Lumbar puncture
Contraindications
- Infection at LP site
- Platelet count <20K
- Platelet counts >50K are safe for LP
- INR >1.5
- Heparin administration in past 24hr
- Hemophilia, von Willebrand disease, other coagulopathies
- Trauma to lumbar vertebrae
See also CT Before Lumbar Puncture
Procedure
- Sterile prep L3-L4 and L4-L5 interspaces; prepare and confirm correct tubes in numerical order
- Positioning
- Pt on side: able to measure opening pressure
- Pt sitting: helpful for difficult habitus, but must move pt to measure opening pressure
- Needle selection
- 3.5 in atraumatic 22ga needle is ideal
- Needle >20ga almost doubles incidence of post-LP headache
- Anesthetize both superficial skin as well as along intended path of LP needle
- Insert needle with bevel facing the ceiling (if pt is on side)
- Opening pressure should be measured with pt on side with legs extended
- Collect 1mL in each tube
Complications
- Post-Lumbar Puncture Headache
- Spinal Epidural Hematoma
Diagnosis
See CSF Studies
See Also
Source
- Tintinalli
- Hasbun, R. et al, (Yale), NEJM, Dec 13, 2001.