Cryopreservation of Red Cells: Achievements and Prospective.

摘要

Preserved red cells are transfused to increase the delivery of oxygen to tissue. It is also essential that the preserved red cells circulate in order to increase the red cell mass and to improve the oxygen carrying capacity. The delivery of oxygen to tissue immediately after transfusion of preserved red cells depends to a great extent on their affinityh for oxygen. Red cells stored in ACD for 7 days at 4 C maintain their ability to carry oxygen, but their ability to release it is impaired. It was not until 1967 that the correlation between oxygen transport function and the red cell 2,3 DPG level was appreciated. More recently investigators have realized the importance of the oxygen delivering capacity or transfused red cells during the first 4 hours after transfusion. The well-being of certain patients may be placed in jeopardy if they are given preserved red cells that have increased affinity for oxygen, since the patient may not be able to meet the accompanying demand for increased blood flow, and the venous oxygen tension may fall to a critical level. Clearly, patients in hemorrhagic and septic shock, those subjected to extracorporeal circulation during cardiac surgery, and anemic patients with myocardial or cerebrovascular insufficiency can be handled most efficaciously by treating them with red cells that have 2,3 DPG levels that are either normal or about twice normal.