17 - Renal Stones Flashcards
How are different stones in the urinary tract classified?
- Staghorn if filling numerous major and minor calices
- Non-staghorn can be calyceal or pelvic
- Ureteral are proximal, middle or distal
What measurements does a kidney stone have to be to require intervention?
- Less than 5mm high chance of being passed
- 5 to 7mm 50% chance of being passed
- Over 7mm require intervention
What are some symptoms of kidney stones?
- Renal colic (flank pain) as stone makes passage down urinary tract
What are some ways of surgically removing kidney stones?
- Ureteroscopy with laser
- Percutaneous Nephrolithotomy (PCNL)
- Shock wave lithotripsy
What is the composition of different types of kidney stones?
- Calcium Oxalate and Calcium Phosphate (80%)
- Uric acid (9%)
- Struvite (10% - bacteria infection with urease enzyme)
- Drugs, cystine, ammonium acid urate (1%)
(composition due to supersaturation in urine at time of formation)
What is the aetiology of renal calculi?
- Hypercalcuria
- Urinary infection with pseudomonas, klebsiella
- Diet high in table salt
- Furosemide
- Cystinuria
- Ketogenic diet
How do we diagnose urolithiasis and what are some differentials?
- Loin to groin pain and haematuria
- CT
- Ultrasound
- Ruptured AA, pancreatitis, appendicitis
How do we treat urate stones?
Usually can be treated by alkalinisation
How does electric shock wave lithotripsy work for renal calculi and how can you tell if this method will work?
- If less than 2cm and can be localised with imaging you can us this technique
- Can’t use if in lower pole calyx
What is cystinuria and what does it predispose to?
Autosomal recessive, high concentrations of cysteine in urine, leading to the formation of cystine stones in the kidneys, ureter, and bladder
Usually why paeds have calculi
What should you do before performing a PCNL?
DMSA split function to check the kidney is working so not wasting time
When would we see ketonuria?
- Diabetic individuals
- Febrile illness
- Cachexia
What are some promoters and inhibitors of kidney stones?
How can we prevent someone from getting recurring kidney stones?
