Urology: stones

Question 1

What is the first line analgesic treatment for renal colic?

Answer 1

-NSAID by any route.
- diclofenac suppository if vomiting.

Question 2

What are risk factors for renal stones?

Answer 2

• Men>women
• Peak age 20-50
• White people
• Obesity
• Excessive oxalate, urate, animal protein diet
• FHx
• anatomically abnormal kidneys e.g. horseshoe
• metabolic disease: gout, hypercalcaemia
• chronic dehydration
• immobilisation
• chronic UTI

Question 3

How does renal colic present - what are the symptoms and signs?

Answer 3

• abrupt onset severe unilateral flank pain which radiates around the abdomen to the groin (may radiate to labia in women or testicle in men)
• pain lasts mins-hours, occurs in spasms (with intervals of no pain or dull ache)
• often assoc nausea, vomiting, haematuria
• usually most severe pain of lifetime
• may report dysuria, frequency, straining - stone irritating detrusor muscle on reaching vesico-ureteric junction
• restless, shifting position to get comfortable (contrast to peritonitis where patients tend to lie still)
• Haematuria supports diagnosis, but lack of haematuria cannot rule it out.

Question 4

When should I arrange immediate hospital admission for a patient with suspected renal colic?

Answer 4

• signs of systemic infection - fever, sweats, signs of sepsis
• increased risk of AKI - e.g. CKD, solitary kidney, kidney transplant, bilateral obstructing stones suspected
• dehydrated, cannot take oral fluids due to nausea and vomiting
• doubtful diagnosis

Complications: irreversible kidney damage, obstructed infected kidney: obstructive pyelonephritis or pyonephrosis -> risk lifethreatening sepsis.
Increased risk RCC, CKD

Question 5

How should those with suspected renal colic not requiring immediate admission be managed? Immediate and longer term management.

Answer 5

• arrange urgent (<24hrs) imaging to confirm diagnosis and assess likelihood of spontaneous stone passage
• CK KUB (non contrast, low dose)
• if pregnant, or child - USS
• NSAID by any route
• If NSAID CI or not sufficient - IV paracetamol if possible
• If both not sufficient or IV paracetamol not available, give opioid e.g tramadol
• further management depends on size/location of stone/symptom severity/age/comorbidities. Include: watchful waiting (if <5mm), medical expulsive therapy - alpha blocker (if distal ureteric stone <10mm), Surgical -e.g shockwave lithotripsy.
• serum calcium
• stone analysis
• dietary advice - increase fluid intake. Advise adults to drink 2.5–3 L of water a day, and children and young people (depending on their age) 1–2 L of water a day.
• add fresh lemon juice to water
• avoid fizzy drinks
• reduce salt intake
• maintain normal calcium intake
• healthy weight
• consider thiazide for adults (if calcium oxalate stones)