Physiology of Pain Flashcards
(37 cards)
pain may enhace disability?
yes – with chronic pain
PAIN accronym
P - pattern - onset / duration
A - area localization - local refer, multiple?
I- intensity - level of pain / rating scale
N - nature - description of how pain feels to patient
nocicpetive pain
pain caused by activation of peripheral nerve fibers by harmful noxious stimuli
neuropathic pain
pain caused by damage to the nervous system 0 burning , tingling, or pins and needless dx of pain
Von Frey Dichotomy?
peripheral nervous system is “perception” component of pain
CNS : “reaction” component of pain
perception component of pain
the stimulation of specific nocicpetors located on free nerve endings (mechnical distortion, heat, or cold)
initiates an action potential - passes along the trigeminal nerve pathways to the nucleaus caudalis within the brain stem
action potentials travel along these primary nociceptor neurons transer the information through synapses to the SPINOTHALAMIC and TRIGEMINOTHALAMIC tracts that sen the information to more rostral areas of the brain
*nociceptor activation
transmission of AP
interpretation and initial interpretation
spinothalamic
pain temp and crude touch
posterior column
position . prorioception, vibration, pressure and fine tough
(dorsal column)
reactive component of pain
the higher brain centers provide the reactive component of noxious stimulaiton
- information is processed- rapidly - indicating the severity, duration, and location of stimulus
also elicits emotional reactions. autonomic responses, and escape behaviors
*emotional overtones, activation of autonomic nervous system, avoidance / escape responses
light myelinated a delta fibers
faster
intitate reflex responses (brainstems)
initiate escape responses (cerebral cortex)
pain interpreted as well localized, sharp or bright quality
pain, heat, cold
smaller unmyelinated C fibers
carried along more diffuse pathways
create what is referred to as secondary pain (diffuse, dull, aching, and or burning)
autonomic
mediators
prostaglandins - can cause free nerve endings to become more reactive to stimulation
severe pain may be attentuated as a result of the erlease of endogenous morphine- like substance - like endorphins and enkepalins – which can inhibit pain pathways via morphine receptors in the brain and spinal cord
wind up or central sensitization
greater or more prolonged pain if pain is not initially managed adequatily – due to plasticity in brain in its pain pathways
gate control theory
theory of pain modulation provides support for pain relief therapies action on different parts of the nervous system
spinal cord dorsal horn cells act as a gate - able to open or close to prevent nocioceptive impulses from reaching the brain
OPENING = influenced by a -delta and C fibers
CLOSING = influenced by a -alpha and a - beta fibers - along with other neuro structures
ABC’s of pain
perception of pain results from a complex interaction among the following:
AFFECTIVE - emotional factors that can effect the experience of pain
BEHAVIORAL = actions taken to express or control pain
COGNITIVE = the meaning, beleifs and attitude towards pain
treating acute dental pain with OMT patient
dental practioner should clarify preferred acute pain management strategies with patients OMT provider or primary pain specialist whenever possible
- prevent compications of combined opioid analgesic therapy
- prevent under tx of pain in the dental patient
pts with hx of opiod addiction fall into four categories
- opiod addict - revocery bases with no pharm
- tx with OMT
- naltrexone therapy
- opioids still using
dosing of the OMT therapy of methadone or buprenorphine?
do NOT adequately control acute pain
- sufficient evidence to suggest that patients receiving chronic opiod medications, in some cases, may have hyperalgesia
- pts receiving chronic opiods usually have some cross-tolerance to the sedative, euphoric, respiratory depressant, and analgesic effects of other opiods
what may be a greater stresser for pts with OMT relapse?
limited but information suggests that inadequate tx of acute pain, onset of physiologic withdrawl or anticipatory anxiety in OMT patients – greater stressor for relpase
how to manage OMT patient - basic
should be continued on OMT or be prescribes an equivalent opiod daily dosage regimn to prevent physiologic withdrawl and disruption o their opiod addiction recovery
event of respiratory depression without cardiac or hemodynamic compromise?
patients should receive respiratory support as opposed to reversal treatemnt with naloxone due to the liklihood of inducing fulminant opiod withdrawl
buprenorphine managemnt
may benefit by dividing the total daily dose of buprenorphine into 3-4 doses throughout day to prvide a better analgesic coverage
in addition to daily dose - think about sublingual low dose (2mg) at 4-6 hr intervals may help with acute managment
acute pain managment in patients receiving naltrexone therapy
receieving daily naltrexone therapy should have their nelrexone discontinued ideally 72 HOURS BEFORE NAY PLANNED SURGICAL OR INTERVENTIONAL PROCEDURES where opioids may be encessary for managment of moderate to severe acute pain
patients receiving depot naltrexone
clinical dilemma
- high dose of opioids are required ot overcome the i-receptor blockade by naltrexone
- patients need continous respiratory monitoring for respiratory depression and oversedation at an appropriate tx facility due to inceased doses of opioids to achieve adequate analgesia
