(3) Traumatic tap
can cause false-positive results in LP samples.
A red color is consistent with a traumatic tap
(specimen has clots) or malignancy (non-traumatic tap has no clots).
The second common presentation was blood-tinged effusion caused by traumatic tap
or due to thickened pleura.
This was not secondary to a traumatic tap
as most of the cells were plasma cells and the differential in the peripheral blood was quite different as described below.
Define gross findings that distinguish a traumatic tap
from a pathologic bleed when a bloody CSF is encountered.
* Ignore the RBC count in the CSF; it represents a traumatic tap
, not an increased risk of HSV.
Additionally, the surveillance officer reviewed admissions for the previous 24 h and reported patients having any one of five clinical syndromes (acute respiratory failure with pleural effusion; hemorrhagic enteritis with fever; a skin lesion characterized by vesicles, ulcer, or eschar; meningitis, encephalitis, or unexplained acute encephalopathy; or anthrax or suspected anthrax infection) and a widened mediastinum on chest radiograph or laboratory findings of a gram-positive bacillus on Gram stain, Bacillus species from culture of a sterile site specimen, or hemorrhagic cerebrospinal fluid, pleural, or peritoneal fluid in patients without a traumatic tap
The practice of using tubes #1 and #4 for counts has become fairly common, as this aids the clinician in determining if the cells come from a traumatic tap
or are actually a problem with the CSF.
They always indicate the attempt of the body to rid a space of RBCs but in CSF they are indications of a pathologic bleed instead of a traumatic tap
because the blood would have to be in the CNS for at least 24 hours.
(14,15) To complicate matters further, there is no generally accepted threshold number for what constitutes a traumatic tap
A While the accepted standard for CSF cell counts is to use tube 3 or 4, some clinicians find it helpful to perform additional testing to determine if the RBCs present are the result of a traumatic tap
or from an actual central nervous system bleed.
(1) A traumatic tap
, however, can complicate the interpretation of the CSF findings since it has features overlapping with those of a subarachnoid hemorrhage.