Urinary Tract Calculi Flashcards
What are urinary tract calculi formed from.
Crystal aggregates.
Where do renal stones for.
Stones form in the collecting ducts and may be deposited anywhere from the renal pelvis to the urethra.
What are the three classical locations for renal stones to get stuck. (3)
Pelviureteric junction.
Pelvic brim.
Vesicoureteric junction.
What is the lifetime incidence of renal stones.
15%.
What is the peak age for renal stones to develop.
20-40.
What is the male:female ratio for renal stones.
3:1.
What type of renal stones are there. (7)
Calcium oxalate (75%). Magnesium ammonium phosphate (struvite/triple phosphate) 15%. Urate (5%). Hydroxyapatite (5%). Brushite. Cystine (1%). Mixed.
What are the typical presentations of renal stones. (13)
Asymptomatic, Renal colic. Renal obstruction. Obstruction of mid-ureter. Obstruction of lower ureter. Obstruction in bladder or urethra. UTI. Haematuria. Proteinuria. Sterile pyuria. Pyonephritis. Pyonephrosis. Anuria.
What are the features of renal colic. (3)
Loin to groin pain.
Nausea/vomiting.
Patient cannot lie still (differentiates from peritonitis).
What are the features of renal obstruction. (3)
Felt in the loin (between rib 12 and lateral edge of lumbar muscle).
Not colicky, more like nerve irritation.
Worse with specific movement, pressure on the specific location.
What are the features of obstruction of mid ureter.
The pain mimics that of diverticulitis/appendicitis.
What are the features of obstruction of lower ureter by a renal stone. (2)
May lead to symptoms of bladder irritability.
Pain in scrotum, penile tip or labia majora.
What are the features of obstruction in bladder or urethra caused by a renal stone. (4)
Pelvic pain.
Dysuria.
Strangury (desire to void, but inability to do so).
Interrupted flow.
What are the features of pyelonephritis. (5)
Fever. Rigors. Loid pain. Nausea. Vomiting.
What is pyonephrosis.
Infected hydronephrosis.
What are the features on examination of a patient with renal stones. (3)
No tenderness on palpation.
May be renal angle tenderness (especially to percussion if there is retroperitoneal inflammation).
What blood tests are usually done in a patient with renal stones. (7)
FBC. UandEs. Calcium. Phosphate. Glucose. Bicarbonate. Urate.
What is the usual result of a urine dipstick in a patient with renal stones.
Positive for blood (90%).
Why is an MSandC done in suspected renal stones.
To rule out infective cause of pain (eg UTI).
What is the imagine technique of choice for detecting a renal stone.
Spiral non contrast CT (99% of stones are visible).
If a KUB XR is done in a patient with suspected renal stones, where do you look on the film for the stones.
Along the ureters for calcification over the transverse processes of the vertebral bodies.
What is the initial management for a patient with renal stones. (3)
Analgesia (diclofenac PR is the best pan relief).
IV fluids.
Antibiotics (cefuroxime or gentamicin) if infected.
What is the management for stones
90-95% will pass spontaneously.
Increase fluid intake.
What is the management for stones >5mm which are causing pain and not resolving. (6)
Medical expulsion therapy:
Nifedipine PO or alpha blocker promote expulsion and reduce analgesia requirements.
Start treatment at presentation.
Most will pass within 48h (>80% after 30 days).
ESWL if
What is ESWL.
Uses ultrasound waves to shatter the stone.
What are the potential side effects of ESWL. (3)
Renal injury.
DM.
Raised BP.
What are the indications for urgent intervention in the case of renal stones. (6)
Presence of infection and obstruction. Urosepsis. Intractable pain or vomiting. Impending ARF. Obstruction in a solitary kidney. Bilateral obstructing stones.
What are some general methods for preventing renal stones. (2)
Drink a lot of water.
NORMAL dietary calcium intake.
What will a calcium oxalate stone look like on XR. (2)
Spiky.
Radio-opaque.
What will a calcium phosphate stone look like on XR. (3)
Smooth.
May be large.
Radio-opaque.
What will a magnesium ammonium phosphate stone look like on XR. (3)
Large.
Horny ‘staghorn’.
Radio-opaque.
What will a urate renal stone look like on XR. (3)
Smooth.
Brown.
Radiolucent.
What will a cystine stone look like on XR. (3)
Yellow.
Crystalline.
Semi-opaque.
What are some risk factors for renal stone development. (7)
Diet (foods rich in oxalate will increase stone formation).
Medications (diuretics, antacids, aspirin, allopurinol).
Recurrent UTIs.
Metabolic abnormalities (hypercalciuria, hypercalcaemia, cystinuria, hyperoxaluria, renal tubular acidosis).
Urinary tract abnormalities (horeshoe kidney, spnge kidney).
Foreign bodies (stents, catheters).
Positive FH.
What are the signs of an infection above a renal stone. (3)
Fever.
Loin tenderness.
Pyuria.
