Chronic Pain
Bridle the burdensome beast

By Diane M. Goodman, RN, C, CCRN
November 1, 2004

Pain — certainly no one wants it. But to those who suffer in its clutches for extended periods, it’s a particularly nasty beast. Nurses are quick to tame acute pain in their patients, but chronic pain is another creature altogether. RNs have learned a great deal about pain treatment options, but accurately assessing and treating neverending pain remains a Godzilla-sized task for any nurse. Effective treatment of the condition requires finesse, skill, and fortitude.

Chronic nonmalignant pain traditionally has been defined as pain that is noncancerous in origin and continues in the absence of ongoing illness or after healing is completed. Patients with chronic pain are five times more likely than those without chronic pain to use health care services.¹

Acute pain, on the other hand, is pain caused by tissue inflammation or injury. Acute pain, unlike chronic nonmalignant pain, typically begins to degrade as tissue healing commences.

Terminology is useful only as a starting point, though. Patients with pain are not easily pigeonholed into specific categories. Acute and chronic pain may overlap; patients may experience physical distress from many different types of pain at the same time.

Neverending nightmare

Effectively assessing a patient for pain includes obtaining a pain history, which assists in identifying patients with chronic nonmalignant pain. These patients may have sought various treatment options or care providers for their symptoms. They may describe pain that is continuous, relentless, burning, stinging, shooting, or electrifying in nature. The pain may disrupt their sleep, their mood, and their daily ability to function. A patient with this type of pain also may appear depressed or withdrawn and may portray a hopeless attitude toward pursuing additional pain treatment plans.

To empathize and effectively treat these patients, caregivers must grasp the complexity of each patient’s condition.

What it looks like

Many complex pain syndromes fall under the heading of “chronic nonmalignant pain.” A few of the more easily recognized pain diagnoses include diabetic neuropathy, postmastectomy pain, complex regional pain syndrome (formerly labeled reflex sympathetic dystrophy, or RSD), postherpetic pain syndrome, phantom limb pain, trigeminal neuralgia, and chronic back pain.

All of these conditions include some component of neuropathic pain. Experts often described neuropathic pain as pain conduction “gone awry” or pain messages that continue to be sent to the spinal cord and brain long after the initial insult or injury to tissue has healed.

Why it happens

Researchers hope to determine why some patients develop chronic nonmalignant pain and others do not. They hypothesize several factors come into play. Those factors include genetic predisposition, as well as the correct “recipe” of sympathetic nervous system stimulators and chemical mediators (for example, prostaglandins, histamine, and bradykinin, among others) at the time of initial injury to tissue.

A relatively minor assault to tissue can lead to disastrous results. Once nerve fibers become “irritated,” they seem determined to transmit pain signals relentlessly, eventually creating wider pathways for the signals to follow. As the pain signal (or conduction “traffic”) continues, high and low pain thresholds may become confused. When this occurs, patients can begin to experience extreme discomfort with such stimuli as light touch, air blowing on a limb, or the weight of linens. This horribly painful condition is referred to as allodynia.

What can be done

Historically, the World Health Organization’s analgesic “Ladder” has guided treatment options for pain.² The Ladder describes “ramping” of analgesics from nonopioid options (i.e., acetaminophen and nonsteroidal anti-inflammatory drugs, or NSAIDS) to strong opioid combinations to use as pain escalates.

But the Ladder, originally designed to guide physicians in treating malignant pain, is not as foolproof with pain that is nonmalignant in origin. Using strong opioid combinations for pain that continues for months or years can be challenging for providers, and long-term opioid use for the treatment of chronic pain is aggressively being studied.² Although addiction potential is extremely rare (<1% overall), newer research suggests long-term opioid treatment actually may increase pain over time through a process described as pro-nociception at specific pain receptors.³

In the interim, opioid use has represented the mainstay for patients experiencing significant pain. Dose adjustment may ultimately be necessary for patients with chronic nonmalignant pain, as opioids have no ceiling dose, and raised doses of medication may be required to achieve an analgesic effect. Alternatively, opioid rotation, a process of switching the patient from one opioid to an opioid from another family of drugs, can be successful in treating refractory pain.

The use of adjunctive medications (see box) also presents an important option for treating chronic pain. Adjunct medications have been used alone or in combination with opioids and have proved successful in alleviating pain via either approach.

A recent article in the Journal of the American Medical Association,² for example, investigated the efficacy of opioid use vs. alternate therapy for the treatment of chronic pain — with somewhat surprising findings. Although patients experienced an equitable analgesic effect whether they were treated with opioids or adjuncts alone, the “treatment factor” found to be most important in the outcome of the patient was engagement with a single physician and not the analgesic prescribed.

These results, along with those of similar studies, have encouraged researchers and physicians to believe nonopioid therapy may hold promise for the future.

More help available

Newer treatment options for chronic nonmalignant pain include combinations of drugs that work synergistically to relieve symptoms. Finding the appropriate mix of adjuvant therapies is often a game of trial and error. As pain continues, it may be the caregiver who has the difficult job of persuading the patient to try yet another medication. Patients suffering from chronic nonmalignant pain may have invested hundreds of dollars in unsuccessful analgesic options to use at home. It may be difficult to persuade these patients to add another medication to their daily regimen or to adjust the dose of an existing medication.

Topical medications, such as the Lidoderm patch, have proved particularly effective for patients with neuropathic pain. Originally created for patients suffering from postherpetic pain, these patches may be cut to appropriate size and left in place for about 12 to 18 hours — a particularly convenient benefit for patients who experience pain overnight. Cutting the patches to size may save patients additional expense and assist in reducing trips to the pharmacy.

Adding an antidepressant or anxiolytic to the mix can work wonders for the patient with chronic nonmalignant pain. The tricyclic group of antidepressants (amitriptyline, nortriptyline, etc.) has been frequently used by physicians for pain prophylaxis. Although dosages vary from those used to treat depressive illnesses, these medications provide mild sedative effects for patients with chronic pain and can lead to improved sleep and function. Desipramine, a less sedating tricyclic agent, can be particularly effective for patients who wish to lessen their pain but avoid the drowsiness associated with other antidepressant medications. A newer agent, venlafaxine, “is just as efficacious against neuropathic pain as the tricyclic antidepressants, with fewer adverse effects.”⁴

Another group of agents being used for pain treatment and prophylaxis includes anticonvulsant therapy (gabapentin, topiramate, divalproex sodium, etc.) or other central nervous system drugs, such as nefazodone hydrochloride (Serzone). Gabapentin, in particular, is thought to work at the cellular level by hyperpolarizing nerve fibers so that depolarization of nerve pathways (required for transmission of pain signals) is slowed or impaired. Gabapentin is relatively nontoxic and can be combined with other agents without the fear of a drug reaction. Dosages of gabapentin have been well-tolerated up to 3,600 mg daily, although patients with renal compromise are restricted to much smaller amounts of the drug.

Conditioning, however, represents perhaps the most important aspect of treatment for chronic nonmalignant pain. Patients in pain often cope by stopping or restricting their movements. This can be detrimental to optimal functioning in the long run. While seeking analgesic treatment, patients need therapy to get them moving again or to return them to their work environments, where they can begin to feel useful and productive. This is an especially difficult step to encourage, and patients may need the benefit of so-called work-hardening programs, which use an interdisciplinary approach to pain treatment. These programs work with numerous types of pain patients, monitoring their drug therapies while enlisting the help of physical and occupational therapists, as well as psychotherapists.

What the future may hold

While we may be a long way from finding a cure for chronic nonmalignant pain, research holds promise for patients with this type of unremitting pain. Studies regarding the use of preemptive analgesia are well under way. Preemptive analgesia employs preoperative and intraoperative use of analgesic agents to reduce the risk of developing neuropathic pain in the first place. This is an important concept to remember when nurses treat preoperative patients who experience pain. Research suggests effective pain treatment in the preoperative phase goes a long way toward reducing problems with pain at a later date.

Developing an understanding of chronic nonmalignant pain assists nurses in assessing and treating patients more effectively. Knowledge also promotes compassion, for this group of patients can be difficult to treat, particularly when nothing seems to be effective to reduce their pain. Newer and more efficacious pain treatment options are surely on the horizon. Until then, nurses require skill, understanding, and tenacity to master this complex phenomenon.

Adjuvant therapy for painAnticonvulsants

gabapentin (Neurontin)
carbamazepine (Tegretol)
topiramate (Topamax)
divalproex sodium (Depakote)

Antispasm agents

baclofen (Lioresal)
clonazepam (Klonopin)

Corticosteroids

dexamethasone (Decadron)

Local anesthetics

EMLA
Lidoderm (5% lidocaine patch)
apply to intact skin

Tricyclic antidepressants, antidepressants

nortriptyline (Pamelor)
amitriptyline (Elavil)
desipramine (Norpramin)
venlafaxine hydrochloride (Effexor)

Nonopioids (NSAIDS & acetaminophen)

acetaminophen (Tylenol)
celecoxib (Celebrex)
diclofenac (Voltaren)
ibuprofen (Motrin, Advil)
ketorolac (Toradol)
nabumetone (Relafen)
rofecoxib (Vioxx)
salsalate (Disalcid)

Chronic nonmalignant pain What causes chronic pain?

"Little is known about why injured nerves sometimes misfire and send painful messages. However, one reason is that when a nerve cell is destroyed, the severed end of the surviving fiber can sprout a tangle of unorganized nerve fibers (neuroma). This bundle of nerve tissue then starts sending spontaneous pain signals. These fibers also refuse to follow normal checks and balances that control the rest of your nervous system, keeping pain at bay."

Rome J. Mayo Clinic on Chronic Pain. 2nd ed. Rochester, Minn.: Kensington Publishing Corp.

Diane M. Goodman, RN, C, CCRN, is a clinical educator, patient care services, and pain resource nurse at Lake Forest Hospital, Ill.

References

1. Marcus D. Treatment of chronic nonmalignant pain.
Am Fam Physician. 2002;61(5):1331-1338.

2. Meldrum M. A capsule history of pain management. JAMA. 2003;290 (18):2470-2475.

3. Ballantyne J, Mao J. Opioid therapy for chronic pain. N Eng J Med. 2003;350:840-842.

4. Vastag B. Scientists find connections in the brain between physical and emotional pain. JAMA. 2003;290(18):2389-2390.