“international health organizations and nursing organizations”

1. Concept Of Pain
SHAHINA BANO
(Lecturer, DUHS, DION&M)
Year 1, semester II
Objectives
At the end of the session learners will be able to:
1. Define the process of pain (physiological changes)
2. Describe the different theories of pain theory.
3. differentiate between acute and chronic pain
4. Discuss the non pharmacologic interventions pain management.
5. identify pharmacologic interventions for pain management
Concept of pain
• . The International Association for the Study of Pain (IASP) defines pain as
• “an unpleasant, subjective sensory and emotional experience associated with actual or potential tissue
damage, or described in terms of such damage” (IASP, 2010).
• It is the most common reason for seeking health care. It occurs with many disorders, diagnostic tests, and
treatments.
Nociception
• The extent to which pain is perceived depends on the interaction between the body analgesia system,
the nervous system's transmission and mind’s interpretations of stimuli and its meaning.
The peripheral nervous system includes specialized primary sensory neurons that detect mechanical, thermal, or
chemical conditions associated with potential tissue damage.
When these nociceptors are activated, signals are transduced and transmitted to the spine and brain where the
signals are modified before they are ultimately understood and then “felt.”
The physiological processes related to pain perception are described as nociception

2. Physiology of pain
• The physiological process are involved in nociception:
1. Transduction
2. Transmission
3. Perception
4. Modulation
Transduction of Pain
• Specialized pain receptors or nociceptors can be excited by mechanical, thermal and chemical stimuli.

3. • Pain stimuli is converted to electrical energy. This electrical energy is known as Transduction. This
stimulus sends an impulse across a peripheral nerve fiber (nociceptor).
Transduction of Pain
• During the transduction phase, harmful stimuli trigger the release of biochemical mediators, such as
prostaglandins, bradykinin, serotonin, histamine, and substance P, which sensitize nociceptors.
• Painful stimulation also causes movement of ions across cell membranes, which excites nociceptors.
• This conversation is known as Transduction.
• Pain medications can work during this phase by blocking the production of prostaglandin (e.g., ibuprofen
or aspirin) or by decreasing the movement of ions across the cell membrane (e.g., local anesthetic)
Transmission
• The second process of nociception, transmission of pain, includes three segments.
• During the first segment of transmission, the pain impulses travel from the peripheral nerve fibers to the
spinal cord.
• There are primarily two types of peripheral nerve fibers that conduct painful stimuli.
1) The fast, myelinated A- delta fibers:
send sharp, localized, and distinct sensations.
2) The small, slow unmyelinated C fibers:
Relay slower impulses that are poorly localized, visceral, and persistent
Example: after stepping on a nail, a person initially feels a sharp localized pain, which is result of A- fiber
transmission. Within a few seconds, the whole foot aches from C-fiber stimulation.
After the pain impulse ascends the spinal cord, information is send quickly to higher centers in the brain.

4. • The second segment is transmission of the pain signal through an ascending pathway in the spinal cord to
the brain
• The third segment involves transmission of information to the brain where pain perception occurs.
• Pain control can take place during this second process of transmission.
• For example, opioids (narcotic analgesics) block the release of neurotransmitters, particularly substance P,
which stops the pain at the spinal level
Perception of Pain
• It is the third process of nociception.
• It is when a person becomes conscious of the pain. It is believed that pain perception occurs in the
cortical structures, which allows for different cognitive behavioral strategies to be applied to reduce the
sensory and affective component of pain
• For example, Cognitive–behavioral therapy and approaches such as distraction ,imagery and music can
help direct the client’s attention away from pain.
Modulation of Pain
• This is the fourth system, often describes as the “descending system,”.
• These descending fibers release substances such as endogenous opioids, serotonin and norepinephrine
which can inhibit the ascending of noxious impulses in the dorsal horn

5. Types of pain
• Pain is categorized by:
➢ Duration (acute or chronic)
➢ Pathological condition (e.g., cancer or neuropathic)
Acute Pain
• Also known as Transient Pain.
• Acute pain is protective, has an identifiable cause, is of short duration, and has limited tissue damage and
emotional response.
• It eventually resolves, with or without treatment, after an injured area heals.
• Acute pain has a predictable ending (healing) and an identifiable cause, health team members are usually
willing to treat it aggressively. Unrelieved acute pain can progress to chronic pain (Kehlet et al., 2006).
Chronic Pain
• Chronic pain, also known as persistent pain, is prolonged, usually recurring or lasting 3 months or longer,
and interferes with functioning.
• Chronic pain is not considered protective, may not have an identified cause, and leads to great personal
suffering.
• Chronic may be noncancerous (non-malignant) or cancerous(malignant).
• Example of chronic pain arthritis, low back pain, headaches and peripheral neuropathy.
Cancer Pain
• Cancer pain may be acute and/or chronic. It can be due to tumor progression and its related pathological
process, invasive procedures toxicities of treatment, infection and physical limitations.

6. • Cancer pain can be sensed at the actual site of the tumor or distant to the site. This kind of pain is called
referred pain.
• Not all clients with cancer will experience pain.
Neuropathic pain
• Neuropathic pain is associated with damaged or malfunctioning nerves due to illness (e.g., diabetic
peripheral neuropathy), injury (e.g., spinal cord injury pain), or undetermined reasons.
• Neuropathic pain is typically chronic; it is described as burning, “electric-shock,” and/or tingling, dull, and
aching.
Episodes of sharp, shooting pain can also be experienced. Neuropathic pain tends to be difficult to treat.
Types of Pain by Location
• Superficial or coetaneous pain
– Pain resulting from stimulation of skin
• Deep or Visceral pain
– Pain resulting from stimulation of internal organ
• Referred pain
– Perception of pain is in unaffected areas. Common phenomena in visceral pain because many
organs themselves have no pain receptors. Example. MI
• Radiating pain
– Sensation of pain extending from initial site of injury to another body part. Example: low back
pain, sciatic nerve irritation radiating down to leg.
INTENSITY of pain
• Most practitioners classify intensity of pain by using a standard scale:
• 0 (no pain) to 10 (worst possible pain) scale.
– 1 to 3 range is deemed mild pain
– 4 to 6 is moderate pain
– 7 to 10 is deemed severe pain and is associated with the worst outcomes
Factors Influencing Pain
• Degree of pain perception
• Past experience

7. • Social factors : attention ,family support
• Physiological factors: Age, Fatigue, Genes
• Social factors: Attention, Previous experience, Family and social support
• Psychological factor :Anxiety, Coping style
• Spiritual factor
• Cultural factor
• Response of health professionals
Gate-Control theory of Pain
Psychologist Ronald Melzack and the anatomist Patrick wall proposed the gate control theory for pain in 1965 to
explain the psychological aspects of pain are as important as the physiological aspects.
• According to them, the pain stimuli transmitted by afferent pain fibers are blocked by Gate mechanism
located at the posterior gray horn of the spinal cord. if the gate is opened, pain is felt. if the gate is closed,
pain is suppressed.
• The gate control theory combines cognitive, sensory, and emotional components in addition to the
physiological aspects.
• The mechanism act on a gate control system to block the individual’s perception of pain.
• Pain perception is regulated through a gating mechanism at the dorsal horn of the spinal cord.
• The gating mechanism causes vasoconstriction and decreased nerve conduction velocity, thereby
reducing the transmission of noxious stimuli.
• As a result, the level of conscious awareness of painful sensation is altered.
• The large-diameter cells have the ability, when properly stimulated, to ‘‘close the gate’’ and thus block
transmission of the pain impulse to the brain .
• Stimulants such as cutaneous massage, opioid release, and excessive stimulation all activate the large-
diameter cells to close the gate.
• Clinically, the effectiveness of several nonpharmacologic modalities, such as massage, acupuncture, and
acupressure, supports the gate control theory

8. Gate-Control theory of Pain

9. • Pain impulses can be regulated or even blocked by gating mechanism located along the central nervous
system.
• The theory suggests that pain impulses pass through when a gate is open and that impulses are blocked
when a gate is closed.
• This gating mechanism can be found in the cells of dorsal horn of the spinal cord, thalamus and limbic
system
Pain Threshold
• Pain threshold is the point at which a person feels pain.
• Pain threshold can be different for different individuals, because stress, exercise and many other factors
increase the release of endorphins, raising an individual’s pain threshold.
• The amount of circulating substances vary with every individual, so the response to pain will be different
among different individuals.
Pain Management
Assessment
As pain intensity is considered the fifth vital sign
In assessing a patient with pain, the nurse reviews the patient’s description of the pain and other factors that may
influence pain (e.g., previous experience, anxiety, and age) as well as the person’s response to pain relief
strategies.
COLDERRA
C= Characteristic of pain, e.g Sharp pain, dull pain, diffused pain, pressure, squeezing, heaviness
O= Onset of pain. When pain started, and how pain initiated?
L= Location of pain.
D= Duration of pain. For how long pain persists?
E= Exacerbating factors. What factor/factors increase the pain? e.g activity, exercise, diet, drug
R=Relieving factors. What factor/factors relieve pain, e.g drug, rest etc
R=radiating. Does pain radiate (spread) anywhere else or not
A=Associated factors. What other symptoms do occur with pain e.g diaphoresis, nausea, vomiting etc
Pain Scale (Liker Scale)

10. PAIN ASSESSMENT FOR ADULTS
• Pain assessment P-Q-R-S-T.
• Visual analogue pain scale.
• Numeric rating pain scale.
• COLDERRA

11. PAIN ASSESSMENT FOR CHILDREN.
• FLACC pain rating scale.
• Oucher pain scale.
• Wong-Baker Faces pain rating scale.

12. The FLACC scale has been validated in children 2 months to 7 years old and rates pain behaviors as manifested by :
Facial expressions, Leg movement, Activity, Cry, and Consolability
measures that yield a score of 0 to 10.

13. Pain Management
• Pain management strategies include both pharmacologic and nonpharmacologic approaches.
• These approaches are selected on the basis of the patient’s requirements and goals.
• Appropriate analgesic medications are used as prescribed. They are not considered a last resort to be
used only when other pain relief measures fail. Any intervention is most successful if initiated before pain
sensitization occurs, and the greatest success is usually achieved if several interventions are applied
simultaneously.
Pharmacological Approaches
• Pharmacologic pain management involves the use of:
➢ Opioids (narcotics)
➢ Nonopioids such as nonsteroidal anti-inflammatory drugs (NSAIDS)
➢ Coanalgesic drugs
• These agents work by different mechanisms. Using two or three types of agents simultaneously can
maximize pain relief while minimizing the potentially toxic effects of any one agent.
• When one agent is used alone, it usually must be used in a higher dose to be effective
Opioids
• Opioids can be administered by various routes, including oral, intravenous, subcutaneous, intraspinal,
intranasal, rectal, and transdermal routes.
• The goal of administering opioids is to relieve pain and improve quality of life; therefore, the route of
administration, dose, and frequency of administration are determined on an individual basis.
Side effects of Opioids
• Respiratory depression
• Nausea and vomiting
• Constipation
• Tolerance and addiction
Nonsteroid Anti-inflammatory Drugs (NSAIDs)
• NSAIDs are thought to decrease pain by inhibiting cyclo-oxygenase (COX), the rate-limiting enzyme
involved in the production of prostaglandin from traumatized or inflamed tissues.
• Example:

14. • Asprin, Ibuprofen, Diclofanic sodium (Dicloran), Acetaaminophen (paracetamol), Mafemanic acid
(Ponston)
Side effects of NSAIDS
• Gastric ulceration
• Impaired kidney and liver function
• Bleeding tendencies
Coanalgesics
• A coanalgesic (formerly known as an adjuvant) is a medication that is not classified as a pain medication.
• Coanalgesics have properties that may reduce pain alone or in combination with other analgesics, relieve
other discomforts, potentiate the effect of pain medications, or reduce the pain medication’s side effects.
• Examples of medications used to reduce the side effects of analgesics include stimulants, laxatives, and
antiemetic.
Non pharmacological Approaches
• Cutaneous Stimulation
– Massage
– Application of heat or cold
– Acupressure
– Contralateral stimulation.
• Transcutaneous Electrical Nerve Stimulation (TENS)
• Cognitive–Behavioral Interventions
– Distraction
– Guided Imagery
– Relaxation Techniques
• Selected Spiritual Interventions
Non Pharmacological Approaches

15. Nursing Care Plane

16. References
• Berman, A., Frandsen, G., Snyder, S., Kozier, B., & Erb, G. L. (2016). Kozier and Erb's fundamentals of
nursing, volumes 1-3 (10th ed.).
• Delaune, S. C. (2010). Fundamentals of nursing (4th ed.). Delmar Pub.