## Abstract The relative merits of apheresis platelets and platelet concentrates are undergoing debate due to evolving issues of safety, inventory, and cost. The application of photochemical inactivation technology may eliminate any rationale for the use of apheresis platelets rather than pooled pl
PLATELET KINETICS AFTER TRANSFUSION
โ Scribed by Yasuhiro Saeki; Kazuko Tada; Toshio Sano; Yuji Takahashi
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 374 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0142-2782
No coin nor oath required. For personal study only.
โฆ Synopsis
A kinetics model is proposed for platelet disposition after transfusion of platelets. In this model, transfusion of platelets and production of endogenous platelets contribute to an increase in the number of platelets in patients, and the life span and age of each platelet contribute to a decrease. The time course of the number of platelets after transfusion of platelets is theoretically described by this model to be a straight line followed by a concave curve. When the platelets have a life span without any variation, a linear pattern is observed in spite of their different ages at the transfusion. This model with a constant life span was applied to three patients receiving platelet transfusion, and the model parameters were calculated by curve fitting the observed platelet levels to the model using the nonlinear least-squares method. As a result, the life span, distribution volume per body weight, and endogenous platelet level (averages for three patients) were calculated as 6.29 d, 0.137 L kg-I, and 1.40 x lo4 counts pL-', respectively. The calculated platelet levels in individual patients were compared with the observed ones during the next transfusions, and the relative and absolute differences between calculated and observed values were 2.0 f. 15.3% and -0.075 f 0.443 x 1 O4 counts pL-l (mean f SD, 15 observed points for three patients), respectively. These case studies suggest that the model could be clinically useful for individual platelet transfusion.
๐ SIMILAR VOLUMES
Platelet transfusions are widely used. Prophylactic transfusions are employed in severely thrombocytopenic patients without evidence of bleeding, but no randomized trial data prove the safety or efficacy of this approach. Randomized trials have demonstrated the equivalence of transfusion triggers of
Fig. 1. a: Brain CT (May 6, 1996). Suprasellar lesion with involvement of diencephalic and chiasmatic regions and extensive peri-lesion edema. b: Brain CT after CdA therapy (May 24, 1996). Complete regression of the brain lesion.
The level of 20x10(9)/L for prophylactic platelet transfusion has rightly been challenged over the last few years, with some units recommending a level as low as 5x10(9)/L. The higher levels are usually based on retrospective data from the 1950s. We examined the more recent data and came to the conc