Table 1 Differential diagnosis of Mg deficiency in the ICU setting
Gastrointestinal disorders |
 Prolonged nasogastric suction |
 Malabsorption syndromes |
 Extensive bowel resection |
 Acute and chronic diarrhea |
 Intestinal and biliary fistulae |
 Protein-calorie malnutrition (parenteral nutrition, anorexia, refeeding syndrome) |
 Acute hemorrhagic pancreatitis |
 Primary intestinal hypomagnesemia (neonatal) |
Renal loss |
 Chronic parenteral fluid therapy |
 Osmotic diuresis (glucose, mannitol, urea) |
 Hypercalcemia |
 Alcohol |
 Drugs (see Table 2) |
 Metabolic acidosis (starvation, ketoacidosis, alcoholism) |
 Renal diseases |
  Chronic pyelonephritis, interstitial nephritis, and glomerulonephritis |
  Diuretic phase of acute tubular necrosis |
  Postobstructive nephropathy |
  Renal tubular acidosis |
  Post-renal transplantation |
  Primary renal hypomagnesemia |