Pain Flashcards
Cost of pain
$10 billion
Congenital Pain Insensitivity
Incapable of experiencing pain
Neuralgia
Pain along nerve of the body
Trigeminal Neuralgia
Pain along nerve in the face
- Provoked by innocuous stimuli
Causalgia
Severe burning pain occurring long after a wound has healed
Beecher
Severely wounded soldiers, only 25% requested morphine
Surgical patients, 80% requested morphine
Different meanings of pain– soldiers got to go home, patients would be inconvienced
Perceived Control of Pain
When people feel in control they will experience less pain
Focus of Attention
People report less pain when they are highly distracted
Guided imagery
Distraction component, relaxation, reinterpretation
Body experiences tissue damage
Algogenic substances released at damage site, free nerve endings are stimulated by damaged area
3 types of nociceptors
A-delta
C
A-Beta
A-delta fibers
Myelinated and fast
Associated with sharp, localized, distinct pain sensations
C-Fibers
Unmyelinated and slow
Dull, burning or aching pains
A-Beta fibers
Myelinated and fast
Innocuous/ harmless sensations– rubbing, scratching
Dorsal horn activity
Fibers release substance P which activates transmission cells to send pain messages to brain
Transmission cells
Can be activated or inhibited depending on if gate is open or closed
Where is the gating mechanism located
Substantia gelatinosa (dorsal horn)
Open gate
Substance P activates transmission sells and pain messages are sent to brain
Closed gate
Transmission cells are inhibited and no pain messages are sent
Pain fiber activity that opens the gate
A-delta and C fibers
Pain fibre activity that closes the gate
A- Beta: Why rubbing your skin during pain stops it
Psych factors that open the gate
Anxiety, depression, boredom, cognitive evaluations
Psych factors that close the gate
Happiness, optimism, relaxation, cognitive evaluations
Stimulation produced analgesia
Stimulating the periaqueductal gray area closes the gate and inhibits pain
Reynolds
Rats stimulated PAG did not show pain from electric shocks and abdominal surgery
Endogenous Opiates
Stimulating PAG releases them, inhibit pain fibers from releasing substance P– transmission cells are not activated and no messages are sent
Gender with more pain sensitivity
Women
Race with lower pain tolerance
Asian
4 pain behaviours
Facial and audible expression
Distortions of posture or gait
Negative Affect
Avoidance of activity
3 types of pain perception
1) Mechanical nociception
Thermal damage
Polymodal nociception
Mechanical Nocicpetion
Perception resulting from mechanical tissue damage
Polymodal nociception
Pain that triggers chemical reactions from tissue damage
Nociceptors
Sense injury, release chemical messengers which conduct to spinal cord and cerebral cortex
Neuromatrix
Networks of neurons create a felt representation of unified physical self– genetically determined but changes with experience
Neurosignature
Neuromatrix generates nerve impulses continuously that are processes into a character pattern– unique signature for every experience
3 types of endogenous opioid peptides
Beta- endorphins
Proenkephalin
Prodynorphins
Beta-endorphins
Produce peptides that project to limbic system and brain stem
Proenkephalin
Widespread neuronal, endocrine and CNS distributions
Prodynorphins
Found in gut, posterior pituitary and brain
Acute Pain
Results from specific injury, disappears when tissue heals (within 6 months)
Chronic
Begins with an acute episode but does not decrease with treatment or time
Chronic Benign
Persists longer than 6 months and is intractable to treatment
Recurrent Acute
Series of intermittent episodes that are acute in character and persist for more than 6 months
Chronic Progressive
Perists longer than 6 months and increases with severity over time
Counterirritation
Inhibiting pain in one area by mildly irritating another
Biofeedback
Make patient aware of body processes to learn how to alter behaviour and thoughts to manage pain
