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

Mnemonic: Stones, Bones, Groans, Moans, Thrones, Psychic Overtones

Stones

• Renal calculi

Bones

• Bone pain/destruction

Groans

• Abdominal pain and vomiting
• Dehydration

Thrones

• Polyuria/polydipsia (Renal insufficiency)
• Constipation

Psychic Overtones

• Lethargy/confusion/Hallucinations

Differential Diagnosis

Causes of Hypercalcemia

• Addison's disease
• Calciphylaxis
• Excess vitamin D
• Hypercalcemia of malignancy
• Hyperparathyroidism
• Hyperthyroidism
• Hypothyroidism
• Lithium
• Milk-alkali syndrome
• Paget disease
• Sarcoidosis
• Thiazide diuretics

Diagnosis

Work-Up

• Calcium
• Phosphate
• Lipase
• UA
• ECG

ECG Findings

• Prolonged PR & QRS
• Shortened QT
• Depressed ST
• Widened T waves
• Bradyarrhythmias / heart block

Treatment

Asymptomatic or Ca <12 mg/dL

• Does not require immediate treatment
• Advise to avoid factors that can aggravate hypercalcemia (thiazide diuretics, Li, volume depletion, prolonged inactivity, high Ca diet)

Mildly symptomatic Ca 12-14 mg/dL

• May not require immediate therapy; however, an acute rise may cause symptoms necessitating treatment as described for severe hypercalcemia (see below)

Symptomatic or Severe hypercalcemia (Ca >14 mg/dL)

• Pts are likely dehydrated and require saline hydration as initial therapy

Hydration

• Isotonic saline at 200-300 mL/hour; adjust to maintain urine output at 100-150 mL/hour

Calcitonin

• Consider adding calcitonin 4 units/kg SC or IV q12hr in patients w/ Ca >14 mg/dL (3.5 mmol/L) who are also symptomatic (lowers Ca w/in 2-4hr)

Bisphosphonates

Give for severe hypercalcemia due to excessive bone resorption (lowers Ca within 12-48hr)

• Pamidronate 90mg IV over 24 hours OR
• Zoledronate 4mg IV over 15 minutes
• Caution in renal failure, though bisphosphonates have been safely used in pts with pre-existing renal failure

Electrolyte Repletion

• Correct hypokalemia
• Correct hypomagnesemia

Diuresis

• Furosemide is NOT routinely recommended
• Only consider in patients with renal insufficiency or heart failure and volume overload

Dialysis

Consider if patient:

• Anuric with Renal Failure
• Failing all other therapy
• Severe hypervolemia not amenable to diuresis
• Serum Calcium level >18mg/dL

Corticosteroids

Decrease Ca mobilization from bone and are helpful w/ steroid-sensitive tumors (e.g. lymphoma, MM)

• Prednisone 60mg PO daily

See Also

• Hypercalcemia of Malignancy