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Hypercalcaemia: Difference between revisions
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(Created page with "'''Hypercalcaemia''' is a disorder of calcium homeostasis characterised by high levels of calcium (free calcium > 1,30 mmol/L). It's a relatively common electrolyte abnormality and is the opposite of hypocalcaemia. A free calcium level of > 2,00 is sometimes called a '''hypercalcaemic crisis'''. 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...") |
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<section begin="clinical biochemistry" />{{Infobox medical condition | |||
| name = Hypercalcaemi | |||
| definition = Free calcium > 1,30 mmol/L | |||
| cause = Parathyroid adenoma, malignancy | |||
| symptoms = Gastrointestinal symptoms, non-specific symptoms, polyuria, altered mental status | |||
| treatment = IV hydration, bisphosphonates, calcitonin | |||
| complications = Acute pancreatitis, nephrocalcinosis, diabetes insipidus, peptic ulcer | |||
}} | |||
'''Hypercalcaemia''' is a disorder of [[calcium homeostasis]] characterised by high levels of calcium (free calcium > 1,30 mmol/L). It's a relatively common electrolyte abnormality and is the opposite of [[hypocalcaemia]]. | '''Hypercalcaemia''' is a disorder of [[calcium homeostasis]] characterised by high levels of calcium (free calcium > 1,30 mmol/L). It's a relatively common electrolyte abnormality and is the opposite of [[hypocalcaemia]]. | ||
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== Diagnosis and evaluation == | == Diagnosis and evaluation == | ||
<section end="clinical biochemistry" /> | |||
=== Different ways to report calcium levels === | === Different ways to report calcium levels === | ||
There are three different ways the laboratory can report a patient's calcium levels. | There are three different ways the laboratory can report a patient's calcium levels. | ||
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A formula was developed to "correct" the total calcium level in case of hypoalbuminaemia. This formula, which the lab often calculates for you and reports as a separate, "albumin-corrected" calcium, unfortunately performs poorly clinically and has actually been shown to be a worse estimator of free calcium level than the uncorrected total calcium level. This formula overestimates the total calcium level and may therefore give a false diagnosis of hypercalcaemia or mask hypocalcaemia. Its use should therefore be avoided and free calcium should be measured instead. | A formula was developed to "correct" the total calcium level in case of hypoalbuminaemia. This formula, which the lab often calculates for you and reports as a separate, "albumin-corrected" calcium, unfortunately performs poorly clinically and has actually been shown to be a worse estimator of free calcium level than the uncorrected total calcium level. This formula overestimates the total calcium level and may therefore give a false diagnosis of hypercalcaemia or mask hypocalcaemia. Its use should therefore be avoided and free calcium should be measured instead. | ||
<section begin="clinical biochemistry" /> | |||
=== Checking the heart === | === Checking the heart === | ||
Hypercalcaemia can cause QT shortening, so [[ECG]] is indicated. | Hypercalcaemia can cause QT shortening, so [[ECG]] is indicated. | ||
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=== Determining the cause === | === Determining the cause === | ||
Measurement of PTH is obligatory as it can help determine the cause. The presence of hyperparathyroidism means a diagnosis of primary hyperparathyroidism is most likely. If the PTH is low, malignancy is the most likely cause and must be ruled out. PTHrP and 1,25-dihydroxyvitamin D should be measured. If PTHrP is elevated, the patient should undergo evaluation for malignancy. If it's negative and 1,25-dihydroxyvitamin D is elevated, granulomatous disease should be ruled out. | Measurement of PTH is obligatory as it can help determine the cause. The presence of hyperparathyroidism means a diagnosis of primary hyperparathyroidism is most likely. If the PTH is low, malignancy is the most likely cause and must be ruled out. PTHrP and 1,25-dihydroxyvitamin D should be measured. If PTHrP is elevated, the patient should undergo evaluation for malignancy. If it's negative and 1,25-dihydroxyvitamin D is elevated, granulomatous disease should be ruled out. | ||
<section end="clinical biochemistry" /> | |||
== Management == | == Management == | ||
Asymptomatic or mildly symptomatic hypercalcaemia does not require treatment. Severe hypercalcaemia or hypercalcaemia with severe symptoms requires treatment. | Asymptomatic or mildly symptomatic hypercalcaemia does not require treatment. Severe hypercalcaemia or hypercalcaemia with severe symptoms requires treatment. | ||
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Arrhythmias are not typical for hypercalcaemia but may occur in severe cases. | Arrhythmias are not typical for hypercalcaemia but may occur in severe cases. | ||
[[Category:Pathophysiology]] | <noinclude>[[Category:Pathophysiology]]</noinclude> | ||