DRUGS FOR THE CONTROL OF PAIN Flashcards
how are pain an nocioception a different phenomena?
pain cannot be inferred soley from activity
what is nocioception?
perception or sensation of pain
what is pain?
unpleasant sensory and emotional experience associated with, actual or potential damage
what is a numeric rating score (NRS)?
-rating pain from 1-10
-used in ppl above the age of 8
-less than 4 (mild pain)
-4-6 (moderate pain)
-7-10 (severe pain)
-0 being no pain, 10 being the worst pain
what are physical signs of pain?
facial expressions, leg movement, activity crying, consolability (FLACC)
the FACES scale is used on what age group?
children (4-18)
why may the FACES pain scale not be accurate?
kids want the nurse/doctor to like them (positive)
-don’t want to see winy
-so they may put a lower number on the scale for this reason
what is acute pain?
-comes on quick
-intense pain that occurs over a defined period of time (from injury to recovery/repair)
-abrupt onset, and brief duration; pain intensity declines as healing begins, or the pain stimulus is removed
what is chronic pain?
-pain that persists longer than 6 months, interferes with daily activities, high incidence of depression
-further divided into non-malignant or malignant (cancer pain)
why should you look at mental health before treating pain?
depression can cause pain (hopelessness)
what is nociceptor pain?
nocioceptors; sensory nerve receptors that initiate pain transmission when stimulated
- associated with tissue injury, somatic pain, sharp localized pain or visceral pain, generalized dull, throbbing/aching pain - respond well to analgesics
what it neuropathic pain?
associated with injury or irritation to nerve tissue, burning, shooting or numbing pain, cause can be difficult to determine
-respond poorly to traditional analgesics
acute pain - injury to experience
- peripheral tissue injury, surgical or trauma
- pain transduction, release of tissue, humeral mediators
- pain transmission, afferent neural transmission
- pain transmission, spinal cord receptors (substantia gelatinosa)
- reflex sympathetic response to the painful stimulus
- pain perception an modulation, transmission to the brain (spine-thalamic tract)
what are the 5 steps of pain physiology?
- transduction: trauma stimulates nociceptors
- transmission in peripheral nerves: pain impulse travels along peripheral nerves to the spinal cord along A an C fibres
- transmission in spinal tracts: pain impulse continues along ascending tracts of the spinal cord
- perception: cerebral cortex recognizes pain stimulus
- modulation: limbic system reacts to pain. Modulating signals sent along descending tracts of spinal cord
what does Tylenol 3 contain?
acetaminophen, codeine (an opioid) an caffeine (enhances absorption)
what does Vicodin contain?
hydrocodone (opioid) an acetaminophen
what are NSAID’s?
- administered to relieve mild to moderate pain, inflammation an fever
- inhibits pain mediators at nociceptor level
- inhibits the inflammatory response to tissue injury
- inhibits activity of cyclooxygenase; enzyme converts arachidonic acid into the inflammatory an pain inducing prostaglandins
acetaminophen
- mechanism of action not completely understood
- does not do anything for inflammation
- binds to CB1
- activity at CB1 an TRPV1 receptors located in the brain
arachadonial esters in membranes are released and converted to what?
arachidonic acid
NSAID’s can reduce opioid requirement by what percentage?
30%
what are endogenous opioids?
- modulate the transmission of pain to the brain an spinal cord
- endogenous opioids include beta endorphins and enkephalins
function of postsynaptic neurons
open K+ channels, causing membrane hyper polarization, inhibiting neuronal activity
function of presynaptic neurons
closes Ca+ channels, inhibiting release of excitatory neurotransmitters; Ach, Substance P, and glutamate
opioids exert analgesic effects via stimulation of what?
mu and kappa opioid receptors in the brain an spinal cord
