CSF sampling via needle insertion into the L3-L4 or L4-L5 interspace.
Indications
- • Suspected meningitis/encephalitis
- • SAH with normal CT
- • Neurological workup
- • Therapeutic (IIH)
- • Intrathecal drug
Contraindications
- ⚠ Raised ICP with mass lesion (imaging first)
- ⚠ Coagulopathy (INR > 1.4, plt < 50)
- ⚠ Overlying infection
- ⚠ Spinal cord compression
Equipment
- • Sterile LP kit
- • Manometer
- • 22-G spinal needle
- • 3 sterile bottles (biochem, cyto, micro)
- • Local anesthetic
Positioning
- • Left lateral fetal position OR sitting, back arched.
Consent
- • Explain indication, benefits, alternatives
- • Explain risks & complications
- • Obtain written/verbal consent as per SOP
- • Document consent
Universal precautions
- • Hand hygiene
- • PPE — gloves, mask, eye protection
- • Aseptic technique
- • Sharps safety
- • Verify patient identity & site
Step-by-step (0/9)
Tap to complete
Tuffier's line — line between iliac crests crosses L4.
Immediate complications
- ⚠ Failed tap
- ⚠ Traumatic tap
- ⚠ Nerve root pain
- ⚠ Cerebral herniation (rare)
Delayed complications
- • Post-LP headache
- • Infection
- • Epidural hematoma
Recognition
- • Positional headache
- • Fever, meningism
Initial management
- • Post-LP headache — fluids, caffeine, blood patch
- • Neurology review if worsening
Prevention
- • Small atraumatic needle
- • Bevel parallel to fibers
Post-procedure observation
- • Neuro obs q1h × 4
Monitoring
- • Headache
- • Fever
Documentation
- • Opening pressure
- • Volume
- • CSF appearance
Patient instructions
- • Report worsening headache, fever, weakness
Educational bedside guide. Perform only under supervision until competent. Follow local SOPs and consent policy.
