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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>