Hypercalcemia

Pt with h/o nephrolithiasis presents with lethargy/weakness, abdominal pain, flank pain, and confusion. Reports recent, excessive intake of vitamin D, calcium, and thiazide diuretic. Family history positive for sarcoidosis, breast cancer. HTN, irregular heartbeat, abdominal tenderness, flank pain, muscle weakness, and lower extremity edema on exam.

  • CMP shows corrected calcium > 10.5 mg/dL

    • Repeat CMP and re-evaluate serum calcium and creatinine levels

    • If repeat serum calcium elevated; obtain PTH level and serum ionized calcium

  • Obtain PTH level

    • PTH > 65 pg/mL: See primary hyperparathyroidism

    • PTH < 20 pg/mL: Obtain PTHrP, 1,25-dihydroxyvitamin D, and 25-dihydroxyvitamin D levels

      • Elevated PTHrP: Obtain CBC, and consider CXR, mammogram, abdominal CT, and/or serum electrophoresis

      • Elevated 1,25-dihydroxyvitamin D: Obtain CXR to r/o sarcoidosis, lymphoma

      • Elevated 25-dihydroxyvitamin D levels: Review all medications and counsel pt about vitamin D toxicity.

      • All levels normal: Consider obtaining TSH, serum protein electrophoresis, cortisol level, and/or vitamin A level

  • EKG shows peaked T waves

  • Treatment

    • Calcium < 14 mg/dL: Stop vitamin D, calcium supplementation and thiazide diuretic; encourage adequate hydration

    • Calcium > 14 mg/dL

      • Start normal saline at 250 mL/hr and adjust to maintain urine output of 100 mL/hr

      • Consider starting once-monthly pamidronate 90 mg IV

Notes