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Suspected obstructed solitary kidney causing acute kidney injury — MSRA MCQ

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HardHematuriaSuspected obstructed solitary kidney causing acute kidney injuryMSRA

A 47-year-old man presents with 7 hours of sudden severe left loin pain radiating to the groin, vomiting once and visible haematuria. He has congenital right renal agenesis and no previous renal impairment. He has passed approximately 50 mL of urine in the past 10 hours. He is afebrile, with blood pressure 142/84 mmHg, pulse 92 beats/minute and temperature 36.8°C. There is left renal angle tenderness. Urine dipstick shows 3+ blood, with negative nitrites, leucocytes and protein. Creatinine is 121 micromol/L; it was 74 micromol/L 3 months ago. He has no diarrhoea, recent NSAID use, urinary catheterisation or symptoms of urinary infection. What is the most appropriate management today?

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Correct answer: D — Send immediately to hospital for urgent imaging and urological assessment for suspected obstruction of a solitary kidney

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

This presentation is most consistent with acute ureteric obstruction from a stone: colicky loin-to-groin pain, vomiting and haematuria, without features suggesting urinary infection. However, the key management discriminator is not simply suspected renal colic. He has a solitary functioning kidney, marked oliguria and acute kidney injury: creatinine has risen by 47 micromol/L from baseline, exceeding the NICE threshold of a 26 micromol/L rise within 48 hours. NICE recommends immediate urological referral for an obstructed solitary kidney and for complications of AKI caused by upper-tract obstruction. He therefore requires immediate hospital assessment, urgent imaging and urological involvement; conservative community management risks loss of function in his only kidney. A is appropriate for uncomplicated suspected renal colic, for which urgent CT within 24 hours is recommended, but is insufficient here because of probable obstructive AKI in a solitary kidney. B delays definitive assessment despite oliguria and AKI. D may have a role in selected uncomplicated ureteric stones, but is inappropriate before exclusion and management of urgent obstruction. E misprioritises a cancer pathway: visible haematuria warrants cancer assessment in appropriate unexplained presentations, but the acute obstructive syndrome requires emergency management first.

Reference: Acute kidney injury: prevention, detection and management (NG148), recommendations 1.3.1 and 1.5.1 (Published 2019; last updated 16 October 2024) — https://www.nice.org.uk/guidance/ng148/chapter/Recommendations Renal and ureteric stones: assessment and management (NG118), recommendation 1.1.1 (2019) — https://www.nice.org.uk/guidance/ng118/chapter/Recommendations