Renal Calculi - Kidney Stones Flashcards
What is Renal Calculi?
Kidney stones that develop through a complex process of precipitation and aggregation of ionic salts
When do Renal Calculi form?
Form when ionic salts such as calcium oxalate, calcium phosphate, uric acid, and struvite precipitate from the urine due to supersaturation.
Where does Renal Calculi usually take place?
Typically occurs in the renal collecting ducts
What happens as the crystals aggregate?
They solidify and can form small stones.
Mot stones increase in size as they move through the renal pelvis
What can small calculi cause?
Haematuria - blood in the urine, resulting from irritation and injury to the urinary tract lining.
Renal Colic - a characteristic unilateral spasmodic pain causes by the obstruction of the urine flow due to the stone’s position
What can Large Calculi cause?
Urinary stagnation - urine cannot flow past the obstruction, it leads to increased pressure within the renal system
Infection risk - stagnation creates an environment conducive to bacterial growth, leading to severe kidney infections such as pyelonephritis
Renal Failure - severe backflow of filtrate due to prolonged obstruction can compromise kidney function, leading to renal failure
Why is Dehydration a risk factor of Renal Calculi?
The kidneys respond by increasing water reabsorption from the renal tubules to conserve water.
This process does not alter the reabsorption of solutes
Urine becomes highly concentrated with solutes - creates an environment conducive to the crystallisation of the solutes leading to the formation of renal calculi
High solute concentration increases the likelihood of supersaturation, where the urine can no longer hold the dissolved substances promoting them to form stones
Why is infection a risk factor of Renal Calculi?
UTI produce inflammation responses and necrotic material, which can further enhance the conditions for stone formation
The necrotic tissue increases the rate of precipitation of urinary constituents as the presence of cellular debris can act as a nucleus for crystallisation
Infections may alter urine pH and composition, making it more favourable for certain types of stones
What are some other risk factors of Renal Calculi?
Males
>30 years of age
Previous history of renal calculi
Endocrinal disorders (eg hyperparathyroidism)
What is the treatment for Renal Calculi?
Pre-hospital treatment - Analgesia
No previous history - refer to ED to rule out
Previous history - treatment is usually elective rather than emergent
