Högman C F, Knutson F
Department of Clinical Immunology and Transfusion Medicine, University Hospital, Uppsala, Sweden.
Transfusion. 2000 Mar;40(3):330-4. doi: 10.1046/j.1537-2995.2000.40030330.x.
Current practice for the preparation of RBCs from whole blood for transfusion results in poorly standardized contents of RBC Hb. The principle of apheresis, metering the anticoagulant into the collected blood, which is pumped into an empty container, allows variation in the collected volume according to properties of the donor.
The total Hb mass of each person in a representative group of Swedish blood donors was evaluated by using Hb concentration and blood volume (BV), with the latter calculated from each donor's weight and height. The number of blood units that could be collected without exceeding 13 percent of the BV was estimated at a standardized content of RBC Hb set at 40, 45, and 50 g.
With Hb standards of 45 and 50 g per unit of RBCs, it would be possible to collect 1 unit, but not more, from 93 female donors in the study; with 40 g of Hb as the standard, 2 units could be collected from 6 percent of the donors. Using a standard of 40 g of Hb, it would be possible to collect 2 units or more from 95 percent of 121 male donors. The corresponding figures at Hb standards of 45 and 50 g were 81 and 50 percent, respectively, of the male donors. The largest number of units that could be collected would thus be obtained at a 40-g Hb standard. However, the greatest total mass of RBC Hb would have been obtained at 45 g. Even the yield of plasma would reach a maximum at this RBC Hb standard.
Depending on the donor's Hb and BV, it is possible to collect either 1 or 2 units of RBCs without exceeding 13 percent of any donor's BV, provided the collected volume of blood in each unit is less than the current standard. Such practice would allow better use of the donor population. Two-unit blood collections may reduce donor exposure in transfusions. Applying a standard at 45 g of RBC Hb per unit was found to permit the collection of maximum RBC Hb and plasma in the evaluated population of Scandinavian donors. Perhaps it is time to discuss a change in current rules for the preparation of RBCs for transfusion.
目前从全血制备用于输血的红细胞的做法导致红细胞血红蛋白含量的标准化程度较差。单采术的原理是将抗凝剂计量加入收集的血液中，然后将血液泵入一个空容器，这使得收集的血量会根据献血者的特性而有所变化。
通过使用血红蛋白浓度和血容量（BV）评估一组具有代表性的瑞典献血者中每个人的总血红蛋白质量，后者根据每个献血者的体重和身高计算得出。在设定的红细胞血红蛋白标准化含量为40、45和50克时，估计在不超过血容量13%的情况下可以采集的血液单位数量。
以每单位红细胞血红蛋白标准为45克和50克时，在该研究中的93名女性献血者中有可能采集1个单位，但不会更多；以40克血红蛋白为标准时，6%的献血者可以采集2个单位。以40克血红蛋白为标准时，在121名男性献血者中有95%可以采集2个单位或更多。血红蛋白标准为45克和50克时，相应的男性献血者比例分别为81%和50%。因此，在40克血红蛋白标准下可以采集到的单位数量最多。然而，在45克时可获得的红细胞血红蛋白总质量最大。即使血浆产量在这个红细胞血红蛋白标准下也会达到最大值。
根据献血者的血红蛋白和血容量，在每个单位采集的血量少于当前标准的情况下，有可能采集1个或2个单位的红细胞而不超过任何献血者血容量的13%。这种做法将能更好地利用献血人群。采集两个单位的血液可能会减少输血时献血者的暴露。发现在评估的斯堪的纳维亚献血者人群中，采用每单位红细胞血红蛋白45克的标准能够采集到最多的红细胞血红蛋白和血浆。或许是时候讨论改变当前制备用于输血的红细胞的规则了。
