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Colorectal cancer screening — USMLE Step 3 MCQ

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HardPreventive Medicine, Epidemiology, BiostatisticsColorectal cancer screeningUSMLE Step 3

An 83-year-old nursing-home resident becomes inattentive after two days of poor oral intake. She is afebrile and has no dysuria, urgency, suprapubic pain, flank pain, or hemodynamic instability. Urinalysis shows pyuria and culture grows E coli; examination suggests dehydration. What is the best management?

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Correct answer: C — Treat dehydration and evaluate other causes of delirium without starting antibiotics for bacteriuria

The best answer is “Treat dehydration and evaluate other causes of delirium without starting antibiotics for bacteriuria”. Bacteriuria and pyuria are common in older long-term-care residents and do not establish symptomatic UTI. In the absence of local genitourinary symptoms, systemic instability, or another convincing infectious syndrome, IDSA recommends assessment for other delirium causes and careful observation rather than antibiotics. Treating asymptomatic bacteriuria adds adverse effects, C difficile risk, and resistance without demonstrated benefit.

Reference: IDSA Clinical Practice Guideline for Asymptomatic Bacteriuria: https://www.idsociety.org/practice-guideline/asymptomatic-bacteriuria/