The hypocalcemic disorders: differential diagnosis and therapeutic use of vitamin D.
2011; Academic Press; Linguagem: Inglês
Autores
Thomas O. Carpenter, Karl Insogna,
Tópico(s)Thyroid and Parathyroid Surgery
ResumoPublisher Summary Hypocalcemia refers to an abnormally low concentration of ionized calcium in extracellular fluid, almost invariably sampled from the bloodstream. Hypomagnesemia or hyperkalemia may present with findings similar to those caused by hypocalcemia, which can be exacerbated in the setting of hypocalcemia. Conversely, hypermagnesemia or hypokalemia can mask symptoms in a hypocalcemic individual. Furthermore, a mineralization defect, distinct from rickets, has been described in hypoparathyroidism; however, these skeletal consequences appear to be more prevalent in normal individuals living in conditions of endemic calcium deficiency, where secondary hyperparathyroidism develops. A number of clinical guidelines have been suggested to correct for the effect of a reduced serum albumin on total serum calcium concentration. One commonly cited rule of thumb is to add 0.8 mg/dl to the total serum calcium for every 1g/dl decline in serum albumin below 4.0 g/dl. However, these estimates have been shown to be somewhat inaccurate under many circumstances, and it is preferable to directly determine the ionized calcium concentration in the setting where the total serum calcium measure is thought to not accurately reflect the concentration of ionized calcium.
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