What additional finding from cerebrospinal fluid is critical to report after a lumbar puncture for suspected meningitis?

In cases of suspected meningitis, the analysis of cerebrospinal fluid (CSF) obtained through a lumbar puncture can provide critical diagnostic information. The leukocyte count is particularly significant; a count of 2000 mm³ strongly suggests an inflammatory response, which is commonly seen in meningitis. Typically, in bacterial meningitis, we expect the leukocyte count to be markedly elevated, often exceeding 1000 cells/mm³, with a predominance of neutrophils. In contrast, viral meningitis would show elevated counts but usually lower than in bacterial infections, often with a predominance of lymphocytes.

The other potential findings, such as glucose levels or protein concentration, also offer valuable information but do not indicate the presence of infection as definitively as a markedly elevated leukocyte count does. Normal glucose levels would generally be around 60% of serum glucose levels, and elevated protein may indicate a breakdown of the blood-brain barrier; however, these findings need to be interpreted in the context of the leukocyte count.

Red blood cell count can indicate trauma or a traumatic tap during the procedure but is less directly indicative of meningitis itself. Therefore, an increased leukocyte count is a crucial finding that should be reported promptly, as it