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PAIN MANAGEMENT.
INTRODUCTION
Pain is a universal human experience and the most common reason people seek medical
care. Pain tells us something is wrong in the structure or function of our body and that we
need to do something about it. Because pain is such a strong motivator for action, it is
considered one of the body’s most important protective mechanisms.
DEFINITIONS OF PAIN
The International Association for the Study of Pain defined pain as “an
unpleasaGnt, subjective, sensory and emotional experience associated with actual
or potential tissue damage or described in terms of such damage” (International
Association for the Study of Pain, 1979).
Pain, however, is much more than a physical sensation caused by a single entity. It is
subjective and highly individual, a complex mechanism with physical, emotional, and
cognitive components.
Pain cannot be objectively measured in the same way as, for example, the chemical
content of urine or the oxygen content level of blood. Only the person who is suffering
knows how the experience feels.
McCaffery defined pain as “whatever the experiencing person says it is and
whenever he says it does” (1979).
The American Pain Society goes further by stating that it is “not the responsibility
of clients to prove they are in pain; it is the nurse’s responsibility to accept the
client’s report of pain” (2005).
PAIN-RELATED TERMINOLOGY
Algesia: Sensitivity to pain.
Breakthrough pain: Transitory increase in pain to a level greater than the client’s well-
controlled baseline level (McCaffery & Pasero, 2003).
Hyperalgesia: Excessive sensitivity to pain.
Idiopathic pain: Chronic pain for which there is no identifiable psychological or physical
cause.
Intractable pain: Pain that is not relieved by ordinary medical, surgical, and nursing
measures (Mosby’s Dictionary, 2009).
Pain threshold: Amount of pain required before individuals feel the pain. The lower the
threshold, the less pain they can endure; the higher the threshold, the more pain they can
endure.
Pain tolerance: Maximum amount and duration of pain a person can endure. Tolerance
varies widely among people and is influenced by emotions and cultural background.
Pain syndrome: A group of symptoms of which pain is the critical element, such as
headaches and post-herpetic neuralgia.
Phantom limb pain: Pain that occurs in a limb after it is removed or as a result of severe
damage to the affected nerve plexus due to perceptual disruption in the brain.
Psychogenic pain: Chronic pain with no identified organic explanation.
Radiating pain: Pain that begins at one place and extends out into nearby tissues.
Referred pain: Pain that is felt at a different location than where tissue was damaged. This
phenomenon occurs because pain fibers in the damaged area synapse near fibers from other
areas of the body; for example, a myocardial infarction may create referred pain in the left
shoulder.
PHYSIOLOGY OF PAIN
The following is a brief review of the four basic concepts that are important to begin to understand the physiology of pain. The concepts are transduction, transmission, modulation, and perception.
Transduction is the process by which afferent nerve endings participate in translating noxious stimuli (e.g., a pinprick) into nociceptive impulses.
Noxious stimulation is first carried by the faster A-delta fibers, and then by the slower C fibers. “Silent nociceptors,””, also involved in transduction, are afferent nerves that do not respond to external stimulation unless inflammatory mediators are present. The peripheral nervous system
contains primary sensory afferent neurons that have an important role in pain signaling. The axons of these afferents diverge from the cell body in the dorsal root ganglion near the spinal cord and send a short fiber centrally into the cord and a long fiber down the peripheral nerve into the tissues. Their receptors detect mechanical, thermal, proprioceptive, and chemical stimuli.
Transmission is the process by which impulses are sent to the dorsal horn of the spinal cord, and then along the sensory tracts to the brain.
The primary afferent neurons are active senders and receivers of chemical and electrical signals. Their axons terminate in the dorsal horn of the spinal cord, where they have connections with many spinal neurons. In turn, spinal neurons have input from many primary afferents. These spinal neurons project axons to the contralateral thalamus, which in turn projects to the somatosensory pathway, frontal cortex, and other areas. The somatosensory cortex is thought to be involved in the sensory aspects of pain, such as the intensity and quality of pain, whereas the frontal cortex and limbic system are thought to be involved with the emotional responses to it.
Modulation is the process of dampening or amplifying these pain-related neural signals. Modulation takes place primarily in the dorsal horn of the spinal cord, but also elsewhere, with input from ascending and descending pathways.
The gate control theory is a popular model of pain modulation proposed by Melzack and Wall in 1965, later revised by Melzack and Casey in 1968. These investigators proposed the existence of an endogenous ability to reduce or increase the degree of perceived pain through modulation of incoming impulses at a gate located in the dorsal horn of the spinal cord. The gate acts on signals from the ascending and descending systems and weighs all of the inputs. The integration of these inputs from sensory neurons, the segmental spinal cord level, and the brain, determines whether the gate will be opened or closed, either increasing or decreasing the intensity of the ascending pain signal. The role of psychological variables in the perception of pain, including motivation to escape pain, and the role of thoughts, emotions, and stress reactions in increasing or decreasing painful sensations, is evident in the gate control theory. An example is when patients report more pain at night, when they are isolated and less distracted from their pain than they might be during the day. The proposed gate can be opened or closed by pharmacologic manipulation
GATE-CONTROL THEORY
Melzack and Wall proposed the gate-control theory to explain the relationship between
pain and the emotions (1982). According to the theory, a gating mechanism occurs when
a pain impulse travels to the substantia gelatinosa in the dorsal horn of the spinal cord.
There, trigger (T) cells influence the transmission of pain impulses. When their activity is
inhibited, the gate closes and impulses are less likely to be transmitted to the brain. This
mechanism is controlled by descending nerve fibers from the thalamus and cerebral
cortex, areas of the brain that regulate thought and emotions. The gate-control theory
helps explain how thoughts and emotions modify the perception of pain and why
interventions, such as imagery and distraction, help relieve it.
n, transduction, transmission and modulation, and psychological intervention.
Perception refers to the subjective experience of pain that results from the interaction of transduction, transmission, modulation, and the psychological aspects of the individual.
As research continues furthering the understanding of this complex process, there is hope that pain treatments can be developed to target specific parts of the physiologic pathway and become more effective than current treatmen
Neurologic transmission of pain stimuli. (Illustration by Jason McAlexander. © 2005,
Wild Iris Medical Education, Inc.)
Factors That Influence Pain
The perception of pain is influenced by physiologic, psychological, and cultural factors,
all of which caregivers need to consider.
PHYSIOLOGICAL FACTORS
Age
Age affects the way people respond to pain. It influences both the development and decline of
the nervous system.. The following table gives a brief overview of the perception of pain relative
to age.
AGE AND THE PERCEPTION OF PAIN
Age Pain Perception
Pre-term infants Have anatomical and functional ability to process pain by mid to late gestation; seem to have greater sensitivity to pain than term infants or children
Newborn infants Response to pain is inborn and does not require prior learning; respond to pain with behaviors such as crying, grimacing, moving body
Infants, 1 month Can metabolize analgesics and anesthesia effectively; can recognize caregiver as comforter
Toddlers/Preschoolers Can describe pain, its location and intensity; respond to pain by crying, anger, sadness; may consider pain a punishment; may hold someone accountable for pain and remember experiences in a certain location, such as a clinic
School-age children May try to be brave when facing a painful procedure; may regress to an earlier stage of development; seek understanding of reasons for pain
Adolescents May be slow to acknowledge pain; may consider showing signs of pain a weakness; may regress to earlier stages of development with persistent pain
Adults Fear of pain may prevent some from seeking care; may believe admission of pain is a weakness and inappropriate for age or sex; may consider pain a punishment for moral failure
Older adults May have decreased sensations or perceptions of pain; may consider pain an inevitable part of aging; chronic pain may produce anorexia, lethargy, depression; may not report pain due to fear of expense, possible treatment, dependency; often describe
AGE AND THE PERCEPTION OF PAIN
Age Pain Perception
pain in nonmedical terms such as “hurt” or “ache”; may fear addiction to analgesics; may not want to bother nurses or be a “bad patient”
Fatigue
Fatigue decreases coping abilities and heightens the perception of pain. When people are
exhausted from physical activity, stress, and lack of sleep, their perception of pain may
be heightened and their coping skills diminished. Thus, sleep and rest from physical,
emotional, and social demands are important measures to manage pain more effectively.
Genetic Makeup
Recent research suggests that sensitivity to and tolerance for pain may a genetically
linked trait (Ruda et al., 2000). This finding does not negate the need to manage pain
adequately, regardless of inherited traits.
Memory
Memory of painful experiences, especially experiences that occurred as a very young
child, may increase sensitivity and decrease tolerance to pain. For example, even young
children remember the pain of an immunization at the doctor’s office and henceforth may
be afraid to visit the doctor again.
Stress Response
Research has shown that “severe, unrelieved pain can cause an overwhelming stress
response in both pre-term and full-term infants which can lead to serious complications
and even death” (Pasero, 2004). In recent years, post-traumatic stress syndrome has been
the subject of extensive research, both as to its cause and its treatment (Hamilton, 2008).
Healing
Recent research suggests that unrelieved acute pain slows postoperative wound healing
(McGuire, 2006). This evidence is not surprising, given our increasing knowledge of the
effect of stress on the human body.
Neurologic Function
Any factor that interrupts or interferes with normal pain transmission affects the
awareness and response of clients to pain and places them at risk for injury. Analgesics,
sedatives, and alcohol depress the functioning of the central nervous system. Some
diseases, such as leprosy, damage peripheral nerves, decrease sensitivity to touch and
pain, and render sufferers more vulnerable to injury.
PSYCHOLOGICAL FACTORS
Fear and Anxiety
The relationship between pain and fear is convoluted and complex. Fear tends to increase
the perception of pain, and pain increases feelings of fear and anxiety. This connection
occurs in the brain because painful stimuli activate portions of the limbic system believed
to control emotional reactions.
Coping
People manage pain and other stressors of life in different ways. Some see themselves as
self-sufficient, internally controlled, and independent. As a result, they may deny pain or
be slow to admit they are suffering.
CULTURAL FACTORS
Cultural beliefs and values affect the way people respond to pain. As children they learn what is
and what is not acceptable behavior when experiencing pain. In some cultures, any expression of
pain is considered cowardly and shameful. In others, noisy demonstrations of pain are expected
and acceptable. The meaning of pain itself may be markedly different in different cultures. Some
ethnic groups see pain as a punishment for wrongdoing
PAIN CLASSIFICATION
There are two basic types of pain: acute and chronic.
Acute pain occurs for brief periods of time and is associated with temporary disorders. However, it is always an alarm signal that something may be wrong.
Chronic pain is continuous and recurrent. It is associated with chronic diseases and is one of their symptoms. Pain intensity not only depends on the type of stimulus that caused it, but also on the subjective
perception of the pain. Despite a wide range of subjective perception, several types of pain have been classified according to:
The stimulus that caused the pain. The pain's duration.
The features of pain (intensity, location, etc.).
The main types of pain described by this system of classification are:
Gnawing pain. Continuous with constant intensity. It generally worsens with movement. Throbbing pain. This is typical of migraine pain. It is caused by dilation and constriction
of the cerebral blood vessels.
Stabbing pain. Intense and severe. It is caused by mechanical stimuli.
Burning pain. A constant, burning feeling, like, for example, the type of pain caused by heartburn.
Pressing pain. Caused by constriction of the blood vessels or muscles.
There are also specific types of pain:
Muscle pain. Also known as myalgia, this pain involves the muscles and occurs after excessive exertion or during inflammation.
Colicky pain. Caused by muscle contractions of certain organs, such as the uterus during the menstrual period. Generally cyclic in nature.
Referred pain. Occurs when the painful sensation is felt in a site other than the one where it is actually occurring, depending upon how the brain interprets information it receives from the body.
Postoperative pain. Occurs after surgery and is due to lesions from surgical procedures.
Classification of Pain
Classification of pain: Classifying pain is helpful to guide assessment and treatment. There are many ways to classify pain and classifications may overlap (Table 1). The common types of pain include:
Nociceptive: represents the normal response to noxious insult or injury of tissues such as skin, muscles, visceral organs, joints, tendons, or bones.
o Examples include:
Somatic: musculoskeletal (joint pain, myofascial pain), cutaneous; often
well localized
Visceral: hollow organs and smooth muscle; usually referred
Neuropathic: pain initiated or caused by a primary lesion or disease in the somatosensory nervous system.
o Sensory abnormalities range from deficits perceived as numbness to hypersensitivity (hyperalgesia or allodynia), and to paresthesias such as tingling.
o Examples include, but are not limited to, diabetic neuropathy, postherpetic neuralgia, spinal cord injury pain, phantom limb (post-amputation) pain, and post-stroke central pain.
Inflammatory: a result of activation and sensitization of the nociceptive pain pathway by a variety of mediators released at a site of tissue inflammation.
o The mediators that have been implicated as key players are proinflammatory cytokines such IL-1-alpha, IL-1-beta, IL-6 and TNF-alpha, chemokines, reactive oxygen species, vasoactive amines, lipids, ATP, acid, and other factors released by infiltrating leukocytes, vascular endothelial cells, or tissue resident mast cells
o Examples include appendicitis, rheumatoid arthritis, inflammatory bowel disease, and herpes zoster.
Clinical Implications of classification: Pathological processes never occur in isolation and consequently more than one mechanism may be present and more than one type of pain may be detected in a single patient; for example, it is known that inflammatory mechanisms are involved in neuropathic pain.
There are well-recognized pain disorders that are not easily classifiable. Our understanding of their underlying mechanisms is still rudimentary though specific therapies for those disorders are well known; they include cancer pain, migraine and other primary headaches and wide-spread pain of the fibromyalgia type.
Pain Intensity: Can be broadly categorized as: mild, moderate and severe. It is common to use a numeric scale to rate pain intensity where 0 = no pain and 10 is the worst pain imaginable:
Mild: <4/10
Moderate: 5/10 to 6/10
Severe: >7/10
Time course: Pain duration
Acute pain: pain of less than 3 to 6 months duration
Chronic pain: pain lasting for more than 3-6 months, or persisting beyond the course of an acute disease, or after tissue healing is complete.
Acute-on-chronic pain: acute pain flare superimposed on underlying chronic pain.
Sources of Pain
The sources of pain are divided into three main categories: nociceptor, non-nociceptor,
and psychogenic.
Nociceptor pain results when tissue damage produces a pain-producing stimulus
that sends an electrical impulse across a pain receptor (nociceptor) by way of a
nerve fiber to the central nervous system. Nociceptor pain is further divided into
visceral and somatic pain.
Visceral pain results from stimulation of nociceptors in the abdominal cavity
and thorax.
Somatic pain is divided into deep somatic and cutaneous pain. Deep somatic
pain arises from bones, tendons, nerves, and blood vessels. Cutaneous pain
originates in the skin or subcutaneous tissue. Some body tissues, such as the
brain and lung, have no nociceptors, and some tissues have many.
Non-nociceptor (neuropathic) pain is caused by direct injury to structures of the
nervous system.
Psychogenic pain is pain for which there is little or no physical evidence of organic
disease or identified injury to tissues in the body. Lack of evidence, however, does not
mean clients are malingering or that they are not suffering.
PHYSIOLOGIC SOURCES OF PAIN
Source: Adapted with permission from Ignatavicius et al., 1999.
Nociceptor: Visceral
Physiologic structures Organs and linings of body cavities
Mechanism Activation of nociceptors
Characteristics Poorly localized, diffuse, deep, cramping or splitting
Sources of acute pain Chest tubes, abdominal drains, bladder and intestinal distention
Sources of chronic pain syndromes
Pancreatitis, liver metastases, colitis
Nociceptor: Somatic
Physiologic structures Cutaneous: skin and sub-cutaneous tissues Deep somatic: blood, muscle, blood vessels, connective tissue
Mechanism Activation of nociceptors
Characteristics Well-localized, constant and achy
Sources of acute pain Incisional pain, insertion sites of tubes and drains, wound complications, orthopedic procedures, skeletal muscle spasms
Sources of chronic pain syndromes
Bony metastases, osteoarthritis, rheumatoid arthritis, low-back pain, peripheral vascular disease
Non-nociceptor (neuropathic)
Physiologic structures Nerve fibers, spinal cord, and central nervous system
Mechanism Non-nociceptive injury to nervous system structures
Characteristics Generalized along distribution of damaged nervous structures
Sources of acute pain Poorly localized: shooting, burning, fiery, shock-like, sharp, painful numbness
Sources of chronic pain syndromes
Nervous tissue injury due to diabetes, HIV, chemotherapy, neuropathies, postherpetic neuralgia, trauma, surgery
Psychogenic
Physiologic structures No organic structures
Mechanism Emotional
Characteristics Variable, often numerous
Sources of acute pain Nonorganic
Sources of chronic pain syndromes
Nonorganic psychological factors
.
PAIN AND THE NURSING PROCESS
The nursing process includes assessment, diagnosis, planning, intervention, and
evaluation. To manage pain responsibly, nurses use each step of the nursing process.
Basic to every strategy for managing pain is showing respect for the validity of a client’s
experience of pain. To communicate respect, nurses:
Acknowledge pain and take action to manage it.
Give accurate information to reduce anxiety and facilitate relief of pain.
Reduce environmental stressors that add to the experience of pain.
Encourage disclosure of feelings and fears.
Provide privacy and maintain confidentiality.
Assessing Pain
Pain is a red flag. It tells us there is a problem somewhere in the body that is crying out
for attention. In fact, pain is such an important indicator of health, its assessment has been
called the “fifth vital sign,” joining temperature, pulse, respiration, and blood pressure.
Even so, until we know more about a specific pain, we cannot fix it. To do this, nurses
must gather information from as many sources as possible, especially the primary source,
the person in pain. This investigation includes obtaining a comprehensive pain history,
making observations of behaviors, performing an appropriate physical examination, and
consulting with other healthcare professionals.
PAIN HISTORY
A pain history is obtained from written documents and from interviews with the person in
pain, family members, and other caregivers. It asks specific questions about the location,
intensity, quality, and history of the pain, as shown in the following box. In some
facilities these questions are printed on an assessment form, with space for answers to be
recorded beside each question.
OBTAINING A PAIN HISTORY
Location: Where is your pain? Ask client to point to the area of pain.
Intensity: On a scale of 0 to 10, with 0 representing no pain, how much pain would you say
you are experiencing? If your pain were a temperature, how cold or hot would it be (warm,
hot, blistering)? If your pain were a sound, how loud would it be (silent, quiet, strident,
booming)?
Quality: In your own words, tell me what your pain feels like (worms under the skin,
shooting, needle pricking, tingling, etc.).
Chronology/pattern: When did the pain start? Does your pain come and go? How often?
How long does it last?
Precipitating factors: What triggers the pain, or what makes it worse?
Alleviating factors: What measures have you found that lessen or relieve the pain? What
pain medications do you use? How much and how often?
Associated symptoms: Do you have other symptoms before, during, or after your pain
begins (dizziness, blurred vision, nausea, and shortness of breath)?
BEHAVIORAL OBSERVATIONS
Most people who suffer pain usually show it either by verbal complaint or nonverbal behaviors.
The following table lists some typical behaviors nurses may observe when they assess people in
pain.
NONVERBAL BEHAVIORS INDICATING PAIN
Facial Expressions Vocalizations Body Movement Social Interaction
Clenched
teeth
Wrinkled
forehead
Biting lips
Scowling
Crying
Moanin
g
Gaspin
g
Groani
Restlessness
Protective
body movement
Muscle tension
Immobility
Silence
Withdrawal
Reduced
attention span
Focus on pain
relief measures
NONVERBAL BEHAVIORS INDICATING PAIN
Facial Expressions Vocalizations Body Movement Social Interaction
Closing eyes
tightly
Widely
opened eyes or
mouth
ng
Gruntin
g
Pacing
Rhythmic
movement
PHYSICAL EXAMINATION
When clients complain of pain or show it by their behavior, nurses need to take action to
find the cause. Assessment is most effective if the pain history interview and behavioral
observations are conducted at the same time as the physical examination. For example, if
a client complains of acute pain on the sole of a foot, the nurse visually examines the foot
for unusual signs, observes the person for behavioral cues of pain, and asks about the
onset, intensity, quality, and pattern of the pain and what makes it worse or better. If the
cause is not identified immediately, the nurse refers the client for further assessment.
Diagnosing Pain
An accurate diagnosis depends on an appropriate assessment that focuses on the exact
nature of the pain. The more specific the diagnosis, the more effective interventions can
be. The North American Nursing Diagnosis Association (NANDA) has identified two
primary diagnoses for pain: acute andchronic.
A complete nursing diagnosis, however, goes further. After identifying whether the pain
is acute or chronic, it adds “related to” the medical diagnosis. For example, “chronic pain
related to osteoarthritis of the left hip.” Then, it adds “manifested by” and lists the
various symptoms experienced by the client or signs confirmed by objective data. Thus, a
complete diagnosis might be “chronic pain, related to osteoarthritis, manifested by
stabbing pain in the left hip with weight-bearing.”
The advantage of clear, specific information is that it leads to more effective
interventions. In this case, an appropriate intervention might be an assistive devise such
as a cane or walker and referral to an orthopedic surgeon for further evaluation.
Planning and Goal Setting
During the planning stage, nurses synthesize information from many sources and,
together with the physician, plan appropriate interventions. The goal of these
interventions is to relieve pain and facilitate the highest possible level of functioning.
Practically speaking, this means identifying what activity the pain is preventing and the
best way to achieve a return of function. For the client described above with chronic hip
pain, the activity the pain is preventing is mobility.
Planning interventions means working in partnership with clients and physicians to
provide specific measures to manage the pain. These interventions may be independent or
collaborative. Independent nursing actions fall within the scope of nursing practice and
include controlling the environment, giving emotional support, and providing comfort.
Collaborative nursing actions involve cooperative interventions with other members of
the healthcare team, such as physical therapists, pharmacists, and physicians.
Goal setting involves the identification of attainable objectives and reasonable priorities.
Because every person is different, the nurse discusses various alternatives with the client,
and together they set priorities. For example, after consulting an orthopedic surgeon, the
person with osteoarthritis may decide to delay hip replacement surgery and maintain
mobility as long as possible with the aid of a cane and analgesics for pain.
Interventions
PAIN MANAGEMENT
PHARMACOLOGIC INTERVENTIONS
There are two primary groups of pain medications: nonopioids and opioids. A third group
of drugs called adjuvants or co-analgesics address symptoms that often accompany pain,
such as insomnia, anxiety, muscle spasm, anorexia, and depression.
Nonopioid Analgesics
Nonopioid analgesics relieve pain by acting on peripheral nerve endings at the injury site
to decrease the level of inflammatory mediators. This group of analgesics includes drugs
such as acetaminophen (Tylenol) and nonsteroidal anti-inflammatory drugs (NSAIDs)
such as acetylsalicylic acid (aspirin) and ibuprofen (Motrin). The specific actions and
dosages of these analgesics vary. Generally speaking, however, they have analgesic,
antipyretic, and anti-inflammatory effects and are useful for mild to moderate pain.
With the exception of acetaminophen, most nonopioids are potent anti-inflammatory
agents. These drugs are especially effective when the primary cause of pain is
inflammation, as occurs in rheumatoid arthritis and bone cancer. When tissue is damaged,
a series of biochemical events leads to the release of prostaglandin, which causes edema,
inflammation, and pain.
Two isoenzymes—cyclo-oxygenase-1 (COX-1) and cyclo-oxygenase-2 (COX-2)—play an
important part in this biochemical process. Drugs that inhibit their action, especially that of COX-
2, reduce prostaglandin production and the inflammation it creates. However, these drugs must
be used with caution because the safety of long-term use has not been verified. The following
table lists some common nonopioid analgesics.
COMMON NONOPIOID ANALGESICS
Drug Adult Dose Considerations
Acetaminophen (Tylenol)
650–975 mg q 4 hr Used for headaches, osteoarthritis; lacks peripheral anti-inflammatory activity of NSAIDs
Aspirin 650–975 mg q 4 hr Used for headaches, osteoarthritis, general pain; antipyretic; inhibits platelet aggregation, causing bleeding
Ibuprofen (Motrin) 400 mg q 4–6 hr Used for osteoarthritis; antipyretic; multiple brand names; available as liquid
Indomethacin (Indocin)
150–200 mg/day Used for gout; anti-inflammatory; anti-rheumatic
Naproxen (Naprosyn)
500 mg initial dose, then 250 mg q 6–8 hr
Used for gout, headaches; anti-inflammatory; anti-rheumatic; available in liquid preparation
Opioid Analgesics
Opioid (narcotic, CNS-acting) analgesics are derivatives of opium and include
such drugs as morphine, codeine, and methadone. These drugs modify the
perception of pain and provide a sense of euphoria by binding to specific opiate
receptors throughout the central nervous system. Opiate receptors have various
names, typically denoted by Greek letters such as mu (μ), kappa (κ), and sigma
(σ). Many of the characteristics of particular opioids relate to the receptor to
which they bind. For example, morphine binds to μ receptors and follow μ
receptor control.
Opioid analgesics are classified as full agonists, partial agonists, and mixed agonist-
antagonists.
o Full agonists bind to μ receptor sites, block pain impulses, and produce maximum
pain control—an “agonist effect.” Full agonists include such drugs as morphine
(Kadian, Avinza, Rylomine intranasal), meperidine (Demerol), fentanyl
(Duragesic patch, Fentanyl oralets), oxycodone hydrochloride (OxyContin), and
hydromorphine (Dilaudid).
o Partial agonists produce a lesser response than full agonists and include such
drugs as buprenorphine (Buprenex) and nalbuphine (Nubain
o Mixed agonist-antagonist analgesics include such drugs as pentazocine
hydrochloride (Talwin) and butorphanol tartrate (Stadol). An antagonist is a drug
that competes with opioid receptor sites. Naloxone hydrochloride (Narcan) is
such a drug. It is used for opioid overdoses and physical dependency.
.
OPIOID ADVERSE EFFECTS AND PREVENTIVE MEASURES
Body System Adverse Side Effects Preventative Measures
Cardiovascular Hypotension, palpitations, flushing
Monitor blood pressure and heart rate
CNS Sedation, disorientation, euphoria, dysphoria, light-headedness, lower seizure threshold, tremors
Inform client that tolerance may develop over 3–5 days; administer stimulants as needed
Gastrointestinal Constipation, nausea, vomiting Offer anti-emetic; change analgesic; increase fluid and fiber intake; increase exercise; administer laxatives
Genitourinary Urinary retention Catheterize as needed; administer opioid antagonist
Integumentary Itching, rash, wheal formation Apply cool packs or lotion; administer antihistamine
Respiratory Respiratory depression; aggravation of asthma
Monitor respirations closely; administer opioid antagonist such as naloxone hydrochloride (Narcan)
Some medications combine nonopioid with opioid analgesics in one tablet to offer two
different levels of pain relief—acting both on peripheral nerve endings at the injury site
and at the level of the central nervous system. Acetaminophen with codeine is such a
medication.
Adjuvant Analgesics
Adjuvant analgesics (co-analgesics) are drugs that were developed for uses other than pain but
have been found to enhance the effects of analgesics. Caregivers need to remember that these
are “helper drugs,” not substitutes for analgesics. Clients in pain still need analgesics. The
following table describes some common adjuvant analgesics.
COMMON ADJUVANT (CO-ANALGESIC) DRUGS
Class of Adjuvant Drugs Indications and Primary Effects
Antidepressants: Tricyclics and serotonin, reuptake inhibitors
Burning, neuropathic pain; improves sleep, enhances mood and analgesic effects
Anti-epileptic drugs Neuralgic and neuropathic pain (sharp, prickling, shooting pain)
Antispasmodic Reflex sympathetic dystrophy syndrome
Anxiolytic drugs: Benzodiazepines, buspirone, venlafaxine
Anxiety and sedation
Botulinum toxin Migraine headache
Lidocaine Neuralgic pain and diabetic neuropathic pain
Psychostimulants Offsets sedating side effects and enhances analgesic effects of opioids
Steroids Inflammatory and chronic pain of cancer, malignant spinal cord compression, headaches, and arthritis
Cannabis (Marijuana)
Cannabis is a psychoactive herb derived from the flowers of hemp plants. Although many
people associate it with the treatment of pain, it is not currently accepted for any use by
the U.S. Drug Enforcement Administration, which lists it as a Schedule 1 drug of the
Controlled Substance Act of 1970. Even so, it is marketed as dronabinol (Marinol) and
used in the treatment of glaucoma and intractable nausea. All parts of the plant contain
various psychoactive substances, including tetrahydrocannabinol (THC), the chemical
believed to cause typical psychic effects such as alterations of mood, memory, motor
coordination, cognitive ability, and self-perception. Many states have established medical
marijuana programs to regulate the growth, sale, and use of cannabis.
Placebos
A placebo is a “sugar pill,” an inactive substance prescribed as if it were an effective dose
of a medication. Research has found that placebos produce hoped-for results in 30% to
50% of the people who take them (Thompson, 2000). This so-called “placebo effect” has
been exploited for centuries by hucksters and charlatans who sell tonics, treatments, and
gadgets to people in pain. Because their purpose is to deceive and strip clients of the right
to make informed decisions, legitimate medical practice does not use placebos. Such
acts violate the ethical principles of honesty and autonomy. The only exception to this
prohibition is when subjects give prior consent for the possible use of placebos in
research studies.
World Health Organization Pain Management Ladder
Because of widespread misconceptions about treatment of chronic pain and addiction, in
1990 the World Health Organization (WHO) recommended a three-step pain
management ladder based on the intensity of pain.
1. Mild pain (intensity 1–3 on the 0–10 standard): Use nonsteroidal anti-
inflammatory drugs and adjuvants. If pain persists, then
2. Mild to moderate pain (intensity 4–6): Use combination medications such as
oxycodone and acetaminophen and adjuvants. If pain persists, then
3. Moderate to severe pain (intensity 7–10): Use potent opioids such as morphine,
fentanylm methadone, and adjuvants.
To prevent under-treatment of malignant cancer pain, some authorities recommend a
different approach. They begin the treatment of malignant cancer pain with strong
opioids, providing immediate relief, then slowly reduce the type and dosage until pain
relief is achieved at the lower level (Jackson & Stanford, 2003).
Routes of Administration
Analgesics can be administered by many routes. Each has advantages and disadvantages as well
as indications and contraindications. The overriding considerations are effectiveness and safety.
The table below lists some of the most common routes for the administration of analgesic
drugs.
ANALGESIC DRUG ADMINISTRATION
Route Indications Contraindications
Oral (per os = PO) Preferred route due to lower cost and convenience; may be prepared as powders, capsules, tablets, liquids, or lozenges
Gastrointestinal irritation; inability to swallow; need for more potent analgesic
Rectal (R) Inability to take oral drugs; can be self-administered; longer duration than oral
Anal or rectal lesions, diarrhea, thrombocytopenia
Intramuscular (IM) Acute, short-term pain relief
Need for prolonged pain relief; absorption may be poor; possible muscle or nerve damage; costly
Intravenous (IV) bolus Offers most rapid pain relief (5–15 min) but lasts less than 60 min
Requires IV access; gives only brief pain relief when prolonged relief is needed
Continuous intravenous (IV) infusion
Gives constant opioid blood level when other methods are ineffective
Requires infusion pumps with alarms and close monitoring
Patient-controlled analgesia (PCA)
Allows predetermined IV bolus of analgesic when client desires pain relief
Requires IV access, client cooperation, close supervision; does not give continuous pain relief
Subcutaneous (SC) opioid infusion
Continuous, prolonged parenteral opioids when IV not possible; allows home use
Requires site change every 7 days of 27-gauge butterfly needle; potential site irritation
Intraspinal (neuraxial), intrathecal, epidural, subarachnoid, intraventricular
Labor contractions; also intractable pain when client cannot tolerate systemic opioids by other routes
Requires expert insertion of catheter into intended space; attached to infusion pump or implanted reservoir; high risk for infection or dislodgment
Regional nerve blocks Continuous or single dose analgesic for acute and chronic pain; used for trauma, burns, and labor
Requires expert insertion of catheter to specific nerve root; attached to infusion pump or implanted reservoir; high risk for infection or dislodgment
Topical (cream-laden anesthetic)
Analgesic for needle sticks, venipuncture, dermatitis,
Must be applied 30–60 min in advance of need
ANALGESIC DRUG ADMINISTRATION
Route Indications Contraindications
and insect stings
Transdermal skin patch
Continuous dose of opioid; allows home use
Costly; when body temperature is over 102°F, absorption is accelerated
Nasal sprays Alternative to IV, IM, and oral opioid administration; rapid onset of action
Nasal exudates or mucosal swelling may prevent consistent absorption
Principles for the Use of Analgesics
To guide caregivers, the American Pain Society (2005) identifies thirteen principles
regarding the use of analgesics to control pain:
1. Individualize the route, dosage, and schedule of analgesics medications.
2. Administer analgesics on a regular basis if pain is present most of the day.
3. Know the dose and time course of several opioid analgesic preparations:
Ask client about prior experience with certain drugs.
Give preference to long-acting, sustained-release opioids such as
OxyContin, which provides up to 12 hours of analgesia; Kadian and
Avinza, controlled-release morphine preparations which provide up to 24
hours of pain relief; and transdermal fentanyl, which provides up to 3 days
of pain relief.
Avoid the adverse effects of emesis by giving anti-emetics.
Rotate opioids to compensate for tolerance.
Use rapid-onset opioids when necessary.
Use concentrated dosage forms when injection volume must be minimized.
4. Give infants and children adequate opioid doses.
5. Follow clients closely, particularly when beginning or changing analgesics.
6. When changing to a new opioid or a different route, first use equianalgesic doses
to estimate the new dose. Then, modify the estimate, based on the clinical
situation and the specific drug.
7. Recognize and treat side effects, such as sedation, constipation, nausea, itching,
respiratory depression, by doing the following:
Change the dose or route of the same drug to maintain constant blood
levels.
Try different opioids analgesics.
Consider multi-drug and multi-modal therapy.
Add another drug that counteracts the adverse effects, such as a stimulant
for sedation.
Use an administration route that minimizes drug concentrations at the site
producing the side effect, such as intraspinal instead of oral when
appropriate.
8. Do not use meperidine (Demerol) because of neurotoxicity risk or mixed agonist-
antagonists (Talwin) because of psychotomimetic effects.
9. Do not use placebos to assess the nature of pain..
NONPHARMACOLOGIC INTERVENTIONS
Although there are myriad drugs to relieve pain, all have some risk and cost. Fortunately,
there are many nonpharmacologic interventions to reduce pain, especially when used in
conjunction with pharmacologic measures. Described as physical and cognitive-
behavioral interventions, many of these approaches are noninvasive, low-risk,
inexpensive, easily performed and taught, and within the scope of nursing practice.
Physical interventions give comfort, increase mobility, and alter physiologic responses.
Cognitive-behavioral interventions alter the perception of pain, reduce fear, give a greater
sense of control, and are considered holistic nursing practice.
Physical Interventions
Comfort measures such as clean and smooth sheets, soft and supportive pillows,
warm blankets, and a soothing environment have been used by nurses throughout
history to relieve pain and suffering. These measures may be difficult to provide
in the noisy, mechanized healthcare facilities of today. Nonetheless, they are
important to the mental and physical well-being of patients.
Position change and movement are well-known pain-relieving interventions.
Moving the body, even a small amount, relieves muscle spasm and provides a
degree of pain relief. So important is movement of the body to health, an entire
profession has developed specializing in physical therapy. However, nurses need
not wait for a specialist to offer these important pain-relieving interventions.
Massage relieves muscle spasm, improves circulation, and provides cutaneous
stimulation. While there are many different massage techniques, they all involve
rubbing the skin in various patterns and degrees of pressure. Once considered an
expected part of basic nursing care, backrubs offer an important noninvasive way
to relieve pain and provide comfort.
Applications of hot and cold are effective pain-relieving measures when used
appropriately. Heat decreases muscle spasm and increases blood flow to an area.
Cold decreases blood flow, edema, and inflammation and may decrease muscle
spasm and pain. Many devices are available to provide hot and cold, including
electric heating pads, patches, and ice packs. Soaks and baths relieve muscle
spasm and are an important means of providing comfort.
Transcutaneous electrical nerve stimulation (TENS) provides a continuous,
mild electric current via 2 to 4 electrodes placed on the skin near a painful site.
The stimulator is a small, battery-operated devise worn by the client. Experienced
as a tingling sensation, TENS works by stimulating large nerve fibers to close the
“gate” in the spinal cord. It also may stimulate endorphin production. TENS may
be used for acute postoperative pain or for chronic conditions such as low back
pain, phantom limb pain, and neuralgia.
Surgical interventions may be recommended when severe pain persists despite
medical treatment. Rhizotomy and cordotomy are two such procedures.
In a rhizotomy the surgeon destroys dorsal posterior nerve roots as they enter the
spinal cord, either by delivering neurolytic chemicals, heat, or extreme cold by way of a
catheter or by performing a laminectomy, isolating the nerve roots, and directly
destroying the nerve
. A chordotomyis more extensive than a rhizotomy, involving resection of the
spinothalamic tract. Both procedures cause permanent loss of pain and thermal
sensations, however they may also cause paralysis due to motor nerve damage.
Cognitive-Behavioral Interventions
Relaxation exercises are useful ways to reduce anxiety, decrease muscle tension, and
lower blood pressure and heart rate. They induce a state of altered consciousness and
give individuals a sense of control and peace of mind. Meditation, yoga, and other such
interventions may effectively relieve pain. One such exercise involves controlled
breathing. A coach speaks in a calm, clear voice, suggesting the subject begin by
breathing slowly and diaphragmatically, allowing the abdomen to rise slowly and the
chest to expand fully. Then, the coach suggests the subject locate an area of muscle
tension, contract the muscles in that area, and then relax them. As the subject relaxes,
pain perception and anxiety diminish.
Guided imagery is similar to relaxation exercises in that a coach leads subjects in a
calm, clear voice, often beginning with a relaxation exercise. The coach then suggests
subjects imagine themselves in some peaceful place where they experience various
sensory pleasures such as the warmth of the sun, the sound of ocean waves, and the
smell of salt water. The purpose of the exercise is to provide an experience of
relaxation and relief from stress and pain.
Distraction diverts the attention of individuals away from painful stimuli. When people
focus on something that gives pleasure, they are less likely to feel acute pain. This
phenomenon occurs because the reticular activating system briefly inhibits the
awareness of pain. Distraction works best for short acute pain, such as a needle stick.
Such things as listening to music, watching an intense scene on television, or describing
something of special interest may temporarily distract a person from pain. Distraction,
however, does not work for chronic, long-term pain.
Biofeedback is a method of treating chronic pain and other stress-related conditions. It
uses an electric device to gather information about physical responses and report them
back to clients. The information goes to the biofeedback machine by way of electrode
sensors placed on the person’s skin. It is displayed as visual signals on a monitor. As
clients watch these signals, they learn to control their responses.
Complementary and Alternative Medicine (CAM)
To relieve their pain, an increasing number of people in the United States are also
turning to theories and practices outside the realm of conventional Western medicine.
In 1991, the federal government established the Office of Alternative Medicine. In
1998, the agency became the National Center for Complementary and Alternative
Medicine (NCCAM), making the center one of 27 institutes and centers of the National
Institutes of Health within the Department of Health and Human Services. NCCAM
defines CAM as “a group of diverse medical and healthcare systems, practices, and
products that are not currently part of conventional medicine” (NCCAM, 2009a).
The mission of NCCAM is to explore “complementary and alternative healing practices
in the context of rigorous science…and [to] disseminate authoritative information to the
public and professionals” (NCCAM, 2007). In this context, “complementary” describes
practices used in conjunction with or to supplement conventional medical treatments,
and “alternative” means those that are used independently or in place of conventional
medicine. Practitioners of such techniques and practices often use the
term holistic because they view health and illness as affecting the whole person—body,
mind, and spirit.
The major categories of complementary and alternative medicine are:
o Biologic (herbal mixtures; macrobiotic diets; orthomolecular, such as
megadoses of vitamins, magnesium, melatonin, etc.)
o Energy fields (acupuncture, therapeutic touch, pulse fields, Reiki, etc.)
o Manipulative and body-based (chiropractic, lymphatic drainage, reflexology,
aromatherapy, deep-muscle massage, shiatsu, etc.)
o Mind-body (biofeedback, hypnosis, art therapy, prayer, etc.) (Diluzio &
Spillane 2002)
Biologic. Plants have been used to treat human ailments throughout history. Their
therapeutic effects are due to the chemical compounds they contain. Such chemicals
may be administered to patients by giving some part of a plant or by extracting or
synthesizing the essential chemical. When prepared in a purified form, the dose is more
precise than it can be from a plant. Some common active chemicals originally derived
from plants are: digitaloid found in the foxglove plant (digitalis), saponins found in
sarsaparilla (irritant laxatives), alkaloids found in nightshades (atropine), and alkaloids
found in the opium poppy (morphine) (McGuigan & Krug, 1942).
Energy fields. Such healing measures are based on theories about unseen forces in the
human body. Acupuncture, for instance, is based on an ancient Chinese theory that two
opposing forces, yin and yang, move along meridians in the body. When these forces
are out of balance, pain and illness result. There are at least 350 acupuncture points by
which energy flows are accessible. The theory posits that by stimulating these points
with very fine needles, the energy flow can be rebalanced and pain relieved (Mayo
Clinic, 2009; NCCAM, 2009b).
o Acupuncture (AH-q-punk-sher) is based on the belief that life forces or energy move through the body in specific paths. These paths are called meridians (mer-IH-d-uns). With acupuncture, a needle is put into the meridian that runs to the area where you have pain. This needle blocks the meridian which stops or decreases the pain.
o Touch energy therapies come from very old beliefs that life forces or energy move through the body in specific paths. Touch therapies believe disease may cause these paths to become blocked. The therapies use touch to help unblock these paths, and allow the energy to flow normally. Unblocking the paths may help you relax and decrease pain.
Chiropractic is a healthcare approach that focuses on the relationship between the
body’s structure—mainly the spine—and its functioning. Although practitioners may
use a variety of treatment approaches, they primarily perform adjustments to the spine
or other parts of the body with the goal of correcting alignment problems and
supporting the body’s natural ability to heal itself. People seek chiropractic care
primarily for pain conditions such as back pain, neck pain, and headache. Side effects
and risks depend on the type of chiropractic treatment used. Ongoing research is
looking at effects of chiropractic treatment approaches, how they might work, and
diseases and conditions for which they may be most helpful. (NCCAM, 2009c.)
Osteopathy is a medical specialty that combines traditional and nontraditional
medicine. Practitioners, called doctor of osteopathy (DO), practice traditional, science-
based medicine, and are licensed to perform surgery and prescribe drugs. They “take a
holistic view of the body as an integrated system and approach prevention, diagnosis,
and treatment by way of the musculoskeletal system” (Asher, 2007).
Biofeedback is a method of treating chronic pain and some stress-related conditions. It
uses an electric device to gather information about physical responses and report them
back to clients. The information goes to the biofeedback machine by way of electrode
sensors placed on the person’s skin. The machine displays information as visual signals
on a monitor. As clients watch the signals, they learn to control their responses.
.
SUMMARY
Pain, however, is much more than a physical sensation caused by a single entity. It is
subjective and highly individual, a complex mechanism with physical, emotional, and
cognitive components. Although there are myriad drugs to relieve pain, all have some
risk and cost. Fortunately, there are many nonpharmacologic interventions to reduce pain,
especially when used in conjunction with pharmacologic measures. Described as physical
and cognitive-behavioral interventions, many of these approaches are noninvasive, low-
risk, inexpensive, easily performed and taught, and within the scope of nursing practice.
Physical interventions give comfort, increase mobility, and alter physiologic responses.
Cognitive-behavioral interventions alter the perception of pain, reduce fear, give a greater
sense of control, and are considered holistic nursing practice.
BIBLIOGRAPHY
Brunner and suddarths ‘ medical surgical nursing”(2000); usa. Lippincott raven, 9th ed. 372-378.
Joyce M.Black. “medical surgical nursing”new delhi, (2005);
Elservier , 7th ed
1706-1724.
http://www.thenewstoday.info/2006/12/10/pain management . htm
http://www.nlm.nih.gov/medlinepluslency article/000077.htm.
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