NURS 330: Pain & Comfort (Giddens)

THEME FIVE Protection and Movement

Types of Pain

  • Acute
    • Characteristics: Localized, Intermittent, No Pain, Minimal Pain, Moderate Pain, Severe Pain
  • Chronic
    • Characteristics: Generalized, Constant

Understanding Pain

  • Definition of Pain:
    • Pain is a conscious experience requiring awareness via an intact central nervous system (CNS) to receive sensory information and interpret it as an unpleasant and painful sensation.
  • Nociception:
    • Physiologic process defined as the response of the sensory nervous system to potentially damaging mechanical, thermal, or chemical stimuli.
    • Pain is a subjective experience that arises from nociception.

Mechanisms of Pain Perception

1. Transduction
  • Process:
    • Tissue damage leads to the release of chemical mediators from damaged cells, activating nociceptors.
    • Chemical Mediators Include: Prostaglandins, Bradykinin, Serotonin, Substance P, and Histamine.
    • These mediators can open sodium channels in nociceptors, generating an action potential.
2. Transmission
  • Action Potential Movement:
    • Moves along specialized afferent nerve fibers (A-delta and C fibers) to the spinal cord.
    • Types of Fibers:
    • A-delta Fibers: Thinly myelinated, transmit sharp, stabbing pain.
    • C Fibers: Unmyelinated, transmit aching, burning pain.
    • Substance P allows action potentials to cross the synaptic cleft to the dorsal horn of the spinal cord, then ascends via the spinothalamic tract to the thalamus and midbrain.
3. Perception
  • Nociceptive Message Routing:
    • Thalamus relays the message to the somatosensory cortex, frontal/parietal lobes, and limbic system for perception and interpretation based on various factors (past experiences, beliefs, attitudes).
4. Modulation
  • Midbrain Activation:
    • Results in the release of endorphins, enkephalins, serotonin, and dynorphin, descending to inhibit pain transmission at the dorsal horn.

Age-Related Differences in Pain Experience

  • General Trends:
    • Mechanisms for nociceptive pain present at birth, functional throughout adult life.
    • Acute pain prevalence does not change significantly with age; chronic pain prevalence increases.
    • More than 50% of older adults in the community and >80% of nursing home residents experience chronic pain.
    • Chronic pain is not a normal part of aging, yet elderly individuals may have reduced tolerance for severe pain.

Pain Classification

  • Acute vs. Chronic Pain:
    • Acute Pain: Sudden onset, linked to specific injury or illness (surgery, trauma). Expected to diminish with healing. Highly individualized.
    • Chronic Pain: Lasts longer than 3 months, persistent, may arise from various conditions including injury, medical treatment, or idiopathic origins.
  • Nociceptive Pain vs. Neuropathic Pain:
    • Nociceptive Pain: Normal function of the sensory system responding to noxious stimuli, also known as eudynic pain (e.g., sunburn, surgery).
    • Neuropathic Pain: Results from damage to or disease of the somatosensory system (e.g., diabetic neuropathy, postherpetic neuralgia).

Neuropathic Pain Types

  • Sympathetically Mediated Pain: Evidence of edema, altered blood flow, abnormal sensations (e.g., allodynia).
  • Deafferentation Pain: Results from loss of afferent input to CNS due to peripheral nerve injury or CNS lesions.
  • Neuralgia Pain: Lancinating pain along a single nerve pathway.
  • Central Pain: Due to CNS lesions, usually follows thalamic infarcts; characterized by constant burning pain.

Physiological Consequences of Pain

  • Stress Response:
    • Results in excessive hormone release (cortisol, catecholamines).
    • Metabolic processes stimulated, leading to rapid catabolism, potential shock, and more.
    • Impact on the immune system: Higher incidence of infections and tumor growth.
    • Respiratory effects: Decreased lung function, leading to increased risk of pneumonia.
    • Cardiovascular effects: Increased risk of myocardial infarction and stroke; increased heart rate and blood pressure.

Psychosocial Consequences of Pain

  • Chronic pain can lead to significant psychological impacts: fear, anger, depression, and anxiety.
  • Social functioning may be impaired, reducing quality of life and ability to maintain relationships.
  • These psychosocial challenges are particularly pronounced in cases where pain is poorly managed or untreated.

Risk Factors for Pain

Populations at Risk
  • Infants and Children:
    • Prone to pain from various medical procedures and lack cognitive skills to report pain.
  • Older Adults:
    • Higher pain incidence due to age-related conditions and treatment reluctance.
  • Veterans:
    • Higher vulnerability to pain due to combat injuries; disparities among different demographics and conditions.
Individual Risk Factors
  • Communication Barriers: Individuals who cannot communicate (infants, cognitively impaired) are at high risk for undertreatment.
  • Cognitive Impairment: Higher prevalence among these individuals; special considerations in assessments.
  • Mental Health Conditions: Chronic pain often linked with psychological disorders; requires comprehensive treatment addressing both pain and mental health.

Comfort-Function Goals in Pain Management

  • Discuss functional goal achievement related to pain management; set pain levels that allow patients to function optimally (goal 2-3 on a 0-10 scale).
  • Address breakthrough pain, particularly when patients experience exacerbations in otherwise manageable pain. Types include incident and idiopathic pain.

Pain Assessment and Management Strategies

Pain Assessment Requirements
  • Regular reassessment of pain is crucial, especially post-analgesia administration.
  • Use alternative measures for patients unable to self-report pain. The pain assessment hierarchy includes self-report, observation, and physiological indicators.
Clinical Management Strategies
  • Pharmacological Interventions: Multimodal pain management strategies incorporating various analgesics (Non-opioids, Opioids, Adjuvants)
  • Nonpharmacologic Strategies: Incorporation of physical therapies (e.g., massage), psychological therapies (cognitive-behavioral), and other holistic approaches (e.g., acupuncture).
  • Invasive Strategies: For chronic or severe pain when other modalities fail, consider surgical options such as nerve blocks, spinal stimulators, etc.
Analgesic Groups
  • Nonopioid Analgesics: (e.g., Acetaminophen, NSAIDs)
  • Opioid Analgesics: (e.g., Morphine, Oxycodone)
  • Adjuvant Analgesics: (e.g., Anticonvulsants, Antidepressants)
  • Adjust routes based on patient needs; oral administration preferred but IV and other routes are utilized based on clinical scenarios.

Conclusion and Nursing Role in Pain Management

  • Vigilant assessment of pain and side effects is critical to ensure patient safety during analgesic administration.
  • Emphasis on patient-centered care as it pertains to pain management, addressing both the physical and psychosocial ramifications of pain.