ID                           Lumbar Puncture
                             ===============

see also:  <LP.TXT>
see also:  <SpinalHA.TXT>

þ First LP
 - LP first done in 1891 by Quicke to relieve increased ICP.

þ Normal Opening Pressure
 - 80-180 mm H2O
 - (higher if patient anxious or tense; note on chart)

þ Side effects:
 - Herniation
 - bleeding
 - paresthesias
 - CN palsy
 - Epidermoid tumor (months later patient develops pain; patient gets skin cells
   into CNS from not using stylet)
 - Headache

þ LP Rules
 - Always check for papilledema
 - check CT first if suspicious of mass lesion
 - treat with antibiotics presumptively if necessary
 - check for anticoagulant use
 - take out only 4cc (2cc in kids)
 - to avoid epidermoid tumors, use a stylet.

þ Correcting WBC for bloody tap
 - normal WBC to RBC ratio 5x10^3 WBC / 5x10^6 RBC, or 1/1000
 - can use this expected ratio to evaluate bloody tap; scale appropriately.
 - divide CSF WBC by RBC and multiply by 5000 and you get the "equivalent" WBC
   (in 10^3) that you can compare to "normal" CBC WBC counts.