<unk>  can be defined in several different ways. All measures of platelet<unk>  are defined by the timing of the post-transfusion platelet count, usually 1 hour post<unk>  or 24 hours post<unk>  or both. Platelet increment (PI) This is the simplest method, and only requires data on the platelet count before and after the<unk> . The platelet increment is also known as the absolute count increment and count increment. PI = post-transfusion platelet count - pre-transfusion platelet count However, it is affected by the number of platelets given in the<unk>  (platelet dose) and the patient's blood volume. Larger patients and smaller platelet doses decrease the platelet increment. These factors are adjusted for in the other methods of defining platelet<unk> . A 1-hour post-transfusion PI of less than 5 to 10 x 109/l is considered evidence of platelet<unk> . Due to lack of data on platelet dose this is often the only measure of platelet<unk>  that can be performed in routine clinical practice. Percentage platelet recovery (PPR) Requires data on the platelet increment (PI), the patient's total blood volume (TBV) - estimated using the patient's weight multiplied by 0.075, and the number of platelets transfused (platelet dose) PPR = ((PI x TBV)/PD) x 100 At 1 hour post-transfusion, a PPR 2), and the number of platelets transfused (PD, in 1011). For example, a PI of 25,000 platelets/µl, a BSA of 1.8m2 and a PD of 4x1011 gives a CCI of 11,250 platelets*m2/1011µl At 1 hour post-transfusion a CCI greater than 7500 indicates a sufficient post-transfusion increment, whereas a CCI less than 7500 is considered diagnostic of platelet<unk> . At 24 hours post<unk>  a CCI less than 5000 suggests platelet<unk> . Platelet dose Some blood banks maintain records of the estimated number of platelets in each unit. Current requirements in the US stipulate that a unit of apheresis platelets must contain at least 3.0 x1011 platelets. In England only 1% of adult platelet components are tested to check the number of platelets meet the minimum required standard of 2.4 x 1011 platelets. Only components that contain fewer than 1.6 x 1011 platelets are discarded. This means that there can be a lot of variability in the number of platelets contained within each<unk> .
Platelet transfusion refractoriness
Pseudothrombocytopenia
COAT platelet defect
Platelet storage pool deficiency
Mechanical hemolytic anemia
Reticulocytopenia
Febrile non-hemolytic transfusion reaction
Transfusion-dependent anemia