Renal stones Flashcards
What are renal stones (nephrolithiasis)?
Crystalline deposits that form in the kidneys, commonly presenting with flank pain and hematuria.
What is the most common presenting symptom of renal stones?
Severe colicky flank pain, often radiating to the groin.
What urinary symptom often accompanies renal stone passage?
Hematuria (blood in the urine).
What systemic symptoms may occur with renal stones?
Nausea and vomiting, due to visceral pain.
What size of renal stones are more likely to pass spontaneously?
Stones smaller than 5mm.
What is the first-line conservative management for small renal stones?
Adequate hydration and analgesia.
What medication class can aid in the expulsion of ureteric stones?
Alpha-blockers, such as tamsulosin.
What is extracorporeal shock wave lithotripsy (ESWL)?
A non-invasive method using shock waves to break up kidney stones, especially effective for stones <2cm.
What is ureteroscopy (URS) used for in stone disease?
To directly visualize and remove or fragment ureteric stones via an endoscope.
What procedure is typically used for large renal stones (>2cm)?
Percutaneous nephrolithotomy (PCNL).
When is urgent urological intervention required in renal stone disease?
In cases of sepsis, obstructed infected system, solitary kidney, or uncontrolled pain/vomiting.
What imaging modality is preferred for diagnosing renal stones?
Non-contrast CT KUB (Kidneys, Ureters, and Bladder).
What complications can arise from untreated renal stones?
Hydronephrosis, renal failure, recurrent infections, or sepsis.
What substances commonly cause supersaturation and form stones?
Calcium, oxalate, uric acid, cystine, phosphate.
What are the four main types of renal stones?
Calcium stones, uric acid stones, struvite stones, cystine stones.
What type of renal stone is most common?
Calcium oxalate stones.
What promotes calcium oxalate stone formation?
Hypercalciuria, hyperoxaluria, low urine citrate, dehydration.
What dietary factors increase oxalate levels and contribute to stone formation?
High intake of spinach, nuts, tea, chocolate.
What urinary condition favors uric acid stone formation?
Persistently acidic urine (pH <5.5).
What medical conditions predispose to uric acid stones?
Gout, high purine diet, tumor lysis syndrome.
What type of stones are associated with urinary tract infections?
Struvite stones (magnesium ammonium phosphate).
What bacteria are commonly involved in struvite stone formation?
Urease-producing bacteria like Proteus and Klebsiella.
How do struvite stones form in the urinary tract?
Urease breaks down urea → ammonia → alkaline urine → precipitation of phosphate salts.
What rare hereditary condition causes cystine stone formation?
Cystinuria – a defect in renal tubular reabsorption of cystine.
What factors inhibit stone formation in urine?
Citrate, magnesium, adequate hydration.
How does dehydration contribute to renal stone formation?
Low urine volume increases concentration of stone-forming solutes, promoting crystallization.
What role does pH play in renal stone formation?
Acidic urine favors uric acid/cystine stones; alkaline urine favors calcium phosphate/struvite stones.
