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Nephrology & Renal Medicine

Calcium Phosphate Nephrolithiasis (Brushite/Apatite)

ICD-10 Code
N20.0_4

Kidney stones predominantly composed of calcium phosphate. Favored by highly alkaline urine (pH > 6.5). Strongly associated with Distal Renal Tubular Acidosis (Type 1 RTA), primary hyperparathyroidism, and Topiramate use.

Clinical Presentation & Protocol

Patient Usually Complains Of

Patient presents with recurrent nephrolithiasis. Stone analysis confirms calcium phosphate (brushite/apatite) composition. History notable for [persistent alkaline urine / distal RTA / primary hyperparathyroidism / Topiramate use]. Symptoms include flank pain, hematuria, and dysuria. No history of urinary tract obstruction or infection at this time.

Clinical Examination Findings

Patient is alert and oriented, in mild distress secondary to flank pain. Vitals stable. Abdominal exam reveals tenderness at the costovertebral angle (CVA) on the [left/right] side. No palpable masses or organomegaly. Skin turgor is normal.

Treatment Protocol

Initiate metabolic workup including serum PTH, calcium, phosphorus, and 24-hour urine collection. Goal: Maintain urine pH < 6.5. Consider potassium citrate therapy if RTA is confirmed. Evaluate for Topiramate discontinuation if applicable. Increase fluid intake to ensure urine volume > 2.5L/day.

Detailed clinical guide coming soon.