Internal Medicine

0521779407-09 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:13

740 Hypercalcemia

➣FBH: elevated Ca, elevated or normal Mg, low or normal

P, inappropriately normal (85%) or slightly elevated (15%)

PTH

➣Vitamin D toxicity: elevated Ca, P, 25-OH vitamin D, suppressed

PTH and PTHrP

➣Lithium: elevated Ca and intact PTH

■Urine

➣Cancer and HPTH: elevated Ca excretion

➣Myeloma: Bence Jones protein or M-spike

➣FBH: reduced Ca excretion (<100 mg/24 hours); Ca/creatinine

clearance (0.01)

➣Vitamin D toxicity, granulomatous disease: marked hypercalci-

uria

Specific Diagnostic Tests

■Skeletal lesions and bone marrow plasmacytosis in myeloma

■Elevated ACE levels in sarcoidosis

■Mutations in 1, calcium-sensing receptor (FBH), menin (MEN 1),

and ret oncogene (MEN 2)

differential diagnosis

■Common cancers: lung, renal, breast, squamous cell, myeloma;

rarely non-Hodgkin’s lymphoma

■Primary HPTH

■Family history of hypercalcemia – FBH or MEN syndromes

■Granulomatous disease: sarcoidosis, tbc, coccidioidomycosis, histo-

plasmosis, cryptococcosis

■Thyrotoxicosis

■Drugs: thiazides, lithium, vitamin A and D

■Rare: milk-alkali syndrome, immobilization

management

What to Do First

■Assess severity of hypercalcemia, dehydration, mental status

changes, cardiovascular status; monitor urine output

■Hydration with normal saline (200–500 ml/hour) to restore intravas-

cular volume, loop diuretics (Lasix 20 to 40 mg IV every 2 to 4 hours)

to induce natriuresis after volume repletion