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Hypocalcaemia: Difference between revisions
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<section begin="clinical biochemistry" />{{Infobox medical condition | |||
| name = Hypocalcaemia | |||
| definition = Free calcium (Ca2+) < 1,15 mmol/L | |||
| cause = Dysfunction of parathyroid gland, chronic kidney disease, vitamin D deficiency | |||
| symptoms = Tetany, paraesthesia, Trosseau sign, Chvostek sign | |||
| treatment = IV supplementation if severe, followed by oral supplementation. Correction of low magnesium and vitamin D | |||
| complications = Arrhythmia, seizures | |||
}} | |||
'''Hypocalcaemia''' is a disorder of [[calcium homeostasis]] characterised by low levels of calcium (free calcium < 1,15 mmol/L). It's a relatively common electrolyte abnormality and the opposite of [[hypercalcaemia]]. | |||
99% of the body's calcium is in the bones. The remaining 1% is in the blood. 40% of calcium in the serum is bound to albumin, 10% is bound to other anions (lactate and citrate), and the remaining 50% exists as free calcium ions (Ca<sup>2+</sup>) in the serum. It is the free calcium which is biologically active and therefore is used to diagnose hypocalcaemia. Bound calcium is inactive. | 99% of the body's calcium is in the bones. The remaining 1% is in the blood. 40% of calcium in the serum is bound to albumin, 10% is bound to other anions (lactate and citrate), and the remaining 50% exists as free calcium ions (Ca<sup>2+</sup>) in the serum. It is the free calcium which is biologically active and therefore is used to diagnose hypocalcaemia. Bound calcium is inactive. | ||
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=== Determining the cause === | === Determining the cause === | ||
Measurement of PTH, vitamin D, magnesium, and phosphorus levels is obligatory as they can help determine the cause. The presence of hypoparathyroidism indicates that hypocalcaemia is secondary to parathyroid gland dysfunction or destruction. Hyperparathyroidism is an appropriate physiological response to hypocalcaemia due to other causes than parathyroid pathology. | Measurement of PTH, vitamin D, magnesium, and phosphorus levels is obligatory as they can help determine the cause. The presence of hypoparathyroidism indicates that hypocalcaemia is secondary to parathyroid gland dysfunction or destruction. Hyperparathyroidism is an appropriate physiological response to hypocalcaemia due to other causes than parathyroid pathology. | ||
<section end="clinical biochemistry" /> | |||
== Management == | == Management == | ||
Asymptomatic hypocalcaemia, unless severe (<0,8), does not require treatment. | Asymptomatic hypocalcaemia, unless severe (<0,8), does not require treatment. | ||
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<references /> | <references /> | ||
[[Category:Pathophysiology]] | <noinclude>[[Category:Pathophysiology]]</noinclude> | ||