Hypercalcemia

Background

• High >10.5 meq/L (>2.7 ionized)
• High! >12.0 meq/L
• 90% of cases assoc w/ malignancy or hyperparathyroidism
• Symptoms most correlated w/ rate of rise of Ca, not absolute level

Clinical Features

1. Stones
   1. Renal calculi
2. Bones
   1. Bone pain/destruction
3. Groans
   1. Abd pain, N/V, constipation
4. Moans
   1. Lethargy/confusion/Hallucinations
5. Also:
   1. Polyuria/polydipsia
   2. Dehydration
   3. Renal insufficiency

Diagnosis

1. ECG
   1. Prolonged PR & QRS
   2. Shortened QT
   3. Depressed ST
   4. Widened T waves
   5. Bradyarrhythmias / heart block

Work-Up

1. Calcium
2. Phosphate
3. Lipase
4. UA
5. ECG

Differential Diagnosis

• Malignancy
• Hyperparathyroidism
• Lithium
• Thiazides
• Hypothyroidism
• Addison's
• Paget's
• Sarcoid
• Hyperthyroid
• Milk-alkali syndrome
• Excess vit D
• Calciphylaxis

Treatment

1. Treatment based on calcium level
   1. Asymptomatic or mildly symptomatic hypercalcemia (Ca <12)
      1. Does not require immediate treatment
      2. Advise to avoid factors that can aggravate hypercalcemia (thiazide diuretics, Li, volume depletion, prolonged inactivity, high Ca diet)
   2. Asymptomatic or mildly symptomatic w/ chronic moderate hypercalcemia (Ca between 12-14)
      1. May not require immediate therapy; however, an acute rise may cause symptoms necessitating treatment as desdcribed for severe hypercalcemia (see below)
   3. Severe hypercalcemia (Ca >14) or symptomatic hypercalcemia are usually dehydrated and require saline hydration as initial therapy
      1. Consider isotonic saline at 200-300 mL/hour; adjust to maintain urine output at 100-150 mL/hour
      2. Consider adding calcitonin 4 units/kg SC or IV q12hr in pts w/ Ca >14 mg/dL (3.5 mmol/L) who are also symptomatic (lowers Ca w/in 2-4hr)
         1. Lowers Ca within 2-4hr
      3. Bisphosphonates
         1. Give for severe hypercalcemia due to excessive bone resorption (lowers Ca within 12-48hr)
         2. Pamidronate 90mg IV over 24 hours
         3. Zoledronate 4mg IV over 15 minutes
2. Electrolyte Repletion
   1. Correct hypokalemia
   2. Correct hypomagnesemia
3. Furosemide is NOT routinely recommended
   1. Consider in pts w/ renal insufficiency or heart failure to prevent fluid overload
4. Dialysis if:
   1. Anuric
   2. ARF
   3. CHF
   4. Calcium level >18
5. Decrease Ca mobilization from bone
   1. Corticosteroids
      1. Prednisone 60mg PO qd
      2. Helpful w/ steroid-sensitive tumors (e.g. lymphoma, MM)

See Also

• Hypercalcemia of Malignancy

Source

• Tintinalli
• Uptodate