Fundamentals of Nursing Flashcards
Four specific processes of nociception
Transduction - tissue damaged by thermal, mechanical, or chemical stimuli activate nociciptors
Transmission - pain-sensitizing substances surround pain fibres in the extracellular fluid, creating the spread of the pain message via afferent peripheral nerve fibres to the spinal cord.
Perception - conscious awareness of pain
Modulation - Increase, decrease in pain signal intensity that can occur before, during and after pain is perceived - inhibitory transmitters
Substances released by damaged tissue
Prostaglandins, bradykinin, histamine, prostaglandins, serotonin, and substance P
Two types of afferent peripheral nerve fibres that conduct painful stimuli
Fast, myelinated A-delta fibres - sharp, localized, distinct sensation, source and intensity
Small, slow, unmyelinated C fibres - poorly localized, burning, and persistent.
Substance P
Excitatory peptide, needed to transmit pain impulses from the periphery to the higher brain centre, causes vasodilation and edema
Serotonin
released from brain stem and dorsal horn, inhibits pain transmission
Prostaglandins
Generated from breakdown of phospholipids in cell membrane, believed to increase sensitivity to pain
Endorphins and Dynorphins
Neuromodulator - body’s natural supply of morphine-like substances
Activated by stress and pain
Located in the brain, spinal cord, and GI tract
Attach to opiate receptors in brain
Bradykinin
Released from plasma that leaks from surrounding blood vessels
Binds to receptors in peripheral nerves, increases pain stimuli
Binds to cells that cause the chain reaction-producing prostaglandins
Factors involved in perception of pain
Brain interprets intensity, quality, character, info from past experience, psychological, social, spiritual and cultural associations
Examples of inhibitory transmittors
Endogenous opioids (endorphins and enkephalins), serotonin, norepinephrine, and gamma amino butyric acid
Substantia gelatinosa
Gatekeeping cells within the dorsal horn of the spinal cord, thalamus and limbic system - physiological, emotional and cognitive processes can influence these gates
Factors that increase release of endorphins
Stress, exercise
Psychological conditions that accompany pain
Exhaustion, anxiety, depression, irritability
Sympathetic Stimulation in reaction to pain
Dilation of bronchial tubes Increased respiratory rate Increased heart rate Vasoconstriction - elevated blood pressure, pallor Increased blood glucose Diaphoresis Increased muscle tension Dilation of pupils Decreased GI motility
Parasympathetic Stimulation in response to pain
Pallor Muscle tension Decreased heart rate and blood pressure Rapid, irregular breathing Weakness and exhaustion
Superficial or Cutaneous pain characteristics
Pain resulting from stimulation of skin
Pain is localized and of short duration, usually sharp sensation
Deep or Visceral pain
Pain resulting from stimulation of internal organs
Pain is diffuse and may radiate in several directions, duration varies, lasts longer than superficial pain, sharp, dull or unique to organ
Referred pain
Common in visceral pain because many organs have no pain receptors, entrance of sensory neurons from affected organ into same spinal cord segment as neurons from areas where pain is felt, perception of pain is in unaffected areas.
Pain is felt in a part of the body separate from the source.
Radiating pain
Sensation extends from initial site to another body part
Pain feels as though it travels
Intermittent or constant
Neuropathic pain
From abnormal or damaged pain nerves as a result of prior injury or disease, certain nerves may continue to send pain messages to brain even though no ongoing tissue damage is present
Pain described as burning, shooting, numbing
Consequence of disease or prior injury to peripheral or central nervous system
Examples of conditions that cause neuropathic pain
Stroke Spinal cord injury MS Diabetic neuropathy Alcohol-nutritional neuropathy Guillain-Barre Nerve root compression Nerve entrapment Trigeminal neuralgia Herpes zoster
Behavioural Indications of Pain
Vocalizations - moaning, crying, gasping, grunting
Facial Expression - grimacing, clenched teeth, wrinkled forehead, tightly closed or wide open eyes, lip biting
Body Movement - restlessness, immobilization, muscle tension, increased hand and finger movements, pacing activities, rhythmic or rubbing motions, protective movement of body parts
Social interaction - avoidance of conversation, focused only on pain relief, avoidance of social contacts, reduced attention span, despondent
Three types of analgesics
Nonsteroidal antinflammatory drugs (NSAIDs) and nonopiods
Opiods
Coanalgesics - enhance analgesics, have analgesic properties
Acetaminophen (Tylenol)
No anti-inflammatory effects Action unknown Adverse effect - hepatotoxicity No effect on platelet function Minimal GI effect
Nonselective NSAIDs
Aspirin and Ibuprofen
Provide relief for mild to moderate acute pain resulting from trauma or inflammatory processes
Inhibit synthesis of prostaglandins
Act of peripheral nerve receptors to reduce transmission of pain stimuli
Adjuvants
Drugs originally developed to treat conditions other than pain but have been shown to have analgesic properties
E.g. anticonvulsants, antidepressants, cannabinoids
