Magnesium

Jurisdiction: JM Part B. States: North Carolina, South Carolina, Virginia, West Virginia. Type: Active LCD

Magnesium is an essential ion in the human body, playing an important role in practically every major metabolic and biochemical process, supporting and maintaining cellular processes critical for human life. Magnesium plays an important physiological role, particularly in the brain, heart, and skeletal muscles. As the second most abundant intracellular cation after potassium, it is involved in over 600 enzymatic reactions including energy metabolism and protein synthesis. Intracellular magnesium stores are found in high concentration in mitochondria, where this element plays a pivotal role in the synthesis of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate. 1 Measurement of magnesium levels is used as an index to (1) metabolic activity in the body such as, carbohydrate metabolism, protein synthesis, nucleic acid synthesis, contraction of muscular tissue and (2) renal function, because 95% of magnesium is filtered through the glomerulus is reabsorbed in the tubules. 2 Covered Indications Magnesium testing is considered reasonable and necessary under the following conditions: 1. H ypomagnesemia which can be induced by 2 major mechanisms: gastrointestinal or renal losses. Symptoms of low magnesium include: weakness, muscle cramps, confusion, irregular heartbeat, seizures. Conditions which can produce hypomagnesemia include but are not limited to the following 2 : cardiac arrhythmias proton pump inhibitors alcohol uncontrolled diabetes mellitus hypercalcemia posttransplant patients other acquired tubular dysfunction malabsorption syndromes familial renal magnesium wasting volume expansion aminoglycoside antibiotics nephrotoxicity amphotericin B nephrotoxicity cisplatin pentamidine calcineurin inhibitors digoxin malabsorption syndromes parenteral alimentation with inadequate magnesium content diarrhea diabetic ketoacidosis diuretic therapy hyperaldosteronism hypoparathyroidism hyperthyroidism prolonged intravenous (IV) therapy prolonged nasogastric suction antibodies targeting the epidermal growth factor (EGF) receptor 2. H ypermagnesemia which can be induced in 2 settings: when kidney function is impaired and /or when a large magnesium load is given, whether intravenously, orally, or as an enema. Symptoms of high magnesium include: muscle weakness, fatigue, nausea and vomiting, trouble breathing, cardiac arrest. Conditions which can produce hypermagnesemia include but are not limited to the following 2 : kidney impairment magnesium infusion oral magnesium ingestion magnesium enemas familial hypocalciuric hypercalcemia hypercatabolic states, such as tumor lysis syndrome diabetic ketoacidosis lithium ingestion milk alkali syndrome adrenal insufficiency rhabdomyolysis Limitations Services that are not reasonable and necessary cannot be covered by Medicare as published in CMS Internet-Only Manual, Pub. 100-08, Medicare Program Integrity Manual, Chapter 13, §13.5.4 Reasonable and Necessary Provision in an LCD and under Title XVIII of the Social Security Act §1862(a)(1)(A).