LP Flashcards
LP
performed by inserting a hollow needle into the subarachnoid space—-the area that carries CSF between the brain and spinal cord
CSF
Clear fluid that protects spinal cord composed of cells, water, proteins and sugars
What are the indications for perfoming a CT before LP
pt. older then 60 immunocompromised pt. c cns lesions pt. who has had a seizure 1 wk prior to presentations AMS Pt. with focal neurological findings
What is the most common neurologic manifestation of elevated ICP
Papilledema which can lead to blindness
Risk of LP
H/A Infection Numbness/pain Temp Bleeding in spinal canal may cause brain herniation
How to perform LP
Pt. lies on side with chich tucked to chest and kness to abd.
OR
Pt sits on the edge of the bed with arms draped over table positioned in front of pt.
Either postion back is arched, helps widen intervertebral spaces
Sterile proceduce, cleans back with antiseptic soliton plus drape with sterile towels, sterile gloves, anesthetize area, hollow needle bevel up. collect 10 drops in 4 test tubes
Position pt flat on back for 1 hr post procedure, rehydrate pt.
Where does a LP occur
L3-L4 or L4-L5
CSF Normal Values
Opening pressure:
Increase in neutrophils
bacterial meningitis, tubercular meningitis, cerebral abscess, subarachnoid bleed, tumor
increase in lymphocytes
viral, tubercular, fungal, syphilitic meningitis, MS, GB syndrome
Increase in Eosinophils
parasitic meningitis, allergic reaction to radiopaque dyes
Increase in macrophages
tubercular, fungal meningitis, hemorrhage, brain infarction
Increase in protein
infectious or inflammatory disease, meningitis, encephalitis, myelitis, CNS tumor
Decreased Gluscose
Bacterial, inflammatory cells or tumor cell
A CSF glucose level less then 60% of drawn blood glucose level may indicate meningitis or neoplasm
CSF change in color
Hyperbilirubinemia, hyperkarotenemia, melanoma, elevated protein levels= yellowish tinge
Cloudy= increase in WBC or protein
Bacterial Meningitis
Appearance: Clear, cloudy, or purulent
Opening pressure: Elevated (>25 cm H2o
WBC count: >100 cells/μL (>90% PMN); partially treated cases may have as low as 1 WBC/μL
Glucose level: Low (50 mg/dL)
Aseptic Viral Meningitis
Appearance: Clear
Opening pressure: Normal or elevated
WBC count: 10-1000 cells/μL (lymph but PMN early) •
Glucose level: >60% serum glucose (may be low in HSV infection)
Protein level: Elevated (>50 mg/dL)
Fungal Meningitis
Appearance: Clear or cloudy
Opening pressure: Elevated
WBC count: 10-500 cells/μL
Glucose level: Low
Protein level: Elevated
TB
Appearance: Clear or opaque
Opening pressure: Elevated
WBC count: 50-500 cells/μL (early PMN then lymph)
Glucose level: Low
Protein level: Elevated
Subarachnoid Hemorrhage
Appearance: Xanthochromia, bloody, or clear
Opening pressure: Elevated
WBC count: (1 additional WBC per 1000 RBCs is considered normal correction)
Glucose level: Normal
Protein level: Elevated
MS
Appearance: Clear
Opening pressure: Normal
WBC count: 0-20 cells/μL (lymph)
Glucose level: Normal
Protein level: Mildly elevated (45-75 mg/dL)
Guillian Barre Syndrome
Appearance: Clear or xanthochromia
Opening pressure: Normal or elevated
WBC count: Normal or elevated
Glucose level: Normal
Protein level: Elevated
