1. PAIN MANAGEMENT

2. • Definition
Pain is an unpleasant sensory and emotional experience
associated with actual or potential tissue damage (Merskey &
Bogduk, 1994)
It is the most common reason for seeking health care. It occurs
with many disorders, diagnostic tests, and treatments
• Nurses encounter patients in pain in a variety of settings, including acute
care, outpatient, and long-term care settings, as well as in the home. Thus,
they must have the knowledge and skills to assess pain, to implement pain
relief strategies, and to evaluate the effectiveness of these strategies,
regardless of setting.

3. • Pain management is considered such an important part of
care that the American Pain Society coined the phrase “Pain:
The 5th Vital Sign” (Campbell, 1995) to emphasize its
significance and to increase the awareness among health care
professionals of the importance of effective pain
management.
• Documentation of pain assessment is now as prominent as
the documentation of the “traditional” vital signs. Pain
assessment and management are also mandated by the Joint
Commission on the Accreditation of Healthcare Organizations
(JCAHO) (2003).

4. • Calling pain the fifth vital sign suggests that the assessment of
pain should be as automatic as taking a patient’s blood
pressure and pulse.
• The JCAHO (2003) has incorporated pain and pain
management into its standards. JCAHO’s standards state that
“pain is assessed in all patients” and that “patients have the
right to appropriate assessment and management of pain.”
These standards reflect the importance of pain management.

5. • In health care, the primary care provider’s role is to assess and manage pain by
administering medications and other treatments.
• In addition, the nurse serves as an educator to the patient and family, teaching
them to manage the pain relief regimen themselves when appropriate
• Although it is important to believe the patient who reports pain, it is equally
important to be alert to patients who deny pain in situations where pain would
be expected.
• A nurse who suspects pain in a patient who denies it should explore with the
patient the reason for suspecting pain, such as the fact that the disorder or
procedure is usually painful or that the patient grimaces when moving or
avoids movement.
• Exploring why the patient may be denying pain is also helpful. Some people
deny pain because they fear the treatment that may result if they report or
admit pain. Others deny pain for fear of becoming addicted to opioids
(previously referred to as narcotics) if these medications are prescribed.

6. Types of Pain
• Pain is categorized according to its duration,
location, severity, nature and etiology.
• Three basic categories of pain are generally
recognized: acute pain, chronic
(nonmalignant) pain, and cancer-related pain.

7. • ACUTE PAIN
• Usually of recent onset and commonly associated with a specific
injury, acute pain indicates that damage or injury has occurred.
• Pain is significant in that it draws attention to its existence and
teaches the person to avoid similar potentially painful situations. If
no lasting damage occurs and no systemic disease exists, acute pain
usually decreases along with healing.
• For purposes of definition, acute pain can be described as lasting
from seconds to 6 months. However, the 6-month time frame has
been criticized (Brookoff, 2000) as inaccurate since many acute
injuries heal within a few weeks and most heal by 6 weeks.
• In a situation where healing is expected in 3 weeks and the patient
continues to suffer pain, it should be considered chronic and
treated with interventions used for chronic pain. Waiting for the full
6-month time frame in this example could cause needless suffering.

8. 2. CHRONIC (NONMALIGNANT) PAIN
• Chronic pain is constant or intermittent pain that persists beyond the expected
healing time and that can seldom (some time) be attributed to a specific cause
or injury.
• It may have a poorly defined onset, and it is often difficult to treat because the
cause or origin may be unclear.
• Although acute pain may be a useful signal that something is wrong, chronic pain
usually becomes a problem in its own right.
• Chronic pain may be defined as pain that lasts for 6 months or longer, although 6
months is an arbitrary period for differentiating between acute and chronic pain.
• An episode of pain may assume the characteristics of chronic pain before 6
months have elapsed (past), or some types of pain may remain primarily acute in
nature for longer than 6 months. Nevertheless, after 6 months, most pain
experiences are accompanied by problems related to the pain itself. Chronic pain
serves no useful purpose. If it persists, it may become the patient’s primary
disorder.
• The nurse may come in contact with patients with chronic pain when they are
admitted to the hospital for treatment or when they are seen out of the hospital
for home care. Frequently the nurse is called on in community-based settings to
assist patients in managing pain.

9. CANCER-RELATED PAIN
Pain associated with cancer may be acute or chronic. Pain in the patient suffering from
cancer can be directly associated with the cancer (eg, bony infiltration with tumor cells
or nerve compression), a result of cancer treatment (eg, surgery or radiation), or not
associated with the cancer (eg, trauma). Most pain associated with cancer, however, is
a direct result of tumor involvement.
PAIN CLASSIFIED BY LOCATION
Pain is sometimes categorized according to location, such as pelvic pain, headache,
and chest pain. This type of categorization is helpful in communicating and treating
pain. For example, chest pain suggests angina or a myocardial infarction and indicates
the need for treatment according to cardiac care standards.
PAIN CLASSIFIED BY ETIOLOGY
Categorizing pain according to etiology is another way to think about pain and its
management. Burn pain and postherpetic neuralgia are examples of pain described by
their etiology.
PAIN CLASSIFIED BY SEVERITY
Mild, Moderate and Sever

10. PATHOPHYSIOLOGY OF PAIN
The sensory experience of pain depends on the interaction between the
nervous system and the environment. The processing of noxious stimuli
and the resulting perception of pain involve the peripheral and central
nervous systems.
PAIN TRANSMISSION
Among the nerve mechanisms and structures involved in the transmission
of pain perceptions to and from the area of the brain that interprets pain
are nociceptors, or pain receptors, and chemical mediators. Nociceptors
are receptors that are preferentially sensitive to a noxious stimulus.
Nociceptors are also called pain receptors.

11. Nociceptors
• Nociceptors are free nerve endings in the skin that respond only to
intense, potentially damaging stimuli. Such stimuli may be mechanical,
thermal, or chemical in nature.
• The joints, skeletal muscle, fascia, tendons, and cornea also have
nociceptors that have the potential to transmit stimuli that produce pain.
• However, the large internal organs (viscera) do not contain nerve endings
that respond only to painful stimuli. Pain originating in these organs
results from intense stimulation of receptors that have other purposes.
For example, inflammation, stretching, ischemia, dilation, and spasm of
the internal organs all cause an intense response in these multipurpose
fibers and can cause severe pain.

12. Peripheral Nervous System
A number of algogenic (pain-causing) substances that affect the
sensitivity of nociceptors are released into the extracellular tissue as a
result of tissue damage.
Histamine, bradykinin, acetylcholine, serotonin, and substance P are
chemicals that increase the transmission of pain. The transmission of
pain is also referred to as nociception. Prostaglandins are chemical
substances thought to increase the sensitivity of pain receptors by
enhancing the pain provoking effect of bradykinin. These chemical
mediators also cause vasodilation and increased vascular permeability,
resulting in redness, warmth, and swelling of the injured area.
Once nociception is initiated, the nociceptive action potentials are
transmitted by the peripheral nervous system (Porth, 2002). The first-
order neurons travel from the periphery (skin, cornea, visceral organs)
to the spinal cord via the dorsal horn.

13. There are two main types of fibers involved in the transmission of
nociception. Smaller, myelinated Aδ (A delta) fibers transmit nociception
rapidly, which produces the initial “fast pain.”
Type C fibers are larger, unmyelinated fibers that transmit what is called
second pain. This type of pain has dull, aching, or burning qualities that last
longer than the initial fast pain. The type and concentration of nerve fibers
to transmit pain vary by tissue type.
If there is repeated C fiber input, a greater response is noted in dorsal horn
neurons, causing the person to perceive more pain. In other words, the same
noxious stimulus produces hyperalgesia, and the person reports greater pain
than was felt at the first stimulus. For this reason, it is important to treat
patients with analgesic agents when they first feel the pain. Patients require
less medication and experience more effective pain relief if analgesia is
administered before the patient becomes sensitized to the pain.

14. Chemicals that reduce or inhibit the transmission or
perception of pain include endorphins and enkephalins.
These morphine like neurotransmitters are endogenous
(produced by the body). They are examples of substances
that reduce nociceptive transmission when applied to certain
nerve fibers. The term “endorphin” is a combination of two
words: endogenous and morphine.
Endorphins and enkephalins are found in heavy
concentrations in the central nervous system, particularly
the spinal and medullary dorsal horn, the periaqueductal
gray matter (gray matter around brain) , hypothalamus, and
amygdala. Morphine and other opioid medications act at
receptor sites to suppress the excitation initiated by noxious
stimuli.

15. Central Nervous System
After tissue injury occurs, nociception (the neurologic transmission of pain impulses)
to the spinal cord via the Aδ and C fibers continues. The fibers enter the dorsal horn.
In the substantia gelatinosa are projections that relay nociception to other parts of the
spinal cord
Nociception continues from the spinal cord to the reticular formation, thalamus,
limbic system, and cerebral cortex.
The involvement of the reticular formation, limbic, and reticular activating systems is
responsible for the individual variations in the perception of noxious stimuli.
Individuals may report the same stimulus differently based on their anxiety, past
experiences, and expectations. This is a result of the conscious perception of pain.
For pain to be consciously perceived, neurons in the ascending system must be
activated. Activation occurs as a result of input from the nociceptors located in the
skin and internal organs. Once activated, the inhibitory interneuronal fibers in the
dorsal horn inhibit or turn off the transmission of noxious stimulating information in
the ascending pathway.

16. Descending Control System
The descending control system is a system of fibers that originate in the
lower and midportion of the brain (specifically the periaqueductal gray
matter) and terminate on the inhibitory interneuronal fibers in the dorsal
horn of the spinal cord.
This system is probably always somewhat active; it prevents continuous
transmission of stimuli as painful, partly through the action of the
endorphins. As nociception occurs, the descending control system is
activated to inhibit pain.
Cognitive processes may stimulate endorphin production in the descending
control system. The effectiveness of this system is illustrated by the effects of
distraction. The distractions of visitors or a favorite TV show may increase
activity in the descending control system. Therefore, the person who has
visitors may not report pain because activation of the descending control
system results in less noxious or painful information being transmitted to
consciousness. Once the distraction by the visitors ends, activity in the
descending control system decreases, resulting in increased transmission of
painful stimuli.

17. The interconnections between the descending neuronal system
and the ascending sensory tract are called inhibitory interneuronal
fibers. These fibers contain enkephalin and are primarily activated
through the activity of non-nociceptor peripheral fibers (fibers
that normally do not transmit painful or noxious stimuli) in the
same receptor field as the pain receptor, and descending fibers,
grouped together in a system called descending control.

18. • First proposed in 1965 by Ronald Melzack and Patrick Wall, The
gate control theory of pain asserts that non-painful input closes
the "gates" to painful input, which prevents pain sensation
from traveling to the central nervous system. Therefore,
stimulation by non-noxious input is able to suppress pain.
• According to the gate control theory, pain signals are not free to
reach the brain as soon as they are generated at the injured
tissues or sites. They need to encounter certain ‘neurological
gates’ at the spinal cord level and these gates determine
whether the pain signals should reach the brain or not.
• In other words, pain is perceived when the gate gives way to
the pain signals and it is less intense or not at all perceived
when the gate closes for the signals to pass through. This
theory gives the explanation for why someone finds relief by
rubbing or massaging an injured or a painful area
GATE CONTROL THEORY

19. Every organ or part of the human body has its own nerve
supply and the nerves carry the electrical impulses
generated in response to various sensations like touch,
temperature, pressure and pain.
These nerves – that constitute the peripheral nervous
system – transmit these impulses to the central nervous
system (the brain and spinal cord) so that these impulses are
interpreted and perceived as sensations.
The peripheral nerves send signals to the dorsal horn of the
spinal cord and from there the sensory signals are
transmitted to the brain through the spinothalamic tract.
Pain is a sensation that alerts a person that a tissue or a
particular part of the human body has been injured or
damaged.

21. According to the axonal diameter and the conduction velocity, nerve
fibers can be classified into three types – A, B and C. The C fibers are the
smallest among all the three types. Among the ‘A’ fibers are four
subtypes: A-alpha, A-beta, A-gamma and A-delta. Among the A subtypes,
the A-alpha fibers are the largest and the A-delta fibers are the smallest.
The A fibers that are larger than the A-delta fibers, carry sensations like
touch, pressure, etc. to the spinal cord. The A-delta fibers and the C
fibers carry pain signals to the spinal cord. A-delta fibers are faster and
carry sharp pain signals while the C fibers are slower and carry diffuse
pain signals.
When considering the conduction velocity, the A-alpha fibers (the large
nerve fibers) have higher conduction velocity when compared to the A-
delta fibers and the C fibers (small nerve fibers). When a tissue is injured,
the A-delta fibers are activated first, followed by the activation of the C
fibers.

25. What does the gate control theory say?
The gate control theory suggests that the signals encounter ‘nerve
gates’ at the level of the spinal cord and they need to get cleared
through these gates to reach the brain. Various factors determine
how the pain signals should be treated at the neurological gates.
They are:
The intensity of the pain signals
The intensity of the other sensory signals (touch, temperature and
pressure), if generated at the site of injury
The message from the brain itself (to send the pain signals or not)
According to the original postulate of Melzack and Wall, the nerve
fibers project to the substantia gelatinosa (SG) of the dorsal horn and
the first central transmission (T) cells of the spinal cord.
The SG consists of inhibitory interneurons that act as the gate and
determine which signals should reach the T cells and then go further
through the spinothalamic tract to reach the brain.

26. When the pain signals carried by the small fibers (A-delta and C
fibers) are less intense compared to the other non-pain sensory
signals like touch, pressure and temperature, the inhibitory
neurons prevent the transmission of the pain signals through the
T cells.
The non-pain signals override the pain signals and thus the pain
is not perceived by the brain. When the pain signals are more
intense compared to the non-pain signals, the inhibitory neurons
are inactivated and the gate is opened.
The T cells transmit the pain signals to the spinothalamic tract
that carries those signals to the brain. As a result, the
neurological gate is influenced by the relative amount of activity
in the large and the small nerve fibers.

27. Emotions and thoughts determine the way how pain is
perceived
• The theory also proposed that the pain signal transmission can
be influenced by emotions and thoughts.
• It is well known that people do not feel a chronic pain or the
pain does not disturb them when they concentrate on other
activities that interest them. Whereas, people who are anxious
or depressed feel intense pain and find it difficult to cope up
with it.
• This is because the brain sends messages through descending
fibers that stop, reduce or amplify the transmission of pain
signals through the gate, depending on the thoughts and
emotions of a person.

28. Gate control theory in pain management
The gate control theory has brought about a drastic revolution in
the field of pain management. The theory suggested that pain
management can be achieved by selectively influencing the larger
nerve fibers that carry non-pain stimuli. The theory has also paved
way for more research on cognitive and behavioral approaches to
achieve pain relief.
One of the tremendous advances in pain management research is
the advent of Transcutaneous Electrical Nerve Stimulation (TENS).
The gate control theory forms the basis of TENS. In this technique,
the selective stimulation of the large diameter nerve fibers carrying
non-pain sensory stimuli from a specific region nullifies or reduces
the effect of pain signals from the region.

29. TENS is a non-invasive and inexpensive pain management approach that
has been widely used for the treatment of chronic and intractable pain
that are otherwise non-responsive to analgesics and surgical
treatments. TENS is highly advantageous over pain medications in the
aspect that it does not have the problem of drug interactions and
toxicity.
Many other invasive and non-invasive electrical stimulation techniques
have been found to be useful in various chronic pain conditions like
arthritic pain, diabetic neuropathy, etc.
The theory has also been extensively studied in the treatment of chronic
back pain and cancer pain. However, favorable results are not attained
in some conditions and the long term efficacy of the techniques based
on the theory is under question.
Nevertheless, the gate control theory has dramatically revolutionized
the field of pain research and it has sown seeds for numerous studies
that aim at presenting a pain-free lifestyle to the patients who suffer
from chronic pain.

31. Harmful Effects of Pain
Regardless of its nature, pattern, or cause, pain that is inadequately treated
has harmful effects beyond the suffering it causes.
EFFECTS OF ACUTE PAIN
Unrelieved acute pain can affect the pulmonary, cardiovascular,
gastrointestinal, endocrine, and immune systems. The stress response
(“neuroendocrine response to stress”) that occurs with trauma also
occurs with other causes of severe pain.
This is particularly harmful in patients compromised by age, illness, or
injury.
The stress response generally consists of increased metabolic rate and
cardiac output, impaired insulin response, increased production of
cortisol, and increased retention of fluids

32. • Increased heart rate and blood Pressure to Better perfusion of vital
organs by Increasing cardiac output due to increased myocardial
contractility
• Increased blood glucose level to increase available energy by increase in
liver and muscle glycogen breakdown and increased breakdown of
adipose tissue triglycerides
• Increase Mental acuity to increase Alert state by Increase in amount of
blood shunted to the brain from the abdominal viscera and skin
• Dilated pupils to Increased awareness by Contraction of radial muscle
of iris
• Increased ventilation (may be rapid and shallow) to Provision of oxygen
for energy by Stimulation of respiratory center in medulla;
bronchodilation
• Increased coagulability of Blood to Prevention of hemorrhage in event
of trauma

33. EFFECTS OF CHRONIC PAIN
Like acute pain, chronic pain also has adverse effects. Suppression of
the immune function associated with chronic pain may promote
tumor growth. Also, chronic pain often results in depression and
disability.
Although health care providers express concern about the large
quantities of opioid medications required to relieve chronic pain in
some patients, it is safe to use large doses of these medications to
control progressive chronic pain. In fact, failure to administer
adequate pain relief may be unsafe because of the consequences of
unrelieved pain (McCracken & Iverson, 2001).

34. Regardless of how the patient copes with chronic pain, pain for an
extended period can result in disability. Patients with a number of
chronic pain syndromes report depression, anger, and fatigue (Meuser,
Pietruck, Radruch et al., 2001; Raymond et al., 2001).
The patient may be unable to continue the activities and interpersonal
relationships he or she engaged in before the pain began. Disabilities
may range from curtailing participation in physical activities to being
unable to take care of personal needs, such as dressing or eating.
The nurse needs to understand the effects of chronic pain on the
patient and family and needs to be knowledgeable about pain relief
strategies and appropriate resources to assist effectively with pain
management.

35. FACTORS INFLUENCING THE PAIN RESPONSE
• Past experiences with pain
• Anxiety
• Culture
• Age
• Gender,
• Expectations about pain relief.

36. Placebo Effect
A placebo effect occurs when a person responds to the
medication or other treatment because of an expectation that the
treatment will work rather than because it actually does so.
Simply receiving a medication or treatment may produce positive
effects.
The placebo effect results from the natural (endogenous)
production of endorphins in the descending control system.

37. A patient’s positive expectations about treatment
may increase the effectiveness of a medication or
other intervention.
A person who is informed that a medication is
expected to relieve pain is more likely to
experience pain relief than one who is told that a
medication is unlikely to have any effect.

38. Nursing Assessment of Pain
The pain assessment begins by observing the patient carefully,
noting the patient’s overall posture and presence or absence of
overt pain behaviors and asking the person to describe, in his or
her own words, the specifics of the pain.
The words used to describe the pain may point toward the
etiology. For example, the classic description of chest pain that
results from a myocardial infarction includes pressure or
squeezing on the chest. A detailed history should follow the
initial description of pain.

39. CHARACTERISTICS OF PAIN
The factors to consider in a complete pain assessment are the:-
1. Intensity (pain tolerance)
2. Timing (the nurse inquires about the onset, duration,
relationship between time and intensity, and whether there
are changes in rhythmic patterns. The patient is asked if the
pain began suddenly or increased gradually
3. Location
4. Quality (burning, aching can be offered )
5. Personal meaning
6. Aggravating and alleviating factors, and
7. Pain behaviors

40. INSTRUMENTS FOR ASSESSING THE PERCEPTION OF PAIN

41. Visual Analogue Scales
Visual analogue scales are useful in assessing the intensity of
pain. One version of the scale includes a horizontal 10-cm line,
with anchors (ends) indicating the extremes of pain. The person
is asked to place a mark indicating where the current pain lies
on the line. The left anchor usually represents “none” or “no
pain,” whereas the right anchor usually represents “severe” or
“worst possible pain.” To score the results, a ruler is placed
along the line and the distance the person marked from the left
or low end is measured and reported in millimeters or
centimeters.
Some patients (eg, children, elderly patients, and visually or
cognitively impaired patients) may find it difficult to use an
unmarked VAS. In those circumstances, ordinal scales (simple
descriptive pain intensity scale, or 0 to 10 numeric pain
intensity scale) may be used.

44. Common Concerns and Misconceptions About Pain and Analgesia
• Complaining about pain will distract my doctor from his primary
responsibility—curing my illness.
• Pain is a natural part of aging.
• I don’t want to bother the nurse—he/she is busy with other patients.
• Pain medicine can’t really control pain.
• People get addicted to pain medicine easily.
• It is easier to put up with pain than with the side effects that come from
pain medicine.
• Good patients avoid talking about pain.
• Pain builds character. It’s good for you.
• Patients should expect to have pain; it’s part of almost every
hospitalization.