Role of Calcium and Magnesium in Anesthesia and Critical Care

Calcium has an important role in large number of physiological actions that are essential for life. Abnormalities in serum calcium concentration may have profound effects on neurological, gastrointestinal, and renal function. Magnesium is the 4th common cation in body after sodium, potassium and calcium. Intracellular, it is the second most common cation after potassium. Magnesium is widely distributed in plant and animal foods, particularly green vegetables, spices, nuts, soya flour and shellfish. Hypo-magnesemia is reported in up to 20% of patients in medical wards and in as many as 65% of patients in ICUs. In fact, magnesium depletion has been described as “the most underdiagnosed electrolyte abnormality in current medical practice”. It is important therefore that the anaesthetist understands calcium and magnesium pathophysiology.