily at addressing cognitive and affective issues that impact on the person's pain experience and disability perception, and teaching pain management skills. Fear of pain appears to be a strong factor in predicting chronicity. Fear of pain and its avoidance need to be taken into account in both the assessment and management of soft tissue injury. Pain confrontation, including encouraging the patient to maintain activity level in spite of pain, should form an integral part of injury management, when pain has persisted beyond expected healing times for soft tissue.

Although the experienced clinician will often have an immediate "feel" for the patient who will be slow to release the sick role due to factors beyond the actual physical injury, there have traditionally been few clinically useful tools available for the objective measurement of Illness behaviour. This, coupled with the time constraints of a busy practice, does not favour the identification of "non-physical" factors that may be influencing recovery from a physical complaint or occupational injury. Due to the increased expense of multidisciplinary treatment, it is not practical to provide all injured patients with this increased "depth" of care.

There are injured patients who could be prevented from developing chronic pain and disability by early recognition and appropriate multidisciplinary care. And there are patients with nonresolving pain and continued disability who will only respond to multidisciplinary management, and who will only be made worse by continued biomedical management. There is therefore a need for reliable and valid screening measures which will allow recognition of individuals who will not respond to treatment under the classic biomedical model. Such measures would presumably allow for cost-effective utilization of multidisciplinary treatment resources.

The Concept of Illness Behaviour

Waddell has defined "illness behaviour", in the context of back pain and disability, as "observable and potentially measurable actions and conduct which express and communicate the individual’s own perception of disturbed health". A certain degreee of illness behaviour is expected and "normal". The busy clinician, however, must be able to efficiently identify those patients who present with, or develope, "abnormal" illness behaviour, defined as "maladaptive overt illness related behaviour which is out of proportion to the underlying physical disease and more readily attributable to associated cognitive and affective disturbances than to the objective physical disease...". IT IS EXTREMELY IMPORTANT THAT SIGNS OF ABNORMAL ILLNESS BEHAVIOUR ARE NOT INTERPRETED AS "MALINGERING" (A CONSCIOUS ATTEMPT TO MISLEAD THE EXAMINER). TRUE MALINGERING IS RARE. ABNORMAL ILLNESS BEHAVIOUR IS RELATIVELY COMMON, AND SHOULD BE INTERPRETED BY THE PHYSICIAN AS AN INDICATION THAT THE BIOMEDICAL MODEL MAY BE INADEQUATE TO DEAL WITH THE PATIENT'S INJURY OR ILLNESS EXPERIENCE.

Abnormal illness behaviour, including "abnormal" pain behaviour, if not recognized as a manifestation psychosocial distress and effectively addressed in conjunction with physical aspects of illness, is associated with poor medical and rehabilitation outcomes, at least in the situation of back injury and chronic pain. Waddell has developed a set of specific "pain behaviours" which should be examined for with as much care as objective signs of dural tension or nerve root compromise. A recording and scoring system for these signs is presented later. The concept of "normal" and "abnormal" illness behaviour is illustrated in the following table:

When faced with a patient’s complaint of pain, it is of paramount importance that the physician establish as soon as possible which subtype of DSM-IV Pain Disorder is represented by the patient’s clinical presentation. It is equally important to monitor the clinical situation for progression from a pain disorder associated with a medical condition to either of the other Pain Disorder subtypes.

"Pathophysiology" (Development of the Syndrome)

When faced with a patient who is not responding to therapy, the physician will generally try another therapeutic approach. If sequential therapeutic interventions are unsuccessful over a period of time (sequence of preferred interventions is highly variable between physicians), the physician will then usually question the physical diagnosis, and pursue an alternate physical diagnosis through further time-consuming and often expensive investigations and consultations with medical collegues.

Within the context of the medical model described previously, the patient is usually led to expect that the resolution of pain must attend upon a physical diagnosis. This expectation will usually be accompanied by advice to avoid fulfilling those physical demands of work and domestic life which produce pain, until a diagnosis has been established, "rational" therapy can be prescribed, and a prognosis can be supplied to the patient and other involved parties. This is based on the concern that the pain may represent a dangerous condition that will be worsened by the continuation of activity which produces symptoms, and it is therefore safer to avoid producing symptoms until the cause is determined and the risk of symptom-producing activity is known. Protracted inactivity, however, also poses serious and often underestimated risks to the person’s well-being, as illustrated in the following quotes:

"Although biomedical factors appear to instigate the initial report of pain, psychosocial and behavioural factors may exacerbate and maintain high levels of pain and subsequent disability. It is important to acknowledge that disability is not solely a function of the extent of physical pathology (impairment) or reported pain severity...Disability is a complex phenomenon that incorporates tissue pathology, the individual’s response to the physical insult, and environmental factors that serve to maintain the disability and associated pain even after the initial physical cause has resolved..."

"Chronic pain, chronic disability and chronic illness behaviour become increasing dissociated from their original physical basis...and there may be little objective evidence of any remaining nociceptive(damaged tissue)stimulus. Instead, chronic pain and disability become increasingly associated with emotional distress, depression, failed treatment, and adoption of a sick role...Physical treatment directed to a supposed but unidentified and possibly nonexistent nociceptive source is not only understandably unsuccessful, but may cause additional...damage; failed treatment may both reinforce and aggravate pain, distress, disability, and illness behaviour..." 

"...Moreover, secondary physical factors may come to play an important role, with physical deconditioning contributing to weakened muscle, loss of muscle flexibility, and reduced physical endurance...Thus pain that persists over time should not be viewed as solely physical or as solely psychologically caused; rather, a set of biomedical, psychosocial, and behavioural factors contribute to the experience of pain..."

Healed tissue is generally considered to differentiate acute from chronic pain. The acute inflammatory and subacute fibroblastic phases of wound healing (discussed in preceding sections) will be complete within weeks. Scar formation, maturation, and tissue remodeling will continue for up to and sometimes beyond 6 months. Chronic pain is therefore generally accepted to be pain continuing past 6 months in the absence of any physical indicators of ongoing healing of a potentially painful somatic injury.

There are at least two difficulties with this approach, implied in the above quotes.

1. First, by the time a person is determined to have a chronic pain syndrome on the basis of 6 months of elapsed time, numerous stressful and unproductive investigations, and a prolonged withdrawl from usual adult behaviour, they will have been placed at great risk for the development of intractable pain and disability by the very process that has served to eventually classify them as having a "chronic pain syndrome". In effect, the process of diagnosis will have substantial potential for creating the disorder in persons who were "normal" at the time of injury.
2. Secondly, it has now been well established that the treatment for chronic pain and disability, in order to have any chance of success, must be multidisciplinary, intense, and prolonged. Even then, the best chronic pain programs are able to claim a less than 50% success rate in returning "patients" to sustained functioning as autonomous individuals in the adult world of work and responsibility. All treatment programs for chronic pain are "labour intensive" and therefore quite expensive. The only reason such programs have developed and continued to exist is because it has been shown that by the time a person has been idle for 1 year, in the absence of multidisciplinary treatment, there is essentially no chance that the person will return to what is generally regarded as adult function. Besides the suffering of the individual, this represents a huge cost to third parties involved in the economic aspects of the person’s care.

The emotional response to chronic pain is typically frustration, depression, and anger. Depression follows deterioration in quality of life and physical capacity, financial difficulties, and marital problems which often occur in association with chronic pain.. As the duration of prescribed inactivity and restriction of adult responsibility lengthens, there will also be an unavoidable increase in the potential of the "other involved parties" to affect the patient’s final outcome. The physician’s role will then often evolve to include meeting the patient’s expectation that the physician will "protect" the patient from the interests of third parties, which interests almost invariably take the form of pressure to return the patient to pre-injury responsibilities (ie work). There may be anger arising from a sense of injustice and entitlement. There may also be anger focussed on the physician for being unhelpful or the employer or other parties seen as responsible for the original injury. It is in this increasingly complex situation of persisting pain and disability that there is the greatest danger of the physician contributing to the severity of the paitent’s illness through defense and medical justification of of symptom-guided inactivity. This will become a cornerstone of the doctor-patient contract as the patient becomes more isolated and more dependent of the physician’s support. As the physician becomes more aware of this dependence, it is increasingly difficult to challenge the patient’s illness, pain, and disability perceptions without having the patient challenge the competence and commitment of the physician.

EVOLUTION OF THE CHRONIC PAIN SYNDROME

"Signs and Symptoms"

How is the physician to recognize the patient at risk for, or in the process of developing, a chronic pain syndrome, for whom the exhaustive search for a diagnosis, and extended passive therapy for persistent pain, will be unproductive and perhaps harmful? 

In the case of back pain, perhaps the single most important historical variable is duration of pain and inability to work since injury or pain onset. The majority of persons with a an episode of acute back pain will either experience significant improvement or recover within 2 months, while those who do not will suffer chronic pain. In general, any patient with back pain and work loss persisting beyond 2 months should be thoroughly investigated to rule out surgical and systemic causes. If conservative management is indicated, then the patient should be referred as soon as possible for comprehensive assessment and consideration for multidisciplinary management. These comments are generalizable to any situation of chronic pain and disability. 

History

Any factor which has been shown to be associated with prolonged work absence or delayed functional recovery following injury, would also be expected to increase the risk for the development of a chronic pain and disability syndrome, for the reasons discussed previously. Dr. K. Postma has presented the following list of factors which may be risks for prolonged work absence following low back injury. This list provides a useful framework for taking a history from a patient with a work-related injury:

Patient Factors

Limited vocational assets (age, physical condition, education)

Job dissatisfaction. Poor work record.

Frequent work absences for minor illness

Language barriers

Socio-economic factors, "secondary gain"

Drug dependency personality

Significant pre-existing medical problems likely to retard healing process (eg Diabetes, COPD)

History of Injury

Exaggerated description of injury. Blaming others.

Anger toward company and its representatives

Dramatic description of symptoms

Inappropriate symptoms

Past history of disabling back pain

Worksite Factors

Heavy work. Limited opportunity for modified job transfer

Inflexible, demanding supervision. Supervisor bias concerning back injury

Patient not popular with supervisor or co-workers

Inappropriate sick benefits structure

Home Factors

Over-protective Spouse

Injury useful in coping with marital or parenting problems

Treatment-related Factors

Frequent change of primary therapist

Use of "inappropriate" therapists

(Insistence on) multiple consultations with physicians in same specialty

Disparagment of previous health care providers

Hospital ER visits for back pain

More than 2 back surgeries

Legal dispute

If any factor is thought to be associated with prolonged functional impairment, it should be actively screened for in the initial evaluation of an injured patient, as part of doing everything possible to minimize the opportunity for the development of chronic pain and disability by minimizing the duration of functional impairment following an injury. 

Pinsky described the following list of "epiphenomena" characterizing the Chronic Pain Syndrome, which provide additional items to be sought during patient interview:

substance use disorders of varying severity, and associated CNS side-effects

multiple pharmacological treatments or surgical procedures, and associated morbid side-effects

decreased physical functioning due to accompanying pain and/or fear that pain is a signal of increased bodily harm

feelings and demonstration of helplessness and hopelessness

emotional conflicts with health care providers, resulting in therapeutic goal interference

emotional conflicts with significant others

increasing withdrawl and loss of gratification from social activity

persistent, unpleasant mood and affective changes

profound demoralization and depression

Physical Exam

During the initial and subsequent physical evaluations of an injured person, the physician will have an opportunity to search for findings which may identify patients at risk for chronic pain. In addition to the characteristic physical findings associated with depression, malnutrition, or significant medical disease processes, there are a group of "abnormal illness" behaviours and physical tests, which, if present, may indicate a need for more aggressive and earlier multidisciplinary management of the patient’s injury. Some of these behaviours and tests are generalizable to any injury, and some are specific to low back injury. As with all physical tests, correct interpretation is dependent on correct testing technique.

General Abnormal Illness Behaviour

Bizarre, inconsistent, or physiologically impossible disorders of gait, posture, or balance

Complaint of severe aggravation of symptoms by the examination

Pain Behaviours

Grimacing

Sighing, moaning, or other verbalization

Bracing

Rubbing

Protecting

Physical Signs

Waddell has formalized a group of findings which can be documented during physical exam , and quantified as a total score. . This score is derived from several tests performed by the physician during screening examination of the subject. "Abnormal" illness behaviour, as indicated by an elevated Waddell score, may be used as a screening mechanism to identify subjects using the "sick role" as a psychological coping mechanism, with a tendency to exaggerate the extent of their dysfunction beyond "what could reasonably be expected for the actual amount of organic disease present". More particularly, work by Hirsch et. al. suggests that in subjects who demonstrated higher levels of illness behaviour (Waddell scores of 3 or more), poor performance on biomechanical testing may be a form of abnormal illness behaviour and thus may not accurately reflect "real" alterations of neuromuscular function. A limitation of this test is that it is not appropriate to patients with injury to areas other than the lumbar spine.

SUMMARY

In the setting of acute injury, pain can be as useful as the other four hallmarks of inflammation (redness, heat, swelling, and loss of function) in monitoring the resolution of injury. During this injury phase, it is entirely appropriate and desirable to use any effective therapeutic intervention to control a patient's pain, including restriction of activity and responsibility. However, if there are clinical indications of inappropriately high levels of distress or pain-focus associated with the injury, or if pain persists beyond expected soft-tissue healing times, the physician probably best serves his or her patient by switching from a symptom-focused biomedical approach to a functional restoration-focused approach to injury management. This involves an early graduated return to as many life activities, including work roles, as soon as safely possible. If there is no clinical indication that pain is associated with progressive injury or objective physiological findings, then there is no benefit to continued restriction of activity or adult responsibility. There is, on the other hand, a significant risk of fostering chronic pain and disability.

BIBLIOGRAPHY

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American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Edition IV.

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Parsons,T., The Social System, Free Press, New York, New York, 1951

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Waddell,G., A New Clinical Model for the Treatment of Low Back Pain, Spine, 12;7:631-641. 1987

Malmivaara, A., et.al., The Treatment of Acute Low Back Pain-Bed Rest, Exercises, or Ordinary Activity?, New England Journal Of Medicine, 332;6:351-355. 1995

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Hirsch,G.,Beach,G.,Cooke,C., Menard,M.,Locke,S., Relationship between Performance on Lumbar Dynamometry and Waddell Score in a Population with Low Back Pain, Spine,16:1039--43. 1991

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Waddell,G., Bircher, M.,Finlayson,D., and Main,C., Symptoms and Signs:Physical Disease or Illness Behaviour, British Medical Journal,289:739-741. 1984

Waddell,G., Pilowsky,I., and Bond,M., Clinical Assessment and Interpretation of Abnormal Illness Behaviour in Low Back Pain, Pain, 39: 41-53. 1989 

Turk,D. and Melzack,R., The Management of Pain and the Assessment of People Experiencing Pain, in The Handbook of Pain Assessment, edited by Turk,D and Melzack,R., Guilford Press, New York, NY,1992: p.8.

Waddell,G., A New Clinical Model for the Treatment of Low Back Pain, Spine, 12;7:631-641. 1987

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From material presented by K. Postma, Medical Examiner, BC WCB

Klenerman,L.,et al, The Prediction of Chronicity in Patients with an Acute Attack of Low Back Pain in a General Practice Setting, Spine, 20;4:478-484. 1995

Medical Examiner, BC Workers Compensation Board

Pinsky,J.J., Psychodynamic Understanding and Treatment of the Chronic Intractable Benign Pain Syndrome-Treatment Outcome, Seminars in Neurology,3;4:346-354. 1984

Waddell,G. and Turk,D., Clinical Assessment of low Back Pain, in The Handbook of Pain Assessment, edited by Turk,D and Melzack,R., Guilford Press, New York, NY,1992

Hirsch et. al., Relationship between Performance on Lumbar Dynamometry and Waddell Score in a Population with Low Back Pain , Spine, 16:1039-1043.1991

Back to Know Your Enemy - Personal observations on the rehabilitation model of chronic pain

Archived in the interests of chronic pain advocacy by
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