Clinical Scenario: 35 yo F with hx of breast cancer currently on chemotherapy, last treatment a week ago, presents for fever, weakness, nausea but no vomiting. She is febrile to 102F in the ED with HR120, BP 110/70, RR16, O2Sat 99%RA. Her exam is unremarkable aside from dry mucous membranes. You start her on IVF, antipyretic and antiemetic. Her labs return and the CBC is concerning for neutropenia.
Question: How do you calculate the absolute neutrophil count and what value matters?
Absolute Neutrophil Count (ANC) = 10 x WBC in the 1000s x (%PMNS+%Bands)
Also available at: https://www.mdcalc.com/absolute-neutrophil-count-anc
E.g. 10 x 1.5 x (37%+13%) = 10 x 1.5 x 50 = 750/mm3
Neutropenia is usually defined as ANC <1500/mm3, with severe neutropenia defined as ANC<500/mm3. The Infectious Diseases Society of America (IDSA) defines neutropenia as ANC <500/mm3 or an ANC expected to decrease to <500/mm3 in the next 48 hours.
*Note that areas overlooked during routine exams of febrile neutropenic patients are: the oral cavity, the perianal area, and IV sites*
Want to read more?
Alison G. Freifeld, Eric J. Bow, Kent A. Sepkowitz, Michael J. Boeckh, James I. Ito, Craig A. Mullen, Issam I. Raad, Kenneth V. Rolston, Jo-Anne H. Young, John R. Wingard; Clinical Practice Guideline for the Use of Antimicrobial Agents in Neutropenic Patients with Cancer: 2010 Update by the Infectious Diseases Society of America, Clinical Infectious Diseases, Volume 52, Issue 4, 15 February 2011, Pages e56–e93, https://doi.org/10.1093/cid/cir073
Stapczynski J. Emergency Complications of Malignancy. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e New York, NY: McGraw-Hill; 2016. http://accessemergencymedicine.mhmedical.com/content.aspx?bookid=1658§ionid=109386926. Accessed January 22, 2018.
[To be continued... Neutropenic fever Part II will be released on Thursday!]