Renal tract calculi Flashcards
What is the medical term for renal tract stones?
Urolithiasis
What is urolithiasis?
Renal tract stones
What are most urinary tract stones made up of?
Calcium (80%)
- as calcium oxalate, calcium phosphate or mixed
What is the most common pathophysiology for urinary tract stones?
Over-saturation of urine
- certain stone types are linked to underlying pathologies
What can different urinary tract stones be made of?
Calcium - oxalate or phosphate
Urate
Cystine
Struvite
What can cause urate stones to form?
High levels of purine in blood due to
- diet (e.g. red meats)
- haematological disorders
Name the three points where ureteric stones are most likely to impact
PUJ - pelviureteric junction
Crossing pelvic brim - where iliac vessels go across the ureter
VUJ - Vesicoureteric junction
How do ureteric stones commonly present?
Ureteric colic pain - sudden onset, severe + radiating from flank to pelvis Nausea + vomiting Haematuria - typically non visible Tenderness on examination
What are some differentials for flank pain?
Renal tract calculi Pyelonephritis Ruptured AAA Biliary pathology Bowel obstruction Lower lobe pneumonia MSK pain
What investigations can be done for renal stones?
Bloods
non- contrast CT scan (gold standard)
Abdo xray
Ultrasound scan - also can assess if any hydronephrosis - not good for finding the stones
Urine dipstick - to look for blood / any infection
Why are X-RAYs not as good as CT for renal stones?
As some stones are radio-lucent - so can’t be seen
How are renal calculi initially managed?
- rehydration / fluid resus
- analgesia
- antibiotics if any signs of infections
Many will pass spontaneously without the need for further intervention
How can renal calculi be treated?
Extracorporeal shock wave lithotripsy - for small stones
Percutaneous nephrolithotomy - for renal stones
Flexible uretero-renoscopy - scope is inserted then laser therapy + fragments removed
How can signs of obstructive nephropathy from renal stones be temporarily managed?
Retrograde stent insertion
Nephrostomy
What is a nephrostomy?
When an opening is made between the renal pelvis of the kidney and the skin. This allows drainage of blocked urine.
What are some complications of renal tract calculi?
Infection
Post renal AKI
Recurrent = scarring + decline in renal function
What condition can cause calcium stones to form?
Primary hyperparathyroidism - check PTH levels
What familial condition can cause cystine stones?
Homocystinuria (go over this)
What can cause bladder stones?
Urine stasis - chronic urinary retention
Secondary to infections such as schistosomiasis
Passed ureteric stones
How are bladder stones treated?
Cystoscopy - with lithotripsy if needed
What can chronic irritation of the bladder epithelium from bladder stones lead to?
Predisposition to squamous cell carcinoma bladder cancer
Which bloods should be done for urinary colic?
Xx
Why is diclofenac a good option of analgesia for renal tract calculi?
As it is an antispasmodic
