Acute Pain Management Flashcards
(24 cards)
- Common sources and key features of acute pain?
sources: surgery, trauma, childbirth, acute disease states, medical procedures.
features: proportional to damage, reflects activation of nociceptors or sensitized central neurons; often associated with autonomic hyperactivity and protective reflexes (splinting, muscle spasm)
- Methods of assessment of acute pain?
- subjective scales both at rest & w/ activity
- ask about intensity, , onset, duration and location
- reassessment after analgesic, interventions and timed intervals
- not reasonable to completely resolve pain, goals to comfort at rest, ambulating and with cough, ideal no interference with mood or sleeping
- Hormonal response to acute pain.
increased ACTH–> protein catabolism
increased cortisol –> lipolysis
increased glucagon/epi, decreased insulin–> decreased protein anabolism
decreased testosterone and insulin–> decreased protein anabolism
increased cortisol, catecholamines and angiotensin II–> CHF, vasoconstriction, increased contractility and HR
increased aldosterone and ADH–> salt and water retension
- Physiologic stress response to acute pain.
CV- Tachy, HTN, increased SVR, increased myocardial O2 consuption, arrhythmogenic, altered regional blood flow
Pulm- surgery reduces VC, TV, RV< FRC and FEV1, causes V/Q mismatch; increased abd down
GI/GU- ileus, N, V, hypomobility or urethra and bladder
Immune: lymphopenia, depression of reticuloendothelial system, leukocytosis, reduced killer T cell
Coagulation: increased platelet adhesion, increased fibrinogen, diminished fibrinolysis,, activation of coag
general: immobility, insomnia, anxiety, fatigue, weakness, feeling helpless
- Role of opioids in acute pain management.
used for moderate to severe pain, ***more effective in nociceptive pain (over neuropathic)
effects: analgesia, sedation, resp depression, euphoria/dysphoria/hallucinations, vasodilation, bradycardia, myocardial depression, miosis, NV, delayed gastric emptying, smooth muscle spasm (constipation, urinary retention, biliary spasm, sk muscle rigiditiy and pruritis
- Chronic physiologic effects opioids.
tolerance- PCA with basal therapy may be necessary; SE faster NV, impairment, sedation and resp depr v slower constipation and miosis
withdrawal- physiologic dependence
addiction- pattern of behaviors
- Commonly used narcotics: morphine
slow onset, metabolized by liver
avoid in renal failure, metabolite3-glucoronide
causes histamine release
slow release prep unsuitable for acute pain
- Commonly used narcotics: hydromorphone
fewer adverse SE than morphine
5-7x more potent than morphine
metabolite 3-glucorinde (no analgesic, neurosecitatory properties
- Commonly used narcotics: Meperidine
more lipid soluble than morphine, 1/10 as potent
fast analgesic effect, short duration, +/- endorphin effect
atropine like side effects
large doses can cause myocardial depression and orthostatic hypotension
AVOID with MAO-Is
generally only given for shivering post procedure metabolite normeperidene (CNS excitation, less potent analgesia, long half life (15-20hr)
avoid background infusion rate
- Common narcotics: fentanyl
highly lipid soluble, rapid onset, short duration
NO histamine release
inactive metabolites
transdermal contraindicated in acute pain
- Common narcotics: mixed opioid agonists/antagonists (nubain)
kappa opioid receptors, limited resp depression
may precipitate withdrawal, lower abuse potential
attenuates opioid induced side effects w/o reversing analgesia
- Common narcotics: tramadol
Avoid concurrent MAOIs and SSRIs no histamine release less resp depression no adverse effects on HR, LVF, CI increase seizure risk may precipitate withdrawal in dependent patients
- Benefits/ contraindications of PCA
benefits: peaks and valleys avoided, better satisfaction
***contra: untrained providers, patient rejection, inability to comprehend technique (age or cognitive impairment)
role in acute pain is to “titrate” opioid plasma concentration near to the “min effect, analgesic concentration” (MEAC)
- Features of adjuncts: NSAIDS
stops PGE2 injur/ inflammation
no reduction in gastric motility
***SE: gastropathy, inhibition of platelet function, renal effects, inhibits bone osteogenesis
(ketorolac is the only parenteral NSAID, no preoperative use, 5 d max)
COX-2 inhibitors can be used preoperatively (does not impair homeostasis)
- Features of adjuncts: ketamine
NMDA receptor antagonist
may reduce pre-operative nausea vomiting
may have preemptive analgesia effect
- Features of adjuncts: alpha 2 antagonists (clonidine and dexmedetomindine)
stimulate presynaptic alpha 2 receptors
SE: Low BP, bradycardia, dry mouth, sedation
- Features of adjuncts: gabapentin
SE: dizziness and somnolence
preop dose may reduce post opioid requirements
- Neuroaxial analgesia: mechanism
epidural: drug likely crosses dura and affects spinal nerves blocking pain, temp, muscle spindle tone, touch, pressure and motor/proprioception (in that order)
- Neuroaxial analgesia: SE
spreading to further spinal segments
respiratory suppression, N,V, pruritus, urinary retention, epidural abscess/hematoma, post dural puncture headache
- Neuroaxial analgesia: benefits and contraindications
benefits: minimize opioid-related SE, toxicity uncommon
contraindications: pt refusal, coag disorder, infection at site, true allergy
8 What is the role of peripheral nerve blocks in acute surgical pain management?
used for neck, trunk or extremity
- Challenges in opioid tolerant patients
chronic use leads to some degree of tolerance, resultant pain can lead to confrontational behavior when tx those with adiction
- Strategies treating in opioid tolerant patients?
multimodal therapy
IVPCA when indicated
avoid short acting PRN formulations
provide analgesia while managing withdrawal
treat comorbiditis (depression)
manage aberrant drug taking behavior
Bonus, what do you inflate the ET tube cuff and LMA cuff to?
ET tube cuff - 5-10 cc air
LMA 20-40cc air
