Pain Management

Definition
Purpose
Precautions
Description
Preparation
Aftercare
Risks
Normal results

Definition

Pain itself is defined by the International Association for the Study of Pain (IASP) as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.” Thus, pain management encompasses all interventions used to understand and ease pain, and if possible to alleviate the cause of the pain.

Purpose

Pain serves to alert a person to potential or actual damage to the body. The definition of damage is quite broad: pain can arise from injury as well as disease. After the message is received and interpreted, further pain can be counterproductive. Pain can have a negative impact on a person’s quality of life and impede recovery from illness or injury, thus contributing to escalating health care costs. Unrelieved pain can become a syndrome in its own right and cause a downward spiral in a person’s health and emotional outlook. Managing pain properly facilitates recovery, prevents additional health complications, and improves an individual’s quality of life.

Yet the experiencing of pain is a completely unique occurrence for each person, a complex combination of several factors other than the pain itself. It is influenced by:

• Ethnic and cultural values. In some cultures, tolerating pain is related to showing strength and endurance. In others, pain is considered punishment for misdeeds.
• Age. Many people have been taught that grownups never cry. On the other hand, in some cultures, the elderly are allowed to complain freely about pain and discomfort.
• Anxiety and stress. This factor is related to being in a strange or unfamiliar place such as a hospital, and the fear of the unknown consequences of the pain and the condition causing it, which can all combined to make pain feel more severe. For patients being treated for pain, knowing the duration of activity of an analgesic leads to anxiety about the return of pain when the drug wears off. This anxiety can make the pain more severe. In addition, patients who interpret their pain as meaning that their disease is recurring or getting worse often experience pain as more severe.
• Fatigue and depression. It is known that pain in itself can actually cause emotional depression. Fatigue from lack of sleep or the illness itself also contributes to depressed feelings.

Precautions

The perception of pain is an individual experience. Healthcare providers play an important role in understanding their patients’ pain. All too often, both physicians and nurses have been found to incorrectly assess the severity of pain. A study reported in the Journal of Advanced Nursing evaluated nurses’ perceptions of a select group of white American and Mexican-American women patients’ pain following gallbladder surgery. Objective assessments of each patient’s pain showed little difference between the perceived severities for each group. Yet, the nurses involved in the study consistently rated all patients’ pain as less than the patients reported, and with equal consistency, believed that better-educated women born in the United States were suffering more than less-educated women. Nurses from a northern European background were more apt to minimize the severity of pain than nurses from eastern and southern Europe or Africa. The study indicated how healthcare staff, and especially nursing staff, need to be aware of how their own background and experience contributes to how they perceive a person’s pain.

Some patient populations are particularly susceptible to inadequate pain management. These include cancer patients; children; trauma victims receiving treatment in hospital emergency departments; and the elderly in nursing homes .

Description

Before considering pain management, a review of pain definitions and mechanisms may be useful. Pain is the means by which the peripheral nervous system

KEY TERMS

Acute— Referring to pain in response to injury or other stimulus that resolves when the injury heals or the stimulus is removed.

Central nervous system (CNS)— The part of the nervous system that includes the brain and the spinal cord.

Chronic— Referring to pain that endures beyond the term of an injury or painful stimulus. Can also refer to cancer pain, pain from a chronic or degenerative disease, and pain from an unidentified cause.

latrogenic— Resulting from the activity of the physician.

Neuropathy— Nerve damage.

Neurotransmitter— Chemicals within the nervous system that transmit information from or between nerve cells.

Nociceptor— A nerve cell that is capable of sensing pain and transmitting a pain signal.

Nonpharmacological— Referring to therapy that does not involve drugs.

Parasympathetic nervous system— That part of the autonomic nervous system consisting of nerves that arise from the cranial and sacral regions and function in opposition to the sympathetic nervous system.

Peripheral nervous system (PNS)— Nerves that are outside of the brain and spinal cord.

Pharmacological— Referring to therapy that relies on drugs.

Stimulus— A factor capable of eliciting a response in a nerve.

Sympathetic nervous system— That portion of the autonomic nervous system consisting of nerves that originate in the thoracic and lumbar spinal cord and function in opposition to the parasympathetic nervous system.

(PNS) warns the central nervous system (CNS) of injury or potential injury to the body. The CNS comprises the brain and spinal cord, and the PNS is composed of the nerves that stem from and lead into the CNS. PNS includes all nerves throughout the body, except the brain and spinal cord. Pain is sometimes categorized by its site of origin, either cutaneous (origating in the skin, or subcutaneous tissue, such as a shaving nick or paper cut), deep somatic pain (arising from bone, ligaments and tendons, nerves, or veins and arteries), or visceral (appearing as a result of stimulation of pain receptor nerves around such organs as the brain, lungs, or stomach and intestines).

A pain message is transmitted to the CNS by special PNS nerve cells called nociceptors, which are distributed throughout the body and respond to different stimuli depending on their location. For example, nociceptors that extend from the skin are stimulated by such sensations as pressure, temperature, and chemical changes.

When a nociceptor is stimulated, neurotransmitters are released within the cell. Neurotransmitters are chemicals found within the nervous system that facilitate nerve cell communication. The nociceptor transmits its signal to nerve cells within the spinal cord, which conveys the pain message to the thalamus, a specific region in the brain.

Once the brain has received and processed the pain message and coordinated an appropriate response, pain has served its purpose. The body uses natural painkillers called endorphins to derail further pain messages from the same source. However, these natural painkillers may not adequately dampen a continuing pain message. Also, depending on how the brain has processed the pain information, certain hormones such as prostaglandins may be released. These hormones enhance the pain message and play a role in immune system responses to injury, such as inflammation. Certain neurotransmitters, especially substance P and calcitonin gene-related peptide, actively enhance the pain message at the injury site and within the spinal cord.

Pain is generally divided into two additional categories: acute and chronic. Nociceptive pain, or the pain that is transmitted by nociceptors, is typically called acute pain. This kind of pain is associated with injury, headaches, disease, and many other conditions. Response to acute pain is made by the sympathetic nervous system (the nerves responsible for the fight-or-flight response of the body). It normally resolves once the condition that precipitated it is resolved.

There are some disorders that produce pain that does not resolve following the disorder. Even after healing or a cure has been achieved, the brain continues to perceive pain. In this situation, the pain may be considered chronic. Chronic pain is within the province of the parasympathetic nervous system, and the changeover occurs as the body attempts to adapt to the pain. The time limit used to define chronic pain typically ranges from three to six months, although some healthcare professionals prefer a more flexible definition and consider chronic pain as pain that endures beyond a normal healing time. The pain associated with cancer, persistent and degenerative conditions, and neuropathy, or nerve damage, is included in the chronic category. Also, unremitting pain that lacks an identifiable physical cause such as the majority of cases of low back pain may be considered chronic. The underlying biochemistry of chronic pain appears to be different from that of acute nociceptive pain.

It has been hypothesized that uninterrupted and unrelenting pain can induce changes in the spinal cord. In the past, severing a nerve’s connection to the CNS has treated intractable pain. However, the lack of any sensory information being relayed by that nerve can cause pain transmission in the spinal cord to go into overdrive, as evidenced by the phantom limb pain experienced by amputees. Evidence is accumulating that unrelenting pain or the complete lack of nerve signals increases the number of pain receptors in the spinal cord. Nerve cells in the spinal cord may also begin secreting pain-amplifying neurotransmitters independent of actual pain signals from the body. Immune chemicals, primarily cytokines, may play a prominent role in such changes.

Managing pain

Considering the different causes and types of pain, as well as its nature and intensity, management usually requires a multidisciplinary approach. The elements of this approach include treating the underlying cause of pain, pharmacological and non-pharmacological therapies, and some invasive (surgical) procedures.

Treating the cause of pain underlies the basic strategy of pain management. Injuries are repaired, diseases are diagnosed, and certain encounters with pain can be anticipated and treated prophylactically (by prevention). However, there are no guarantees of immediate relief from pain. Recovery can be impeded by pain and quality of life can be damaged. Therefore, pharmacological and other therapies have developed over time to address these aspects of disease and injury.

PHARMACOLOGICAL OPTIONS. General guidelines developed by the World Health Organization (WHO) have been developed for pain management. These guidelines operate upon the three-step ladder approach, including:

• Mild pain is alleviated with acetaminophen or a non-steroidal anti-inflammatory drug (NSAID). NSAIDs and acetaminophen are available as over-the-counter (OTC) and prescription medications, and are frequently the initial pharmacological treatment for pain. These drugs can also be used as adjuncts to the other drug therapies that might require a doctor’s prescription. NSAIDs include aspirin, ibuprofen (Motrin, Advil, Nuprin), naproxen sodium (Aleve), and ketoprofen (Orudis KT). These drugs are used to treat pain from inflammation and work by blocking production of pain-enhancing neurotransmitters. Acetaminophen is also effective against pain, but its ability to reduce inflammation is limited. NSAIDs and acetaminophen are effective for most forms of acute (sharp, but of a short duration) pain.
• Mild to moderate pain is eased with a milder opioid medication, plus acetaminophen or NSAIDs. Opioids include both drugs derived from the opium poppy, such as morphine and codeine, and synthetic drugs based on the structure of opium. This drug class includes drugs such as oxycodone, methadone, and meperidine (Demerol). They provide pain relief by binding to specific opioid receptors in the brain and spinal cord. One drawback of opioids, however, is that they frequently cause constipation because they slow down the rhythmic muscular contractions of the intestines that push food along during the process of digestion.
• Moderate to severe pain is treated with stronger opioid drugs, plus acetaminophen or NSAIDs. Morphine is sometimes referred to as the gold standard of palliative care as it is not expensive; can be given by starting with smaller doses and gradually increased; and is highly effective over a long period of time. It can also be given by a number of different routes, including by mouth, rectally, or by injection.

Although antidepressant drugs were developed to treat depression, it has been discovered that they are also effective in combating chronic headaches, cancer pain, and pain associated with nerve damage. Antidepressants that have been shown to have analgesic (pain-reducing) properties include amitriptyline (Ela-vil), trazodone (Desyrel), and imipramine (Tofranil). Anticonvulsant drugs share a similar background with antidepressants. Developed to treat epilepsy, anticonvulsants were found to relieve pain as well. Drugs such as phenytoin (Dilantin) and carbamazepine (Tegretol) are prescribed to treat the pain associated with nerve damage.

In some cases, chronic pain caused by complications of diabetes or cancer can be eased by administering local anesthetics. The most commonly used are mexiletine (Mexitil) and a lidocaine patch.

Corticosteroids are another class of drugs commonly given to manage chronic pain caused by arthritis or other diseases affecting the muscles and joints; they may also be given to control nausea. Dexamethasone (Decadron) and prednisone are the most commonly used corticosteroids in pain management. They work by reducing inflammation and suppressing the immune system.

Close monitoring of the effects of pain medications is required in order to assure that adequate amounts of medication are given to produce the desired pain relief. When a person is comfortable with a certain dosage of medication, oncologists typically convert to a long-acting version of that medication. Transdermal fentanyl patches (Duragesic) are a common example of a long-acting opioid drug often used for cancer pain management. A patch containing the drug is applied to the skin and continues to deliver the drug to the person for an average of three days. Pumps are also available that provide an opioid medication upon demand when the person is experiencing pain. By pressing a button, they can release a set dose of medication into an intravenous solution or an implanted catheter. Another mode of administration involves implanted catheters that deliver pain medication directly to the spinal cord. Because these pumps offer the patient some degree of control over the amount of analgesic administered, the system, commonly called patient-controlled analgesia (PCA), reduces the level of anxiety about availability of pain medication. Delivering drugs in this way can reduce side effects and increase the effectiveness of the drug. Research is underway to develop toxic substances that act selectively on nerve cells that carry pain messages to the brain. These substances would kill the selected cells and stop transmission of the pain message.

NONPHARMACOLOGICAL OPTIONS. Pain treatment options that do not use drugs are often used as adjuncts to, rather than replacements for, drug therapy. One of the benefits of nondrug therapies is that an individual can take a more active role in pain management. Such relaxation techniques as yoga and meditation are used to focus the brain elsewhere than on the pain, decrease muscle tension, and reduce stress. Tension and stress can also be reduced through biofeedback, in which an individual consciously attempts to modify skin temperature, muscle tension, blood pressure, and heart rate.

Hypnosis is another nonpharmacological option for pain relief. Although doctors do not yet fully understand how hypnosis works, it is used successfully in some patients to manage pain related to childbirth, oral surgery, burn treatment, and other procedures that require the patient to remain conscious.

Participating in normal activities and exercising can also help control pain levels. Through physical therapy, an individual learns beneficial exercises for reducing stress, strengthening muscles, and staying fit. Regular exercise has been linked to production of endorphins, the body’s natural painkillers.

Acupuncture involves the insertion of small needles into the skin at key points. Acupressure uses these same key points, but involves applying pressure rather than inserting needles. Both of these methods may work by prompting the body to release endorphins. Applying heat or being massaged are very relaxing and help reduce stress. Transcutaneous electrical nerve stimulation (TENS) applies a small electric current to certain parts of nerves, potentially interrupting pain signals and inducing release of endorphins. To be effective, use of TENS should be medically supervised.

INVASIVE PROCEDURES. There are three types of invasive procedures that may be used to manage or treat pain: anatomic, augmentative, and ablative. These procedures involve surgery, and certain guidelines should be followed before carrying out a procedure with permanent effects. First, the cause of the pain must be clearly identified. Next, surgery should be done only if noninvasive procedures are ineffective. Third, any psychological issues should be addressed. Finally, there should be a reasonable expectation of success.

Anatomic procedures involve correcting the injury or removing the cause of pain. Relatively common anatomic procedures are decompression surgeries such as repairing a herniated disk in the lower back or relieving the nerve compression related to carpal tunnel syndrome. Another anatomic procedure is neurolysis, also called a nerve block, which involves destroying a portion of a peripheral nerve.

Augmentative procedures include electrical stimulation or direct application of drugs to the nerves that are transmitting the pain signals. Electrical stimulation works on the same principle as TENS. In this procedure, instead of applying the current across the skin, electrodes are implanted to stimulate peripheral nerves or nerves in the spinal cord. Augmentative procedures also include implanted drug-delivery systems. In these systems, catheters are implanted in the spine to allow direct delivery of drugs to the CNS.

Ablative procedures are characterized by severing a nerve and disconnecting it from the CNS. However, this method may not address potential alterations within the spinal cord. These changes perpetuate pain messages and do not cease, even when the connection between the sensory nerve and the CNS is severed. With growing understanding of neuropathic pain and development of less invasive procedures, ablative procedures are used less frequently. However, they do have applications in select cases of peripheral neuropathy, cancer pain, and other disorders.

Preparation

Prior to beginning management, the patient’s pain should be thoroughly evaluated, including a psychosocial as well as a physical assessment. Pain scales or questionnaires can be administered by a member of the healthcare team, although there is no single questionnaire that is universally accepted as of 2007. Some questionnaires are verbal, while others use pictures or drawings to help the patient describe the pain. Some questionnaires are filled out by the patient, while others may be given to relatives or friends to complete. It is often necessary to ask other family members to complete a pain questionnaire if the patient is cognitively impaired.

In spite of their limitations, questionnaires and self-report forms do allow healthcare workers to better understand the pain being suffered by the patient. Evaluation also includes physical examinations and diagnostic tests to determine the underlying physical causes of the pain. Some evaluations require assessments from several viewpoints, including neurology, psychiatry and psychology, and physical therapy. If the pain is caused by a medical procedure, management consists of anticipating the type and intensity of associated pain and managing it preemptively.

Nurses or physicians often take what is called a pain history. This history will help to provide important information that can help health care providers to better manage the patients pain. A typical pain history includes the following questions:

• Where is the pain located?
• On a scale of 1 to 10, with 1 indicating the least pain, how would the person rate the pain being experienced?
• What does the pain feel like?
• When did (or does) the pain start?
• How long has the person had it?
• Is the person sometimes free of pain?
• Is the pain constant, or is it episodic?
• Does the person know of anything that triggers the pain or makes it worse?
• Does the person have other symptoms (nausea, dizziness, blurred vision, etc.) during or after the pain?
• What pain medications or other measures has the person found to help in easing the pain?
• How does the pain affect the person’s ability to carry on normal activities?
• What does it mean to the person that he or she is experiencing pain?

Aftercare

An assessment by nursing staff as well as other healthcare providers should be made to determine the effectiveness of the pain management interventions employed. There are objective, measurable signs and symptoms of pain that can be looked for. The goal of good pain management is the absence of these signs. Signs of acute pain include:

• rise in pulse and blood pressure
• more rapid breathing
• perspiring profusely, clammy skin
• taut muscles
• more tense appearance, fast speech, very alert
• unusually pale skin
• dilated pupils of the eye

Signs of chronic pain include:

• lower pulse and blood pressure
• changeable breathing pattern
• warm, dry skin
• nausea and vomiting
• slow or monotone speech
• inability or difficulty in getting out of bed and performing activities of daily living (ADLs)
• constricted pupils of the eye

When these signs are absent and the patient appears to be comfortable, healthcare providers can consider their interventions to have been successful. It is also important to document interventions used, and which ones were successful.

Risks

Owing to toxicity over the long term, some drugs can only be used for acute pain or as adjuncts in chronic pain management. NSAIDs have the well-known side effect of causing gastrointestinal bleeding, and long-term use of acetaminophen has been linked to kidney and liver damage. Other drugs, especially narcotics, have such serious side effects as constipation, drowsiness, and nausea. Serious side effects can also accompany pharmacological therapies; mood swings, confusion, bone thinning, cataract formation, increased blood pressure, and other problems may discourage or prevent use of some analgesics.

Nonpharmacological therapies carry little or no risks. However, individuals recovering from serious illness or injury should consult with the health care providers or physical therapists before making use of adjunct therapies. Invasive procedures carry risks similar to other surgical procedures, such as infection, reaction to anesthesia, and iatrogenic (injury as a result of treatment) injury.

A traditional concern about narcotics use has been the risk of promoting addiction. As narcotic use continues over time, the body becomes accustomed to the drug and adjusts normal functions to accommodate to its presence. Therefore, to elicit the same level of action, it is necessary to increase dosage over time. As dosage increases, an individual may become physically dependent on narcotic drugs.

However, physical dependence is different from psychological addiction. Physical dependence is characterized by discomfort if drug administration suddenly stops, while psychological addiction is characterized by an overpowering craving for the drug for reasons other than pain relief. Psychological addiction is a very real and necessary concern in some instances, but it should not interfere with a genuine need for narcotic pain relief. However, caution must be taken with people who have a history of addictive behavior.

Normal results

Effective application of pain management techniques reduces or eliminates acute or chronic pain. This treatment can improve an individual’s quality of life and aid in recovery from injury and disease.

Resources

BOOKS

Gould, Harry J., III. Understanding Pain: What It Is, Why It Happens, and How It’s Managed. St. Paul, MN: American Academy of Neurology Press, 2007.

Hughes, John, ed. Pain Management: From Basics to Clinical Practice. New York: Churchill Livingstone/Elsevier, 2008.

Main, Chris J., Michael J. L. Sullivan, and Paul J. Watson. Pain Management: Practical Applications of the Biop-sychosocial Perspective in Clinical and Occupational Settings. Edinburgh and New York: Churchill Livingstone, 2008.

PERIODICALS

Cleary, J. F. “The Pharmacologic Management of Cancer Pain.” Journal of Palliative Medicine 10 (December 2007): 1369–1394.

Coyle, N. “Assessing Cancer Pain in the Adult Patient.” Oncology (Williston Park) 20 (September 2006): 41–49.

Curtis, K. M., H. F. Henriques, G. Fanciullo, et al. “A Fentanyl-based Pain Management Protocol Provides Early Analgesia for Adult Trauma Patients.” Journal of Trauma 63 (October 2007): 819–826.

D’Arcy, Yvonne. “Keep Your Patient Safe during PCA.” Nursing 38 (January 2008): 50–55.

Marx, T. L. “Partnering with Hospice to Improve Pain Management in the Nursing Home Setting.” Journal of the American Osteopathic Association 105 (March 2005): S22–S26.

McPherson, M. L., C. D. Ponte, and R. M. Respond (eds.). “Profiles in Pain Management.” Journal of the American Pharmacists Association (June 2003).

Schwartz, S. R. “Perioperative Pain Management.” Oral and Maxillofacial Surgery Clinics of North America 18 (May 2006): 139–150.

ORGANIZATIONS

American Chronic Pain Association (ACPA). P.O. Box 850, Rocklin, CA 95677-0850. (800) 533-3231. http://www.theacpa.org/index.asp (accessed April 2, 2008).

American Pain Society. 4700 West Lake Ave., Glenview, IL 60025. (847) 375-4715. http://www.ampainsoc.org (accessed April 2, 2008).

International Association for the Study of Pain (IASP). 111 Queen Anne Avenue North, Suite 501, Seattle, WA 98109-4955. (206) 283-0311. http://www.iasp-pain.org//AM/Template.cfm?Section=Home (accessed April 2, 2008).

OTHER

National Cancer Institute (NCI). Pain, health professional version. Bethesda, MD: NCI, 2007. http://www.cancer.gov/cancertopics/pdq/supportivecare/pain/HealthProfessional (accessed April 2, 2008).

National Institute of Neurological Disorders and Stroke (NINDS). Pain: Hope through Research. NIH Publication 01-2406. Bethesda, MD: NINDS, 2007.

Joan M. Schonbeck

Sam Uretsky, PharmD

Rebecca Frey, PhD

Pain relievers seeAnalgesics

Pain Management

Definition

If pain can be defined as a highly unpleasant, individualized experience of one of the body's defense mechanisms indicating an injury or problem, pain management encompasses all interventions used to understand and ease pain, and, if possible, to alleviate the cause of the pain.

Purpose

Pain serves to alert us to potential or actual damage to the body. The definition for damage is quite broad; pain can arise from injury as well as disease. After the message is received and interpreted, further pain can be counter-productive. Pain can have a negative impact on a person's quality of life and impede recovery from illness or injury, thus contributing to escalating health care costs. Unrelieved pain can become a syndrome in its own right and cause a downward spiral in a person's health and outlook. Managing pain properly facilitates recovery, prevents additional health complications, and improves an individual's quality of life.

Yet the experiencing of pain is a completely unique occurrence for each person, a complex combination of several factors other than the pain itself. It is influenced by:

• Ethnic and cultural values. In some cultures tolerating pain is related to showing strength and endurance. In others, it is considered punishment for misdeeds.
• Age. The concept that grownups don't cry.
• Anxiety and stress related to being in a strange, fearful place such as a hospital, fear of the unknown consequences of the pain and the condition causing it can all make pain feel more severe.
• Fatigue and depression. It is known that pain in itself can actually cause depression. Fatigue from lack of sleep or the illness itself also contribute to depressed feelings.

Precautions

As noted, the perception of pain is an individual experience. Health care providers play an important role in understanding their patients' pain. All too often, both physicians and nurses have been found to incorrectly assess the severity of pain. A study reported in the Journal of Advanced Nursing evaluated nurses' perceptions of a select group of American-born and Mexican-American women patients' pain following gallbladder surgery. Objective assessments of each patient's pain showed little difference between the severity for each group. Yet nurses involved in the study consistently rated all patients' pain as less than the patients reported, and with equal consistency, believed that better-educated women born in the United States were suffering more than less educated, Mexican-American women. Nurses from a Northern European background were more apt to minimize the severity of pain than nurses from Eastern and Southern Europe or Africa. Health care staff, and especially nursing staff, need to be aware of how their own background and experience contributes to how they perceive a person's pain.

Description

Before considering pain management, a review of pain definitions and mechanisms may be useful. Pain is the means by which the peripheral nervous system (PNS) warns the central nervous system (CNS) of injury or potential injury to the body. The CNS comprises the brain and spinal cord, and the PNS is composed of the nerves that stem from and lead into the CNS. PNS includes all nerves throughout the body except the brain and spinal cord. Pain is sometimes categorized by its site of origin, either cutaneous (originating in the skin of subcutaneous tissue, such as a shaving nick or paper cut), deep somatic pain (arising from bone, ligaments and tendons, nerves or veins and arteries), or visceral (appearing as a result of stimulation of pain receptor nerves around organs such as the brain, lungs, or those in the abdomen).

A pain message is transmitted to the CNS by special PNS nerve cells called nociceptors. Nociceptors are distributed throughout the body and respond to different stimuli depending on their location. For example, nociceptors that extend from the skin are stimulated by sensations such as pressure, temperature, and chemical changes.

When a nociceptor is stimulated, neurotransmitters are released within the cell. Neurotransmitters are chemicals found within the nervous system that facilitate nerve cell communication. The nociceptor transmits its signal to nerve cells within the spinal cord, which conveys the pain message to the thalamus, a specific region in the brain.

Once the brain has received and processed the pain message and coordinated an appropriate response, pain has served its purpose. The body uses natural painkillers, called endorphins, to derail further pain messages from the same source. However, these natural painkillers may not adequately dampen a continuing pain message. Also, depending on how the brain has processed the pain information, certain hormones, such as prostaglandins, may be released. These hormones enhance the pain message and play a role in immune system responses to injury, such as inflammation. Certain neurotransmitters, especially substance P and calcitonin gene-related peptide, actively enhance the pain message at the injury site and within the spinal cord.

Pain is generally divided into two additional categories, acute and chronic. Nociceptive pain, or the pain that is transmitted by nociceptors, is typically called acute pain. This kind of pain is associated with injury, headaches, disease, and many other conditions. Response to acute pain is made by the sympathetic nervous system (the nerves responsible for the fight or flight response of the body). It normally resolves once the condition that precipitated it is resolved.

Following some disorders, pain does not resolve. Even after healing or a cure has been achieved, the brain continues to perceive pain. In this situation, the pain may be considered chronic. Chronic pain is within the province of the parasympathetic nervous system, and the changeover occurs as the body attempts to adapt to the pain. The time limit used to define chronic pain typically ranges from three to six months, although some health care professionals prefer a more flexible definition, and consider chronic pain as pain that endures beyond a normal healing time. The pain associated with cancer, persistent and degenerative conditions, and neuropathy, or nerve damage, is included in the chronic category. Also, unremitting pain that lacks an identifiable physical cause, such as the majority of cases of low back pain, may be considered chronic. The underlying biochemistry of chronic pain appears to be different from regular nociceptive pain.

It has been hypothesized that uninterrupted and unrelenting pain can induce changes in the spinal cord. In the past, severing a nerve's connection to the CNS has treated intractable pain. However, the lack of any sensory information being relayed by that nerve can cause pain transmission in the spinal cord to go into overdrive, as evidenced by the phantom limb pain experienced by amputees. Evidence is accumulating that unrelenting pain or the complete lack of nerve signals increases the number of pain receptors in the spinal cord. Nerve cells in the spinal cord may also begin secreting pain-amplifying neurotransmitters independent of actual pain signals from the body. Immune chemicals, primarily cytokines, may play a prominent role in such changes.

Managing pain

Considering the different causes and types of pain, as well as its nature and intensity, management can require an interdisciplinary approach. The elements of this approach include treating the underlying cause of pain, pharmacological and nonpharmacological therapies, and some invasive (surgical) procedures.

Treating the cause of pain underpins the idea of managing it. Injuries are repaired, diseases are diagnosed, and certain encounters with pain can be anticipated and treated prophylactically (by prevention). However, there are no guarantees of immediate relief from pain. Recovery can be impeded by pain and quality of life can be damaged. Therefore, pharmacological and other therapies have developed over time to address these aspects of disease and injury.

PHARMACOLOGICAL OPTIONS. General guidelines developed by the World Health Organization (WHO) have been developed for pain management. These guidelines operate upon a three-step ladder approach:

• Mild pain is alleviated with acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID). NSAIDs and acetaminophen are available as over-the-counter and prescription medications, and are frequently the initial pharmacological treatment for pain. These drugs can also be used as adjuncts to the other drug therapies that might require a doctor's prescription. NSAIDs include aspirin, ibuprofen (Motrin, Advil, Nuprin), naproxen sodium (Aleve), and ketoprofen (Orudis KT). These drugs are used to treat pain from inflammation and work by blocking production of pain-enhancing neurotransmitters, such as prostaglandins. Acetaminophen is also effective against pain, but its ability to reduce inflammation is limited. NSAIDs and acetaminophen are effective for most forms of acute (sharp, but of a short course) pain.
• Mild to moderate pain is eased with a milder opioid medication plus acetaminophen or NSAIDs. Opioids are both actual opiate drugs such as morphine and codeine, and synthetic drugs based on the structure of opium. This drug class includes drugs such as oxycodon, methadone, and meperidine (Demerol). They provide pain relief by binding to specific opioid receptors in the brain and spinal cord.
• Moderate to severe pain is treated with stronger opioid drugs plus acetaminophen or NSAIDs. Morphine is sometimes referred to as the gold standard of palliative care as it is not expensive, can be given starting with smaller doses and gradually increased, and is highly effective over a long period of time. It can also be given by a number of different routes, including by mouth, rectally, or by injection.

Although antidepressant drugs were developed to treat depression, it has been discovered that they are also effective in combating chronic headaches, cancer pain, and pain associated with nerve damage. Antidepressants that have been shown to have analgesic (pain-reducing) properties include amitriptyline (Elavil), trazodone (Desyrel), and imipramine (Tofranil). Anticonvulsant drugs share a similar background with antidepressants. Developed to treat epilepsy, anticonvulsants were found to relieve pain as well. Drugs such as phenytoin (Dilantin) and carbamazepine (Tegretol) are prescribed to treat the pain associated with nerve damage.

Close monitoring of the effects of pain medications is required in order to assure that adequate amounts of medication are given to produce the desired pain relief. When a person is comfortable with a certain dosage of medication, oncologists typically convert to a long-acting version of that medication. Transdermal fentanyl patches (Duragesic) are a common example of a long-acting opioid drug often used for cancer pain management. A patch containing the drug is applied to the skin and continues to deliver the drug to the person for typically three days. Pumps are also available that provide an opioid medication upon demand when the person is experiencing pain. By pressing a button, they can release a set dose of medication into an intravenous solution or an implanted catheter. Another mode of administration involves implanted catheters that deliver pain medication directly to the spinal cord. Delivering drugs in this way can reduce side effects and increase the effectiveness of the drug. Research is underway to develop toxic substances that act selectively on nerve cells that carry pain messages to the brain, killing these selected cells and thus stopping transmission of the pain message.

In 2004, two popular pain medications were taken off the market. Drug maker Merck stopped production of Vioxx (rofecoxib), its arthritis and acute pain medication. The withdrawal was based on three-year data from a prospective, randomized, placebocontrolled clinical trial, the APPROVe (Adenomatous Polyp Prevention on VIOXX) trial. The trial, which was halted, was designed to evaluate the efficacy of Vioxx 25 mg in preventing recurrence of colorectal polyps in patients with a history of colorectal adenomas. In this study, there was an increased relative risk for confirmed cardiovascular events, such as heart attack and stroke, beginning after 18 months of treatment in the patients taking Vioxx compared to those taking placebo. In 2005, the U.S. Food and Drug Administration (FDA) requested that Pfizer suspend sales of Bextra in the United States. The FDA concluded that there is an increased risk of rare but serious skin reactions associated with Bextra, prescribed to treat arthritis and chronic pain. The FDA is requiring all manufacturers of prescription non-steroidal antiinflammatory arthritis medicines (NSAIDs), such as Pfizer's Celebrex (celecoxib), to provide additional information about cardiovascular and gastrointestinal risks. The FDA also asked all the manufacturers of over-the-counter NSAIDs to revise their labels to include more information on cardiovascular, gastrointestinal and skin risks.

NONPHARMACOLOGICAL OPTIONS. Pain treatment options that do not use drugs are often used as adjuncts to, rather than replacements for, drug therapy. One of the benefits of non-drug therapies is that an individual can take a more active stance against pain. Relaxation techniques, such as yoga and meditation, are used to focus the brain elsewhere than on the pain, decrease muscle tension and reduce stress. Tension and stress can also be reduced through biofeedback, in which an individual consciously attempts to modify skin temperature, muscle tension, blood pressure, and heart rate.

Participating in normal activities and exercising can also help control pain levels. Through physical therapy, an individual learns beneficial exercises for reducing stress, strengthening muscles, and staying fit. Regular exercise has been linked to production of endorphins, the body's natural pain killers.

Acupuncture involves the insertion of small needles into the skin at key points. Acupressure uses these same key points, but involves applying pressure rather than inserting needles. Both of these methods may work by prompting the body to release endorphins. Applying heat or being massaged are very relaxing and help reduce stress. Transcutaneous electrical nerve stimulation (TENS) applies a small electric current to certain parts of nerves, potentially interrupting pain signals and inducing release of endorphins. To be effective, use of TENS should be medically supervised.

INVASIVE PROCEDURES. There are three types of invasive procedures that may be used to manage or treat pain: anatomic, augmentative, and ablative. These procedures involve surgery, and certain guidelines should be followed before carrying out a procedure with permanent effects. First, the cause of the pain must be clearly identified. Next, surgery should be done only if noninvasive procedures are ineffective. Third, any psychological issues should be addressed. Finally, there should be a reasonable expectation of success.

Anatomic procedures involve correcting the injury or removing the cause of pain. Relatively common anatomic procedures are decompression surgeries, such as repairing a herniated disk in the lower back or relieving the nerve compression related to carpal tunnel syndrome. Another anatomic procedure is neurolysis, also called a nerve block, which involves destroying a portion of a peripheral nerve.

Augmentative procedures include electrical stimulation or direct application of drugs to the nerves that are transmitting the pain signals. Electrical stimulation works on the same principle as TENS. In this procedure, instead of applying the current across the skin, electrodes are implanted to stimulate peripheral nerves or nerves in the spinal cord. Augmentative procedures also include implanted drug-delivery systems. In these systems, catheters are implanted in the spine to allow direct delivery of drugs to the CNS.

Ablative procedures are characterized by severing a nerve and disconnecting it from the CNS. However, this method may not address potential alterations within the spinal cord. These changes perpetuate pain messages and do not cease even when the connection between the sensory nerve and the CNS is severed. With growing understanding of neuropathic pain and development of less invasive procedures, ablative procedures are used less frequently. However, they do have applications in select cases of peripheral neuropathy, cancer pain, and other disorders.

Preparation

Prior to beginning management, pain is thoroughly evaluated. Pain scales or questionnaires are used to attach an objective measure to a subjective experience. Objective measurements allow health care workers a better understanding of the pain being suffered by the patient. Evaluation also includes physical examinations and diagnostic tests to determine underlying causes. Some evaluations require assessments from several viewpoints, including neurology, psychiatry and psychology, and physical therapy. If pain is due to a medical procedure, management consists of anticipating the type and intensity of associated pain and managing it preemptively.

Nurses or physicians often take what is called a pain history. This will help to provide important information that can help health care providers to better manage the patient's pain. A typical pain history includes the following questions:

• Where is the pain located?
• On a scale of 1 to 10, with 1 meaning the least pain, how would the person rate the pain they are experiencing?
• Describe what the pain feels like.
• When did (or does) the pain start?
• How long has the person had it?
• Is the person sometimes free of pain?
• Does the person know of anything that triggers the pain, or makes it worse?
• Does the person have other symptoms (nausea, dizziness, blurred vision, etc.) during or after the pain?
• What pain medications or other measures have the person found to help in easing the pain?
• How does the pain affect the person's ability to carry on normal activities?
• What does it mean to the person that they are experiencing pain?

Aftercare

An assessment by nursing staff as well as other health care providers should be made to determine the effectiveness of the pain management interventions employed. There are objective, measurable signs and symptoms of pain that can be looked for. The goal of good pain management is the absence of these signs:

Signs of acute pain:

• rise in pulse and blood pressure
• more rapid breathing
• perspiring profusely, clammy skin
• taut muscles
• more tense appearance, fast speech, very alert
• unusually pale skin
• pupils of the eye are dilated

Signs of chronic pain:

• lower pulse and blood pressure
• changeable breathing pattern
• skin is warm and dry
• nausea and vomiting
• slow speech in monotone
• inability, or difficulty in getting out of bed and doing activities
• pupils of the eye are constricted

When these signs are absent and the patient appears to be comfortable, health care providers can consider their interventions to have been successful. It is also important to document interventions used, and what ones were successful.

Complications

Owing to toxicity over the long term, some drugs can only be used for acute pain or as adjuncts in chronic pain management. NSAIDs have the wellknown side effect of causing gastrointestinal bleeding, and long-term use of acetaminophen has been linked to kidney and liver damage. Other drugs, especially narcotics, have serious side effects, such as constipation, drowsiness, and nausea. Serious side effects can also accompany pharmacological therapies; mood swings, confusion, bone thinning, cataract formation, increased blood pressure, and other problems may discourage or prevent use of some analgesics.

Nonpharmacological therapies carry little or no risks. However, it is advised that individuals recovering from serious illness or injury consult with their health care providers or physical therapists before making use of adjunct therapies. Invasive procedures carry risks similar to other surgical procedures, such as infection, reaction to anesthesia, iatrogenic (injury as a result of treatment) injury, and failure.

A traditional concern about narcotics use has been the risk of promoting addiction. As narcotic use continues over time, the body becomes accustomed to the drug and adjusts normal functions to accommodate to its presence. Therefore, to elicit the same level of action, it is necessary to increase dosage over time. As dosage increases, an individual may become physically dependent on narcotic drugs.

However, physical dependence is different from psychological addiction. Physical dependence is characterized by discomfort if drug administration suddenly stops, while psychological addiction is characterized by an overpowering craving for the drug for reasons other than pain relief. Psychological addiction is a very real and necessary concern in some instances, but it should not interfere with a genuine need for narcotic pain relief. However, caution must be taken with people with a history of addictive behavior.

Results

Effective application of pain management techniques reduces or eliminates acute or chronic pain. This treatment can improve an individual's quality of life and aid in recovery from injury and disease.

Health care team roles

Physicians, both primary care physicians (PCPs) and surgeons, treat both the conditions causing the pain, and the pain itself. The physician's role as teacher is an important one, alleviating fears about both the patient's condition and the possibility of addiction to narcotics, which is often a fear among patients on narcotic medication. Some physicians specialize in the treatment of pain, and work out of pain clinics.

Registered nurses (RNs) are the professional staff member that will likely spend the most time with the patient, whether the patient is in the hospital or other health care facility, or at home. Gathering the necessary information regarding the person's pain through a pain history, and careful observation and listening can help tremendously in the provision of pain relief. RNs also administer the medications at times, and provide information to the patient about the various medications that may be used, and allay concerns about the use of them.

Licensed practical nurses (LPNs) also spend considerable time with the patient in a health care facility or at home. Like RNs, LPNs administer medications as necessary, and provide information to patients.

Pain clinic staff may be any of the above, or psychologists, social workers, occupational or recreational therapists, or other people with specific training in group therapy, yoga, meditation, or other nonpharmacological means of relieving pain.

Pharmacists fill prescriptions for pain-relieving medications, monitor the use of narcotic medications, and provide information regarding the uses and side-effects of the medications.

KEY TERMS

Acute— Referring to pain in response to injury or other stimulus that resolves when the injury heals or the stimulus is removed.

Chronic— Referring to pain that endures beyond the term of an injury or painful stimulus. Can also refer to cancer pain, pain from a chronic or degenerative disease, and pain from an unidentified cause.

CNS or central nervous system— The part of the nervous system that includes the brain and the spinal cord.

Iatrogenic— Resulting from the activity of the physician.

Neuropathy— Nerve damage.

Neurotransmitter— Chemicals within the nervous system that transmit information from or between nerve cells.

Nociceptor— A nerve cell that is capable of sensing pain and transmitting a pain signal.

Nonpharmacological— Referring to therapy that does not involve drugs.

Parasympathetic nervous system— That part of the autonomic nervous system consisting of nerves that arise from the cranial and sacral regions and function in opposition to the sympathetic nervous system.

Pharmacological— Referring to therapy that relies on drugs.

PNS or peripheral nervous system— Nerves that are outside of the brain and spinal cord.

Stimulus— A factor capable of eliciting a response in a nerve.

Sympathetic nervous system— That portion of the autonomic nervous system consisting of nerves that originate in the thoracic and lumbar spinal cord and function in opposition to the parasympathetic nervous system.

Resources

BOOKS

Boswell, Mark V. Weiner's Pain Management: A Practical Guide for Clinicians Boca Raton, FL: CRC Press, 2005.

Gatchel, Robert J. Clinical Essentials of Pain Management Washington: American Psychological Association, 2004.

Warfield, Carol A., and Zahid H. Baiwa Principles & Practices of Pain Management New York: McGraw-Hill, 2004.

PERIODICALS

Armstrong, F. Daniel. "Analgesia for Children with Acute Abdominal Pain: A Cautious Move to Improved Pain Management." Pediatrics (October 2005): 1018-1019.

Bates, Betsy. "Need for Chronic Pain Management is Unmet." Family Practice News (Oct. 15, 2005): 65.

Dieppe, Paul A., and L. Stefan Lohmander. "Pathogenesis and Management of pain in Osteoarthritis." The Lancet (March 12, 2005): 965.

Jancin, Bruce. "Implications of Expected Big Drop in NSAID Use: Cardiovascular Side Effects Likely to Cause Physicians to Seek Other Options for Chronic pain Management." Family Practice News (July 15, 2005): 5.

ORGANIZATIONS

American Chronic Pain Association. P.O. Box 850, Rocklin, CA 95677-0850. (800) 533-3231. www.theacpa,org

American Pain Society. 4700 West Lake Ave., Glenview, IL 60025. (847) 375-4715. 〈http://www.ampainsoc.org〉.

Pain management

Definition

If pain can be defined as a highly unpleasant, individualized experience of one of the body's defense mechanisms indicating an injury or problem, pain management encompasses all interventions used to understand and ease pain, and, if possible, to alleviate the cause of the pain.

Purpose

Pain serves to alert us to potential or actual damage to the body. The definition for damage is quite broad; pain can arise from injury as well as disease. After the message is received and interpreted, further pain can be counter-productive. Pain can have a negative impact on a person's quality of life and impede recovery from illness or injury, thus contributing to escalating health care costs. Unrelieved pain can become a syndrome in its own right and cause a downward spiral in a person's health and out-look. Managing pain properly facilitates recovery, prevents additional health complications, and improves an individual's quality of life.

Yet the experiencing of pain is a completely unique occurrence for each person, a complex combination of several factors other than the pain itself. It is influenced by:

• Ethnic and cultural values. In some cultures tolerating pain is related to showing strength and endurance. In others, it is considered punishment for misdeeds.
• Age. The concept that grownups don't cry.
• Anxiety and stress related to being in a strange, fearful place such as a hospital, fear of the unknown consequences of the pain and the condition causing it can all make pain feel more severe.
• Fatigue and depression. It is known that pain in itself can actually cause depression. Fatigue from lack of sleep or the illness itself also contribute to depressed feelings.

Precautions

As noted, the perception of pain is an individual experience. Health care providers play an important role in understanding their patients' pain. All too often, both physicians and nurses have been found to incorrectly assess the severity of pain. A study reported in the Journal of Advanced Nursing evaluated nurses' perceptions of a select group of American-born and Mexican-American women patients' pain following gallbladder surgery. Objective assessments of each patient's pain showed little difference between the severity for each group. Yet nurses involved in the study consistently rated all patients' pain as less than the patients reported, and with equal consistency, believed that better-educated women born in the United States were suffering more than less educated, Mexican-American women. Nurses from a Northern European background were more apt to minimize the severity of pain than nurses from Eastern and Southern Europe or Africa. Health care staff, and especially nursing staff, need to be aware of how their own background and experience contributes to how they perceive a person's pain.

Description

Before considering pain management, a review of pain definitions and mechanisms may be useful. Pain is the means by which the peripheral nervous system (PNS) warns the central nervous system (CNS) of injury or potential injury to the body. The CNS comprises the brain and spinal cord , and the PNS is composed of the nerves that stem from and lead into the CNS. PNS includes all nerves throughout the body except the brain and spinal cord. Pain is sometimes categorized by its site of origin, either cutaneous (originating in the skin of subcutaneous tissue, such as a shaving nick or paper cut), deep somatic pain (arising from bone, ligaments and tendons, nerves, or veins and arteries), or visceral (appearing as a result of stimulation of pain receptor nerves around organs such as the brain, lungs , or those in the abdomen).

A pain message is transmitted to the CNS by special PNS nerve cells called nociceptors. Nociceptors are distributed throughout the body and respond to different stimuli depending on their location. For example, nociceptors that extend from the skin are stimulated by sensations such as pressure, temperature, and chemical changes.

When a nociceptor is stimulated, neurotransmitters are released within the cell. Neurotransmitters are chemicals found within the nervous system that facilitate nerve cell communication. The nociceptor transmits its signal to nerve cells within the spinal cord, which conveys the pain message to the thalamus, a specific region in the brain.

Once the brain has received and processed the pain message and coordinated an appropriate response, pain has served its purpose. The body uses natural painkillers, called endorphins, to derail further pain messages from the same source. However, these natural painkillers may not adequately dampen a continuing pain message. Also, depending on how the brain has processed the pain information, certain hormones, such as prostaglandins, may be released. These hormones enhance the pain message and play a role in immune system responses to injury, such as inflammation. Certain neurotransmitters, especially substance P and calcitonin gene-related peptide, actively enhance the pain message at the injury site and within the spinal cord.

Pain is generally divided into two additional categories, acute and chronic. Nociceptive pain, or the pain that is transmitted by nociceptors, is typically called acute pain. This kind of pain is associated with injury, headaches, disease, and many other conditions. Response to acute pain is made by the sympathetic nervous system (the nerves responsible for the fight or flight response of the body). It normally resolves once the condition that precipitated it is resolved.

Following some disorders, pain does not resolve. Even after healing or a cure has been achieved, the brain continues to perceive pain. In this situation, the pain may be considered chronic. Chronic pain is within the province of the parasympathetic nervous system, and the changeover occurs as the body attempts to adapt to the pain. The time limit used to define chronic pain typically ranges from three to six months, although some health-care professionals prefer a more flexible definition, and consider chronic pain as pain that endures beyond a normal healing time. The pain associated with cancer , persistent and degenerative conditions, and neuropathy, or nerve damage, is included in the chronic category. Also, unremitting pain that lacks an identifiable physical cause, such as the majority of cases of low back pain, may be considered chronic. The underlying biochemistry of chronic pain appears to be different from regular nociceptive pain.

It has been hypothesized that uninterrupted and unrelenting pain can induce changes in the spinal cord. In the past, severing a nerve's connection to the CNS has treated intractable pain. However, the lack of any sensory information being relayed by that nerve can cause pain transmission in the spinal cord to go into overdrive, as evidenced by the phantom limb pain experienced by amputees. Evidence is accumulating that unrelenting pain or the complete lack of nerve signals increases the

number of pain receptors in the spinal cord. Nerve cells in the spinal cord may also begin secreting pain-amplifying neurotransmitters independent of actual pain signals from the body. Immune chemicals, primarily cytokines, may play a prominent role in such changes.

Managing pain

Considering the different causes and types of pain, as well as its nature and intensity, management can require an interdisciplinary approach. The elements of this approach include treating the underlying cause of pain, pharmacological and nonpharmacological therapies, and some invasive (surgical) procedures.

Treating the cause of pain underpins the idea of managing it. Injuries are repaired, diseases are diagnosed, and certain encounters with pain can be anticipated and treated prophylactically (by prevention). However, there are no guarantees of immediate relief from pain. Recovery can be impeded by pain and quality of life can be damaged. Therefore, pharmacological and other therapies have developed over time to address these aspects of disease and injury.

PHARMACOLOGICAL OPTIONS. General guidelines developed by the World Health Organization (WHO) have been developed for pain management. These guidelines operate upon a three-step ladder approach:

• Mild pain is alleviated with acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID). NSAIDs and acetaminophen are available as over-the-counter and prescription medications, and are frequently the initial pharmacological treatment for pain. These drugs can also be used as adjuncts to the other drug therapies that might require a doctor's prescription. NSAIDs include aspirin, ibuprofen (Motrin, Advil, Nuprin), naproxen sodium (Aleve), and ketoprofen (Orudis KT). These drugs are used to treat pain from inflammation and work by blocking production of pain-enhancing neurotransmitters, such as prostaglandins. Acetaminophen is also effective against pain, but its ability to reduce inflammation is limited. NSAIDs and acetaminophen are effective for most forms of acute (sharp, but of a short course) pain.
• Mild to moderate pain is eased with a milder opioid medication plus acetaminophen or NSAIDs. Opioids are both actual opiate drugs such as morphine and codeine, and synthetic drugs based on the structure of opium. This drug class includes drugs such as oxy-codon, methadone, and meperidine (Demerol). They provide pain relief by binding to specific opioid receptors in the brain and spinal cord.
• Moderate to severe pain is treated with stronger opioid drugs plus acetaminophen or NSAIDs. Morphine is sometimes referred to as the gold standard of palliative care as it is not expensive, can be given starting with smaller doses and gradually increased, and is highly effective over a long period of time. It can also be given by a number of different routes, including by mouth, rectally, or by injection.

Although antidepressant drugs were developed to treat depression, it has been discovered that they are also effective in combating chronic headaches, cancer pain, and pain associated with nerve damage. Antidepressants that have been shown to have analgesic (pain-reducing) properties include amitriptyline (Elavil), trazodone (Desyrel), and imipramine (Tofranil). Anticonvulsant drugs share a similar background with antidepressants. Developed to treat epilepsy, anticonvulsants were found to relieve pain as well. Drugs such as phenytoin (Dilantin) and carbamazepine (Tegretol) are prescribed to treat the pain associated with nerve damage.

Close monitoring of the effects of pain medications is required in order to assure that adequate amounts of medication are given to produce the desired pain relief. When a person is comfortable with a certain dosage of medication, oncologists typically convert to a long-acting version of that medication. Transdermal fentanyl patches (Duragesic) are a common example of a long-acting opioid drug often used for cancer pain management. A patch containing the drug is applied to the skin and continues to deliver the drug to the person for typically three days. Pumps are also available that provide an opioid medication upon demand when the person is experiencing pain. By pressing a button, they can release a set dose of medication into an intravenous solution or an implanted catheter. Another mode of administration involves implanted catheters that deliver pain medication directly to the spinal cord. Delivering drugs in this way can reduce side effects and increase the effectiveness of the drug. Research is underway to develop toxic substances that act selectively on nerve cells that carry pain messages to the brain, killing these selected cells and thus stopping transmission of the pain message.

NONPHARMACOLOGICAL OPTIONS. Pain treatment options that do not use drugs are often used as adjuncts to, rather than replacements for, drug therapy. One of the benefits of non-drug therapies is that an individual can take a more active stance against pain. Relaxation techniques, such as yoga and meditation , are used to focus the brain elsewhere than on the pain, decrease muscle tension and reduce stress. Tension and stress can also be reduced through biofeedback, in which an individual consciously attempts to modify skin temperature, muscle tension, blood pressure , and heart rate.

Participating in normal activities and exercising can also help control pain levels. Through physical therapy , an individual learns beneficial exercises for reducing stress, strengthening muscles, and staying fit. Regular exercise has been linked to production of endorphins, the body's natural pain killers.

Acupuncture involves the insertion of small needles into the skin at key points. Acupressure uses these same key points, but involves applying pressure rather than inserting needles. Both of these methods may work by prompting the body to release endorphins. Applying heat or being massaged are very relaxing and help reduce stress. Transcutaneous electrical nerve stimulation (TENS) applies a small electric current to certain parts of nerves, potentially interrupting pain signals and inducing release of endorphins. To be effective, use of TENS should be medically supervised.

INVASIVE PROCEDURES. There are three types of invasive procedures that may be used to manage or treat pain: anatomic, augmentative, and ablative. These procedures involve surgery, and certain guidelines should be followed before carrying out a procedure with permanent effects. First, the cause of the pain must be clearly identified. Next, surgery should be done only if noninvasive procedures are ineffective. Third, any psychological issues should be addressed. Finally, there should be a reasonable expectation of success.

Anatomic procedures involve correcting the injury or removing the cause of pain. Relatively common anatomic procedures are decompression surgeries, such as repairing a herniated disk in the lower back or relieving the nerve compression related to carpal tunnel syndrome . Another anatomic procedure is neurolysis, also called a nerve block, which involves destroying a portion of a peripheral nerve.

Augmentative procedures include electrical stimulation or direct application of drugs to the nerves that are transmitting the pain signals. Electrical stimulation works on the same principle as TENS. In this procedure, instead of applying the current across the skin, electrodes are implanted to stimulate peripheral nerves or nerves in the spinal cord. Augmentative procedures also include implanted drug-delivery systems. In these systems, catheters are implanted in the spine to allow direct delivery of drugs to the CNS.

Ablative procedures are characterized by severing a nerve and disconnecting it from the CNS. However, this method may not address potential alterations within the spinal cord. These changes perpetuate pain messages and do not cease even when the connection between the sensory nerve and the CNS is severed. With growing understanding of neuropathic pain and development of less invasive procedures, ablative procedures are used less frequently. However, they do have applications in select cases of peripheral neuropathy, cancer pain, and other disorders.

Preparation

Prior to beginning management, pain is thoroughly evaluated. Pain scales or questionnaires are used to attach an objective measure to a subjective experience. Objective measurements allow health care workers a better understanding of the pain being suffered by the patient.

KEY TERMS

Acute —Referring to pain in response to injury or other stimulus that resolves when the injury heals or the stimulus is removed.

Chronic —Referring to pain that endures beyond the term of an injury or painful stimulus. Can also refer to cancer pain, pain from a chronic or degenerative disease, and pain from an unidentified cause.

CNS or central nervous system —The part of the nervous system that includes the brain and the spinal cord.

Iatrogenic —Resulting from the activity of the physician.

Neuropathy —Nerve damage.

Neurotransmitter —Chemicals within the nervous system that transmit information from or between nerve cells.

Nociceptor —A nerve cell that is capable of sensing pain and transmitting a pain signal.

Nonpharmacological —Referring to therapy that does not involve drugs.

Parasympathetic nervous system —Pertaining to that part of the autonomic nervous system consisting of nerves that arise from the cranial and sacral regions and which oppose the action of the sympathetic nervous system.

Pharmacological —Referring to therapy that relies on drugs.

PNS or peripheral nervous system —Nerves that are outside of the brain and spinal cord.

Stimulus —A factor capable of eliciting a response in a nerve.

Sympathetic nervous system —The portion of the autonomic nervous system consisting of nerves that originate in the thoracic and lumbar spinal cord and that function in opposition to the parasympathetic nervous system.

Evaluation also includes physical examinations and diagnostic tests to determine underlying causes. Some evaluations require assessments from several viewpoints, including neurology, psychiatry and psychology, and physical therapy. If pain is due to a medical procedure, management consists of anticipating the type and intensity of associated pain and managing it preemptively.

Nurses or physicians often take what is called a pain history. This will help to provide important information that can help health care providers to better manage the patient's pain. A typical pain history includes the following questions:

• Where is the pain located?
• On a scale of 1 to 10, with 1 meaning the least pain, how would the person rate the pain they are experiencing?
• Describe what the pain feels like.
• When did (or does) the pain start?
• How long has the person had it?
• Is the person sometimes free of pain?
• Does the person know of anything that triggers the pain, or makes it worse?
• Does the person have other symptoms (nausea, dizziness, blurred vision , etc.) during or after the pain?
• What pain medications or other measures has the person found to help in easing the pain?
• How does the pain affect the person's ability to carry on normal activities?
• What does it mean to the person that they are experiencing pain?

Aftercare

An assessment by nursing staff as well as other health care providers should be made to determine the effectiveness of the pain management interventions employed. There are objective, measurable signs and symptoms of pain that can be looked for. The goal of good pain management is the absence of these signs:

Signs of acute pain:

• rise in pulse and blood pressure
• more rapid breathing
• perspiring profusely, clammy skin
• taut muscles
• more tense appearance, fast speech, very alert
• unusually pale skin
• pupils of the eye are dilated

Signs of chronic pain:

• lower pulse and blood pressure
• changeable breathing pattern
• skin is warm and dry
• nausea and vomiting
• slow speech in monotone
• inability, or difficulty in getting out of bed and doing activities
• pupils of the eye are constricted

When these signs are absent and the patient appears to be comfortable, health care providers can consider their interventions to have been successful. It is also important to document interventions used, and what ones were successful.

Complications

Owing to toxicity over the long term, some drugs can only be used for acute pain or as adjuncts in chronic pain management. NSAIDs have the well-known side effect of causing gastrointestinal bleeding, and long-term use of acetaminophen has been linked to kidney and liver damage. Other drugs, especially narcotics, have serious side effects, such as constipation, drowsiness, and nausea. Serious side effects can also accompany pharmacological therapies; mood swings, confusion, bone thinning, cataract formation, increased blood pressure, and other problems may discourage or prevent use of some analgesics .

Nonpharmacological therapies carry little or no risks. However, it is advised that individuals recovering from serious illness or injury consult with their health care providers or physical therapists before making use of adjunct therapies. Invasive procedures carry risks similar to other surgical procedures, such as infection , reaction to anesthesia, iatrogenic (injury as a result of treatment) injury, and failure.

A traditional concern about narcotics use has been the risk of promoting addiction. As narcotic use continues over time, the body becomes accustomed to the drug and adjusts normal functions to accommodate to its presence. Therefore, to elicit the same level of action, it is necessary to increase dosage over time. As dosage increases, an individual may become physically dependent on narcotic drugs.

However, physical dependence is different from psychological addiction. Physical dependence is characterized by discomfort if drug administration suddenly stops, while psychological addiction is characterized by an overpowering craving for the drug for reasons other than pain relief. Psychological addiction is a very real and necessary concern in some instances, but it should not interfere with a genuine need for narcotic pain relief. However, caution must be taken with people with a history of addictive behavior.

Results

Effective application of pain management techniques reduces or eliminates acute or chronic pain. This treatment can improve an individual's quality of life and aid in recovery from injury and disease.

Health care team roles

Physicians, both primary care physicians (PCPs) and surgeons, treat both the conditions causing the pain, and the pain itself. The physician's role as teacher is an important one, alleviating fears about both the patient's condition and the possibility of addiction to narcotics, which is often a fear among patients on narcotic medication. Some physicians specialize in the treatment of pain, and work out of pain clinics.

Registered nurses (RNs) are the professional staff member that will likely spend the most time with the patient, whether the patient is in the hospital or other health care facility, or at home. Gathering the necessary information regarding the person's pain through a pain history, and careful observation and listening can help tremendously in the provision of pain relief. RNs also administer the medications at times, and provide information to the patient about the various medications that may be used, and allay concerns about the use of them.

Licensed practical nurses (LPNs) also spend considerable time with the patient in a health care facility or at home. Like RNs, LPNs administer medications as necessary, and provide information to patients.

Pain clinic staff may be any of the above, or psychologists, social workers, occupational or recreational therapists, or other people with specific training in group therapy, yoga, meditation, or other non-pharmacological means of relieving pain.

Pharmacists fill prescriptions for pain-relieving medications, monitor the use of narcotic medications, and provide information regarding the uses and side-effects of the medications.

Resources

BOOKS

Kozier, Barbara, RN, MN, Glenora Erb, RN, BSN, Kathleen Blais, RN, EdD, and Judith M. Wilkinson, RNC, MA, MS. Fundamentals of Nursing, Concepts, Process and Practice. 5th ed. Redwood City, CA: Addison-Wesley, 1995.

Salerno, Evelyn, and Joyce S. Willens, eds. Pain Management Handbook: An Interdisciplinary Approach. St. Louis: Mosby, 1996.

ORGANIZATIONS

American Chronic Pain Association. P.O. Box 850, Rocklin, CA 95677-0850. (916) 632-0922. <http://members.tripod.com/~widdy/acpa.html>.

American Pain Society. 4700 West Lake Ave., Glenview, IL 60025. (847) 375-4715. <http://www.ampainsoc.org>.

National Chronic Pain Outreach Association, Inc. P.O. Box 274, Millboro, VA 24460-9606. (540) 597-5004.

OTHER

What We Know About Pain. National Institute of Dental Research, National Institute of Health, Bethseda, MD20892. (301) 496-4261.

Joan M. Schonbeck

Pain management

Definition

If pain can be defined as a highly unpleasant, individualized experience of one of the body's defense mechanisms indicating an injury or problem, pain management encompasses all interventions used to understand and ease pain, and, if possible, to alleviate the cause of the pain.

Purpose

Pain serves to alert a person to potential or actual damage to the body. The definition for damage is quite broad: pain can arise from injury as well as disease. After the message is received and interpreted, further pain can be counterproductive. Pain can have a negative impact on a person's quality of life and impede recovery from illness or injury, thus contributing to escalating health care costs. Unrelieved pain can become a syndrome in its own right and cause a downward spiral in a person's health and outlook. Managing pain properly facilitates recovery, prevents additional health complications, and improves an individual's quality of life.

Yet, the experiencing of pain is a completely unique occurrence for each person, a complex combination of several factors other than the pain itself. It is influenced by:

• Ethnic and cultural values. In some cultures, tolerating pain is related to showing strength and endurance. In others, it is considered punishment for misdeeds.
• Age. This refers to the concept that grownups never cry.
• Anxiety and stress. This is related to being in a strange, fearful place such as a hospital, and the fear of the unknown consequences of the pain and the condition causing it, which can all combined to make pain feel more severe. For patients being treated for pain, knowing the duration of activity of an analgesic leads to anxiety about the return of pain when the drug wears off. This anxiety can make the pain more severe.
• Fatigue and depression. It is known that pain in itself can actually cause depression. Fatigue from lack of sleep or the illness itself also contribute to depressed feelings.

Precautions

The perception of pain is an individual experience. Health care providers play an important role in understanding their patients' pain. All too often, both physicians and nurses have been found to incorrectly assess the severity of pain. A study reported in the Journal of Advanced Nursing evaluated nurses' perceptions of a select group of white American and Mexican-American women patients' pain following gallbladder surgery. Objective assessments of each patient's pain showed little difference between the perceived severities for each group. Yet, the nurses involved in the study consistently rated all patients' pain as less than the patients reported, and with equal consistency, believed that better-educated women born in the United States were suffering more than less-educated Mexican-American women. Nurses from a northern European background were more apt to minimize the severity of pain than nurses from eastern and southern Europe or Africa. The study indicated how health care staff, and especially nursing staff, need to be aware of how their own background and experience contributes to how they perceive a person's pain.

In a 1990 study reported in the journal Pain, nurses were found to overestimate the severity of pain in patients with severe burns. In most other studies, nurses and physicians ascribe a lower pain severity than do patients.

Description

Before considering pain management, a review of pain definitions and mechanisms may be useful. Pain is the means by which the peripheral nervous system (PNS) warns the central nervous system (CNS) of injury or potential injury to the body. The CNS comprises the brain and spinal cord, and the PNS is composed of the nerves that stem from and lead into the CNS. PNS includes all nerves throughout the body, except the brain and spinal cord. Pain is sometimes categorized by its site of origin, either cutaneous (originating in the skin of subcutaneous tissue, such as a shaving nick or paper cut), deep somatic pain (arising from bone, ligaments and tendons, nerves, or veins and arteries), or visceral (appearing as a result of stimulation of pain receptor nerves around organs such as the brain, lungs, or those in the abdomen).

A pain message is transmitted to the CNS by special PNS nerve cells called nociceptors, which are distributed throughout the body and respond to different stimuli depending on their location. For example, nociceptors that extend from the skin are stimulated by sensations such as pressure, temperature, and chemical changes.

When a nociceptor is stimulated, neurotransmitters are released within the cell. Neurotransmitters are chemicals found within the nervous system that facilitate nerve cell communication. The nociceptor transmits its signal to nerve cells within the spinal cord, which conveys the pain message to the thalamus, a specific region in the brain.

Once the brain has received and processed the pain message and coordinated an appropriate response, pain has served its purpose. The body uses natural painkillers, called endorphins, to derail further pain messages from the same source. However, these natural painkillers may not adequately dampen a continuing pain message. Also, depending on how the brain has processed the pain information, certain hormones such as prostaglandins may be released. These hormones enhance the pain message and play a role in immune system responses to injury, such as inflammation. Certain neurotransmitters, especially substance P and calcitonin gene-related peptide, actively enhance the pain message at the injury site and within the spinal cord.

Pain is generally divided into two additional categories: acute and chronic. Nociceptive pain, or the pain that is transmitted by nociceptors, is typically called acute pain. This kind of pain is associated with injury, headaches, disease, and many other conditions. Response to acute pain is made by the sympathetic nervous system (the nerves responsible for the fight-or-flight response of the body). It normally resolves once the condition that precipitated it is resolved.

Following some disorders, pain does not resolve. Even after healing or a cure has been achieved, the brain continues to perceive pain. In this situation, the pain may be considered chronic. Chronic pain is within the province of the parasympathetic nervous system, and the changeover occurs as the body attempts to adapt to the pain. The time limit used to define chronic pain typically ranges from three to six months, although some health care professionals prefer a more flexible definition, and consider chronic pain as pain that endures beyond a normal healing time. The pain associated with cancer; persistent and degenerative conditions; and neuropathy, or nerve damage, is included in the chronic category. Also, unremitting pain that lacks an identifiable physical cause such as the majority of cases of low back pain may be considered chronic. The underlying biochemistry of chronic pain appears to be different from regular nociceptive pain.

It has been hypothesized that uninterrupted and unrelenting pain can induce changes in the spinal cord. In the past, severing a nerve's connection to the CNS has treated intractable pain. However, the lack of any sensory information being relayed by that nerve can cause pain transmission in the spinal cord to go into overdrive, as evidenced by the phantom limb pain experienced by amputees. Evidence is accumulating that unrelenting pain or the complete lack of nerve signals increases the number of pain receptors in the spinal cord. Nerve cells in the spinal cord may also begin secreting pain-amplifying neurotransmitters independent of actual pain signals from the body. Immune chemicals, primarily cytokines, may play a prominent role in such changes.

Managing pain

Considering the different causes and types of pain, as well as its nature and intensity, management can require an interdisciplinary approach. The elements of this approach include treating the underlying cause of pain, pharmacological and non-pharmacological therapies, and some invasive (surgical) procedures.

Treating the cause of pain underpins the idea of managing it. Injuries are repaired, diseases are diagnosed, and certain encounters with pain can be anticipated and treated prophylactically (by prevention). However, there are no guarantees of immediate relief from pain. Recovery can be impeded by pain and quality of life can be damaged. Therefore, pharmacological and other therapies have developed over time to address these aspects of disease and injury.

pharmacological options. General guidelines developed by the World Health Organization (WHO) have been developed for pain management. These guidelines operate upon the following three-step ladder approach:

• Mild pain is alleviated with acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID). NSAIDs and acetaminophen are available as over-the-counter and prescription medications, and are frequently the initial pharmacological treatment for pain. These drugs can also be used as adjuncts to the other drug therapies that might require a doctor's prescription. NSAIDs include aspirin , ibuprofen (Motrin, Advil, Nuprin), naproxen sodium (Aleve), and ketoprofen (Orudis KT). These drugs are used to treat pain from inflammation and work by blocking production of pain-enhancing neurotransmitters. Acetaminophen is also effective against pain, but its ability to reduce inflammation is limited. NSAIDs and acetaminophen are effective for most forms of acute (sharp, but of a short duration) pain.
• Mild to moderate pain is eased with a milder opioid medication, plus acetaminophen or NSAIDs. Opioids are both actual opiate drugs such as morphine and codeine, and synthetic drugs based on the structure of opium. This drug class includes drugs such as oxy-codon, methadone, and meperidine (Demerol). They provide pain relief by binding to specific opioid receptors in the brain and spinal cord.
• Moderate to severe pain is treated with stronger opioid drugs, plus acetaminophen or NSAIDs. Morphine is sometimes referred to as the gold standard of palliative care as it is not expensive, can be given by starting with smaller doses and gradually increased, and is highly effective over a long period of time. It can also be given by a number of different routes, including by mouth, rectally, or by injection.

Although antidepressant drugs were developed to treat depression, it has been discovered that they are also effective in combating chronic headaches, cancer pain, and pain associated with nerve damage. Antidepressants that have been shown to have analgesic (pain-reducing) properties include amitriptyline (Elavil), trazodone (Desyrel), and imipramine (Tofranil). Anticonvulsant drugs share a similar background with antidepressants. Developed to treat epilepsy, anticonvulsants were found to relieve pain as well. Drugs such as phenytoin (Dilantin) and carbamazepine (Tegretol) are prescribed to treat the pain associated with nerve damage.

Close monitoring of the effects of pain medications is required in order to assure that adequate amounts of medication are given to produce the desired pain relief. When a person is comfortable with a certain dosage of medication, oncologists typically convert to a long-acting version of that medication. Transdermal fentanyl patches (Duragesic) are a common example of a long-acting opioid drug often used for cancer pain management. A patch containing the drug is applied to the skin and continues to deliver the drug to the person for typically three days. Pumps are also available that provide an opioid medication upon demand when the person is experiencing pain. By pressing a button, they can release a set dose of medication into an intravenous solution or an implanted catheter. Another mode of administration involves implanted catheters that deliver pain medication directly to the spinal cord. Because these pumps offer the patient some degree of control over the amount of analgesic administered, the system, commonly called patient controlled analgesia (PCA), reduces the level of anxiety about availability of pain medication. Delivering drugs in this way can reduce side effects and increase the effectiveness of the drug. Research is underway to develop toxic substances that act selectively on nerve cells that carry pain messages to the brain. These substances would kill the selected cells and thus stop transmission of the pain message.

non-pharmacological options. Pain treatment options that do not use drugs are often used as adjuncts to, rather than replacements for, drug therapy. One of the benefits of non-drug therapies is that an individual can take a more active stance against pain. Relaxation techniques such as yoga and meditation are used to focus the brain elsewhere than on the pain, decrease muscle tension, and reduce stress. Tension and stress can also be reduced through biofeedback, in which an individual consciously attempts to modify skin temperature, muscle tension, blood pressure, and heart rate.

Participating in normal activities and exercising can also help control pain levels. Through physical therapy, an individual learns beneficial exercises for reducing stress, strengthening muscles, and staying fit. Regular exercise has been linked to production of endorphins, the body's natural painkillers.

Acupuncture involves the insertion of small needles into the skin at key points. Acupressure uses these same key points, but involves applying pressure rather than inserting needles. Both of these methods may work by prompting the body to release endorphins. Applying heat or being massaged are very relaxing and help reduce stress. Transcutaneous electrical nerve stimulation (TENS) applies a small electric current to certain parts of nerves, potentially interrupting pain signals and inducing release of endorphins. To be effective, use of TENS should be medically supervised.

invasive procedures. There are three types of invasive procedures that may be used to manage or treat pain: anatomic, augmentative, and ablative. These procedures involve surgery, and certain guidelines should be followed before carrying out a procedure with permanent effects. First, the cause of the pain must be clearly identified. Next, surgery should be done only if noninvasive procedures are ineffective. Third, any psychological issues should be addressed. Finally, there should be a reasonable expectation of success.

Anatomic procedures involve correcting the injury or removing the cause of pain. Relatively common anatomic procedures are decompression surgeries such as repairing a herniated disk in the lower back or relieving the nerve compression related to carpal tunnel syndrome. Another anatomic procedure is neurolysis, also called a nerve block, which involves destroying a portion of a peripheral nerve.

Augmentative procedures include electrical stimulation or direct application of drugs to the nerves that are transmitting the pain signals. Electrical stimulation works on the same principle as TENS. In this procedure, instead of applying the current across the skin, electrodes are implanted to stimulate peripheral nerves or nerves in the spinal cord. Augmentative procedures also include implanted drug-delivery systems. In these systems, catheters are implanted in the spine to allow direct delivery of drugs to the CNS.

Ablative procedures are characterized by severing a nerve and disconnecting it from the CNS. However, this method may not address potential alterations within the spinal cord. These changes perpetuate pain messages and do not cease, even when the connection between the sensory nerve and the CNS is severed. With growing understanding of neuropathic pain and development of less invasive procedures, ablative procedures are used less frequently. However, they do have applications in select cases of peripheral neuropathy, cancer pain, and other disorders.

Preparation

Prior to beginning management, pain is thoroughly evaluated. Pain scales or questionnaires are used to attach an objective measure to a subjective experience. Objective measurements allow health care workers to better understand the pain being suffered by the patient. Evaluation also includes physical examinations and diagnostic tests to determine underlying causes. Some evaluations require assessments from several viewpoints, including neurology, psychiatry and psychology, and physical therapy. If pain is due to a medical procedure, management consists of anticipating the type and intensity of associated pain and managing it preemptively.

Nurses or physicians often take what is called a pain history. This will help to provide important information that can help health care providers to better manage the patient's pain. A typical pain history includes the following questions:

• Where is the pain located?
• On a scale of 1 to 10, with 1 indicating the least pain, how would the person rate the pain being experienced?
• What does the pain feel like?
• When did (or does) the pain start?
• How long has the person had it?
• Is the person sometimes free of pain?
• Does the person know of anything that triggers the pain, or makes it worse?
• Does the person have other symptoms (nausea, dizziness, blurred vision, etc.) during or after the pain?
• What pain medications or other measures has the person found to help in easing the pain?
• How does the pain affect the person's ability to carry on normal activities?
• What does it mean to the person that he or she is experiencing pain?

Aftercare

An assessment by nursing staff as well as other health care providers should be made to determine the effectiveness of the pain management interventions employed. There are objective, measurable signs and symptoms of pain that can be looked for. The goal of good pain management is the absence of these signs. Signs of acute pain include:

• rise in pulse and blood pressure
• more rapid breathing
• perspiring profusely, clammy skin
• taut muscles
• more tense appearance, fast speech, very alert
• unusually pale skin
• dilated pupils of the eye

Signs of chronic pain include:

• lower pulse and blood pressure
• changeable breathing pattern
• warm, dry skin
• nausea and vomiting
• slow speech in monotone
• inability, or difficulty in getting out of bed and doing activities
• constricted pupils of the eye

When these signs are absent and the patient appears to be comfortable, health care providers can consider their interventions to have been successful. It is also important to document interventions used, and which ones were successful.

Risks

Owing to toxicity over the long term, some drugs can only be used for acute pain or as adjuncts in chronic pain management. NSAIDs have the well-known side effect of causing gastrointestinal bleeding, and long-term use of acetaminophen has been linked to kidney and liver damage. Other drugs, especially narcotics, have serious side effects such as constipation, drowsiness, and nausea. Serious side effects can also accompany pharmacological therapies; mood swings, confusion, bone thinning, cataract formation, increased blood pressure, and other problems may discourage or prevent use of some analgesics .

Non-pharmacological therapies carry little or no risks. However, it is advised that individuals recovering from serious illness or injury consult with the health care providers or physical therapists before making use of adjunct therapies. Invasive procedures carry risks similar to other surgical procedures, such as infection, reaction to anesthesia, and iatrogenic (injury as a result of treatment) injury.

A traditional concern about narcotics use has been the risk of promoting addiction. As narcotic use continues over time, the body becomes accustomed to the drug and adjusts normal functions to accommodate to its presence. Therefore, to elicit the same level of action, it is necessary to increase dosage over time. As dosage increases, an individual may become physically dependent on narcotic drugs.

However, physical dependence is different from psychological addiction. Physical dependence is characterized by discomfort if drug administration suddenly stops, while psychological addiction is characterized by an overpowering craving for the drug for reasons other than pain relief. Psychological addiction is a very real and necessary concern in some instances, but it should not interfere with a genuine need for narcotic pain relief. However, caution must be taken with people who have a history of addictive behavior.

Normal results

Effective application of pain management techniques reduces or eliminates acute or chronic pain. This treatment can improve an individual's quality of life and aid in recovery from injury and disease.

Resources

books

kozier, barbara, glenora erb, kathleen blais, and judith m. wilkinson. fundamentals of nursing, concepts, process and practice, 5th edition. redwood city, ca: addison-wesley, 1995.

salerno, evelyn, and joyce s. willens, eds. pain management handbook: an interdisciplinary approach. st. louis: mosby, 1996.

periodicals

choiniere, m., r. melzack, n. girard, j. rondeau, and m. j. paquin. "comparisons between patients' and nurses' assessment of pain and medication efficacy in severe burn injuries." pain 40, no.2 (february 1990): 143–52.

everett, j. j., d. r. patterson, j. a. marvin, b. montgomery, n. ordonez, and k. campbell. "pain assessment from patients with burns and their nurses." journal of burn care rehabilitation 15, no.2 (mar–apr 1994): 194–8.

mcpherson, m. l., c. d. ponte, and r. m. respond (eds.). "profiles in pain management." journal of the american pharmacists association (june 2003).

organizations

american chronic pain association. p.o. box 850, rocklin, ca 95677-0850. (916) 632-0922. <http://members.tripod.com/~widdy/acpa.html>.

american pain society. 4700 west lake ave., glenview, il 60025. (847) 375-4715. <http://www.ampainsoc.org>.

national chronic pain outreach association, inc. p.o. box 274, millboro, va 24460-9606. (540) 597-5004.

other

what we know about pain. national institute of dental research, national institute of health, bethseda, md 20892. (301) 496-4261.

Joan M. Schonbeck Sam Uretsky, PharmD

Pain Management

Definition

Pain management encompasses pharmacological, nonpharmacological, and other approaches to prevent, reduce, or stop pain sensations.

Purpose

Pain serves as an alert to potential or actual damage to the body. The definition for damage is quite broad; pain can arise from injury as well as disease. After the message is received and interpreted, further pain can be counter-productive. Pain can have a negative impact on a person's quality of life and impede recovery from illness or injury. Unrelieved pain can become a syndrome in its own right and cause a downward spiral in a person's health and outlook. Managing pain properly facilitates recovery, prevents additional health complications, and improves an individual's quality of life.

Description

What is pain?

Before considering pain management, a review of pain definitions and mechanisms may be useful. Pain is the means by which the peripheral nervous system (PNS) warns the central nervous system (CNS) of injury or potential injury to the body. The CNS comprises the brain and spinal cord, and the PNS is composed of the nerves that stem from and lead into the CNS. The PNS includes all nerves throughout the body except the brain and spinal cord.

A pain message is transmitted to the CNS by special PNS nerve cells called nociceptors. Nociceptors are distributed throughout the body and respond to different stimuli depending on their location. For example, nociceptors that extend from the skin are stimulated by sensations such as pressure, temperature, and chemical changes.

When a nociceptor is stimulated, neurotransmitters are released within the cell. Neurotransmitters are chemicals found within the nervous system that facilitate nerve cell communication. The nociceptor transmits its signal to nerve cells within the spinal cord, which conveys the pain message to the thalamus, a specific region in the brain.

Once the brain has received and processed the pain message and coordinated an appropriate response, pain has served its purpose. The body uses natural pain killers, called endorphins, that are meant to derail further pain messages from the same source. However, these natural pain killers may not adequately dampen a continuing pain message. Also, depending on how the brain has processed the pain information, certain hormones, such as prostaglandins, may be released. These hormones enhance the pain message and play a role in immune system responses to injury, such as inflammation. Certain neurotransmitters, especially substance P and calcitonin gene-related peptide, actively enhance the pain message at the injury site and within the spinal cord.

Pain is generally divided into two categories: acute and chronic. Nociceptive pain, or the pain that is transmitted by nociceptors, is typically called acute pain. This kind of pain is associated with injury, headaches, disease, and many other conditions. It usually resolves once the condition that caused it is resolved.

Following some disorders, pain does not resolve. Even after healing or a cure has been achieved, the brain continues to perceive pain. In this situation, the pain may be considered chronic. The time limit used to define chronic pain typically ranges from three to six months, although some healthcare professionals prefer a more flexible definition, and consider chronic pain as pain that endures beyond a normal healing time. The pain associated with cancer, persistent and degenerative conditions, and neuropathy, or nerve damage, is included in the chronic category. Also, unremitting pain that lacks an identifiable physical cause, such as the majority of cases of low back pain, may be considered chronic. The underlying biochemistry of chronic pain appears to be different from regular nociceptive pain.

Some researchers have said that uninterrupted and unrelenting pain can induce changes in the spinal cord. In the past, intractable pain has been treated by severing a nerve's connection to the CNS. However, the lack of any sensory information being relayed by that nerve can cause pain transmission in the spinal cord to go into overdrive, as evidenced by the phantom limb pain experienced by amputees. Evidence is accumulating that unrelenting pain or the complete lack of nerve signals increases the number of pain receptors in the spinal cord. Nerve cells in the spinal cord may also begin secreting pain-amplifying neurotransmitters independent of actual pain signals from the body. Immune chemicals, primarily cytokines, may play a prominent role in such changes.

Scientists have long recognized a relationship between depression and chronic pain. In 2004, a survey of California adults diagnosed with major depressive disorder revealed that more than one-half of them also suffered from chronic pain.

Managing pain

Considering the different causes and types of pain, as well as its nature and intensity, management can require an interdisciplinary approach. The elements of this approach include treating the underlying cause of pain, pharmacological and nonpharmacological therapies, and some invasive (surgical) procedures.

Treating the cause of pain underpins the idea of managing it. Injuries are repaired, diseases are diagnosed, and certain encounters with pain can be anticipated and treated prophylactically (by prevention). However, there are no guarantees of immediate relief from pain. Recovery can be impeded by pain and quality of life can be damaged. Therefore, pharmacological and other therapies have developed over time to address these aspects of disease and injury.

PHARMACOLOGICAL OPTIONS. Pain-relieving drugs, otherwise called analgesics, include nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, narcotics, antidepressants, anticonvulsants, and others. NSAIDs and acetaminophen are available as over-the-counter and prescription medications, and are frequently the initial pharmacological treatment for pain. These drugs can also be used as adjuncts to the other drug therapies, which might require a doctor's prescription.

NSAIDs include aspirin, ibuprofen (Motrin, Advil, Nuprin), naproxen sodium (Aleve), and ketoprofen (Orudis KT). These drugs are used to treat pain from inflammation and work by blocking production of pain-enhancing neurotransmitters, such as prostaglandins. Acetaminophen is also effective against pain, but its ability to reduce inflammation is limited.

NSAIDs and acetaminophen are effective for most forms of acute (sharp, but of a short course) pain, but moderate and severe pain may require stronger medication. Narcotics handle intense pain effectively, and are used for cancer pain and acute pain that does not respond to NSAIDs and acetaminophen. Narcotics are classified as either opiates or opioids, and are available only with a doctor's prescription. Opiates include morphine and codeine, which are derived from opium, a substance naturally found in some poppy species. Opioids are synthetic drugs based on the structure of opium. This drug class includes drugs such as oxycodon, methadone, and meperidine (Demerol). In August 2004, the Drug Enforcement Administration (DEA) issued new guidelines to help physicians prescribe narcotics appropriately without fear of being arrested for prescribing the drugs beyond the scope of their medical practice. DEA is trying to work with physicians to ensure that those who need to drugs receive them but to ensure opioids are not abused.

Narcotics may be ineffective against some forms of chronic pain, especially since changes in the spinal cord may alter the usual pain signaling pathways. In such situations, pain can be managed with the help of with antidepressants and anticonvulsants, which are also only available with a doctor's prescription.

Although antidepressant drugs were developed to treat depression, it has been discovered that they are also effective in combating some chronic headaches, cancer pain, and pain associated with nerve damage. Antidepressants that have been shown to have analgesic (pain reducing) properties include amitriptyline (Elavil), trazodone (Desyrel), and imipramine (Tofranil). Anticonvulsant drugs share a similar background with antidepressants. Developed to treat epilepsy, certain anticonvulsants were found to relieve pain as well. Drugs such as phenytoin (Dilantin) and carbamazepine (Tegretol) are prescribed to treat the pain associated with nerve damage.

Other prescription drugs are used to treat specific types of pain or specific pain syndromes. For example, corticosteroids are effective against pain caused by inflammation and swelling, and sumatriptan (Imitrex) was developed to treat migraine headaches.

Drug administration depends on the drug type and the required dose. Some drugs are not absorbed very well from the stomach and must be injected or administered intravenously. Injections and intravenous administration may also be used when high doses are needed or if an individual is nauseous. Following surgery and other medical procedures, patients may have the option of controlling the pain medication themselves. By pressing a button, they can release a set dose of medication into an intravenous solution. This procedure has also been employed in other situations requiring pain management. Another mode of administration involves implanted catheters that deliver pain medication directly to the spinal cord. Delivering drugs in this way can reduce side effects and increase the effectiveness of the drug.

NONPHARMACOLOGICAL OPTIONS. Pain treatment options that do not use drugs are often used as adjuncts to, rather than replacements for, drug therapy. One of the benefits of non-drug therapies is that an individual can take a more active stance against pain. Relaxation techniques, such as yoga and meditation, are used to decrease muscle tension and reduce stress. Tension and stress can also be reduced through biofeedback, in which an individual consciously attempts to modify skin temperature, muscle tension, blood pressure, and heart rate.

Participating in normal activities and exercising can also help control pain levels. Through physical therapy, an individual learns beneficial exercises for reducing stress, strengthening muscles, and staying fit. Regular exercise has been linked to production of endorphins, the body's natural pain killers.

Acupuncture involves the insertion of small needles into the skin at key points. Acupressure uses these same key points, but involves applying pressure rather than inserting needles. Both of these methods may work by prompting the body to release endorphins. Applying heat or being massaged are very relaxing and help reduce stress. Transcutaneous electrical nerve stimulation (TENS) applies a small electric current to certain parts of nerves, potentially interrupting pain signals and inducing release of endorphins. To be effective, use of TENS should be medically supervised.

INVASIVE PROCEDURES. There are three types of invasive procedures that may be used to manage or treat pain: anatomic, augmentative, and ablative. These procedures involve surgery, and certain guidelines should be followed before carrying out a procedure with permanent effects. First, the cause of the pain must be clearly identified. Next, surgery should be done only if noninvasive procedures are ineffective. Third, any psychological issues should be addressed. Finally, there should be a reasonable expectation of success.

Anatomic procedures involve correcting the injury or removing the cause of pain. Relatively common anatomic procedures are decompression surgeries, such as repairing a herniated disk in the lower back or relieving the nerve compression related to carpal tunnel syndrome. Another anatomic procedure is neurolysis, also called a nerve block, which involves destroying a portion of a peripheral nerve.

Augmentative procedures include electrical stimulation or direct application of drugs to the nerves that are transmitting the pain signals. Electrical stimulation works on the same principle as TENS. In this procedure, instead of applying the current across the skin, electrodes are implanted to stimulate peripheral nerves or nerves in the spinal cord. Augmentative procedures also include implanted drug-delivery systems. In these systems, catheters are implanted in the spine to allow direct delivery of drugs to the CNS.

Ablative procedures are characterized by severing a nerve and disconnecting it from the CNS. However, this method may not address potential alterations within the spinal cord. These changes perpetuate pain messages and do not cease even when the connection between the sensory nerve and the CNS is severed. With growing understanding of neuropathic pain and development of less invasive procedures, ablative procedures are used less frequently. However, they do have applications in select cases of peripheral neuropathy, cancer pain, and other disorders.

Preparation

Prior to beginning management, pain is thoroughly evaluated. Pain scales or questionnaires are used to attach an objective measure to a subjective experience. Objective measurements allow health care workers a better understanding of the pain being experienced by the patient. Evaluation also includes physical examinations and diagnostic tests to determine underlying causes. Some evaluations require assessments from several viewpoints, including neurology, psychiatry and psychology, and physical therapy. If pain is due to a medical procedure, management consists of anticipating the type and intensity of associated pain and managing it preemptively.

Risks

Owing to toxicity over the long term, some drugs can only be used for acute pain or as adjuncts in chronic pain management. NSAIDs have the well-known side effect of causing gastrointestinal bleeding, and long-term use of acetaminophen has been linked to kidney and liver damage. Other drugs, especially narcotics, have serious side effects, such as constipation, drowsiness, and nausea. Serious side effects can also accompany pharmacological therapies; mood swings, confusion, bone thinning, cataract formation, increased blood pressure, and other problems may discourage or prevent use of some analgesics.

KEY TERMS

Acute— Referring to pain in response to injury or other stimulus that resolves when the injury heals or the stimulus is removed.

Chronic— Referring to pain that endures beyond the term of an injury or painful stimulus. Can also refer to cancer pain, pain from a chronic or degenerative disease, and pain from an unidentified cause.

CNS or central nervous system— The part of the nervous system that includes the brain and the spinal cord.

Iatrogenic— Resulting from the activity of the physician.

Neuropathy— Nerve damage.

Neurotransmitter— Chemicals within the nervous system that transmit information from or between nerve cells.

Nociceptor— A nerve cell that is capable of sensing pain and transmitting a pain signal.

Nonpharmacological— Referring to therapy that does not involve drugs.

Pharmacological— Referring to therapy that relies on drugs.

PNS or peripheral nervous system— Nerves that are outside of the brain and spinal cord.

Stimulus— A factor capable of eliciting a response in a nerve.

Nonpharmacological therapies carry little or no risk. However, it is advised that individuals recovering from serious illness or injury consult with their health care providers or physical therapists before making use of adjunct therapies. Invasive procedures carry risks similar to other surgical procedures, such as infection, reaction to anesthesia, iatrogenic (injury as a result of treatment) injury, and failure.

A traditional concern about narcotics use has been the risk of promoting addiction. As narcotic use continues over time, the body becomes accustomed to the drug and adjusts normal functions to accommodate to its presence. Therefore, to elicit the same level of action, it is necessary to increase dosage over time. As dosage increases, an individual may become physically dependent on narcotic drugs.

However, physical dependence is different from psychological addiction. Physical dependence is characterized by discomfort if drug administration suddenly stops, while psychological addiction is characterized by an overpowering craving for the drug for reasons other than pain relief. Psychological addiction is a very real and necessary concern in some instances, but it should not interfere with a genuine need for narcotic pain relief. However, caution must be taken with people with a history of addictive behavior.

Normal results

Effective application of pain management techniques reduces or eliminates acute or chronic pain. This treatment can improve an individual's quality of life and aid in recovery from injury and disease.

Resources

PERIODICALS

Finn, Robert. "More than Half of Patients With Major Depression Have Chronic Pain." Family Practice News October 15, 2004: 38.

"New Guidelines Set for Better Pain Treatment." Medical Letter on the CDC & FDA September 5, 2004: 95.

ORGANIZATIONS

American Chronic Pain Association. P.O. Box 850, Rocklin, CA 95677-0850. (916) 632-0922. 〈http://members.tripod.com/∼widdy/ACPA.html〉.

American Pain Society. 4700 West Lake Ave., Glenview, IL 60025. (847) 375-4715. 〈http://www.ampainsoc.org〉.

National Chronic Pain Outreach Association, Inc. P.O. Box 274, Millboro, VA 24460-9606. (540) 997-5004.