Traumatic lumbar puncture (LP) is fairly common and occurs when the needle causes bleeding into the subarachnoid space. Introduction of peripheral red blood cells (RBCs) in cerebrospinal fluid (CSF) increases CSF protein levels, thereby complicating diagnosis of bacterial meningitis.
This study examined the association between CSF RBC count and CSF protein level in a prospective cohort of 1298 children (median age, 3 months; age range, 0 days –23 years) who underwent LP in the emergency department at a children’s hospital in Boston and did not have evidence of meningitis. Most LPs were performed to evaluate for possible meningitis.
Overall, 189 patients (15%) had traumatic LPs (CSF RBC count >1000/mm3). CSF protein level increased by 1.1 mg/dL for every 1000-cell increase in CSF RBC count.