Search results
Results from the WOW.Com Content Network
Platelet concentration in the blood (i.e. platelet count), can be measured manually using a hemocytometer, or by placing blood in an automated platelet analyzer using particle counting, such as a Coulter counter or optical methods. [47] Most common blood testing methods include platelet count in their measurements, usually reported as PLT. [48]
In a typical set of rules, a platelet donor must weigh at least 50 kg (110 lb) and have a platelet count of at least 150 x 10 9 /L (150,000 platelets per mm³). [2] One unit has greater than 3×10 11 platelets. Therefore, it takes 2 liters of blood having a platelet count of 150,000/mm³ to produce one unit of platelets.
EDTA-dependent agglutination. In some individuals, clinically insignificant antibodies may cause in vitro agglutination of platelets. As a result of platelet clumping, platelet counts reported by automated counters may be much lower than the actual count in the blood because these devices cannot differentiate platelet clumps from individual cells.
A normal human platelet count ranges from 150,000 to 450,000 platelets/microliter (μL) of blood. [4] Values outside this range do not necessarily indicate disease. One common definition of thrombocytopenia requiring emergency treatment is a platelet count below 50,000/μL. [ 5 ]
A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide information about the cells in a person's blood.The CBC indicates the counts of white blood cells, red blood cells and platelets, the concentration of hemoglobin, and the hematocrit (the volume percentage of red blood cells).
High platelet counts can occur in patients with polycythemia vera (high red blood cell counts), and is an additional risk factor for complications. [ citation needed ] A very small number of people report symptoms of erythromelalgia , a burning sensation and redness of the extremities that resolves with cooling, or aspirin or both.
Bleeding time may be affected by platelet function, certain vascular disorders and von Willebrand Disease—not by other coagulation factors such as haemophilia.Diseases that may cause prolonged bleeding time include thrombocytopenia, disseminated intravascular coagulation (DIC), Bernard-Soulier disease, and Glanzmann's thrombasthenia.
A hemocytometer. The two semi-reflective rectangles are the counting chambers. Loading a chamber Hemocytometer grid (see table). The hemocytometer (or haemocytometer, or Burker's chamber) is a counting-chamber device originally designed and usually used for counting blood cells.