Lumbar puncture

Contraindications

1. Infection at LP site
2. Platelet count <20K
   1. Platelet counts >50K are safe for LP
3. INR >1.5
4. Heparin administration in past 24hr
5. Hemophilia, von Willebrand disease, other coagulopathies
6. Trauma to lumbar vertebrae

See also CT Before Lumbar Puncture

Procedure

1. Sterile prep L3-L4 and L4-L5 interspaces; prepare and confirm correct tubes in numerical order
2. Positioning
   1. Pt on side: able to measure opening pressure
   2. Pt sitting: helpful for difficult habitus, but must move pt to measure opening pressure
3. Needle selection
   1. 3.5 in atraumatic 22ga needle is ideal
   2. Needle >20ga almost doubles incidence of post-LP headache
4. Anesthetize both superficial skin as well as along intended path of LP needle
5. Insert needle with bevel facing the ceiling (if pt is on side)
6. Opening pressure should be measured with pt on side with legs extended
7. Collect 1mL in each tube

Complications

1. Post-Lumbar Puncture Headache
2. Spinal Epidural Hematoma

Diagnosis

See CSF Studies

See Also

• Meningitis

Source

• Tintinalli
• Hasbun, R. et al, (Yale), NEJM, Dec 13, 2001.