Search results
Results from the WOW.Com Content Network
The platelet increment is also known as the absolute count increment and count increment. [5] [10] PI = post-transfusion platelet count - pre-transfusion platelet count However, it is affected by the number of platelets given in the transfusion (platelet dose) and the patient's blood volume.
Higher platelet transfusion thresholds have been used in premature neonates, but this has been based on limited evidence. [19] There is now evidence that using a high platelet count threshold (50 x 10 9 /L) increases the risk of death or bleeding compared to a lower platelet count threshold (25 x 10 9 /L) in premature neonates. [20]
One common definition of thrombocytopenia requiring emergency treatment is a platelet count below 50,000/μL. [5] Thrombocytopenia can be contrasted with the conditions associated with an abnormally high level of platelets in the blood – thrombocythemia (when the cause is unknown), and thrombocytosis (when the cause is known). [6] [7]
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.
The diagnosis of NAIT is usually made after an incidental finding of a low platelet count on a blood test or because of bleeding complications ranging from bruising or petechiae to intracranial hemorrhage in the fetus or newborn. [6] Frequently, the reduction in platelet count is mild and the affected neonates remain largely asymptomatic. [6]
Tests in platelet rich plasma (close to real conditions in the body, but restrictions as to the terms of work), Tests in whole blood (the most adjusted to human physiology; the test can be started immediately; but the least convenient due to terms of blood storage and difficulties of the results' interpretation).
Normal count is in the range of 150 × 10 9 to 450 × 10 9 platelets per liter of blood, [1] but investigation is typically only considered if the upper limit exceeds 750 × 10 9 /L. When the cause is unknown, the term thrombocythemia is used, as either primary thrombocythemia or essential thrombocythemia .
This results in platelet activation and the formation of platelet microparticles, which initiate the formation of blood clots; the platelet count falls as a result, leading to thrombocytopenia. [1] [7] In addition, the reticuloendothelial system (mostly the spleen) removes the antibody-coated platelets, further contributing to the thrombocytopenia.