ch 44- pain management Flashcards
defines it as “an unpleasant, subjective sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage
International Association for the Study of Pain (IASP)
improves quality of life, reduces physical discomfort, promotes earlier mobilization and return to previous baseline functional activity levels, results in fewer hospital and clinic visits, and decreases hospital lengths of stay, resulting in lower health care costs.
Effective pain management
transduction, transmission, perception, and modulation
four physiological processes of nociception:
is the protective physiologic series of events that bring awareness of actual or potential tissue damage.
nociceptive pain
observable activity in the nervous system in response to an adequate stimulus (third-person perspective)
nociceptive pain
is the process whereby an activated nociceptor converts energy produced by these stimuli (e.g., exposure to pressure or a hot surface) into an action potential
Transduction
thermal, chemical, or mechanical stimuli can cause nociceptive pain when the amount of stimuli is strong enough to meet the activation threshold of nociceptors, which are specialized nerve endings distributed throughout the skin, muscles, joints, and viscera
Transduction
-Generated from the breakdown of phospholipids in cell membranes
• Thought to increase sensitivity to pain
Prostaglandins (Neurophysiology of Pain: Neuroregulators)
- Released from plasma that leaks from surrounding blood vessels at the site of tissue injury
- Binds to receptors on peripheral nerves, increasing pain stimuli
- Binds to cells that cause the chain reaction producing prostaglandins
Bradykinin(Neurophysiology of Pain: Neuroregulators)
- Found in pain neurons of dorsal horn (excitatory peptide)
- Needed to transmit pain impulses from periphery to higher brain centers
- Causes vasodilation and edema
Substance P(Neurophysiology of Pain: Neuroregulators)
• Produced by mast cells, causing capillary dilation and increased capillary permeability
Histamine(Neurophysiology of Pain: Neuroregulators)
• Released from the brainstem and dorsal horn to inhibit pain transmission
Serotonin(Neurophysiology of Pain: Neuroregulators)
- Are the natural supply of morphinelike substances in the body
- Activated by stress and pain
- Located within the brain, spinal cord, and gastrointestinal tract
- Cause analgesia(inability to feel pain) when they attach to opiate receptors in the brain
- Present in higher levels in people who have less pain than others with a similar injury
Neuromodulators (Inhibitory)/(Neurophysiology of Pain: Neuroregulators)
neurons carrying nociceptive input include projection neurons, local interneurons, and propriospinal neurons.
Dorsal horn
transmit sharp, localized nociceptive information
fast-transmitting myelinated A-delta fibers (transmission)
relay impulses that are dull, achy, and poorly localized
smaller-diameter unmyelinated C fibers (transmission)
Once a pain stimulus reaches the cerebral cortex, the brain interprets the quality of the pain and processes information from past experience, knowledge, and cultural associations in the perception of the pain
Perception
person is aware of nociceptive impulses and perceives pain.
Perception
identifies the location and intensity of pain
somatosensory cortex(Perception)
primarily the limbic system, determines how a person feels about it. There is no single pain center.
association cortex (Perception)
Projection neurons activate endogenous descending inhibitory mediators (see Box 44.1), such as endorphins (endogenous opioids), serotonin, norepinephrine, and gamma-aminobutyric acid (GABA), that aid in producing an analgesic effect
Modulation (fourth and last phase of the normal pain process)
Projection neurons activate endogenous descending inhibitory mediators , such as endorphins (endogenous opioids), serotonin, norepinephrine, and gamma-aminobutyric acid (GABA), that aid in producing an analgesic effect
Modulation (fourth and last phase of the normal pain process)
include expansion of the pain beyond the initial location, exaggerated response to noxious(harmful) stimuli known as hyperalgesia(increased sensitivity/ response to pain), and pain in response to normally non-noxious stimuli, also called allodynia.
Clinical manifestations of central sensitization//
Modulation (fourth and last phase of the normal pain process)
include trauma, drugs, tumor growth, and metabolic disorders.
factors that disrupt the pain process