Chronic Pain: The Role of EMS

You respond to a call for a 28-year-old female whose mother reports that her daughter "suddenly felt paralyzed and couldn't move, even to get out of bed." The pajama-clad young woman has numerous medications on the nightstand and bureau. Adaptive devices like a wheelchair, walker, television and other paraphernalia create a hospital room-like atmosphere.

"What seems to be the problem?"

"I can't move," says the young woman. Her words seem slurred. "I'm paralyzed from the waist down. My meds just aren't working anymore."

Neurovascular assessment shows that the patient can wiggle her toes and flex her ankles and knees, but cannot sit up due to severe pain in her hips and lower back. Further questioning reveals a five-year history of chronic pain due to RSD (reflex sympathetic dystrophy) resulting from a motor vehicle accident. She has severe pain all over her body and has been disabled for three years.

"Why did you tell the dispatcher your daughter was paralyzed?" you ask the mother.

"Because she can't move."

You realize the patient and her mother think that she is paralyzed because increased pain makes movement more difficult than usual.

Treatment and transport are complicated by the fact that the patient cannot even tolerate your touch on her skin, and she screams in pain when the bedsheets brush across her legs. This makes an accurate assessment of her pain scale score nearly impossible. You have never encountered anything like this before. You consider possible causes of the change in her condition. Despite the severe pain, she dozes off while answering your questions. You consider medication side effects and assess vital signs, contacting medical control to discuss pain medication.

This scenario illustrates why emergency response teams must be ready for anything. The first surprise was the misinterpretation of the term "paralyzed." As the crew rode to the scene, they considered stroke, spinal cord injury or poisoning, yet they found a patient with obvious chronic disease, who was using an array of medications and who was in pain but not paralyzed. This meant considering medication toxicities.

Finally, they were confronted with a disease entity that was new to all of them: RSD, also known as CRPS (complex regional pain syndrome).

What Is Chronic Pain?

Emergency personnel must understand chronic pain and its medical implications. Knowledgeable providers can help correct common misconceptions and assist patients in coping with their symptoms.

Pain can take many forms and can originate emotionally or physically, each sphere manifesting itself in the other. Pain is not only integral to life experience, it is necessary, since it is the body's warning of physical danger.1 Although medical science has always treated pain, it has only recently addressed it aggressively.2 The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) now recommends that pain be identified as a "fifth vital sign" and addressed appropriately. Hospitals are using formal pain scales for assessment, establishing formal bills of patients' rights and providing information about pain treatment. More work on policy, protocol and education is needed to address all aspects of pain management.

Chronic vs. Acute Pain; Nociceptive vs. Neuropathic Pain

Acute ("normal") pain is short-lived and of sudden onset (see Table I). Unintentional, accidental or surgical pain stemming from tissue injury can be intense, but is usually relatively brief, lasting hours or days.3 Acute pain is the type of pain that warns us of bodily damage so we can protect ourselves, either involuntarily (reflexively) or voluntarily (see the sidebar titled Voluntary vs. Involuntary Reactions to Pain).

Most types of acute pain, including that from burns, blunt trauma, cuts, fractures, abrasions and freezing, are called nociceptive pain. Nociceptive pain is an essential part of life and can usually be expected to dissipate in time. It rarely becomes chronic. Everyone can expect some amount of nociceptive pain to occur on a daily basis. Without nociceptive pain, we could not survive because we would leave ourselves susceptible to further injury.

An unfortunate few will experience excessive or unusually long-lived bouts of nociceptive pain from major trauma or illnesses such as cancer. If not treated aggressively, these episodes occasionally become chronic.

Pain that persists for more than three to six months is termed chronic pain.4 Chronic pain may affect as many as a third of American adults.5 It is estimated that 40 million people have debilitating headaches, 90 million have joint pain and about 100 million report back pain annually.6 Many conditions associated with chronic pain are incurable.

Chronic pain is frequently neuropathic (literally "sick nerve"), derived from the nerve itself, rather than arising from normal tissue that has been injured. An abnormal nerve that is causing neuropathic pain is like a high-voltage cable writhing and snapping in a puddle on a stormy night.

Neuropathic pain is fundamentally different from nociceptive pain. Neuropathic pain is usually described as burning, tingling, hot, cold, freezing, searing or electrical. It is the type of feeling one gets from hitting the "funny bone" (compression of the ulnar nerve at the elbow) or like the tingling of a limb that has "fallen asleep." Evidence indicates that neuropathic pain may be caused by functional or structural lesions in the peripheral or central nervous systems and can occur without peripheral nociceptive stimulation.7

The accumulation of undetected injuries in those with chronic neuropathic pain, especially if associated with numbness, could lead to severe structural damage. For example, diabetics and others with severe peripheral neuropathy (nerve damage that decreases normal sensation) can develop a type of arthritis known as Charcot's arthropathy.

Chronic pain is known to be extremely unpleasant. Its consistency and resistance to treatment can instill feelings of hopelessness and despair in its victims. The complicated management of chronic pain may require care at specialty pain centers. (See sidebar below for a discussion of the pathophysiology of pain.)

Scope of the Problem

The sources and treatments of chronic pain are so common that all emergency professionals can expect to participate in calls of this nature at some time in their careers.

The prevalence of chronic pain in the U.S. is between 15%¡V30%. A Michigan study reported that 20% of 1,500 adults surveyed suffered from some type of chronic or recurrent pain, and 77% of those with chronic pain reported that it lasted more than one year.8 Exacerbations can occur at any time with or without analgesics.

Chronic pain may originate in any body part or result from any disorder, including common problems such as back or neck pain, diabetic neuropathy, implanted surgical hardware, arthritis, temporomandibular joint syndrome (TMJ), fibromyalgia syndrome (FMS), postherpetic neuralgia (shingles), chronic headaches, osteoporosis or even dental problems (see Table II).

Osteoarthritis (OA), mankind's most prevalent disease, affects over 20 million Americans, leading to more than seven million physician visits and costing the economy nearly $65 billion annually.9

Chronic pain is associated with sleep disturbances, because the relative lack of external stimuli allows greater focus on the intrusion of pain. This in turn may lead to an increased likelihood of 9-1-1 calls.

Medications and Side Effects

In checking the patient's medications in the opening case, you find Neurontin, Vioxx, diazepam, a multivitamin, hydrocodone 7.5/500, and Oxycontin 80. The last two bottles are empty, but the dates and quantities indicate that the analgesic prescriptions should have lasted at least another two weeks. Noting that the hydrocodone was prescribed for six a day and the Oxycontin for three, you realize she's been taking twice as many as she should have. When you ask her why, she replies, "Because the pain was so bad, I had to."

Considering what you have seen so far, you believe her.

Pain medications are broadly known as analgesics (Table III on page 78), and may be taken orally (PO), intravenously (IV), intramuscularly (IM) or by transdermal patch. Most patients first try aspirin, acetaminophen (Tylenol), NSAIDs (nonsteroidal anti-inflammatory agents) or propoxyphene (Darvon). NSAIDs are meant to treat inflammation, and their ability to control pain is a secondary effect. Although NSAIDs are widely perceived to be safe, they can cause stomach ulcers, high blood pressure or decreased kidney function, especially in the elderly. This problem is exacerbated by the fact that some NSAIDs are available over the counter.

Propoxyphene is a mild synthetic opioid, usually used in combination with acetaminophen, and may be mildly habit-forming.

If the above medications are insufficient, or for those with underlying medical illnesses or the elderly, it is appropriate to prescribe opioids (derivatives of morphine, commonly known as narcotics). This class of drugs includes codeine, hydrocodone (Vicodin), oxycodone (Oxycontin, Percocet), morphine and others. Although best known for their ability to cause dependence or addiction, these drugs are the most effective pain medications known and are widely used for both acute and chronic pain. For many, these drugs are the only treatments capable of allowing some normal activity. These medications do not cause serious side effects in major organ systems like the stomach, kidney or liver, and, for selected patients, may be safer than aspirin or NSAIDs.

Many patients on chronic opioid therapy are also placed on co-analgesics, medications capable of enhancing analgesics' pain-relieving qualities. Drugs used as co-analgesics include antidepressants, antiseizure drugs, topical anesthetics and others (Table IV). Some co-analgesics, notably the tricyclic antidepressants such as amitriptyline (Elavil) and imipramine (Tofranil), may be used alone, especially for neuropathic pain such as diabetic neuropathy.

Impaired cognitive ability, such as drowsiness, hallucinations or confusion, is the most common side effect of pain medications. Other side effects include blurred vision, constipation, difficulty with urination and itching. The development of side effects is dependent upon such variables as age, body size, pre-existing liver or kidney problems, comorbid medical diseases or other medications, some of which can increase serum drug levels (Table V).

Addiction vs. Physical Dependence: Myths About Opioid Analgesics

Several factors may create artificial obstacles to the appropriate treatment of pain. Even though opioids are the most potent pain medications known, some physicians will not prescribe them, nor will some patients take them. Reasons for this include:10

1. Failure to understand the difference between abuse and legitimate medical use (the biggest obstacle, in our opinion).
2. Failure to understand the difference between addiction and physical dependence.
3. Patients may reject their use because of inappropriate fear of addiction.
4. Patients may reject their use because of judgment by well-intentioned family members or friends.
5. Some patients may seek opioids for support of their drug habits.
6. Doctors fear the regulatory scrutiny that may arise from the abuse of these drugs or from their side effects.
7. Doctors fear frivolous lawsuits, which can and do arise from the abuse or side effects of these drugs.
8. Oxycontin, Percocet, Vicodin and other painkillers have a high street value as drugs of abuse.
9. Inadequate medical school training in pain management.

Physical dependence frequently occurs after using opioids for a few days. The longer opioid therapy is used, the stronger the potential withdrawal symptoms, including anxiety, tremors, sleeplessness, sweating, nausea or fever. Some patients experience "restless legs" and are not able to achieve a comfortable position. These symptoms are unpleasant, but not dangerous, and do not signify addiction. They are an expected consequence of the legitimate medical use of opioids, just as other medications have potential consequences.11

Addiction is a psychiatric disorder with a strong emotional craving for the drug of choice, whether or not the drug is medically necessary. Physical dependence is certainly a feature of addiction, but not the only feature. The addict does not take the drug to treat pain, but rather for the mental and physical euphoria. Addicts will attempt to get the drug to the extent of performing harmful acts, such as committing crimes or destroying family relationships.12

Patients with real pain experience fewer euphoric effects, as the drugs are bound to areas of the brain and spinal cord responsible for pain sensation. Patients with real pain whose dose of medication is lowered or stopped will have a few days of discomfort and their pain may worsen, or they may lobby their medical providers for more medicine.

In contrast, the addict will be intensely uncomfortable, both physically and mentally. The addict's claims of physical discomfort extend far beyond the normal range of time when symptoms of withdrawal should subside.

Patients with chronic pain are often unfairly labeled as addicts because their pain may be inadequately treated, so their legitimate attempts to increase their medication doses are perceived as "drug-seeking" behavior. This is a difficult area of the specialty of pain management, since we have no objective means of measuring pain. Complaints of pain and interpretation by medical care providers are dependent upon many subjective factors, including the education, social standing and personalities of both patient and provider.

EMS providers may find it difficult to remain objective when faced with patients withdrawing from prescription opioids or those requesting higher doses, especially those whose doses are already higher than usual (see the sidebar titled Opioid Dosing). There may be no way to distinguish between physical dependence and addiction at the time of service; however, it is the responsibility of EMS personnel to assume there is a legitimate reason for a prescription. It is up to other providers to change medication therapy. EMS personnel should avoid causing underdoses or overdoses during treatment and transfer.

Psychodynamic Factors and Behavioral Reactions

Physical pain causes emotional turmoil, and fear intensifies physical pain, making it difficult to distinguish between physical and psychogenic pain at an emergency scene. Pain that does not wax and wane or is completely unresponsive to medications should heighten awareness that a medical condition has changed or that pain may be psychogenic in nature.13

Patients with chronic disease may view pain as a harbinger of death and an end to constant suffering-quite a different view from that of most normal people who experience self-limited bouts of nociceptive pain.

Emergency personnel must remain objective in the face of reactions that may seem unreasonable or ungracious. Preconceived notions of pain and its treatment, especially the use of opioids, may complicate the issue.

However, the possibility that pain complaints may be psychogenic should not change treatment in the field. Deal with each situation compassionately and provide comfort measures until arrival at the hospital. Body language and use of the pain scale can assist in determining the severity of pain and the appropriate time to request analgesic orders. When in doubt, err on the side of treating the patient for real physical pain. In our view, it is better to treat a few patients' pain unnecessarily than to let one patient suffer needlessly. An emergency situation is not the time to make complicated and subjective judgments.

Evaluating Patient History

Anxiety and fear can distort the subjective perception of pain severity. Patients may experience pain long after injuries or disease have occurred. These variables should influence the tone and direction of the interview.

Correlation of pain and physical symptoms may be difficult in emergency situations and can lead to inappropriate dismissal of symptoms as psychogenic in nature. Evaluation of pain is complicated by the fact that pain is not a physical finding, it cannot be seen with the naked eye, and pain thresholds differ markedly in each individual.

The prehospital pain history should include the following:

• Character and description of pain (neuropathic versus nociceptive).
• Pain scale level, either visual or verbal.
• PQRST (provocative events, quality, radiation, severity, time of onset).
• Associated signs and symptoms and aggravating factors.
• Whether pain is new or is an exacerbation of pre-existing pain.

Questions to ask the patient:

• Is this pain different from usual pain?
• What medications have already been tried? When? How much? (Include OTC, herbal and prescription medications.)
• Was a fall associated with the current episode of pain?
• Has the patient been diagnosed with osteoporosis?

Pitfalls in the prehospital history include:

• Patients with mental illness or other disabilities, such as mental retardation, may be more difficult to interview accurately because of multiple medications, lack of understanding or obsessive-compulsive disorders.
• Patients lacking family support, living alone or exhibiting active psychosis may make interviews difficult or impossible.
• Children suffering from chronic pain may not be able to explain their pain adequately or may continuously cry. Children experience pain globally, thus making them more difficult to assess.
• Methadone may be used for pain control without any history of drug abuse. Patients on methadone should be questioned about the reasons for its use before conclusions are drawn.

There are many reasons pain may feel more severe or a patient may be less able to cope with pain of any degree.

Prehospital Management

Pay particular attention to the location and severity of pain. Observe posture and facial expression.

Bone pain, in particular, can elicit severe outbursts of crying or yelling. It is easy to be unintentionally rough, especially with frail, elderly patients who have fallen and are unable to get up. Old, osteoporotic bone can be so thin that a normal person can put a finger through it.

Determine the level of pain by using a visual or verbal pain scale rated from 1 to 10. A simple algorithm may help to organize this process (Figure 1 on page 83).

According to one source, 9-1-1 calls usually indicate significant discomfort: "Evidence suggests that the numerical severity of pain and the degree of functional impairment are not linear. Although many patients can function at a normal level of activity with mild to moderate pain, as the level of pain intensifies beyond moderate, the impairment level becomes disproportionately higher than the numerical rating."15

The golden rule in dealing with chronic pain is "handle with care." Avoid rough movement or unnecessary physical contact. Physical examinations should not be repeated unnecessarily. Failing to handle with care will undoubtedly increase anxiety and pain and complicate further evaluation.

Be aware of adverse medication reactions and drug interactions. Question the patient about alcohol and drug use.

Pain may also increase oxygen demand, so apply oxygen accordingly. Consider an immobilized patient to be at risk for DVT (deep venous thrombosis).

Chronic use of NSAIDs may irritate the gastrointestinal tract and cause bleeding or ulceration. A history of hepatitis or significant alcohol consumption may indicate liver disease.

Tolerance to medication ("immunity" to the pain-relieving effects) may mean underlying illnesses such as cancer are progressing, resulting in the need for higher doses.

Cultural or regional differences also play a part in pain tolerance. Members of any cultural or racial group may exhibit exaggerated responses when in the presence of family members, especially elderly patients in the presence of children or adolescents in the presence of parents.

Contact medical control if a patient seems to need analgesics during transport. Prior to and after administering opioid analgesics, assess vital signs, including respiratory status and oxygen saturation. In the event of a medical or inadvertent overdose of opioids, administer Narcan.

Conclusion

RSD is a poorly understood disorder of the sympathetic nervous system. This part of the nervous system controls blood pressure and temperature and is barely mentioned in most EMS classes. The exact mechanism of RSD development is not specifically known, but the most common precipitating events are traumatic, as in the patient in the opening scenario. The trauma can be of any kind and of any magnitude, even things as minor as a hand caught in a door. Occasionally, RSD results from medical illnesses such as myocardial infarction, stroke or pancreatitis. It is not uncommon for RSD victims to experience intractable pain, usually in just one or two extremities, but sometimes everywhere.

All of us experience pain. Perception of severity varies with each individual and is dependent upon numerous complex psychosocial and medical factors. Individual reactions to pain may be unpredictable. Fear, depression, sleep disorders, anxiety or prior experience with medical situations can cause unexpectedly serious pain for those with chronic illness. Patients may dial 9-1-1 when they feel that they cannot cope with their pain, even though the pain may be no worse.

Each patient, especially if already diagnosed with chronic pain, must be treated on an individual basis and given the benefit of the doubt. It is difficult for EMS personnel to assess the psychosocial aspects of a case in the short time allotted for an emergency call and ambulance run. Never assume that these patients are malingering or suffering from psychogenic pain. Your job is to help the patient obtain relief. To do otherwise may cause needless suffering.

Unexpected findings in the history and physical exam are reasons to search for other causes of pain. Neuropathic pain in particular is a type of chronic pain that can have severe effects, including, but not limited to, decreased functioning, psychological changes, social isolation and societal consequences.16 Approximately 1.5% of the United States population is affected by neuropathic pain, and most are taking some form of prescriptive medication.

Questions of abuse of prescribed medications are complicated and require specialized expertise, except, of course, in the presence of violent or dangerous behavior. Be observant, ask pertinent questions and try to understand why pain medications may be necessary. The gold standard of prehospital treatment is thorough assessment, evaluation and pain control. ƒÞ

References

1. Ruoff G, et al. Recent Advances and Current Trends in Managing Pain: A Case-Based Approach. An Interactive CD-ROM/Monograph CME Program for Primary Care Physicians, pp. 4–17, 2002.
2. Milton D. Pain management: Alternative and complementary therapies provide options for treatment Advance For Nurse: New England, pp. 21–23, October 27, 2003.
3. Ruoff G, et al. Recent Advances and Current Trends in Managing Pain: A Case-Based Approach. An Interactive CD-ROM/Monograph CME Program for Primary Care Physicians, pp. 4–17, 2002.
4. Finley R. Treating chronic non-malignant pain. US Pharmacist, pp. 79–90, Sept. 2002.
5. Martin PR. Headaches. Health Care: A Behavioral Approach. King NJ, Remenyi (eds). Sydney, Australia: Grune & Stratton, pp. 145–157, 1986.
6. Rasmusen BK, Jensen R, Schrel N, et al. Epidemiology of headache in a general population: A prevalence study. J Clin Epidemiol 44:1147–1157, 1994.
7. Nicholson B. Observations on Neuropathic Pain. Internet: https://www.medscape.com.
8. Finley R. Treating chronic non-malignant pain. US Pharmacist, pp. 79–90, Sept. 2002.
9. Ruoff G, et al. Recent Advances and Current Trends in Managing Pain: A Case-Based Approach. An Interactive CD-ROM/Monograph CME Program for Primary Care Physicians, pp. 4–17, 2002.
10. Portenoy R, Kanner M. Pain Management: Theory and Practice. Philadelphia, PA: F. A. Davis Company, 1996.
11. ibid.
12. Mann AR. Pain management in acute care: Effective management can result in shorter hospital stays, fewer complications, decreased costs and improved patient satisfaction. Advance For Nurses, pp. 17–23, Feb. 17, 2003.
13. Sadock B, Sadock V. Kaplan and Sadock's Synopsis of Psychiatry, 9th Ed, pp. 66–68, 655–658, 1342–1346. New York, NY: Lippincott Williams and Wilkins, 2003.
14. Finley R. Treating Chronic Non-Malignant Pain. US Pharmacist, pp. 79–90, Sept 2002.
15. ibid.
16. Berdine H, O'Neill C. US Pharmacist, pp. 1–15, Dec. 2003.
17. Ruoff G, et al. Recent Advances and Current Trends in Managing Pain: A Case-Based Approach. An Interactive CD-ROM/Monograph CME Program for Primary Care Physicians, pp. 4–17, 2002.
18. Huether K, McCane K. Understanding Pathophysiology, pp. 319–326, 340–41. Boston, MA: Mosby, 1996.
19. ibid.
20. ibid.

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