These are crystal-like objects, which form in various parts of the urinary tract. They consist mainly of mineral salts i.e. crystal forming ions. Some of the common stone-types include calcium oxalate, calcium phosphate, magnesium ammonium phosphate and uric acid.
CAUSES
• Hypercalcaemia
• Hyperuricaemia
• Urinary stasis
• Urinary tract infection
• Foreign body - including urinary catheter and suture material
• Idiopathic hypercalciuria
• Dehydration
• Immobilisation especially in the elderly
• Inborn errors of metabolism e.g. cystinuria
LOCATION OF CALCULI |
SYMPTOMS |
SIGNS |
Kidney/Ureter |
• Loin Pain
• Ureteric colic
• Sudden acute agonizing paroxysymal pain, which begins in the loin, then radiates around the flank towards the bladder and testis in the male and labium majus in the female. May be associated with nausea, vomiting and sweating.
• Haematuria |
• Signs may be few but tenderness in the loin and abdomen would be felt during a painful attack.
• Sometimes there may be associated abdominal distension and fever if there is superadded infection.
• A hydronephrotic kidney may be palpable. |
Bladder/Urethra |
• Suprapubic pain
• Frequency
• Urgency
• Haematuria
• Strangury - An uncontrollable and often painful desire to pass urine which results in little or no urine (may be blood -stained) being voided.
• Retention of urine |
• Suprapubic tenderness
• Palpable bladder (from retention or a large stone)
• Hard urethral lump (impacted stone)
• Haematuria |
INVESTIGATIONS
• Urinalysis
• Urine culture
• Blood urea, electrolytes and creatinine
• Plain x-ray of abdomen.
• Ultrasound scan of abdomen
The following tests are usually available in Teaching and Regional hospitals:
• Serum calcium, uric acid, phosphorus, oxalates
• 24 hour urine calcium, and phosphorous
• Intravenous urogram
• Retrograde ureteropyelogram
• Stone analysis
TREATMENT
Therapeutic objectives
• To control pain during acute attack
• To aid passage of the calculus or ensure complete removal of calculus
• To prevent recurrence if the cause is known
Treatment depends on the location of the calculus
A. Kidney/Ureteric stone
(Evidence rating: C)
• Admit
• Give parenteral analgesic for pain e.g. Pethidine, IM, 100 mg 4 hourly as required or Diclofenac, IM or by suppository, 75 mg 12 hourly
CAUTION: Avoid morphine as it may cause further ureteric spasm and worsening of symptoms
• Give antibiotics if urinary tract infection is present. (see section on urinary tract infection)
• Encourage fluid intake.
B. Bladder/Urethral stone
• Manage acute urinary retention by urethral catheterisation or suprapubic cystostomy
REFER
Refer to a Regional or Teaching hospital for definitive treatment after initial management.
