Interpretation of traumatic lumbar puncture. A prospective experimental model

Area of Science:

• Neurology
• Clinical Chemistry
• Laboratory Medicine

Background:

• Cerebrospinal fluid (CSF) analysis is crucial for diagnosing neurological conditions.
• Accidental blood contamination during lumbar puncture (LP) can confound test results.
• Establishing accurate interpretation guidelines for blood-contaminated CSF is essential.

Purpose of the Study:

• To prospectively evaluate the impact of blood contamination on CSF laboratory parameters in children.
• To develop evidence-based guidelines for interpreting CSF results following traumatic LPs.

Main Methods:

• An experimental model was used, adding varying amounts of blood to normal pediatric CSF.
• Red blood cell counts ranged from 1,000 to 600,000 cells/mm³.
• Observed values for white blood cell count, protein, neutrophils, and glucose were compared to expected values.

Main Results:

• CSF glucose levels remained unchanged despite blood contamination.
• Ratios of observed to expected values varied for white blood cells (mean 0.96), protein (mean 0.97), and neutrophils (mean 1.17).
• Significant variability was noted in white blood cell counts and neutrophil percentages.

Conclusions:

• Blood contamination significantly affects CSF white blood cell counts and protein levels, requiring careful interpretation.
• CSF glucose is a reliable marker unaffected by blood contamination.
• Guidelines are proposed to aid in the interpretation of CSF laboratory studies after traumatic lumbar punctures.