Resistant Hypercalcemia
| Autor: | Omotosho YB; CMS-RFUMS Internal Medicine Residency Program at Northwestern McHenry Hospital, Zahra F; Northwestern Mchenry/RFMUS |
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| Jazyk: | angličtina |
| Zdroj: | 2021 Jan. |
| Abstrakt: | Hypercalcemia is referred to as serum calcium (Ca) level over two standard deviations above the average mean values. That equates to the total serum calcium level greater than 10.5 mg/dl or ionized calcium level greater than 5.3 mg/dl.[1] Normal serum calcium levels often range from 9.0 to 10.5 mg/dl. However, values may vary across laboratories. Only about 45% of serum calcium is in the free or ionized state; almost half of the serum concentration is bound to albumin, and about 10% is partially bound to small ions, including phosphate and citrate.[2] Any state of dehydration or the process of hemoconcentration that occurs during venipuncture can falsely elevate total serum albumin levels and falsely account for elevated total serum calcium levels, whereas ionized calcium may remain normal. Changes in blood pressure can also alter serum albumin–calcium-binding. That is, alkalosis enhances binding, whereas acidosis decreases binding. Also, factors that cause low serum albumin levels, such as malnutrition and liver cirrhosis, will lead to falsely low reported serum calcium levels. Therefore, calcium levels must be corrected for abnormal serum albumin levels before the diagnosis of hypercalcemia can be established. This can be calculated as the measured total serum calcium (Mg/dL) + [4.0 - serum albumin (g/dL) X 0.8] or, measured total serum + [40 - serum albumin (g/L) X 0.02].[3] Hypercalcemia can be grouped based on serum calcium levels as follows: Mild hypercalcemia, which is total serum calcium ranging between 10.5 mg/dL and 11.9 mg/dL. Moderate hypercalcemia, which is total serum calcium level ranging between 12 mg/dL and13.9 mg/dL. Hypercalcemic crisis which is total serum calcium above 14 mg/dL. Resistant hypercalcemia can be defined as persistently elevated calcium levels despite multiple therapy modalities or if re-administration is required within two weeks of initial therapy.[4] (Copyright © 2021, StatPearls Publishing LLC.) |
| Databáze: | MEDLINE |
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