RESUMEN
BACKGROUND: The purpose of this study is to examine whether the blood cells in the platelet concentrate (PC) and the PC arrangement method can affect the pH which is one of the important factors influencing the survival and function of the preserved PCs. METHOD: Two groups of CPDA-1 added PC were preserved at 20 ~ 24degrees C for 7 days. The PCs in group I were overlapped one another while those in group II were not overlapped and arranged separately during the preservation period. The number of RBC, WBC and platelets were measured at the first day of the preservation period while the pH was measured at the 1st, 3rd, 5th and 7th day. RESULTS: The number of blood cells in the PC was 0.6x109 for WBC, 1.6x109 for RBC and 800x109 for platelet. As for the average pH, the 1st day's average pH was 7.4 for group I and 7.3 for group II, while at the 7th day, both decreased by 0.6. According to the correlation analysis between the blood cells and the pH changes, as for group I, the more the number of platelets were, the lower the pH decreased, and as for group II, the more the WBC and platelets were, the lower the pH decreased. (p<0.01) CONCLUSION: This study indicates that the major parameter affecting the pH of the preserved PCs is the number of platelets. In addition to platelet, the number of WBCs affected the pH when PCs were overlapped during storage. Conclusionally the key factor which affects pH of stored PCs was the number of platelets. And the number of contaminated WBCs also were thought to be an important factor.