Frequency of Serum Ionized Hypomagnesemia in Patient with Ionized Hypocalcemia

Lim, Ji Hun; Kim, Young Chul; Kim, Yoon Hee; Chun, Sail; Min, Won Ki

Abstract

INTRODUCTION: Hypomagnesemia, major cause of hypocalcemia, is developed due to insufficient oral intake in hospitalized patient and high prevalence in intensive care unit (ICU) patient. It is important to monitoring ionized magnesium in ICU patient because hypomagnesemia has been implicated in the development of cardiovascular dysfunction. So, in this study we determine the relation between ionized calcium and ionized magnesium and validate the measurement of ionized magnesium. MATERIAL AND METHOD: From March 2005 to may 2005, total 2876 samples were enrolled, which was requested to measure ionized calcium. We measured ionized calcium and ionized magnesium using NOVA CCX (Nova Biomedical, Waltman, MA, USA). Reference range of ionized calcium and ionized magnesium was 3.9~4.5 and 1.1~1.5 mg/dL, respectively. The patients were grouped as adult above 18 years old and pediatric below 18 years old. The ward was intensive care unit (ICU), general ward, outpatient and emergency room. We investigate the frequency of hypocalcemia and hypomagnesemia.
RESULTS
The prevalence of ionized hypocalcemia (Ca2+ < 3.9mg/dL) was 22.2% and the prevalence of ionized hypomagnesemia (Mg2+ < 1.1mg/dL) was 41.9%. Of 2876 samples, 377 samples had ionized hypocalcemia and ionized hypomagnesemia simultaneously. Fifty-nine percent samples showing ionized hypocalcemia had ionized hypomagnesemia. In pediatric patients 13.3% of all patients had ionized hypocalcemia, 20.0% showing ionized hypercalcemia and 37.6% showing ionized hypomagnesemia. In adult patients 24.3% of all patients had ionized hypocalcemia, 14.3% showing ionized hypercalcemia, 48.2% showing ionized hypomagnesemia and one patient had ionized hypermagnesemia. When considering total cases of ionized calcium, the average level of ionized calcium was lowest in emergency room. When considering in case of patients, ICU showed the lowest level of ionized calcium.
CONCLUSION
Ionized hypomagnesemia had known to be one of the major causes of ionized hypocalcemia and is common in ionized hypocalcemia. It is easy to found by measuring simultaneously. We found high coincidence rate of ionized hypocalcemia and ionized hypomagnesemia. We recommend that all samples ordered to be measuring ionized calcium must be checked ionized magnesium simultaneously.