🧠 CSF WBC Correction (Traumatic LP)
After a traumatic lumbar puncture, the CSF WBC correction removes white cells introduced by admixed blood using the peripheral counts.
A common rule of thumb subtracts roughly 1 WBC per 500–1000 RBC, or uses ~1:700 when the blood count is normal (original synthesis · not guideline verbatim).
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
When to use
Enter CSF white and red cell counts plus peripheral blood WBC and RBC; the tool returns the corrected CSF WBC and the predicted admixed white cells.
How it works
Predicted admixed WBC = CSF RBC × (blood WBC / blood RBC) in matched units; corrected CSF WBC = measured CSF WBC − predicted admixed.
Key points
- A common rule of thumb subtracts roughly 1 WBC per 500–1000 RBC, or uses ~1:700 when the blood count is normal (original synthesis · not guideline verbatim).
- The correction is an estimate; suspected meningitis still rests on glucose/protein, Gram stain, culture, and PCR.
- Differential cytology and a high pretest probability should override a reassuring corrected count.
References
- Greenberg RG, et al. Traumatic lumbar punctures in neonates: test performance of the cerebrospinal fluid white blood cell count. Pediatr Infect Dis J. 2008.
- Mazor SS, et al. Interpretation of traumatic lumbar punctures: who can go home? Pediatrics. 2003.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| CSF white cells | 100 /μL |
|---|---|
| CSF red cells | 10000 /μL |
| Peripheral blood WBC | 10 ×10⁹/L |
| Peripheral blood RBC | 5 ×10¹²/L |
→Corrected CSF WBC80/μL
- Predicted admixed WBC：20 /μL
Frequently asked questions
- What is CSF WBC Correction (Traumatic LP)?
- After a traumatic lumbar puncture, the CSF WBC correction removes white cells introduced by admixed blood using the peripheral counts.
- How is CSF WBC Correction (Traumatic LP) calculated? What is the core formula?
- Predicted admixed WBC = CSF RBC × (blood WBC / blood RBC) in matched units; corrected CSF WBC = measured CSF WBC − predicted admixed.
- When is CSF WBC Correction (Traumatic LP) used?
- Enter CSF white and red cell counts plus peripheral blood WBC and RBC; the tool returns the corrected CSF WBC and the predicted admixed white cells.
- What are the key clinical points for CSF WBC Correction (Traumatic LP)?
- A common rule of thumb subtracts roughly 1 WBC per 500–1000 RBC, or uses ~1:700 when the blood count is normal (original synthesis · not guideline verbatim). The correction is an estimate; suspected meningitis still rests on glucose/protein, Gram stain, culture, and PCR. Differential cytology and a high pretest probability should override a reassuring corrected count.
- What are the limits and cautions when using CSF WBC Correction (Traumatic LP)?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is CSF WBC Correction (Traumatic LP) calculated in practice? Can you show a worked example?
- Inputs: CSF white cells 100 /μL, CSF red cells 10000 /μL, Peripheral blood WBC 10 ×10⁹/L, Peripheral blood RBC 5 ×10¹²/L → Result: Corrected CSF WBC 80 /μL（Predicted admixed WBC: 20 /μL）