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Asymptomatic bacteriuria in an older adult with delirium — MSRA MCQ

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HardUrinary Tract InfectionsAsymptomatic bacteriuria in an older adult with deliriumMSRA

An 86-year-old woman living in a care home is assessed for acute confusion. She has moderate vascular dementia but, until today, is normally conversational and independently mobile with a frame. Staff report fluctuating inattention and disorientation since this morning; a 4AT score is 7. She has no dysuria, new frequency, new incontinence, suprapubic pain, loin pain, rigors, vomiting or visible haematuria. She is afebrile (36.7°C), blood pressure is 128/74 mmHg, pulse 82 beats/minute, respiratory rate 16 breaths/minute and oxygen saturation 97% on air. There is no suprapubic or costovertebral-angle tenderness. A care-home urine dipstick was positive for nitrites and leukocyte esterase. A urine culture, sent before GP review, has grown >10⁵ CFU/mL Escherichia coli susceptible to nitrofurantoin and cefalexin. She has no urinary catheter. Her eGFR is 64 mL/minute/1.73 m². Her repeat prescription record shows that oxybutynin was started 4 days ago for urge incontinence. What is the most appropriate management?

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Correct answer: B — Withhold antibiotics and assess alternative causes of delirium, including medication-related harm

Explanation lettering: B = shown as A · E = shown as B · A = shown as C · C = shown as D · D = shown as E

This is acute delirium without localising urinary features or systemic evidence of infection. In frail older adults and care-home residents, asymptomatic bacteriuria and pyuria are common; therefore, a positive dipstick or urine culture cannot establish UTI in the absence of a compatible clinical syndrome. The current UK primary-care diagnostic tool advises that, where delirium is present but symptoms do not suggest UTI, clinicians should seek and manage other causes. Oxybutynin is a clinically important potential precipitant because of its anticholinergic adverse effects, particularly in an older person with cognitive impairment. A prompt delirium assessment should also consider dehydration, constipation, pain, hypoxia and non-urinary infection. Antibiotics should be reconsidered only if urinary symptoms, fever or other convincing features of infection emerge. A and B inappropriately treat bacteriuria rather than symptomatic infection; susceptibility does not make an incidental culture clinically diagnostic. C is inappropriate because dipsticks are not recommended to diagnose UTI in older adults at high risk of asymptomatic bacteriuria. D is not indicated because she is haemodynamically stable and has no features suggesting sepsis or pyelonephritis.

Reference: Diagnosis of urinary tract infections: quick reference tools for primary care (Updated 7 July 2025) — https://www.gov.uk/government/publications/urinary-tract-infection-diagnosis/diagnosis-of-urinary-tract-infections-quick-reference-tools-for-primary-care Urinary tract infections in adults: Quality statement 3, Antibiotic treatment for asymptomatic bacteriuria in men and non-pregnant women (Updated 15 February 2023) — https://www.nice.org.uk/guidance/qs90/chapter/Quality-statement-3-Antibiotic-treatment-for-asymptomatic-bacteriuria-in-men-and-non-pregnant-women