Hypercalcemia in the ED: prevalence, etiology, and outcome.

Purposes: The aim of the study was to describe the prevalence, demographic, and clinical characteristics and etiologies of hypercalcemia in emergency department patients.

Basic Procedures: In this retrospective cross-sectional descriptive study, all patients admitted between April 1, 2008, and March 31, 2011, to the emergency department of Inselspital, University Hospital Bern, were screened for the presence of hypercalcemia, defined as a serum calcium exceeding 2.55 mmol/L after correction for serum albumin. Demographic, laboratory, and outcome data were gathered. A detailed medical record review was performed to identify causes of hypercalcemia.

Main Findings: During the study period, 14 984 patients (19% of all admitted patients) received a measurement of serum calcium. Of these, 116 patients (0.7%) presented with hypercalcemia. Median serum calcium was 2.72 mmol/L (first quartile, 2.64; third quartile, 2.88), with 4.3 mmol/L being the maximum serum calcium value observed. Underlying malignancy in 44% of patients and hyperparathyroidism in 20% (12% secondary and 8% primary) were the leading causes of hypercalcemia. Twenty-six percent of patients presented with symptomatic hypercalcemia. Weakness was the most common symptom of hypercalcemia, followed by nausea and disorientation.

Principal Conclusions: Hypercalcemia is a rare but harmful electrolyte disorder in emergency department patients. Unspecific symptoms such as a change in mental state, weakness, or gastrointestinal symptoms should prompt physicians to order serum calcium measurements, at least in patients with known malignancy or renal insufficiency.