Bloody Specimen

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Bloody Specimen

When blood is present in a CSF specimen, it is necessary to determine whether the blood is due to a traumatic puncture or to a pathologic condition. There are several clues to help make this distinction:

Traumatic tap:

  • More blood is present in tube 1 than in tubes 2, 3, or 4.
  • When sample is centrifuged within one hour, supernatant is clear.
  • Blood clots on standing.
Subarachnoid or cerebral hemorrhage:
  • Blood is evenly distributed in all tubes.
  • When sample is centrifuged within one hour, supernatant is pink or yellow.
  • Blood does not clot on standing.