Low risk for subsequent subarachnoid hemorrhage for emergency department patients with headache, bloody cerebrospinal fluid, and negative findings on cerebrovascular imaging.

Unlabelled: OBJECT.: When patients present to the emergency department (ED) with acute headache concerning for subarachnoid hemorrhage (SAH) and a lumbar puncture (LP) shows blood in the CSF, it is difficult to distinguish the results of a traumatic LP from those of SAH. CT angiography (CTA) is often performed, but the long-term outcome for patients with a positive LP and normal neurovascular imaging remains uncertain.

Interpreting red blood cells in lumbar puncture: distinguishing true subarachnoid hemorrhage from traumatic tap.

Objectives: The study purpose was to determine the optimal use of lumbar puncture (LP) red blood cell (RBC) counts to identify subarachnoid hemorrhage (SAH) when some blood remains in the final tube.

Methods: A case series was performed at a tertiary emergency department (ED). Records of 4,496 consecutive adult patients billed for LPs between 2001 and 2009 were reviewed.