Renal Stones Flashcards
What are Renal Stones?
Urinary calculi form when urinary solutes exceed their maximum urinary solubility (Common Precipitates include Calcium, Struvite, Uric Acid, Cystine, Phosphate).
Patients with renal stones are at increased risk of pyelonephritis due to the stasis of urine
What will you find on a history taking of Renal Stones?
Symptoms: Lion Pain moving to the groin/testis Haematuria Urinary retention Fever – Pyelonephritis Nausea and vomiting Dysuria
Risk Factors: Men 30-50 years old Structural Urinary tract/renal deformity Family history Hypertension Gout Hyperparathyroidism Dehydration Diuretic Use
Differentials: Biliary Colic AAA rupture Pyelonephritis Acute abdomen – Appendicitis, pancreatitis Testicular Torsion
What will you find on examination of Renal Stones?
End of the bed:
Patient writhing in pain
Abdomen:
Loin Tenderness
May have reduced bowel sounds as a result of severe pain
Pain in testis but not tender to palpation
What investigations will you order in Renal Stones?
Bedside:
Urinalysis – Wil have haematuria, may have raised leukocytes and nitrites if infection has occurred
Urine culture – looking for infection
24-hour urine collection – Looking for precipitants e.g. Calcium, Phosphate, Urate
Bloods:
FBC – Looking for signs of infection
CRP – May be raised in infection
U&E – Looking for impaired renal function as a result of infection post obstructive AKI etc
Serum Calcium, Phosphate, Urate, Creatinine – Looking for cause of stone
Clotting if surgery indicated
Imaging:
CT scan – Will show any stones
Abdominal X-ray – Can be used to track movement of stone once it has been found on CT
Special Tests:
Stone analysis – In first time renal stones, recurrent stone formation on medical therapy. Get the patient to “catch the stone” with tea strainer etc
What is the treatment of Renal Stones?
Decide if patient requires home or hospital treatment (Indications for hospital admission are Fever, Unmanageable pain, Structural deformity, Anuria, Pregnancy, Inability to meet fluid requirements)
Hospital Management:
IV fluids if not able to meet requirement orally – 3L per day to flush it out
Analgesia – NSAIDs first line, Parenteral morphine second line
Antiemetics - To limit nausea and vomiting
Stone should pass in 1-3 weeks, X-ray weekly to track progress
Home Management:
Drink a lot of fluids – 3L per day
Analgesia: paracetamol for mild-to-moderate pain; codeine can be added if more pain relief is required.
Fast track referral to hospital via GP if needed
Void urine into a container or through a tea strainer to catch any identifiable calculus.
Stone should pass in 1-3 weeks, X-ray weekly to track progress
Surgical: If stone has not passed within 3 weeks or is causing obstruction (20% of stones require surgery)
If the ureter is blocked a JJ stent is usually inserted using a cystoscope as a short-term management. Long term treatment includes:
Extracorporeal shock wave lithotripsy (ESWL) - Shock waves break up the stone. The stone particles will then pass spontaneously.
Percutaneous nephrolithotomy –Stones are removed using nephoscopy (Used for larger stones)
Ureteroscopy – Laser therapy breaks up the stone. The stone particles will then pass spontaneously.
Open surgery – Rarely used, only in complicated cases or other failed surgical options
What is the treatment of recurrent renal stones?
Lifestyle: Preventative measures in patients prone to stones depends on the type of stone. Give prophylactic treatment as shown below
Recurrent UTI – Prophylactic Antibiotics
Calcium stones – Thiazide Diuretics, Low Na diet
Urate Stones - Allopurinol
Phosphate Stones – Ammonium Chloride
Oxalate Stones – Low Oxalate diet (less rhubarb, spinach)
Cystine Stones – Penicillamine
