Urinary Tract Calculi Flashcards
What are urinary tract calculi?
crystal deposition within the urinary tract
AKA. nephrolithiasis.
What are the 4 types of stone in urinary tract calculi? List them from most common to least common
Calcium oxalate
Struvite
Urate
Cysteine
What is the most common cause of urinary tract calculi?
Idiopathic
Give 4 metabolic causes of urinary tract calculi
Hypercalciuria
Hyperuricaemia
Hypercystinuria
Hyperoxaluria
Give 2 non metabolic causes of urinary tract calculi
UTI
Drugs: Indinavir
Give 2 risk factors for urinary tract calculi
Low fluid intake
Structural urinary tract abnormalities (e.g. horseshoe kidney)
List 4 symptoms of urinary tract calculi
Often ASYMPTOMATIC SEVERE loin to groin pain Nausea + vomiting Urinary urgency, frequency or retention Haematuria
Describe the epidemiology of urinary tract calculi
COMMON
2-3% of general population
M > F
Age group affected: 20-50 yrs
Bladder stones more common in developing countries
Upper urinary tract stones more common in industrialised countries
List 3 signs of urinary tract calculi
Loin to lower abdominal tenderness
NO signs of peritonism
Signs of systemic sepsis if there is an obstruction + infection above the stone
What bloods should be taken in urinary tract calculi?
FBC: high WCC if infection U+Es: check renal function Calcium (Hyperparathyroidism) Urate (Uric acid high in Gout) Phosphate (hyperparathyroidism)
What urinalysis is performed in urinary tract calculi?
Dipstick: haematuria is common
MC+S: Infection
Why perform an X-ray KUB for urinary tract calculi?
X-Ray KUB
80% of kidney stones are radio-opaque
What imaging modalities are usually used in suspected renal tract calculi?
Non contrast CT: Calcification, Hydronephrosis
US (Pregnant/ Kids)
What is the acute management of urinary tract calculi?
Analgesia
Bed rest
Fluid replacement
Urine collection: try to retrieve any stone that has passed
Give 3 surgical interventions for urinary tract calculi?
Urethroscopy
Extracorporeal shock wave lithotripsy (ESWL)
Percutaneous Nephrolithotomy (PCNL)
What is Urethroscopy?
A scope is passed into the bladder + up the ureter to visualise the stone
Remove by basket or break up with a laser
If stone cant be removed, insert a JJ stent to allow urine drainage
What is extracorporeal shock wave lithotripsy?
Electromagnetic shockwave focused onto the calculus to break it up into smaller fragments that can pass spontaneously
Non-invasive
When is Percutaneous Nephrolithotomy performed?
For large, complex stones (e.g. staghorn calculi)
After making a nephrostomy tract, a nephroscope is inserted, which allows disintegration + removal of stones
What general management should you do for urinary tract calculi?
TREAT CAUSE
Depends on the cause e.g.
Parathyroidectomy if hypercalcaemia due to hyperparathyroidism
Allopurinol if hyperuricaemia
What advice can you give to patients prophylactically for urinary tract calculi?
Increase oral fluid intake
List 3 complications of urinary tract calculi
Infection (PYELONEPHRITIS)
Septicaemia
Urinary retention
Give 2 complications of ureteroscopy for urinary tract calculi
Perforation
False passage
What is the prognosis in urinary tract calculi?
GOOD
However, infection of the calculus could lead to irreversible renal scarring
Recurrence of about 50% over 5 yrs
What is the main ddx in older men?
Leaking AAA
What happens to most stones that are <5mm?
Pass spontaneously
How should an obstructed, infected kidney be treated?
As an EMERGENCY
Treat ASAP to relieve obstruction (e.g. by placing a percutaneous nephrostomy)
Give 2 complications of extracorporeal shock wave lithotripsy for urinary tract calculi?
Pain
Haematuria
