Which laboratory value would the nurse assess if concerned about infection in a patient?

White blood cell count (WBCs) is the laboratory value that is most directly associated with the body’s immune response to infection. An increase in WBCs, also known as leukocytosis, typically indicates that the body is fighting an infection. This elevation is due to the bone marrow producing additional white blood cells in response to pathogens. Conversely, a low WBC count, or leukopenia, may suggest a weakened immune system or inability to mount an adequate response to infection.

The other laboratory values, while important for overall health assessment, are not as specific to infection. Hemoglobin levels primarily assess oxygen-carrying capacity and anemia, platelet counts relate to clotting ability, and electrolyte levels monitor various bodily functions but do not provide direct information about the presence of infection. Measuring WBC levels is therefore critical for determining the likelihood of infection in a patient.