Hyperkalemia Hyperkalemia may only become apparent when a person's platelet concentration is more than 500,000/microL in a clotted blood sample (serum blood sample). Potassium leaks out of platelets after clotting has occurred. On the other hand, processing of heparinised, unclot blood does not cause falsely elevated potassium. In addition to that, high white cell count (greater than 120,000/microL) in patient with chronic lymphocytic leukemia increases red blood cells fragility, thus causing pseudohyperkalemia during blood processing. This problem can be avoided by processing serum samples, because formation of clot protect the cells from haemolysis during processing. A familial form of pseudohyperkalemia may
Dilute Russell's viper venom time specificity than the aPTT test for the detection of lupus anticoagulant, because it is not influenced by deficiencies or inhibitors of clotting factors VIII, IX or XI as the venom only activates factors V and X. Variations in the test can affect the results. The dRVVT is one component of a workup of a suspected antiphospholipid antibody, the other component being the serological testing for anticardiolipin antibodies and anti-β2 glycoprotein-I antibodies using ELISA technology. The Sapporo criteria require at least one of the above laboratory tests to be positive and the patient to have at least one clinical manifestation of