What is the significance of cerebrospinal fluid (CSF) with elevated red blood cells (RBC) and white blood cells (WBC)?

From the Guidelines

The cerebrospinal fluid (CSF) results showing 93 red blood cells (RBCs) and 40 white blood cells (WBCs) per cubic millimeter suggest an abnormal CSF profile that requires further investigation, and empiric antimicrobial therapy should be considered immediately. This pattern could indicate several conditions including viral meningitis, early bacterial meningitis, partially treated bacterial meningitis, or subarachnoid hemorrhage. The elevated WBC count is concerning for an inflammatory or infectious process in the central nervous system.

Key Considerations

• Additional CSF studies should be performed immediately, including glucose, protein, Gram stain, culture, viral PCR panel, and cytology.
• While awaiting results, empiric antimicrobial therapy should be considered, typically with ceftriaxone 2g IV every 12 hours plus vancomycin 15-20 mg/kg IV every 8-12 hours, with the addition of acyclovir 10 mg/kg IV every 8 hours if herpes encephalitis is suspected 1.
• The presence of RBCs could represent a traumatic tap or true bleeding, which can be differentiated by comparing the first and last tubes of CSF collected or checking for xanthochromia.
• Clinical correlation with symptoms such as fever, headache, neck stiffness, altered mental status, and focal neurological deficits is essential for proper diagnosis and management.

Diagnostic Approach

• The diagnosis of bacterial meningitis is typically made based on CSF analysis, including glucose, protein, and white blood cell count, as well as Gram stain and culture 1.
• The ESCMID guideline recommends that cranial imaging may be considered to evaluate for signs of brain shift as a precaution in selected patients before lumbar puncture, but treatment should not be delayed 1.
• The use of CSF AD biomarkers may be considered in the diagnostic evaluation of patients with dementia, but this is not relevant to the current case 1.

Management

• Empiric antimicrobial therapy should be started immediately, and the patient should be closely monitored for signs of clinical improvement or deterioration.
• Further management will depend on the results of the CSF studies and the patient's clinical course.

From the Research

CSF Analysis

• The presence of RBC 93 and WBC 40 in the cerebrospinal fluid (CSF) may indicate a potential infection or subarachnoid hemorrhage 2.
• CSF analysis is a diagnostic tool for many conditions affecting the central nervous system, including bacterial meningitis, viral meningitis, and subarachnoid hemorrhage 2.
• The high mortality rate associated with bacterial meningitis and subarachnoid hemorrhage necessitates urgent diagnosis and treatment 2.

Potential Causes

• Bacterial meningitis can present with high CSF white blood cell counts, elevated CSF protein levels, and a low CSF:serum glucose ratio 2.
• Viral meningitis can present similarly to bacterial meningitis but usually has a low mortality rate 2.
• Subarachnoid hemorrhage is characterized by xanthochromia and an elevated red blood cell count in the CSF 2.

Treatment Options

• Ceftriaxone is a third-generation cephalosporin that has been effective in treating various infections, including meningitis 3, 4.
• The effectiveness of ceftriaxone in treating MSSA bloodstream infections has been evaluated, and it may provide an alternative to standard of care therapy 5.
• However, ceftriaxone can cause drug-induced immune hemolytic anemia, and its effect on erythrocyte parameters should be monitored 6.

Laboratory Findings

• Automated hematology analyzers can detect incorrect results due to ceftriaxone-induced erythrocyte agglutinins, and peripheral blood smear examination may be necessary for accurate diagnosis 6.
• Serological testing may not be possible, but timely reactions and corresponding laboratory procedures can prevent potential complications due to drug administration 6.