When bones are growing, liver cells are damaged, or a biliary obstruction occurs, alkaline phosphatase levels rise considerably. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding . Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
Many drugs affect the level of alkaline phosphatase in the blood.
Afterward, there may be some throbbing . Usually children are not measured because of the potential for such high amounts, so the abnormal results refer to adults. This test is usually performed as part of the Chem-20 battery. It should not be relied on for a screening test because sometimes levels are high for unknown reasons and return to normal. Veins and arteries vary in size from one patient to another and from one side of the body to the other.