pain physiology

Question 1

nociception of pain has 4 stages

Answer 1

transduction
transmission
perception
modulation

Question 2

transduction

Answer 2

nociceptors convert painful stimuli to neuronal action potentials.
-physical and chemical mediators alter the membrane potential of the pain receptor

Question 3

chemical mediators of transduction

Answer 3

K, H, lactate, histamine, serotonin, bradykinins, prostaglandins

Question 4

Transduction and NSAIDS

Answer 4

cyclooxygenase is needed to convert arachidonic acid to prostaglandin form. Which can then be used as a chemical mediator for pain.
NSAIDs block cycloosygenase, unable to convert arachidonic acid

Question 5

transmission

Answer 5

action potentials transmitted to the CNS by means of specialized sensory fibers

Question 6

sensory fibers

Answer 6

a fibers

c fibers

Question 7

a fibers

Answer 7

mylinated
10% of pain fibers
fast traveling
sharp, stinging, cutting, pinching

Question 8

c fibers

Answer 8

unmyelinated
90% of pain fibers
slower traveling
dull, burning, aching

Question 9

trasmission in spinal cord

Answer 9

enter through the dorsal horn, synapse on interneurones, cross the cord and project centrally in the anterolateral tract

Question 10

anterolateral tract has 2 divisions

Answer 10

neospinothalmic tract

paleospinothalamic tract

Question 11

neospinothalmic tract

Answer 11

carries A fiber input, projects to thalamus and then sensory cortex

Question 12

paleospinothalmic tract

Answer 12

carries C fiber input, protects diffusely to the reticular formation, mesencephalon, and thalamus

Question 13

sensory dermatome

Answer 13

brain can localize pain sensation to a particular part of the body because nociceptor pathways are kept in specific anatomic order in the cord and somatosensory cortex

Question 14

perception

Answer 14

result of neural processing of pain sensations in the brain

Question 15

pain threshold

Answer 15

level beyond which a pain stimulation causes pain:

-similar between people

Question 16

pain tolerance

Answer 16

degree of pain an individual is willing to bear before seeking relief
- differs with people

Question 17

modulation

Answer 17

alters synaptic transmission of pain signals
occurs within
- peripheral nociceptors
- spinal cord
- brain
– descending pathways from brain release neurotransmitters that can inhibit synaptic transmission of pain signals

Question 18

endogenous opiods

Answer 18

enkephalins, endorphins
play important role in pain modulation
-have different effects depending on the types of receptors they activate

Question 19

receptors with analgesic activities

Answer 19

mu (brain)

kappa (spinal cord)

Question 20

gate control theory

Answer 20

rubbing, pressing, or shaking the painful area may reduce pain
-impulses carried by A fibers can close the gate on nociceptor impulses; pain signals would be blocked

Question 21

types of pain

Answer 21

physiologic pain

pathologic pain

Question 22

physiologic pain

Answer 22

when tissue injury has occured

Question 23

pathologic pain

Answer 23

occurs after tissue injury, but longterm changes occur along sensory pathways

Question 24

classification of pain

Answer 24

duration (acute, chronic)
source (cancer, neuropathic, ischemic)
location (referred pattern)

Question 25

Acute pain

Answer 25

results from tissue injury and resolves when the injury heals -less than 3 months

Question 26

S/S acute pain

Answer 26

increase sympathetic activity - increased HR - increased RR - HTN - pallor - sweating - nausea - grimacing - crying or moaning

Question 27

pain relief with acute pain

Answer 27

nonopiod and opiod medicatoins - risk of becoming dependent minimal - try to not use opiods

Question 28

chronic pain

Answer 28

gradual in onset, persists beyond the time for normal healing: 3 months allodynia hyperalgesia

Question 29

Examples of chronic pain

Answer 29

headaches low back pain osteoarthritis fibromyalgia

Question 30

tx of chronic pain

Answer 30

multimodal therapies | opiods are neither safe nor effective

Question 31

fibromyalgia

Answer 31

chronic widespread pain affecting all four extremities

Question 32

fibromyalgia s/s

Answer 32

``` sleep disturbance/insomnia difficulty concentrating fatigue depression irritable bowl syndrome ```

Question 33

tx of fibromyalgia

Answer 33

antidepressant restore sleep patterns regular exercise pregabalin to target pain pathways

Question 34

cancer pain

Answer 34

infiltration of organs compression of structures by an expanding tumor cancer treatments

Question 35

cancer pain s/s

Answer 35

mixture of sympathetic NS and behavioral changes

Question 36

cancer pain tx

Answer 36

multifaceted approace and use of potent meds: opiods

Question 37

neuropathic pain

Answer 37

results from nerve damage or dysfunction constant aching with intermittent burning or shock-like pain results from alteration in any of the stages of nociception

Question 38

neuropathic pain s/s

Answer 38

``` allodynia hyperalgesia atrophy of affected extremity coldness in affected area dystrophic changes - hair loss, shiny skin ```

Question 39

neuropathic pain tx

Answer 39

antidepressants | anticonvulsants

Question 40

allodynia

Answer 40

hurts when it shouldn't | - light touch

Question 41

hyperalgesia

Answer 41

hurts more than it should

Question 42

trigeminal neuralgia

Answer 42

sudden, momentary, excruciating sharp pains along the II and III divisions of the trigeminal nerve compression of nerve causing demyelination and irritation

Question 43

trigeminal neuralgia tx

Answer 43

anticonvulsants surgical nerve decompression gamma knife radiosurgery

Question 44

postherpetic neuralgia

Answer 44

caused by peripheral nerve damage by the reactivation of the latent herpes zoster virus - burning follows a dermatomal pathway - pain lasts > 8 weeks

Question 45

postherpetic neuralgia tx

Answer 45

``` early use of antiviral meds within 72 hours of rash can decrease risk for postherpetic neuralgia liodcain capsaicin crea anticonvulsants antidepressants vaccine ```

Question 46

diabetic neuropathy

Answer 46

damage to the large peripheral nerves by inflammation and demyelination

Question 47

diabetic neuropathy s/s

Answer 47

burning pain numbness, tingling weakness loss of vibratory sense and proprioception

Question 48

diabetic neuropathy tx

Answer 48

pt education for foot care and glucose control antidepressants anticonvulsants

Question 49

ischemic pain

Answer 49

sudden or profound loss of blood flow chronic ischemic pain associated with atherosclerosis; intermittent claudication - pain with activity and alleviated with rest activates inflammatory response

Question 50

ischemic pain s/s

Answer 50

aching burning tingling

Question 51

ischemic pain tx

Answer 51

``` improving blood flow and reducing tissue hypoxia wt loss smoking cessation exercise lipid-lowering meds surgical bypass vascular stents ```

Question 52

referred pain

Answer 52

perceived in an area other than the site of injury | result of convergence of visceral nociceptor activity with primary somatic afferents in the posterior horn

Question 53

physiologic responses to pain

Answer 53

``` sympathetic nervous system activation during acute pain leads to -dilated pupils perspiration pallor increased HR and BP increased blood sugar decreased GI motility hypomotility of the bladder increased RR ```

Question 54

Pain in young and elderly

Answer 54

- pain perception doesn't decrease with age, but communication and expression of main may vary - infants have pain perception - inadequate pain treatment in neonates and infants can result in persistent behavioral changes and physical changes in the CNS

Question 55

pain tx modality points

Answer 55

nociception spinal cord brain

Question 56

interrupting peripheral transmission of pain

Answer 56

NSAIDs: dec. prostaglandins local anesthetic agents - blocking sodium influx through fast channels

Question 57

modulating at spinal cord

Answer 57

cutaneous stimulation activates large sensory fibers that block the central progression of nociceptive transmission at the interneurons - TENS - massage - acupuncture - heat/cold - theraeutic touch - epidural and intrathecal analgesia - dorsal column stimulators

Question 58

altering pain perception in brain

Answer 58

``` analgesics: NSAIDs opiods nonpharmacologic - distraction -guided imagery -relaxation -biofeedback -hypnosis ```