ANC v.1

Absolute Neutrophil Count (ANC), used to assess neutropenic fever in chemotherapy patients.

Daniel Keszthelyi

models@cambiocds.com

The ANC can be critical in assessing an immunocompromised patient’s risk for developing opportunistic infections. 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.

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. ANC is often measured daily in critically ill patients to assess the bone marrow’s response after chemotherapy, for example. ANC is dynamic - it is an absolute value and is expected to drop during the patient’s nadir after chemotherapy. ANC can be calculated with the following formula: Absolute neutrophil count = 0.01 x WBC count x (% PMNs + % bands) Can be used to stratify patients: Neutropenia: ANC <1,500 cells/mm3 - Mild neutropenia: 1,000-1,500 cells/mm³ - Moderate neutropenia: 500-999 cells/mm³ - Severe neutropenia: <500 cells/mm³

The ANC calculation is not a static measurement done only once upon hospital admission

[1] Al-Gwaiz LA, Babay HH. The diagnostic value of absolute neutrophil count, band count and morphologic changes of neutrophils in predicting bacterial infections. Med Princ Pract. 2007;16(5):344–7. doi:10.1159/000104806. [2] Thomas BN, Karen MP, Soora W, David D, Gabriel JE. Interpreting Complete Blood Counts Soon After Birth in Newborns at Risk for Sepsis. Pediatrics 2010;126(5):903-909. doi:10.1542/peds.2010-0935. [3]Rivera E, Haim Erder M, Fridman M, Frye D, Hortobagyi GN. First-cycle absolute neutrophil count can be used to improve chemotherapy-dose delivery and reduce the risk of febrile neutropenia in patients receiving adjuvant therapy: a validation study. Breast Cancer Research : BCR. 2003;5(5):R114-R120.

OBSERVATION.lab_test-full_blood_count_anc.v1, EVALUATION.anc_assessment.v0