A nurse notes a patient with pneumonia has a history of diabetes. Which assessment would be most informative for monitoring infection control?

• A. White blood cell count
• B. Serum calcium level
• C. Cholesterol level
• D. Blood urea nitrogen

Answer: (A)

Monitoring infection control centers on the body's immune response, and white blood cell count shows how actively that response is engaged. In pneumonia, white blood cells rise as the body fights the infection, so tracking this count helps gauge whether the infection is improving with treatment or persisting. This is especially important in someone with diabetes, where immune function can be impaired and responses may be blunted or delayed, making trends in the WBC count a useful guide for management.

The other measurements don’t directly reflect infection control: calcium level relates to mineral metabolism and endocrine function; cholesterol level is a lipid measure not tied to acute infection status; blood urea nitrogen indicates kidney function and hydration, which can be affected for reasons other than the infection itself.