1. Lecture II – Pain Management
Dr. Irene Roco

2. LEARNING OBJECTIVES
On completion of the chapter, the learner will be able to:
1. Describe the pathophysiology of pain.
2. Differentiate between acute pain, chronic pain, and cancer pain.
3. Describe the negative consequences of pain.
4. Describe factors that can alter the perception of pain.
5. Demonstrate appropriate use of pain measurement instruments.
6. Identify appropriate pain relief interventions for selected groups of patients.
7. Develop a plan to prevent and treat the adverse effects of opioid analgesic agents.
8. Use the nursing process as a framework for the care of patients with pain.
Dr. Irene Roco

3. Outline Terminologies Definition of Pain Pathophysiology
Types , Effects , Characteristics of Pain
Factors that influence Pain Response
Pain Scales
Pain Relief Interventions : Pharmacologic, Non Pharmacologic, Neurologic and Neurosurgical Methods
Nursing Process
Dr. Irene Roco

4. TERMINOLOGIES
Addiction- a behavioral pattern of substance use characterized by a compulsion to take the drug primarily to experience its psychic effects
algogenic: causing pain
breakthrough pain - a sudden increase in pain despite the administration of pain-relieving medications
endorphins and enkephalins - morphine like substances produced by the body. Primarily found in the central nervous system, they have the potential to reduce pain.
Dependence- occurs when a patient who has been taking opioids experiences a withdrawal syndrome when the opioids are discontinued; often occurs with opioid tolerance and does not indicate an addiction
Dr. Irene Roco

5. TERMINOLOGIES
nociception: activation of sensory transduction in nerves by thermal, mechanical, or chemical energy impinging on specialized nerve endings. The nerves involved convey information about tissue damage to the central nervous system.
nociceptor: a receptor preferentially sensitive to a noxious stimulus
non-nociceptor: nerve fiber that usually does not transmit pain
opioid: a morphine-like compound that produces bodily effects including pain relief, sedation, constipation, and respiratory depression. This term is preferred over narcotic.
Dr. Irene Roco

6. TERMINOLOGIES
pain: an unpleasant sensory and emotional experience resulting from actual or potential tissue damage
Pain threshold is the smallest stimulus for which a person reports pain
Pain tolerance is the maximum amount of pain a person can tolerate.
placebo effect: analgesia that results from the expectation that a substance will work, not from the actual substance itself
Dr. Irene Roco

7. TERMINOLOGIES
prostaglandins: chemical substances that increase the sensitivity of pain receptors by enhancing the pain-provoking effect of bradykinin
sensitization: a heightened response seen after exposure to a noxious stimulus. Response to the same stimulus is to feel more pain.
tolerance: occurs when a person who has been taking opioids becomes less sensitive to their analgesic properties (and usually side effects). Characterized by the need for increasing doses to maintain the same level of pain relief
Dr. Irene Roco

8. Pain - “The fifth vital sign”
Unpleasant sensory, emotional experience with actual or potential tissue damage
Most common reason for seeking health care ; occurs with many disorders, diagnostic tests, and treatments.
It disables and distresses more people than any single disease.
Joint Commission (2005) standards: “pain is assessed in all patients,” “patients have the right to appropriate assessment and management of pain.”
“Pain is whatever a person says it is, existing whenever the experiencing person says it does” (McCaffery & Pasero, 1999)
Dr. Irene Roco

9. Reasons why patients Deny Pain
Fear of treatment that may result if they report or admit pain
Fear of becoming addicted to opioids if these medications are prescribed
Dr. Irene Roco

10. Pathophysiology of Pain
PAIN TRANSMISSION (NOCICEPTION) : to and from the brain
Nociceptors (pain receptors)
Chemical substances
Increases Pain Transmission : Histamine, Bradykinin, Acetylcholine, Serotonin, Substance P, Prostaglandins (increase sensitivity of pain receptors)
Decreases / Suppresses Pain Transmission : Endorphins, enkephalins
Dr. Irene Roco

11. Nociception System Showing Ascending and Descending Pathways of the Dorsal Horn
Dr. Irene Roco

12. PAIN TRANSMISSION
Lower and Mid portion of the brain Reticular Formation, Thalamus, Limbic System,
(periaqueductal gray matter) Cerebral Cortex
( nociception is localized ; Individual Variation
(descending control) ( intensity, characteristic) (3rd Order neurons)
Ventral horn of the spinal Cord
Motor (Efferent Neurons (ascending pathways)
2nd Order Neurons
Dorsal horn of the spinal Cord
A delta fibers C fibers
( smaller myelinated ) (larger, unmyelinated)
“Fast pain” (second pain) “ dull, aching,
burning, lasts longer
Nociceptors / 1st order Neurons ( skin, cornea, visceral organs )
CNS
Autonomic
Involuntary
Somatic
(Voluntary)
PNS
Noxious stimuli ( tissue injury) (mechanical, chemical, thermal)
Dr. Irene Roco

13. PAIN TRANSMISSION
Dr. Irene Roco

14. PAIN TRANSMISSION INHIBITORY INTERNEURONAL FIBERS
Interconnections between the descending neuronal system and ascending sensory tract that contains Enkephalins and are primarily activated through the activity of non nociceptor peripheral fibers
Dr. Irene Roco

15. Gate Control System Theory
This theory proposes a specialized system of large-diameter fibers that activate selective cognitive processes via the modulating properties of the spinal gate.
The noxious impulses are influenced by a “gating mechanism.”
“ stimulation of the large-diameter fibers inhibits the transmission of pain, thus “closing the gate; when smaller fibers are stimulated, the gate is opened.
Dr. Irene Roco

16. Gate Control System Theory
The first theory to suggest that psychological factors play a role in the perception of pain and guided research towards the :
cognitive behavioral approaches to pain management.
distraction and music therapy provide pain relief.
Dr. Irene Roco

17. Gate Control System Theory
The nervous system is made up of stimulatory and inhibitory fibers. When nociceptor is stimulated it will stimulate transmission at the next fiber junction (represented as +>–). The interneuronal fiber is an inhibitory neuron (−>–). When it is stimulated it, in turn, inhibits or shuts off transmission at the next junction. So a placebo has a (+) stimulatory effect on the descending control system, which has a stimulatory effect (+) on the interneuronal fiber, which has an inhibitory effect (−) on the ascending control system. A topical anesthetic has an inhibitory effect (−) on nerve transmission at the nociceptor level and a spinal anesthetic has the same impact (−) on the ascending nociceptive fibers.
Dr. Irene Roco

18. Types of Pain According to duration
Acute pain, Chronic pain; Cancer-related pain
According to location
Pelvic pain, headache, chest pain
According to Etiology
Burn pain; herpetic neuralgia
Dr. Irene Roco

19. Types of Pain According to duration
ONSET / CHARACTER
DURATION
LOCATION
Signs
Acute pain
recent ; commonly associated with specific injury ; Damage or injury has occurred; decreases along with healing ; sharp,
Seconds to 6 months
When healing is expected in 3 weeks and patient continues to suffer pain, it should be considered chronic
Localized
Tachycardia Hypertension Tachypnea, pallor, diaphoresis, Dilated pupil
Crying & moaning , Rubbing site (area) Holding area , Guarding, Frowning, Grimacing
Chronic pain
Constant or intermittent that persists beyond expected healing time; seldom attributed to specific cause or injury ; Often as dull , diffuses and aching
Lasts for 6 months or longer
Difficult to pinpoint
Normal vital signs; Normal or dilated pupils, weight loss
Physical immobility Hopelessness, restlessness, Loss of libido, Exhaustion & fatigue
Dr. Irene Roco

20. Types of Pain According to duration
ONSET / CHARACTER
DURATION
Cancer-related pain
May be classified by location or etiology
May be acute or chronic ; Moderate to severe pain
Associated with cancer; second most common fear of newly diagnosed patient with cancer
May not be associated with cancer ( trauma)
Dr. Irene Roco

21. Pain Syndromes Complex regional pain syndrome
Postmastectomy pain syndrome
Fibromyalgia
Hemiplegia associated shoulder pain
Pain associated with sickle cell disease
AIDS-related pain
Burn pain
Guillain-Barré syndrome, pain
Opioid tolerance
Dr. Irene Roco

22. Phantom Limb Pain
Pain that occurs in the place of a missing limb after surgery.
Melzack (1996) theorized that in the absence of modulating inputs from the missing limb, the active neuromatrix ( thalamus and cortex and between the cortex and the limbic system) produces a neurosignature pattern that is perceived as pain.
The neuromatrix theory highlights the role of the brain in sustaining the experience of pain.
Dr. Irene Roco

23. Effects of Pain Sleep deprivation Acute pain
Can affect respiratory ( unable to take a deep breath ) , cardiovascular and may experience increased fatigue and decreased mobility, endocrine (increased production of cortisol)
immune systems ( Stress response increases metabolic rate, cardiac output, risk for physiologic disorders (increased retention of fluids)
Dr. Irene Roco

24. Effects of Pain (cont’d)
Chronic pain
Depression
Increased disability
Suppression of immune function
Dr. Irene Roco

25. Question
What is the time frame for pain that can be classified as chronic?
1 month
2 to 3 months
4 to 5 months
Longer than 6 months
D. Longer than 6 months
Rationale: Chronic pain is constant or intermittent pain that persists beyond the expected healing time and that can seldom be attributed to a specific cause or injury. Chronic pain may be defined as pain that lasts for 6 month or longer, although 6 months is an arbitrary period for differentiating between acute and chronic pain.
Dr. Irene Roco

26. Question Tell whether the following statement is true or false:
Endorphins represent the same mechanism of pain relief as nonnarcotic analgesics.
False.
Rationale:
Endorphins do not represent the same mechanism of pain relief as nonnarcotic analgesics. Endorphins release inhibits the transmission of painful impulses. They are endogenous neurotransmitters structurally similar to opioids. They are found in heavy concentration in the central nervous system.
Dr. Irene Roco

27. Factors that Influence Pain Response
Past experience - Once a person experiences severe pain, that person knows just how severe it can be. Conversely, someone who has never had severe pain may have no fear of such pain.
Anxiety - anxiety that is relevant or related to the pain may increase the patient’s perception of pain ; Anxiety that is unrelated to the pain may distract the patient and may actually decrease the perception of pain.
Depression - Longer durations of pain are associated with an increased incidence of depression
Dr. Irene Roco

28. Factors that Influence Pain Response
Culture - Beliefs about pain and how to respond to it differ from one culture to the next
Age - The way an older person responds to pain may differ from the way a younger person responds. If pain perception is diminished in the elderly person, it is most likely secondary to a disease process (eg, diabetes) rather than to aging (American Geriatrics Society, 1998)
Gender - Women had higher pain intensity, pain unpleasantness, frustration, and fear compared to men. Robinson, Riley, Meyers et al. (2001); men being more anxious about their pain ( Edwards, Auguston and Fillingim (2000)
Dr. Irene Roco

29. Characteristics of Pain
Intensity - none to mild discomfort to excruciating.
Timing - onset, duration, relationship between time and intensity, and changes in rhythmic patterns; sudden or gradual increase
Location - have the patient point to the area of the body involved
Quality- patient describes the pain in his or her own words without offering clues
Personal meaning – effect of pain in person’s daily life.
Dr. Irene Roco

30. Characteristics of Pain
Aggravating, alleviating factors - anything makes the pain worse and what makes it better ; relationship between activity and pain
Pain behaviors - nonverbal and behavioral expressions of pain are not consistent or reliable indicators of the quality or intensity of pain, and they should not be used to determine the presence of or the degree of pain experienced ( grimace, cry, rub the affected area, guard the affected area, or immobilize it, moaning , groaning, grunt, or sigh. )
Dr. Irene Roco

31. Pain Intensity Scales
Dr. Irene Roco

32. Faces Pain Scale, revised
Refer to fig. 13-4
Dr. Irene Roco

33. Question
The RN asks a patient to describe the quality of pain. Which of the following is a descriptive term for the quality of pain?
Burning
Chronic
Intermittent
Severe
A. Burning
Rationale: A descriptive term for the quality of pain is burning. Chronic and intermittent pain are examples of types of pain. Severe is a descriptive term for the intensity of pain.
Dr. Irene Roco

34. 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.
The placebo effect results from the natural (endogenous) production of endorphins in the descending control system. It is a true physiologic response that can be reversed by naloxone, an opioid antagonist (Wall, ).
“ placebos (tablets or injections with no active ingredients) should not be used to assess or manage pain in any patient regardless of age or diagnosis” The American Society of Pain Management Nurses (1996)
Dr. Irene Roco

35. Gerontologic Considerations
More likely to have adverse drug effects, drug interactions
Increased likelihood of chronic illness
May need to have more time between doses of medication due to decreased excretion, metabolism related to aging changes
Dr. Irene Roco

36. Pain Relief Interventions:
Pharmacologic
Non Pharmacologic
Neurologic and Neurosurgical Interventions
Dr. Irene Roco

37. Physiologic Basis for Pain Relief : I - Pharmacologic Interventions
CATEGORIES OF ANALGESICS:
Opioid analgesics act on CNS to inhibit activity of ascending nocioceptive pathways
NSAIDS decrease pain by inhibiting cyclo-oxygenase (enzyme involved in production of prostaglandin)
Local anesthetics block nerve conduction when applied to nerve fibers
Using two or three types of agents simultaneously can maximize pain relief while minimizing the potentially toxic effects of any one agent ( Balanced analgesia)
When one agent is used alone, it usually must be used in a higher dose to be effective.
Dr. Irene Roco

38. Approaches for Using Analgesic Agents
Balanced analgesia – use of more than one form of analgesia concurrently to obtain more pain relief with fewer side effects.
“PRN” medications (pro re nata(PRN), or “as needed.”
Routine administration: around the clock (ATC) or preventive approach; analgesic agents are administered at set intervals so that the medication acts before the pain becomes severe and before the serum opioid level falls to a subtherapeutic level.
Dr. Irene Roco

39. Approaches for Using Analgesic Agents
Individualized dosage - The dosage and the interval between doses should be based on the patient’s requirements rather than on an inflexible standard or routine. People metabolize and absorb medications at different rates and experience different levels of pain.
PCA: patient-controlled analgesia
Dr. Irene Roco

40. Opioid Tolerance and Addiction
Maximum safe opioid dosage must be individually assessed
Tolerance develops in all patients who take opioids for prolonged periods
With tolerance, increased usage needed to effect pain relief
Dependence (body adapts to drugs) occurs with tolerance, physical symptoms occur when opioid is discontinued
Addiction
behavioral pattern ( compulsive drug use) characterized by need to take drug for psychic effects
Addiction from therapeutic use of opioid is negligible
Dr. Irene Roco

41. CATEGORIES OF ANALGESICS:
2. NSAIDS (Aspirin, Ibuprofen, Naproxen Na)- decrease pain by inhibiting cyclo-oxygenase (COX), the rate-limiting enzyme involved in the production of prostaglandin from traumatized or inflamed tissues
Dr. Irene Roco

42. CATEGORIES OF ANALGESICS:
3. Local anesthetics – ( Topicals, patches, sprays )
blocks nerve conduction when applied directly to the nerve fibers.
are rapidly absorbed into the bloodstream, resulting in decreased availability at the surgical or injury site and an increased anesthetic level in the blood, increasing the risk of toxicity
Therefore, a vasoconstrictive agent (eg, epinephrine or phenylephrine) is added to the anesthetic agent to decrease its systemic absorption and to maintain its concentration at the surgical or injury site. –
Dr. Irene Roco

43. Intrathecal and Epidural Catheter Placement
Intra - spinal administration - Intermittent or continuous administration of local anesthetic agents through an epidural catheter
Dr. Irene Roco

44. Adverse Effects of Analgesic Agents
Respiratory depression
Sedation
Nausea, vomiting
Constipation
Pruritus
Dr. Irene Roco

45. Tricyclic Antidepressant Agents and Anticonvulsant Medications
tricyclic antidepressant agents ( amitriptyline (Elavil) or imipramine (Tofranil) - therapeutic effect may not occur before 3 weeks.
Antiseizure medications (phenytoin (Dilantin) or carbamazepine (Tegretol) used in lower doses
indicated for Pain of neurologic origin ( causalgia, tumor impingement on a nerve, postherpetic neuralgia, dysesthesia (burning or cutting pain)
Dr. Irene Roco

46. II - Nonpharmacologic Interventions
Cutaneous stimulation, massage – produces muscle relaxation
Thermal therapies
ice should be applied no longer than 20 minutes at a time
Heat
3. Transcutaneous electrical nerve stimulation (TENS) uses battery operated unit with electrodes applied to the skin to produce a tingling, vibrating, or buzzing sensation in the area of pain
4. Distraction focusing the patient’s attention on something other than the pain (cognitive techniques)
(TENS)
Dr. Irene Roco

47. Nonpharmacologic Interventions (cont’d)
5. Relaxation techniques - abdominal breathing at a slow, rhythmic rate. 6. Guided imagery - using one’s imagination in a special way to achieve a specific positive effect; consist of combining slow, rhythmic breathing with a mental image of relaxation and comfort 7. Hypnosis 8. Alternative therapies (Music therapy, touch therapy, reflexology, magnetic therapy, electrotherapy, acupressure, aromatherapy)
aromatherapy
magnetic therapy,
acupressure,
Dr. Irene Roco

48. III - Neurologic and Neurosurgical Methods for Pain Control
indicated for Intractable pain ( pain that cannot be relieved satisfactorily by the usual approaches, including medications; usually is the result of malignancy (especially of the cervix, bladder, prostate, and lower bowel),
Stimulation procedures - intermittent electrical stimulation of a tract or center to inhibit the transmission of pain impulses ( TENS, Spinal Cord stimulation)
administration of intraspinal opioids
Dr. Irene Roco

49. III - Neurologic and Neurosurgical Methods for Pain Control
3. Interruption of pain pathways (destructive procedures)
Cordotomy - division of certain tracts of the spinal cord
Rhizotomy - Sensory nerve roots are destroyed where they enter the spinal cord.
Cordotomy
Rhizotomy
Dr. Irene Roco

50. Nursing Process Framework for Pain Management
Identify goals for pain management
Factors to consider:
severity of the pain, as judged by the patient.
anticipated harmful effects of pain. A high risk patient is at much greater risk for the harmful effects of pain than a young healthy patient.
anticipated duration of the pain.
Dr. Irene Roco

51. Nursing Process Framework for Pain Management
Establish nurse-patient relationship, teaching
Provide physical care
Manage anxiety related to pain
Evaluate pain-management strategies
Ref: Brunner & Suddarth’s Medical Surgical Nursing
Dr. Irene Roco