Clinical Chemistry: Estimation of Serum Calcium PDF

Almaaqal University Clinical Chemistry ESTIMATION OF SERUM CALCIUM Dr/ Wael Sobhy Darwish Lab-2  Calcium Calcium is one of the most important minerals in the body, required for proper functioning of muscles, nerves, heart, as well as essential in blood clotting and bo...

Almaaqal University Clinical Chemistry ESTIMATION OF SERUM CALCIUM Dr/ Wael Sobhy Darwish Lab-2  Calcium Calcium is one of the most important minerals in the body, required for proper functioning of muscles, nerves, heart, as well as essential in blood clotting and bone formation. There are two types of calcium blood tests: Total calcium: This test measures the calcium attached to certain proteins in your blood and “free” or unattached calcium. Ionized calcium: This test measures the calcium that is unattached or "free" from certain proteins in your blood.  Corrected calcium Corrected calcium which is the measured calcium value adjusted for the albumin concentration. This is because abnormally high or low albumin concentrations can alter total calcium concentration independently of ‘ionised’ (active) calcium concentration. Therefore, ‘adjusted calcium’ gives a better indication of the ‘ionised’ levels. Urine calcium is used to indicate how much calcium is being excreted by the kidneys. Calcium is tested to help diagnosis, and monitor a range of conditions relating to the bones, heart, nerves, and kidneys. The amount of calcium in the blood is controlled by parathyroid hormone (PTH) 1, 25-dihydroxyvitamin D (Vitamin D). Calcitonin  When is it requested? Calcium can be used as a diagnostic test if individuals have symptoms that suggest:: kidney stones bone disease, or neurologic (nerve-related) disorders. Doctor may also request a calcium test if individuals have: kidney disease, because low calcium is common in those with kidney failure Symptoms of excessive calcium, such as thirst, frequent or excessive urination, constipation, tiredness, weakness, loss of appetite or nausea and vomiting symptoms of low calcium, such as abdominal/muscle cramps, tingling fingers, numbness around the mouth. Urine calcium may be requested if individuals have symptoms of kidney stones  Sample Fresh serum collected in the fasting state is the preferred specimen. Serum or plasma should be separated from blood cells as soon as possible, because prolonged contact with the clot may cause lower calcium value. Calcium in serum is stable for 7 days at room temperature, 10 days refrigerated at 4 C and for one month when frozen.  PROCEDUREIPLE Many colorimetric methods have been developed for the determination of calcium Mix, and Incubate for 5 minutes at room temperature. Measure the absorbance of specimen (Aspecimen) and standard (Astandard) against reagent blank. The color is stable for 60 minutes.  PROCEDURE Wavelength 575 nm 540-600 nm Cuvette 1 cm light path Temperature 20-25 0C Zero adjustment against reagent blank Expected Value Normal blood calcium level for adults is 8.5 to 10.2 milligrams/deciliter However, laboratories may have different reference ranges for normal blood calcium levels. Corrected calcium = serum calcium + 0.8 * (4 - serum albumin)  What does the result mean Hypercalcemia ❑Hyperparathyroidism ❑Cancer ❑Hyperthyroidism ❑Sarcoidosis ❑Tuberculosis ❑Acute kidney injury ❑Excess Vitamin D intake Hypocalcemia Hypoparathyroidism. Vitamin D deficiency Kidney failure (renal failure). Hypomagnesemia. Pancreatitis Celiac disease or other conditions that cause malabsorption. Certain medications and diets can also decrease your blood calcium levels.  Is there anything else I should know? Blood and urine calcium measurements cannot be used to assess how much calcium is in the bones. A test similar to an X-ray, called a bone density or 'Dexa' scan, is needed for this purpose. THANKS