Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 8 Sept 2026Clinical review pending
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Obstruction with infection or threatened renal function
Fever, rigors, circulatory disturbance, anuria or obstruction of a solitary functioning kidney changes the urgency even when the stone is small.
Action: Obtain urgent senior and urological assessment, investigate obstruction and organ dysfunction, and arrange emergency drainage when indicated alongside resuscitation and immediate antibiotics for infection.
Synopsis
Recognise ureteric colic, test the important alternatives and distinguish a painful stone that can be observed from obstruction requiring urgent intervention.
Acute loin pain radiating towards the groin with restlessness suggests ureteric colic, but neither pain location nor haematuria establishes the diagnosis.
NICE recommends low-dose noncontrast CT within twenty four hours for adults with suspected colic; use ultrasound instead during pregnancy and as the initial examination in people under sixteen.
Give an appropriate NSAID first; if it is contraindicated or insufficient, offer intravenous paracetamol, then consider an opioid if both earlier choices are unsuitable or inadequate.
Key red flags
Fever or rigors with an obstructed collecting system requires emergency source assessment, not routine outpatient stone follow-up.
Anuria, bilateral obstruction or a solitary functioning kidney with new obstruction threatens total renal output.
Syncope, shock, a pulsatile abdominal mass or a vascular history requires assessment for aortic disease alongside the urinary differential.
Infection within an obstructed system
Fever, chills, tachycardia, hypotension or new confusion with hydronephrosis can indicate infected obstruction. A negative bladder nitrite result cannot reliably describe organisms trapped above a complete blockage. Treat the physiological emergency and involve the team that can decompress the collecting system.
Investigation priorities
01
Urine testing and indicated cultureFirst step
Look for urinary inflammation or bleeding and identify evidence that changes the infection pathway.
Management branches
Worked caseVerify an uncomplicated small distal stone
A thirty six year old man presents with abrupt left loin pain radiating towards his groin.
He is restless but afebrile and circulatorily stable, passes urine normally and has no solitary-kidney history. Creatinine is 82 micromol/litre against a baseline of 80, and urine has blood without nitrites. Examination finds no peritonism or testicular abnormality. His medication history contains no NSAID, anticoagulant or relevant allergy, and he has no ulcer, vascular or hepatic disease.
He receives diclofenac sodium 75 mg as the selected 3 ml preparation by deep intragluteal injection. Pain falls from eight to two out of ten within the observed treatment period and he retains oral fluids. Low-dose noncontrast CT demonstrates a four millimetre distal left ureteric stone with mild upstream dilation and a normal right kidney; it identifies no alternative acute cause.
Key medicines
Voltarol diclofenac sodium 75 mg per 3 ml ampouleFor an eligible adult with renal colic, give 75 mg intramuscularly by deep intragluteal injection; a second 75 mg may be given after thirty minutes if needed, with a maximum of 150 mg from all diclofenac formulations in twenty four hours. Do not use ampoules beyond two days.Exclude renal or hepatic failure, active or recurrent peptic ulcer/bleeding, previous NSAID-related bleeding, established ischaemic heart or cerebrovascular disease, peripheral arterial disease and NYHA II–IV heart failure. Do not use after NSAID-triggered asthma, angioedema or urticaria, or with diclofenac or metabisulphite allergy. Review dehydration, renal function, anticoagulants, other NSAIDs, lithium, methotrexate and ACE inhibitor/diuretic combinations. Stop for bleeding, renal decline or hypersensitivity. This ampoule is not recommended for children; avoid routine use in pregnancy, with particular fetal risk from twenty weeks and contraindication in the third trimester. Its IV indication concerns postoperative pain, and it must never be injected as an IV bolus. The selected Voltarol label states that it should not be administered during breastfeeding.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 8 Sept 2026; clinical approval remains outstanding.