Magnesium in the Critically Ill Patient.

Magnesium is an electrolyte essential for life and plays a crucial role in several biochemical and physiologic processes in the body. Dysmagnesemia, defined as the presence of either hypomagnesemia or hypermagnesemia, is common in critically ill patients and is associated with prolonged hospitalization and increased mortality. This article reviews: (1) magnesium homeostasis, the physiologic roles of magnesium in the body and measurement of magnesium; (2) causes of dysmagnesemia in the critically ill patient; (3) the clinical and biochemical manifestations of dysmagnesemia; and (4) treatment of dysmagnesemia.