Lumbar Puncture Flashcards
where is an LP done
L3-4/L4-5
4 diseases it is used to investigate
meningitis, subarachnoid haemorrhage, malignancy, MS
would you do an LP in someone with raised ICP
no
5 contraindications of CSF
CVS/Resp instability infection at puncture site unstable bleeding disorder raised ICP chiari malformations
why is an LP done at L3-4/L-5
the spinal cord is terminated at this point (L1-2) and good intervertebral space
name of position you do an LP in
lateral decubitus
what secondary test can be done on LP
manometry - measure the CSF pressure
common lab tests of CSF
culture, stain, glucose, protein, cell count
position in an infant LP
sitting holding hand and feet together
true/false CSF pressure can be measured accurately in the sitting position
false - only in lateral decubitus
which of the following is not a complication of an LP:
a. back pain
b. stroke
c. headache
d. infection
e. subarachnoid epidermal cyst
f. brainstem herniation (coning)
g. nerve trauma
b. stroke
who are LP headaches most common in
young adult females, lower BMI, PMH
treatment of spinal headache
hydration and IV caffeine and epidural blood patch
what does nerve trauma present like
back pain, electric shock
if something goes wrong in an LP, what is pretty much always the best thing to do
withdraw the needle immediately
features of coning
altered mental status, followed by cranial nerve defects, cushing triad
what is the cushing’s triad
irregular decreased resp rate, bradycardia, systolic hypertension
what is the cushing’s triad a sign of
coning
what is coning
the brainstem herniating through foramen magnum
in what LP complication should you raise the bed to 45 degrees to improve venous return from brain
coning (brainstem herniation)
general management of coning
fluids, intubation and hyperventilate, bed to 30-45 degrees
what is an epidermal inclusion cyst
when a core of skin is driven by the stylet into the spinal space
what is the Munro-Kelly doctrine
pressure volume relationship between ICP, CSF volume, blood volume, brain volume. Treats situation as a closed box
