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 (in addition to saline hydration) only in patients with calcium >14 mg/dL (3.5 mmol/L) who are also symptomatic (Grade 2B). (See 'Severe hypercalcemia' above and 'Calcitonin' above.)

1. Volume Repletion
   1. Goal UOP = 500cc/hr
   2. Start NS @ 250-500cc/hr until pt is euvolemic; then decrease to 100-150cc/hr
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. Calcitonin
      1. 4 units/kg SC or IV q12hr
      2. Lowers Ca within 2-4hr
   2. Corticosteroids
      1. Prednisone 60mg PO qd
      2. Helpful w/ steroid-sensitive tumors (e.g. lymphoma, MM)
   3. Bisphosphonates
      1. Lowers Ca within 12-48hr
      2. Pamidronate 90mg IV over 24 hours
      3. Zoledronate 4mg IV over 15 minutes

See Also

• Hypercalcemia of Malignancy

Source

Tintinalli