Source: Pai, AB. Disorders of Calcium
and Phosphorus Homeostasis. In: DiPiro, JT, Talbert RL, Yee GC, Matzke
GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach.
8th ed. http://www.accesspharmacy.com/content.aspx?aid=7983818.
Accessed August 18, 2012.
- Total serum calcium >10.5 mg/dL (>2.62 mmol/L)
- Most commonly caused by cancer and primary
of malignancy common complication with:
- Squamous cell carcinomas of the lung, head, and neck
- Multiple myeloma
- T-cell lymphomas
- Ovarian cancer
- Kidney cancer
- Bladder cancer
- Breast cancer
- Chronic hypercalcemia caused by:
- Endocrine and granulomatous disorders
- Physical immobilization
- High bone-turnover states (adolescence and Paget disease)
- Primary homeostatic mechanisms increased:
- Bone resorption
- Gastrointestinal (GI) absorption
- Tubular reabsorption by kidneys
- Parathyroid-related protein (PTHrP) secreted by tumors (especially
breast and squamous cell lung cancers).
- Binds to
receptors, resulting in enhanced bone resorption.
- Incidence of primary hyperparathyroidism in United States
ranges from 10–30 cases per 100,000 people; primarily occurs
- Hypercalcemia of cancer occurs in ~20–40% of
patients at some time in course of disease and predominantly seen
- Mild to moderate hypercalcemia (serum calcium <13 mg/dL [3.25
mmol/L]): often asymptomatic
- Severe hypercalcemia (serum calcium >13 mg/dL [3.25
- Rapid onset (e.g., hypercalcemia
- Hypercalcemic crisis
- Acute increase in serum
calcium to >15 mg/dL [>3.75 mmol/L])
- Acute renal insufficiency
- If untreated, progresses to oliguric renal failure, coma,
and life-threatening ventricular arrhythmias
- Chronic hypercalcemia (e.g., hyperparathyroidism)
- Metastatic calcification
- Chronic renal insufficiency
- Electrocardiogram (ECG) changes include shortening of QT interval
and coving of ST-T wave.
Means of Confirmation
- Serum calcium concentration >10.5 mg/dL (>2.62
to moderate hypercalcemia: up to 13 mg/dL (3.25 mmol/L)
- Severe hypercalcemia: >13 mg/dL (3.25 mmol/L)
- Metabolic panel
- Serum calcium
- Corrected total serum calcium calculated as follows:
- Corrected Sca (mg/dL) = measured
Sca (mg/dL) + [0.8 x (40 g/dL – measured
albumin (g/dL))] or Corrected Sca (mmol/dL) = measured
Sca (mmol/dL) + [0.02 x (40
g/L – measured albumin (g/L))]
- Serum albumin
- Renal tubular acidosis
- Reverse signs and symptoms
- Restore normocalcemia
- Correct or manage underlying cause
- Treatment depends on degree of hypercalcemia, acuity of
onset, and presence of symptoms requiring emergent treatment (Figure 1).
for acutely hypercalcemic patient. Serum calcium of 12 mg/dL equivalent
to 3 mmol/L. (EKG, electrocardiogram.) Reprinted with permission
from Wells BG, DiPiro JT, Schwinghammer TL, et al. Pharmacotherapy
Handbook. 8th ed. New York: McGraw-Hill, 2012.
- Management of moderate to severe hypercalcemia in absence
of life-threatening symptoms begins with attention to underlying
condition and correction of fluid and electrolyte abnormalities.