Absolute Neutrophil Count (ANC)
The ANC can be critical in assessing an immunocompromised patient’s risk for developing opportunistic infections. It is commonly used in the hospital setting, clinic, and emergency department. If a patient undergoing active myelosuppressive chemotherapy presents with a sustained fever (with or without localizing symptoms), there is a risk of progression to sepsis. Thus, it is imperative to calculate the ANC to empiric antibiotics should be initiated.
- The ANC calculation is not a static measurement done only once upon hospital admission. Rather, it is often measured daily in critically ill patients to assess the bone marrow’s response after chemotherapy, for example.
- Recall that the ANC is dynamic - it is an absolute value and is expected to drop during the patient’s nadir after chemotherapy.
The calculation can be completed with a routine complete blood count and differential. It is a tool to provide a rapid risk stratification. No additional laboratory work is needed to complete the calculation.