DRG Category: 640

Mean LOS: 5.1 days

Description MEDICAL: Nutritional and Miscellaneous Metabolic Disorders with Major CC

classification section:



Hypomagnesemia occurs when the serum magnesium concentration is less than 1.7 mg/dL (1.4 mEq/L). The normal serum magnesium level is 1.7 to 2.7 mg/dL (1.4 to 2.3 mEq/L). An average-sized adult has approximately 25 g of magnesium in her or his body. About 50% of the body's total magnesium is found in the bones, 1% is located in the extracellular compartment, and the remainder is found within the cells. The body's requirement is met by ingesting foods such as meat, milk, and chlorophyll-containing vegetables and fruits. The risk of hypomagnesemia is 2% in the general population, 10% to 20% in hospitalized patients, 50% to 60% in critically ill patients, 30% to 80% in alcohol-dependent patients, and 5% in diabetic outpatients.

Magnesium is regulated by vitamin D–regulated gastrointestinal (GI) absorption and renal excretion. Magnesium plays an important role in neuromuscular function. It also has a role in several enzyme systems, particularly the metabolism of carbohydrates and proteins, as well as maintenance of normal ionic balance (it triggers the sodium-potassium pump), osmotic pressure, myocardial functioning, and bone metabolism. Deficits of magnesium lead to deficits in calcium, and the two electrolyte imbalances are difficult to differentiate. The hypocalcemia that accompanies hypomagnesemia cannot be corrected unless the magnesium is replaced. Hypomagnesemia is also a stimulus for renin release, which leads to aldosterone production, potassium wasting, and hypokalemia. Because magnesium regulates calcium entry into cells, consequences of magnesium deficiency include ventricular dysrhythmias, an enhanced digitalis toxicity, and sudden cardiac death. Deficits in potassium and calcium potentiate the dysrhythmogenic effect of low magnesium.