Ureteric Calculus

Objectives

To guide healthcare professionals in the assessment and management of patients presenting with suspected or confirmed renal or ureteric calculi in deployed environments.

Scope

This guideline gives an approach to assessing and managing a patient with suspected renal or ureteric calculi.

Key red flags for complications of renal and ureteric calculus are described along with criteria for further urological referral.

This guideline does not describe a generic approach to the patient with abdominal or flank pain which can be found elsewhere within CGOs.

Audience

This guideline is intended for the use of registered healthcare professionals fulfilling a general role in forward medical locations or in an Emergency Department on deployed operations.

Initial Assessment & Management

Background: Renal and ureteric stones are a common cause of acute flank pain and can lead to significant morbidity if not managed appropriately. Most stones <5 mm pass spontaneously, but larger stones or those associated with complications (such as sepsis or acute kidney injury) require urgent intervention. Management must be adapted to the resources available at each level of care, with early identification of red flags and appropriate escalation.

Red Flags: If any of the following are present evacuate to deployed hospital care urgently, keep nil by mouth unless prolonged evacuation is predicted, and start IV fluids:

 - Signs of sepsis (See Sepsis CGO)

 - Oligo/Anuria (Urine output <0.5mls/kg/hr)

 - Uncontrolled pain despite analgesia

 - Peritonitis / Anterior abdominal pain (not in keeping with ureteric colic, consider alternative diagnosis)

Investigations

  • Urinalysis - usually reveals Blood (~80%); nitrites and/or WBCs may indicate concurrent infection
  • Urinary Pregnancy Test - must be completed in all women of childbearing age presenting with symptoms which could be renal/ureteric calculus.
  • Point of Care Ultrasound - May be used to exclude Abdominal Aortic Aneurysm (AAA) in patients over 50 years old presenting with flank/back pain.

Treatment:

  • Analgesia:
    • NSAIDs first line, consider rectal/IM routes if vomiting
    • IV Paracetamol second line
    • Follow deployed analgesia guidance including use of strong opioids if required.
    • There is no evidence to support the use of anti-spasmodic: these are not recommended.
  • Hydration - Encourage high-normal fluid intake.
  • Anti-emetic - If nausea/vomiting give IV Ondansetron regularly.
  • Evacuate - Unless transient pain only, all cases will require further investigation and management.

Antibiotics are not required routinely but should be given intravenously if evidence of infection on urinalysis or clinically septic casualty.

Advanced Assessment & Management

Red Flags: Urgent surgical opinion should be sought if any remain present from initial management. There are additional red flags after blood tests and imaging are completed:

- Acute Kidney Injury (see acute renal failure CGO)

- Imaging reveals a calculus felt unlikely to pass spontaneously

- Imaging reveals hydronephrosis secondary to a calculus

Investigations:

  • Blood tests - U&Es, FBC, Calcium, Phosphate, Urate (as available)
  • Imaging:
    • Gold standard is CT KUB
    • Ultrasound KUB in females <40yo, paediatrics or if CT unavailable
    • Consider XR KUB if CT AND Ultrasound unavailable

Treatment:

  • Principles remain as for initial management.
  • Urinary catheter should be placed if persisting oligo/anuria.
  • If available an alpha blocker (e.g. Tamsulosin) should be started to aide medical expulsion of the calculus.
  • In addition to the red flags above Surgical +/- Urological advice (including remote reach-back if required) should be obtained for:
    • Calculi >5mm
    • Persistent or recurrent symptoms or stone formation
    • Solitary kidney
    • Persistent renal impairement

Calculi <5mm usually pass spontaneously and only symptomatic management may be required. Simple calculi of this nature will not usually require evacuation from theatre; further investigation/management may be delayed until return to the home base.

Prevention:Recurrence of Renal and Ureteric calculi can be reduced by the following:

  • Increasing fluid intake - Adults should target 2.5-3L per day.
  • Reduce salt intake - Adults should ingest <6g salt per day.
  • Eat a balanced diet including (where possible) plenty of fruits and vegetables.

 

Prolonged Casualty Care

If evacuation is delayed or impossible:

Monitor renal function and hydration (hourly urine output as a minimum; daily U+Es if available).

Continue analgesia and alpha-blockers if indicated/available.

Monitor for signs of infection or obstruction.

Repeat imaging (if possible) if clinical deterioration.

Maintain hydration and symptom control.

Escalate via telemedicine if possible.

Paediatric Considerations

Ultrasound preferred for imaging first line.

Adjust analgesia and fluid management according to paediatric weight-based requirements.

Early urological input is recommended; avoid use of alpha blockers unless instructed by urology.

Consider metabolic causes - investigation likely to be delayed until home base or R4 care.

Last reviewed: 01/04/2026

Next review date: 01/04/2027