Kidney Stones and Urinary Tract Obstruction Flashcards
What are the types of kidney stones?
Calcium Oxalate 40%
Mixed calcium/phosphate 25%
Triple phosphate 10%
Calcium phosphate 10%
Urate 5-10%
Cystine 1%
Xanthine < 1%
What is the most common type of kidney stone?
Calcium oxalate
Which stones are opaque on imaging?
Start of alphabet
Calcium oxalate
Mixed calcim oxalate/phosphate
Triple phosphate
Calcium phosphate
Cystine, semi opaque
Which stones are radio-luscent on imaging?
End of alphabet
Urate stones
Xanthine stones
Which stones are associated with acidic urine?
Uric acid
Which stones are associated with alkaline urine?
Struvate
Calcium phosphate
Which stones are associated with variable urine pH?
Calcium oxalate
Which stones are associated with normal pH?
Cystine
Calcium phosphate
What type of kidney stone is known as ‘stag horn’?
Struvite/triple phosphate
What is the prognosis of kidney stones?
50% will reoccur within 10 years
Which group are kidney stones more common?
M>F
3:1
What can cause kidney stones?
Idiopathic
Dehydration
Infection
Obstruction
Hyperparathyroidism, hypercalcaemia, hypercalciuria
Polycystic kidney disease
Renual tubular acidosis
Drugs
How do kidney stones present?
Asymptomatic
Severe colicky loin pain, radiating to groin, testicles/vulvula
N&V
Dysuria
Oliguria
Haematuria
Strangury
Persistent urinary infection
Pyrexia/signs of sepsis
What investigations are used in kidney stone diagnosis?
Urinalysis and culture
FBC and CRP for associated infection
U&E’s and creatinine
Ca2+ and urate to assess type ofs tone
Non contrast KUB CT within 14 hours of admission, diagnostic investigation
How are kidney stones managed?
NSAID/IM diclofenac
CCB can often be used to aid spontaneous passage of stones
Stones less than 5mm will pass within 4 weeks of symptom onset
Nephrostomy tube placement, insertion of ureteric catheters or ureteric stent placement in obsturction
Shockwave lithotripsy
Ureteroscopy and stenting
Percutaneous nephrolithotomy
What is appropriate management for stone burden of less than 2cm in aggregate?
Lithotripsy
What is appropriate management for stone burden of less than 2cm in pregnant females?
Uteroscopy
What is appropriate management for complex renal calculi and staghorn calculi?
Percutaneous nephrolithotomy
What is appropriate management for ureteric calculi less than 5mm?
Manage expectantly
How can renal stones be prevented?
Calcium
- High fluid intake
- Low salt diet
- Thiazide diuretics
Oxalate
- Cholestyramine reduces urinary oxalate secretion
- Pyridoxine reduces urinary oxalate secretion
Uric acid
- Allopurinol
- Oral bicarbonate
What pathogen is associated with staghorn kidney stones?
proteus mirabilius
What are the 3 locations of upper urinary tract obstruction?
Pelvic-Ureteric Junction
Ureter
Vesico-Ureteric Junction
What are the unilateral causes of urinary tract obstruction?
Pelvic-ureteric obstruction (congenital or acquired)
Aberrant renal vessels
Calculi
Tumours of renal pelvis
What are the bilateral causes of urinary tract obstruction?
Stenosis of the urethra
Urethral valve
Prostatic enlargement
Extensive bladder tumour
Retro-peritoneal fibrosis
