Renal Colic

Clinical Notes : Urology

Incidence

Peak incidence is in the summer due to dehydration
- fluid intake <1L a day greatly increases risk
occurs in 5% to 15% of the population
- Peak incidence at age 20 to 50
- male:female 3:1
- x3 higher incidence with a +ve Family History
Small ureteral stones (<10mm) usually pass spontaneously
- 50% recurrence rate
Diseases associated with stone formation include
- Hypercalcaemic disorders e.g. hyperparathyroidism
- Gastrointestinal disease, especially malabsorptive conditions
- After bariatric surgery
- Recurrent UTI
- Gout
- Anatomical abnormalities e.g. polycystic kidneys

Diagnosis

Pain
- Acute or insidious onset
- Loin, groin or loin to groin
- Abdominal examination is usually normal
- Classically “the worst pain ever”
- Unable to get comfortable
Other possible associated symptoms
- Dysuria, freq, urgency (especially distal stones)
- Haematuria
- Negative dipstick does NOT rule out renal colic
- N&V
- Fever/ rigors
Differential diagnosis
- AAA (Abdominal Aoertic Aneurysm) if older +/- known cardiovascular risks. (This is easily missed!)
- Appendicitis
- Ovarian pathology
- Testicular torsion

Management

Refer to A+E if :
- Previous AKI
- Solitary kidney or transplanted kidney
NSAIDS first line
- Consider 100mg PR diclofenac stat for pain rather than oral or IM analgesia
- wait for 1 hr
- refer to A+E if not settled after 1 hr
Antispasmodics (e.g. Buscopan)
- conflicting evidence
- No benefit from combining NSAID with antispasmodic
- not recommended
Opioids if NSAID contraindicated
- less effective than NSAIDs
- α- blockers (e.g. nifedipine)
- conflicting evidence
- high doses required
- not recommended
Prevention of recurrence (by up to 50%)
- High fluid intake to produce > 2.5L urine / 24 hours
- Reduce animal protein and avoid urate rich food (as in gout)
- No need to restrict calcium (ineffective)