Question

A 7-year-old child has just had a lumbar puncture in the emergency department for complaints of elevated temperature and a stiff neck. Which of the following cerebral spinal fluid findings would indicate that this child has bacterial meningitis?

1) Markedly lower than normal pressure
2) Glucose 20 mg/dL
3) White blood cell count 3 cells/mm3
4) Clear fluid

Answer 1

In a 7-year-old child with suspected bacterial meningitis, a CSF glucose level of 20 mg/dL would indicate bacterial meningitis, as this level is significantly below the normal range of 50–80 mg/dL and suggestive of bacterial invasion in the central nervous system.

Step-by-step explanation:

The cerebrospinal fluid (CSF) findings that would indicate bacterial meningitis in a 7-year-old child who has just had a lumbar puncture include abnormal levels of polymorphonuclear neutrophils (PMNs), low glucose levels, and elevated protein in the CSF. Given the options presented in the student's question, a glucose level of 20 mg/dL in the CSF is highly suggestive of bacterial meningitis. Normally, CSF glucose is about two thirds of the blood glucose level, with a normal range of 50–80 mg/dL. Thus, a glucose level of 20 mg/dL (below 45 mg/dL) is a significant finding that, along with other clinical signs such as a stiff neck and elevated temperature, can indicate bacterial meningitis. Other findings in bacterial meningitis typically include cloudy CSF and a high white blood cell count (significantly greater than the normal 5–20 cells/mm³, often reaching into the thousands).