Is hypercalcemia immediately life-threatening ? A prospective study.

Abstract

Objective: Hypercalcemia is often considered as an emergency because of a potential risk life-threatening arrhythmias or coma. However, there is little evidence, apart from case studies, that hypercalcemia can be immediately life-threatening. The aim of our study was to assess prospectively, if hypercalcemia (Ca ≥ 3 mmol/L) was associated with immediately life-threatening complications.

Design and methods: We conducted a prospective observational study aiming to include the first one hundred patients aged ≥ 18, who had a calcium concentration ≥ 3 mmol/L, admitted to the Emergency Department. The primary outcome was the number of life-threatening cardiac arrhythmias (ventricular tachycardia, ventricular fibrillation, sinus arrest and 2nd or 3rd degree atrioventricular blocks) or neurological complications defined by a Coma Glasgow Score < 9 during the stay on the ED. The secondary outcomes were correlation between calcium concentrations and ECG QTc intervals, Coma Glasgow Scores and mortality at 7 days and 12 months.

Results: Median calcium concentration was 3.3 mmol/L (3.1-3.7). Cancer was the first cause of hypercalcemia. No patient presented a life-threatening cardiac arrhythmia during stay on the ED. Three patients presented a life-threatening neurological complication. There was no correlation between calcemia and QTc intervals or Coma Glasgow Score. Prognosis was poor, 43 patients died during the 12 months.

Conclusions: We found no cases of immediately life-threatening cardiac arrhythmias. Three patients had indeed a life-threatening neurological complication but always had at least one other major factor which could severely alter mental status such as profound metabolic acidosis.