Renal colic and pyelonephritis

Differentiate uncomplicated stone disease from infection, sepsis and an infected obstructed system.

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Flank pain / suspected stone flowchart

  1. Suspected stoneObservations, urinalysis, pregnancy test when relevant, FBC, CRP and U&E. Give analgesia: NSAID first line if suitable.
  2. Infection or high-risk obstruction?Fever/sepsis, anuria, AKI, bilateral obstruction, solitary/transplanted kidney or clinical deterioration.
  3. Yes — urgent UrologyCultures, current sepsis/antimicrobial pathway and immediate Urology discussion. Infected obstruction requires Urgent decompression.
    No — imageChoose imaging by age and pregnancy.
  4. Age under 16?
  5. Under 16 — SheffieldDiscuss with Sheffield paediatric service. NICE recommends ultrasound first; consider low-dose non-contrast CT only if uncertainty remains.
    Age 16+ — CT KUBUrgent low-dose non-contrast CT KUB within 24 hours. If pregnant, use ultrasound instead.
  6. ReassessDiscuss/admit for infection, AKI, anuria, solitary kidney, uncontrolled pain/vomiting or diagnostic uncertainty. Otherwise discharge with analgesia, safety-netting and stone follow-up.

Do not miss infected obstruction

Fever or sepsis with suspected upper-tract obstruction is a urological emergency. Start the current sepsis pathway, obtain cultures and blood tests, give antimicrobials according to the current DBTH policy, and contact Urology immediately for urgent source-control planning. Do not delay escalation while waiting for all results.