Quick Reference Guide
Quick Reference Guide
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Ultrasound-guided lumbar puncture
The key facts on one page.
| Topic | Key points | Source |
|---|---|---|
| Meningitis | Do not delay antibiotics. Image first only for NICE contraindications: space-occupying lesion risk, new focal signs or seizures, abnormal pupils, GCS 9 or less, falling consciousness | NICE NG240 |
| SAH | CT negative within 6 h: do not routinely LP. CT negative after 6 h: consider LP, at least 12 h after onset; spectrophotometry | NICE NG228 |
| Bleeding risk | Platelets, clotting, anticoagulants and antiplatelets: follow local thresholds and timings | Association of Anaesthetists 2013 |
| Level | Cord usually ends at L1 to L2. Use L3/4 or L4/5. Intercristal line is about L4 to L4/5 but often misjudged | |
| Ultrasound | Curvilinear probe. Transverse: spinous process tip and shadow = midline. Paramedian: count up from the sacrum. Measure depth to the posterior complex; mark a cross | BMJ 2013 |
| Position | Lateral for opening pressure. Sitting can help when landmarks are hard | |
| Needle | Atraumatic (pencil-point) needle; length from the measured depth; stylet in when advancing and before withdrawing | BMJ 2018 |
| Skin | 0.5% chlorhexidine in alcohol for neuraxial procedures, allowed to dry | Association of Anaesthetists 2014 |
| Opening pressure | Lying on the side, relaxed; 60 to 200 mm CSF generally normal (up to 250 mm in some overweight people) | Doherty 2014 |
| Samples | Number in order of collection; fluoride tube with paired blood glucose; SAH: last sample, protected from light, by hand | UK NEQAS 2008 |
Stop and get help
- A NICE contraindication to lumbar puncture without imaging
- Sharp shooting leg pain that persists
- You reach your trust's limit on attempts
- After the procedure: new leg weakness, numbness, or bladder or bowel problems
Sources for this chapter
- National Institute for Health and Care Excellence. Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management (NG240) (2024), recommendations 1.4.6 to 1.4.12
- National Institute for Health and Care Excellence. Subarachnoid haemorrhage caused by a ruptured aneurysm: diagnosis and management (NG228) (2022), recommendations 1.1.7 to 1.1.15
- Harrop-Griffiths W, Cook T, Gill H, et al. Regional anaesthesia and patients with abnormalities of coagulation (Association of Anaesthetists, OAA and RA-UK). Anaesthesia 2013;68:966–972
- Shaikh F, Brzezinski J, Alexander S, et al. Ultrasound imaging for lumbar punctures and epidural catheterisations: systematic review and meta-analysis. BMJ 2013;346:f1720
- Rochwerg B, Almenawer SA, Siemieniuk RAC, et al. Atraumatic (pencil-point) versus conventional needles for lumbar puncture: a clinical practice guideline. BMJ 2018;361:k1920
- Association of Anaesthetists. Safety guideline: skin antisepsis for central neuraxial blockade. Anaesthesia 2014;69:1279–1286
- Doherty CM, Forbes RB. Diagnostic lumbar puncture. Ulster Med J 2014;83(2):93–102
- Cruickshank A, Auld P, Beetham R, et al. Revised national guidelines for analysis of cerebrospinal fluid for bilirubin in suspected subarachnoid haemorrhage. Ann Clin Biochem 2008;45:238–244
These notes support a simulation course. They do not replace your trust's lumbar puncture policy, the manufacturer's instructions for your equipment, or supervised workplace training and sign-off.
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