From the Research
A white cell count (WCC) greater than 50 x 10^9/L in the setting of resolving pneumonia is concerning and requires further evaluation, though it may not necessarily indicate treatment failure. This elevated count could represent a robust inflammatory response to the infection, a complication such as empyema or lung abscess, or potentially a different underlying condition. The most recent and highest quality study 1 suggests that poor outcomes can occur with empiric ceftriaxone ± azithromycin for community-acquired pneumonia caused by methicillin-susceptible Staphylococcus aureus, highlighting the importance of appropriate antibiotic coverage.
Key Considerations
- Continue the current antibiotic regimen if the patient is clinically improving with decreasing fever, improved respiratory symptoms, and better oxygenation.
- Additional investigations should include:
- Repeat chest imaging to rule out complications
- Blood cultures if not already done
- Consideration of broader spectrum antibiotics if clinical deterioration occurs
- Procalcitonin levels may help distinguish between bacterial infection and other causes of inflammation.
- The timing of the WCC elevation is important - if it occurs early in treatment but is trending downward with clinical improvement, this is reassuring.
- If the count is rising despite appropriate therapy, consider antibiotic resistance, inadequate coverage, or a non-infectious cause.
Management Approach
Given the potential for complications and the importance of appropriate antibiotic therapy, consult with infectious disease specialists if the patient is not improving as expected or if the WCC remains persistently elevated despite appropriate therapy. This approach is supported by studies such as 2 and 3, which highlight the efficacy of different antibiotic regimens in the treatment of community-acquired pneumonia. However, the most recent study 1 emphasizes the need for careful consideration of the causative pathogen and the potential for poor outcomes with certain empiric treatments.