We’re back with a USMLE® Step 2 CK Question of the Day! Today’s case involves a 72-year-old man battling fever, fatigue, and more while undergoing lymphoma treatment. With a contraindicated test looming based on his symptoms, including abdominal tenderness, an erythematous pharynx, and a sacral pressure wound, can you identify the crucial examination for this patient’s evaluation?
A 72-year-old man presents to the emergency department for evaluation of fever for two days. The patient reports fatigue, cough, anorexia, severe headache, sore throat and chills. The patient has also had abdominal cramping and several episodes of hematochezia. The patient is currently being treated for diffuse large B-cell lymphoma and last received chemotherapy three days ago. Temperature is 39.0 °C (102.2 °F), pulse is 108/min, respiratory rate is 16/min, blood pressure is 105/65 mmHg, and oxygen saturation is 98% on room air. Physical examination demonstrates dry mucous membranes, generalized abdominal tenderness, and a port over the right chest wall. The posterior pharynx appears erythematous. The patient has a stage 2 sacral pressure wound without overlying erythematous changes or exudate. Laboratory studies show an absolute neutrophil count of 300 cells/µL. Which of the following tests or examinations is contraindicated based on this patient’s presentation?
A. Digital rectal examinationB. Wound culture
C. Lumbar puncture
D. Blood cultures from the port
E. Throat culture
Scroll down for the correct answer!
The correct answer to today’s USMLE® Step 2 CK Question is…
A. Digital rectal examination
Before we get to the Main Explanation, let’s see why the answer wasn’t B, C, D, or E. Skip to the bottom if you want to see the correct answer right away!
Incorrect answer explanations
Today’s incorrect answers are…
B. Wound culture
Incorrect: Patients with neutropenic fever are at high risk for Gram-negative bacteremia which can occur from wounds. Culturing known wounds does not increase the risk of inducing bacteremia and should always be performed.
C. Lumbar puncture
Incorrect: This patient has febrile neutropenia and several sources of possible infection. Neutropenia is not an absolute contraindication to performing a lumbar puncture.
D. Blood cultures from the port
Incorrect: Patients with neutropenic fever should have their port accessed and have at least one set blood cultures obtained from it.
E. Throat culture
Incorrect: Throat culture and analysis is not contraindicated in this patient population.
Main Explanation
This patient who is actively receiving chemotherapy presents with febrile neutropenia (neutropenic fever). This patient has multiple potential sources for a localizing infectious process and should receive a thorough physical examination and workup (e.g., lumbar puncture, chest radiograph, CT imaging of the abdomen). While this patient has evidence of hematochezia, digital rectal examination is contraindicated in patients with febrile neutropenia due to the risk of microtrauma and inadvertent translocation of bacteria into the bloodstream.
Febrile neutropenia is defined as either a single oral temperature of 101 ºF or a temperature of 100.4 ºF lasting an hour or more, in the setting of an absolute neutrophil count (ANC) lower than 1500 cells/µL. Patients on chemotherapy are generally at the highest risk for this condition within the first several days of treatment. Patients should be questioned about any recent port access or minimally invasive procedure (e.g. tooth removal). Physical exam should assess for wounds, indwelling lines or catheters, and any intraoral pathology. Blood cultures should be obtained from two sites including any ports or central lines that are in place. If appropriate, wound culture, urine culture, and lumbar puncture may be performed. Chest radiography should always be performed. CT imaging of the abdomen and pelvis may also be indicated depending on the suspected source of infection.
Major takeaway
Physical examination for patients with febrile neutropenia should be thorough. However, digital rectal examination is contraindicated due to the risk of microtrauma and inadvertent translocation of bacteria into the bloodstream.
References
Taplitz, R. A., Kennedy, E. B., Bow, E. J., Crews, J., Gleason, C., Hawley, D. K., Langston, A. A., Nastoupil, L. J., Rajotte, M., Rolston, K., Strasfeld, L., & Flowers, C. R. (2018). Outpatient Management of Fever and Neutropenia in Adults Treated for Malignancy: American Society of Clinical Oncology and Infectious Diseases Society of America Clinical Practice Guideline Update. Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 36(14), 1443–1453. https://doi.org/10.1200/JCO.2017.77.6211
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/cir073Baden, L. R., Swaminathan, S., Angarone, M., Blouin, G., Camins, B. C., Casper, C., Cooper, B., Dubberke, E. R., Engemann, A. M., Freifeld, A. G., Greene, J. N., Ito, J. I., Kaul, D. R., Lustberg, M. E., Montoya, J. G., Rolston, K., Satyanarayana, G., Segal, B., Seo, S. K., Shoham, S., … Smith, C. (2016). Prevention and Treatment of Cancer-Related Infections, Version 2.2016, NCCN Clinical Practice Guidelines in Oncology. Journal of the National Comprehensive Cancer Network : JNCCN, 14(7), 882–913. https://doi.org/10.6004/jnccn.2016.0093
Swartz MN. Clinical practice. Cellulitis. N Engl J Med 2004; 350:904.––––––––––––
Want more USMLE® Step 2 CK practice questions? Try Osmosis by Elsevier today! Access your free trial and find out why millions of current and future clinicians and caregivers love learning with us.
Leave a Reply