Renal Tract Stones Flashcards
Also called
Renal calculi, urolithiasis and nephrolithiasis
ESSENCE
Hard stones form in renal pelvis, which travel down ureters
Assymptomatic until they irritate or get stuck in ureters
Most common point where stones get stuck
Vesico-ureteric junction
Two key complications
Obstruction (leading to acute kidney injuiry)
Infection with obstructive pyelonephritis
Types of stones
- Calcium based stones most common (80%)
- Calcium oxalate (most common)
- Calcium phosphate
- Other stones
- Uric acid - cannot see on x-ray
- Struvite - produced by bacteria so associated with infection
- Cystine - associated with cystinuria, autosomal recessive disease
AETIOLOGY
Risk factors for calcium based stones
- Hypercalcaemia
- Low urine output
What is staghorn calculus
Stones form in shape of renal pelvis, giving appearance similar to stags horn
Usually made of struvite
CLINICAL FEATURES
Presentation
- May be assymptomatic
- Renal colic
- Unilateral severe loin to groin pain
- Colicky (fluctuating in severity) as stone moves and settles
- Haematuria
- Nausea or vomiting
- Reduced urine output
- Symptoms of sepsis if infection present
INVESTIGATIONS
First choice
- Urine dipstick - haematuria
- Blood tests - infection and kidney function, serum calcium
- Abdominal x-ray - show stones
- CT KUB - investigation of choice for diagnosis
- US KUB - less preferred alternative
AETIOLOGY
Causes of hypercalcaemia
- Calcium supplementation
- Hyperparathyroidism
- Cancer (myeloma, breast or lung cancer)
Presentation of hypercalcaemia
“Renal stones, painful bones, abdominal groans and psychiatric moans”
MANAGEMENT
General principles
- Analgesia - NSAIDS
- Antiemetics - if nausea and vomiting
- Antibiotics - if infection
- Watchful waiting - if <5mm
- Tamsulosin (alpha blocker) - aid passage
- Surgical intervention
MANAGEMENT
Antiemetic options
Metoclopramide, prochlorperazine or cyclizine
MANAGEMENT
Surgical intervention options
- Extracorporeal shock wave lithotripsy (ESWL)
- Ureteroscopy and laser lithotripsy
- Percutaneous nephrolithotomy (PCNL)
- Open surgery
What is extracorpeal shock wave lithotripsy
External machine generates shock waves directed at stone under x-ray guidance
These break stone into smaller parts, making easier to pass
