Chapter 15

1. Chapter 15 Pain Management

2. Definition of Pain International Association for the Study of Pain defines it as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage” McCaffery, a nurse and leader in the pain management field, has a more useful definition for nurses: “Pain is whatever the person experiencing it says it is and exists whenever he says it does”

3. Physiology of Pain Sensory experiences: time/space, emotions, cognition Afferent pathways Nerves that carry messages to the brain for interpretation Efferent (or descending) pathways Carry messages away from the brain via spinal cord Nociceptors Receptors that activate the afferent pathways Unevenly distributed in muscles, tendons, subcutaneous tissue, and the skin

4. Physiology of Pain Pain receptors are sensitive to chemical changes, temperature, mechanical stimuli, and tissue damage Pain receptors are unable to adapt to repeated stimuli and thus continue to react until stimuli are removed When pain receptors are stimulated, impulses are transmitted to the spinal cord

5. Physiology of Pain Impulses then travel up the spinal cord to the brain In the brain, the cortex interprets the impulses as pain and identifies the location and qualities of the pain Endorphins and enkephalins, natural opioid-like substances: block transmission of painful impulses to the brain

6. Gate-Control Theory Pain reflects physical and psychosocial factors Painful impulses are transmitted to the spinal cord through small-diameter nerve fibers in the afferent pathway When these fibers are stimulated, the gating mechanism opens in the spinal cord, which permits the transmission of impulses from the spinal cord to the brain

7. Gate-Control Theory Factors that cause the gate to open include tissue damage, a monotonous environment, and fear of pain Stimulation of large-diameter fibers can close the gate and interfere with impulse transmission between spinal cord and the brain, causing diminished pain perception

8. Figure 15-1

9. Factors Influencing Response to Pain Although people may have the same injury or insult, they may respond differently because many physical and psychosocial factors affect the response to pain Important for health professionals to be nonjudgmental and to avoid comparing one individual in pain with another

10. Physical Factors Pain threshold Point at which stimulus causes sensation of pain Pain tolerance Intensity of pain that a person will endure Age Physical activity and nervous system integrity Surgery and anesthesia Type of surgery performed and the type of anesthesia used can influence the response to pain

11. Psychological Factors Culture and ethnicity Different ways of expressing/responding to pain Religious beliefs Some patients may pray and believe that divine intervention will help them to endure the pain Others may view pain as a punishment for sins Some believe that suffering is required before pain relief

12. Psychological Factors Past experiences and anxiety May have developed positive coping strategies to deal with previous painful experiences If strategies were unsuccessful, may be very anxious and overwhelmed by another painful experience Situational factors If pain associated with a serious illness, it may have a greater effect on mood and activity than if the pain were associated with a less serious condition

13. Autonomic Nervous System Activates the fight-or-flight response; certain physiologic responses initiated The nervous system responses measured by increased heart rate, respiratory rate, and blood pressure Acute and chronic pain elicit different kinds of responses

14. Acute Pain Follows the normal pathway for pain from nociceptor activation to the brain and may be called nociceptive pain Cause is known and treatable It serves as a warning of tissue damage and subsides when healing takes place Behavioral and physiologic signs: when patient guards or rubs a body part, wrinkles the brow, bites the lip, and has changes in the heart rate, blood pressure, and respiratory rate

15. Chronic Pain Persists/recurs for >6 months; may last a lifetime Most chronic pain is neuropathic pain because it follows an abnormal pathway for pain Results from nerve damage from anatomic and physiologic conditions and underlying diseases Includes unusual sensations such as burning, shooting pain, and abnormal sensations that occur when there is no painful stimulus present See Table 15-2, p. 206

16. Comparison of Acute and Chronic Pain Chronic pain serves no useful purpose; acute warns of tissue damage and trauma Nursing assessment to identify Type and amount of pain Chronic or acute If acute and chronic pain at the same time

17. Figure 15-2

18. Nursing Care of the Patient in Pain

19. Assessment Should be done on admission and on a regular basis Assessment of vital signs is called the fifth vital sign

20. Assessment Six steps Accept the patient’s report Determine the status of the pain Describe the pain Location, quality, intensity, aggravating and alleviating factors Examine the site of the pain Identify coping methods Document assessment findings and evaluate interventions

21. Figure 15-5

22. Nonpharmacologic Interventions Those that do not employ drugs Physical interventions Physical comfort measures Environmental control Stimulation techniques Anxiety reduction Distraction Psychological interventions Relaxation Imagery

23. Pharmacologic Interventions Nonopioid analgesics Aspirin, acetaminophen, and nonsteroidal anti-inflammmatory drugs (NSAIDs) such as ibuprofen Generally initial treatment choice for mild pain Act mostly on the peripheral nervous system Antipyretic (fever-reducing), analgesic (pain-reducing), and/or anti-inflammatory (inflammation-reducing) properties See Table 15-4, p. 216

24. Pharmacologic Interventions: Opioid Analgesics For moderate to severe acute pain, chronic cancer pain, and some other types of pain Opioids: potency/duration of action vary Opioid agonists Examples: codeine, methadone (Dolophine), hydromorphone (Dilaudid), meperidine (Demerol), morphine, and fentanyl

25. Pharmacologic Interventions: Opioid Analgesics Opioid agonist-antagonists Examples: buprenorphine (Buprenex), nalbuphine (Nubain), butorphanol (Stadol), and pentazocine (Talwin)

26. Pharmacologic Interventions: Opioid Analgesic Misconceptions Patients, families, nurses, and physicians have misconceptions about addiction; therefore, the term must be defined and differentiated from the terms tolerance and physical dependence Tolerance and physical dependence are normal responses to continued opioid administration for pain relief; they do not lead to a craving for the drug for its mind-altering effects Fear of addiction greatly exaggerated; rare (<1%) in patients taking opioids for pain relief

27. Pharmacologic Interventions: Opioid Analgesics Routes of administration Oral Intramuscular Sublingually Intravenously: intermittent bolus injections, continuous infusions, or patient-controlled analgesia (PCA) Epidural or intrathecal route

28. Pharmacologic Interventions: Opioid Analgesics Side effects Constipation Nausea, with or without vomiting Sedation Respiratory depression Confusion Hypotension (especially orthostatic) Dizziness Urinary retention

29. Pharmacologic Interventions: Placebos Inactive substances (e.g., saline) used in research or clinical practice to determine the effects of a legitimate drug or treatment Appropriately used in studies in which patients consent to participate

30. Pharmacologic Interventions: Placebos Many health care organizations take the position that placebos should not be used to assess or manage pain Nurses have ethical obligation to ensure that patients are not deceived and that institutional policies related to placebos are followed

31. Pharmacologic Interventions: Adjuvant Analgesics and Medications Drugs not usually classified as analgesics may relieve pain in certain situations A patient who has undergone back surgery may complain more about muscle spasms than incisional pain A muscle relaxant may be more effective in relieving pain than an opioid alone

32. Pharmacologic Interventions: Adjuvant Analgesics and Medications Specific pain syndromes, especially neuropathic, may be controlled with drugs other than the commonly known analgesics See Table 15-6, p. 219

33. Problem Solving with Pain Medication Patients whose prescribed analgesic drugs do not relieve pain Ask questions about the analgesic drug and the “five rights” (right dose, right patient, right time, right route, right analgesic) to determine why the patient is not getting adequate pain relief See Box 15-8, p. 221