w10 Flashcards
what is pain?
pain is an unpleasant, subjective sensory and emotional experience associated w/ actual or potential tissue damage, or described in terms of such damage
what is nociceptive pain?
experience of pain that occurs in response to tissue injury. it involves the neural processing of noxious stimuli that occurs when nociceptors (pain-sensing nerves) are activated by tissues damage or inflammation
what is neuropathic pain?
involves the abnormal processing of stimuli due to a lesion or disease in the peripheral or central nervous system
what are the four processes of nociception?
transduction, transmission, perception, and modulation
what is transduction?
- first process of nociception
- when tissues cells are damaged by thermal stimuli, (burn) mechanical stimuli, (cut) or chemical stimuli (chemo) the damaged cells release pain-sensitizing inflammatory substances including prostaglandins, bradykinin, histamine, serotonin and substance P
- generates electrical activity in the peripheral terminals (action potential)
what is transmission?
-second process
-pain-sensitizing and inflammatory substances around the pain nerve fibres in the extracellular fluid, creating the spread of pain message via the afferent peripheral nerve fibres to the dorsal horn of the spinal cord.
w/in the dorsal horn of the spinal cord, a synaptic transmission from the afferent (sensory) peripheral nerve to the spinothalamic tract nerves occur through a complex neurophysiologicall and neurochemical mechanisms =signalling to various higher brain centers
what are the two types of afferent peripheral nerve fibres?
fast, myelinated A-delta fibres, and the small, slow, unmyelinated C fibres
what are the A fibres?
- myelinated
- send sharp, localized and distinct sensations that focus the source of the pain and detect its intensity
- think of more acute pain like stepping on a nail
what are the c-fibres
slow and unmyelinated fibres
-that are poorly localized, burning, and persistent
think of chronic pain
what is perception?
- third nociceptive process
- conscious awareness of pain
- once a pain stimulus reaches the cerebral cortex, the brain interprets the intensity, quality, and character of the pain, and information from past experiences
- the somatosensory cortex identifies the location and intensity of the pain, and the association cortex determines how we feel about the pain
- limbic system plays a role in processing the emotional reaction to pain, and the memory of pain experience
- perception gives awareness and meaning to pain so that a person can reaction
true or false- a humans ability to remember pain depends on cognitive ability (explicitly memory)
false
-infants can even remember pain and even those born prematurely
what is modulation?
- final nociceptive phase and refers to the increase or decrease in pain signal intensity that can occur before, during, or after the pain is perceived
- once the brain perceives pain, inhibitory neurotransmitters are released- including endogenous opioids (endorphins and enkephalins) serotonin, norepinephrine, and gamma aminobutyric acid, which work to hinder the transmission of pain and help produce an analgesic effect
what pain threshold?
minimal intensity of a stimulus that is perceived as painful
autonomic nervous system vs parasympathetic nervous system w/ pain
- ANS-pain impulses ascend the spinal cord toward the brain stem and thalamus, the ANS becomes stimulated as a part of the stress response
- if pain is continuous, severe, deep, to involved the visceral organs the parasympathetic nervous system is triggered (i.e. gallbladder stones, MI)
nonverbal or behavioural indicators of pain may include:
body movements, facial expressions, and vocalizations
-bracing, splitting, protecting the painful part, rocking, body stiffening, jaw clenching, grimacing, frowning, crying, moaning, or screaming
affective responses to pain include:
social w/drawl, changes in eating or sleep patterns, stoicism, fear, anxiety, anger, or feelings of hopelessness
what is acute pain?
- usually has an identifiable cause–> either somatic, visceral, or nociceptive
- short duration (less than 6months)
- has a predictable ending (healing) and eventually resolves w/ or w/out treatment after a damaged area heals
what is chronic pain?
- defined as pain that persists past the normal time of healing
- can be intermittent or persistent
- pt may have sleep disturbances, depression, anxiety and anger
- major cause of psychological and physical disability–> leading to job loss, inability to perform ADL’s, sexual dysfunction, and social isolation
what is cancer pain
may be acute, chronic or both
- may be nociceptive, neuropathic or both
- it can be sensed at the actual site of the tumour or distant to the site
what is referred pain?
when pain is sensed at a site that is distant to the area of tissue damage
nociceptive pain is subdivided into _ and _
somatic (musculoskeletal) and visceral (internal organ)
what is breakthrough pain?
-some pts experience occasional, transitory exacerbations of their baseline pain- the pain “breaks through” the regular pain medication or treatment that adequately controls the baseline pain
what is incident pain?
when breakthrough pain is brief and precipitated by an activity-related action, such as movement, sneezing or coughing
what is idiopathic pain?
- another subtype of breakthrough pain
- not associated w/ identifiable cause and has longer duration than that of incident pain
what is somatic pain?
arises from bone, joint, muscle, skin, or connective tissues
-usually aching or throbbing and is well localized
what is visceral pain?
- arises from visceral organs, such as the GI tract, pancreas etc.
- can be subdivided:
- tumour involviert of the organ capsule, which causes aching and fairly well-localized pain
- obstruction of hollow viscus, which causes intermittent cramping and poorly localized pain
what is centrally generated pain?
deafferentation pain. Injury to either the peripheral or central nervous system. Examples:
Phantom pain may reflect injury to the peripheral nervous system; burning pain below the level of a spinal cord lesion reflects injury to the central nervous system.
what is painful polyneuropathies- peripheral pain
Pain is felt along the distribution of many peripheral nerves.
Examples: Diabetic neuropathy, alcohol-nutritional neuropathy, and those associated with
Guillain-Barré syndrome.
what is painful mononeuropathies.- peripheral pain
Usually associated with a known peripheral nerve injury, and
pain is felt at least partly along the distribution of the damaged nerve. Examples: Nerve root compression, nerve entrapment, trigeminal neuralgia.
what are the subtypes of breakthrough pain?
- Incident pain: Cause of pain is generally identifiable but occurrence may be unpredictable.
a. Predictable incident pain: Something identifiable, such as movement,
predictably causes the pain.
b. Unpredictable incident pain: Occurrence of pain is unpredictable and
may be caused by events such as bladder spasm. This pain occurs
spontaneously. - Idiopathic pain: Cause is not readily identifiable.
- End-of-dose pain: An increase in baseline pain that occurs prior to a scheduled dose of around-the-clock analgesic. Onset is usually gradual, and duration may be longer than that of incident or idiopathic pain.
what is pain tolerance
the greatest level of pain an individual is prepared to endure in a given situation
