21/12/2025
Lumbar puncture (LP) – also called a spinal tap
*is a medical procedure used to collect cerebrospinal fluid (CSF) from the lower back for diagnosis or treatment.
☑️ Purpose / Indications
Used to:
⚫ Diagnose meningitis (bacterial, viral, TB, fungal)
⚫ Diagnose subarachnoid hemorrhage (when CT is normal)
⚫Evaluate neurological disorders (e.g. multiple sclerosis, Guillain-Barré syndrome)
⚫ Measure CSF opening pressure
⚫Administer intrathecal drugs (antibiotics, chemotherapy, spinal anesthesia)
📍 Site
⚫Needle inserted between L3–L4 or L4–L5
⚫Below the end of the spinal cord (safer area)
🧍♂️ Patient Position
⚫Lateral decubitus (lying on side, knees flexed) → best for pressure measurement
OR
Sitting position, leaning forward
🧪 CSF Tests Commonly Done
⚫Appearance (clear, cloudy, bloody)
⚫Cell count
⚫Protein
⚫Glucose
⚫Culture & sensitivity
⚫Special tests (e.g. TB, cryptococcal antigen)
⚠️ Complications
Post–lumbar puncture headache (most common)
⚫Back pain
⚫Infection
⚫Bleeding
⚫Nerve irritation (usually temporary)
☑️Lumbar Puncture
⚫Lying Position
⚫Sitting Position
Procedure Site
⚫Needle inserted between L3–L4 or L4–L5
⚫Below the spinal cord termination (L1–L2)
