Prodigy- neuraxials Flashcards
Explain where the spinal cord starts, ends, whats below it
Starts at the foramen magnum → L1-L2
Ends as a tapered segment: conus medullaris
Below that is the cauda equina - bundle of nerve fibers that branch off and extend from L1-S5
What is the sacral hiatus?
An opening where the last sacral lamina is which is not completely closed
What colums transmit light touch and proprioception
Pain and temp?
What columns contain neurons that eventually enter the sympathetic chain?
dorsal colums
Lateral spinothalmic tract
lateral grey columns
What does the ARrtery of Adamkiewicz supply blood to?
The anterior 2/3 of the spinal cord
*Anterior Spinal Artery syndrome can result from clamping of the aorta and results in
→flaccid paralysis of lower extremities and blowel & bladder dysfunction
→ sensation is unchanged
where are the posterior spinal arteries derived from?
what do they supply?
the posterior cerebral circulation
posterior 1/3 of the spinal cord
Normal CSF production in ml/hr
how much per day
how much at any given time
21ml/hr
over 1/2 L /day
150ml @ any given time
What forms CSF?
choroid plexuses in the ventricles
What 2 drugs we use increases the absoprtion rate of CSF?
What increases vs decreases CSF secretion (1 each)
isoflurane (no effect on secretion)
→think blood:gas 143 , i love you, i want to absorb you
Fentanyl
→junkies want to absorb all the fentanyl
Des → increases secretion (adds fire to the flame)
Etomidate→ decreases secretion (less CSF pressure, makes your wanna vomit [evomidate]
Why can a healthy patient become solument after a spinal?
Bc it reduces the amount of sensory input htat goes to the reticular activating system (responsible for maintaining consciousness)
- less stimulation to that area, less awake
Why might you not want to do a spinal in someone who is already in extreme pain or who is under the influence of a lot of opioids or other CNS depressants?
the painful stimulus might be the primary sensory input maintaining their wakefulness and once the spinal takes effect and the pain is eleminated, the effects of their meds could result in CNS depression or unconsciousness
Where does the GI tract receive parasympathetic vs sympathetic innervation from?
what happens with neuraxial anesthesia nd the gut?
parasympathatic = vagus nerve
sympathetic = T5- L2
The sympathetic block leads to unopposed parasympahtic stimulation
→ general contraction of bowel
→ increased blood flow to bowel
→ increased peristalsis
T/f: neuraxial anesthesia preserves shivering and vasoconstriction in response to heat loss
false- it’s inhibited - throw a damn bair hugger on them
What can result from not letting the antiseptic solution dry before puncturing the skin?
Arachnoiditis
What are the two pops appreciated with a spinal anesthetic?
- ligamentum flavum
- dura
Why isnt a confinous spinal infusion used for labor?
risk of dural puncture (PDPH?) like your obviously puncturing the dura for a spinal…
T/F: height, weight, and BMI have little effect on the spread of local anesthetics injected into the subarachnoid space
True
i think the exception is if they are really tall or really short; like >6 foot, <5 foot