Renal stones Flashcards
What are urinary tract stones also referred to as?
urolithiasis
What are kidney stones also referred to as?
nephrolithiasis
Where do stones tend to form?
- pelviureteric junction
- pelvic brim
- vesicoureteric junction
What is the peak age for urinary stone to form??
20-40
What are the different types of stones?which is the most common?
Calcium oxalate - 75%
Magnesium ammonium phosphate (struvite/triple phosphate - 15%)
Urate 5%
Hydroxyapatite 5%
How can urinary tract stones presents?
Asymptomatic or
- Pain + N&V
- Infection co-existing
- Haematuria
- Proteinuria
- Sterile pyuria
- Anuria
What is the character of pain that can be experienced with urinary stones?
Excruciating spasms of renal colic Loin to groin
Where is kidney obstruction pain felt?
loin between rib 12 and lateral edge of lumbar muscles
How does obstruction of mid-ureter present?
mimic appendicitis or diverticulitis
How can obstruction of lower ureter present?
sx of bladder irritability and pain in scrotum, penile tip or labia major
how does obstruction in bladder or urethra present?
pelvic pain
dysuria
strangury - desire but inability to void
+/- interrupted flow
What blood tests would u order
FBC U&E ESR/CRP Ca2+ PO43- Glucose Bicarb Urate
What urine tests would u do
- Urine dipstick + culture - usually +ve for blood
- MSU:
i. MC+S
ii. Urine pH
iii. 24hr urine for: calcium, oxalate, urate, citrate, sodium, creatinine
What imaging would u do
- Non-contrast CT KUB(99% visible)
- KUB XR (80% visible)
- US for hydronephrosis or hydroureter
What is the initial treatment of renal stones/colic?
diclofenac 75mg IM/IV
If CI: opioids
+ IV fluids if unable to tolerate PO
Abx if infection
What is rx of stones <5mm
90-95% pass spontaneously
What is rx of stones >5mm/pain not resolving?
Medical expulsive therapy:
- Nifedipine PO or alpha-blockers
- Extracorporeal shockwave lithotripsy (ESWL) or ureteroscopy using a basket
- Percutaneous nephrolithotomy
What intervention is used to remove large, multiple or complex stones?
percutaneous nephrolithotomy
What are the indications for urgent intervention?what is the intervention
- presence of infection AND obstruction
- urosepsis
- intractable pain or vomiting
- impending AKI
- obstruction in a solitary kidney
- bilateral obstructing stones
What is rx of stone present w infection and obstruction?
percutaneous nephrostomy or ureteric stent
What are the general preventative measures for stones?
drinks plenty
normal dietary calcium intake
What is prevention of calcium stones?
in hypercalciuria, thiazide diuretic to reduce Ca2+ excretion
What is prevention of oxalate stones?
reduce oxalate intake
e.g. darker coloured fruits and veg
What is the prevention of struvite stones?
treat infection (stones form readily in urine of those that are infected w ammonia producing organisms)
What is the prevention of urate crystals?
allopurinol
What is the prevention of cystine stones
vigorous hydration to keep UO >3L/day and urinary alkalinisation
What are the causes of calcium stones?
high fluid intake low animal protein, low salt diet (a low calcium diet has not been shown to be superior to a normocalcaemic diet) thiazides diuretics (increase distal tubular calcium resorption)
when do stones become an emergency?what is the treatment?
when ureteric stones cause obstruction in the presence of infection rx: - nephrostomy tube placement - ureteric catheter - ureteric stent
