Kidney Stones

Question 1

Calcium Oxalate

Answer 1

Due to: hyperparathyroidism, malabsorption, distal RTA

Envelope shaped crystals

Question 2

Uric Acid

Answer 2

Due to gout or myeloproliferative disorders

Rhomboid crystals, radiolucent

tx with urine alkalinization with citrate, allopurinol second line.

Question 3

Struvite

Answer 3

Recurrent urinary tract infections

Staghorn Calculi, coffin lid crystals

Question 4

Cystine

Answer 4

Due to decreased reabsorption of cystine in kidney

hexagonal crystals, large branched claculi

Generally stones present at young age (childhood/adolescence).

Question 5

Dietary interventions to reduce Ca stone recurrence

Answer 5

Reduce sodium (decreases urinary Ca excretion)
Reduce animal protein (decreases uric acid and Ca excretion).
Increase dietary Ca (binds to oxalate in gut –> dec absorption of oxalate) - not Ca supplement
Increase fluid
Increase citrate ingestion
Increase fruits and vegetables (increases citrate excretion in kidney).