Pressure-aided transfusion of platelets: does it affect the platelets?

Background: In massively bleeding patients, pressure infusers are used for transfusion of red blood cells and plasma but not for platelets (PLTs) due to an assumed negative effect on the PLTs. This study examined whether pressure-aided in vitro transfusion affected the number, activation state, and/or function of the PLTs as measured by flow cytometry and thrombelastography (TEG).

Study Design And Methods: PLT concentrates stored for 1 (n = 8) or 8 (n = 7) days were transfused in vitro by means of a pressure inducer (300 mmHg). Samples before and after transfusion were measured for PLT concentration and expression of CD62P, CD63, and PAC-1. These activation markers were measured by flow cytometry on resting PLTs as well as PLTs stimulated with thrombin receptor-activating peptide. Clot generation and strength was examined by TEG by measuring the angle (degree) and maximum amplitude (mm), values that are highly dependent on the PLT function.

Results: PLT concentrations were unchanged after pressure-aided transfusion reflecting no destruction. With respect to activation state and in vitro functional capacity either no or only minor differences (<7%) were detected.

Conclusion: In this study, use of a pressure inducer decreased the transfusion time of in vitro PLT transfusion by approximately 50%. No or only minor and inconsistent changes of the PLT number and function were observed. Consequently, this study indicates that pressure infusers could be used for transfusion of PLTs if clinically indicated, that is, in massively bleeding patients. However, in vivo studies to assess the safety and utility of pressure-aided PLT transfusion are warranted.