Hypocalcemia

In neonates, hypocalcemia is more likely to occur in infants born of diabetic or preeclamptic mothers. Hypocalcemia also may occur in infants born to mothers with hyperparathyroidism. Clinically evident hypocalcemia generally presents in milder forms and is usually the result of a chronic disease state. In emergency department patients, chronic or subacute complaints secondary to mild or moderate hypocalcemia are more likely to be a chief complaint than severe symptomatic hypocalcemia. Once laboratory results demonstrate hypocalcemia, the first question is whether the hypocalcemia is true—that is, whether it is representative of a decrease in ionized calcium. The presence of chronic diarrhea or intestinal disease (eg, Crohn disease, sprue, chronic pancreatitis) suggests the possibility of hypocalcemia due to malabsorption of calcium and/or vitamin D. The patient's past medical history should be explored for pancreatitis, anxiety disorders, renal or liver failure, gastrointestinal disorders, and hyperthyroidism or hyperparathyroidism. Previous neck surgery suggests hypoparathyroidism; a history of seizures suggests hypocalcemia secondary to anticonvulsants. The patient may have a recent history of thyroid, parathyroid, or bowel surgeries or recent neck trauma. The length of time that a disorder is present is an important clue. Hypoparathyroidism and pseudohypoparathyroidism are lifelong disorders. Instead, acute transient hypocalcemia may be associated with acute gastrointestinal illness, nutritional deficiency, or acute or chronic renal failure. In an elderly patient, a nutritional deficiency may be associated with a low intake of vitamin D. A history of alcoholism can help diagnose hypocalcemia due to magnesium deficiency, malabsorption, or chronic pancreatitis. Inquire about recent use of drugs associated with hypocalcemia, including the following: Radiocontrast Estrogen Loop diuretics Bisphosphonates Calcium supplements Antibiotics Antiepileptic drugs Cinacalcet Other considerations in the history include the following: Family history of hypocalcemia Low-calcium diet Lack of sun exposure