A 54-year-old woman with breast cancer is brought to the emergency room with progressive confusion, anorexia, constipation, weight loss, and weakness. Vital signs are:
BP 94/57 mm Hg
HR 87 beats/min
SaO2 96% on RA
On examination, she is drowsy but easily arousable and oriented to person. Her neurologic examination is otherwise unremarkable. Lab studies are notable for:
What is the most appropriate initial treatment?A. 0.9% normal saline infusion with furosemide
Correct Answer: B
Hypercalcemia accounts for 0.6% of hospital admissions. It can present with a variety of nonspecific symptoms that affect multiple organ systems. Symptoms include neurological disturbances (ranging from anxiety and confusion, to lethargy and coma), gastrointestinal disturbances (anorexia, nausea, constipation, and pancreatitis), renal dysfunction (polyuria, dehydration, AKI), and musculoskeletal abnormalities (weakness, cramping). ECG may show a shortened QT interval, and in severe cases of hypercalcemia, arrhythmias and ventricular tachycardia may be present. Severity of symptoms correlates with the severity of hypercalcemia.
Up to 90% of the cases of hypercalcemia are due to hyperparathyroidism and malignancy (lung cancer, multiple myeloma, and renal cell). Other causes, however, include medications (thiazide diuretics, antacids such as calcium carbonate, vitamin A and D supplements, and lithium), immobilization, granulomatous diseases (sarcoidosis), and thyrotoxicosis. When an elevated plasma calcium level is identified, it should be confirmed to ensure true hypercalcemia (serum calcium level is affected by albumin concentration, and hypoalbuminemia falsely elevates the serum calcium level). In addition ionized calcium levels should be interpreted in the context of the patient’s pH. Parathyroid hormone level and serum phosphorus level should also be measured.
Treatment of hypercalcemia depends on the severity of the patient’s symptoms. While asymptomatic patients can be treated on an outpatient basis, symptomatic patients and those with significantly elevated calcium levels should be hospitalized for IV fluid therapy. If a malignancy is detected as the underlying cause of hypercalcemia, the patient should undergo definitive treatment for malignancy, if possible.
IV fluid therapy with 0.9% NS is the cornerstone of treatment of patients with hypercalcemia. Dehydration is secondary to decreased intake (anorexia, nausea) and increased urine output (polyuria). Calcitonin is quick acting and can be given for initial stabilization in addition to IV fluids. Bisphosphonates take 48 hours to work and are utilized for longterm management of hypercalcemia. Furosemide is no longer recommended due to the risk of dehydration and lack of evidence of benefit.