Multimodal Pain Management Flashcards
What are the different types of a pain stimulus?
mechanical, thermal, chemical, sensitizing hormones
What are the 2 pathways from free nerve endings to CNS?
Fast (sharp) and Slow (chronic)
Describe fast pain signals.
sharp, to spinal cord by small alpha and delta fibers, velocities 6-30 m/sec, mechanical and thermal
Describe slow pain signals.
chronic, to spinal cord by C fibers, velocities 0.5-2 m/sec, chemical and/or persistent mechanical or thermal
What is multimodal pain management?
use of multiple classes of analgesic drugs to act on different receptors along the pain pathway. Drugs act synergistically to enhance analgesia and reduce side effects
What are the 4 elements of pain processing?
transduction–stimuli converted to action potential
transmission–AP conducted through nervous system
modulation–altering afferent transmission along pain pathway
perception–pain recognized and interpreted by the brain
Which element of pain processing should multimodal pain management try to affect?
all 4 elements
What type of receptors are opioid receptors and where are they located?
g-protein coupled, brain/spine/periphery
What is biased agonism?
distinct ligands can bind to g-protein coupled receptor activating differential signaling pathways. Same receptor but different physiologic outcomes. Activates a subset of signaling pathway. Goal to activate analgesic action without side effects.
What are the pharmacokinetics of NSAIDS?
absorbed completely with minimal first pass metabolism, tightly protein bound, small volume of distribution
What is the primary effect of NSAIDS?
inhibition of cyclooxygenase (COX) preventing transformation of arachidonic acid to prostaglandins
What is the fastest to slowest absorption by site?
intercostal->caudal epidural->lumbar epidural->brachial plexus->subq tissue
What are indications for regional/neuraxial analgesia?
acute post surgical pain, severe chronic pain
What are the physiologic effects of neuraxials?
blockade of sympathetic fibers peripheral T1-L2, cardiac T1-T4, splanchnic T6-L1. unopposed parasympathetic stimulation
What are contraindications to regional/neuraxial?
Pt refusal (only absolute), sepsis/infection, allergy to meds, inability to position, preexisting neuropathy, spinal stenosis, previous spine surgery, multiple sclerosis, spina bifida, aortic stenosis, coagulopathy
