Result of storage of packed RBCs

Answer: b) Decrease in 2-3DPG.* 2, 3-BPG is essential for the normal oxygen transport function of hemoglobin.* However, storing blood in the currently available media results in a decrease in 2, 3-PBG.* Stored blood displays an abnormally high oxygen affinity, and fails to unload its bound oxygen properly in the tissues.* Hemoglobin deficient in 2,3-BPG thus acts as an oxygen "trap" rather than as an oxygen transport system.* Transfused RBCs are able to restore their depleted supplies of 2,3-BPG in 6-24 hours.* However, severely ill patients may be compromised if transfused with large quantities of such 2, 3-BPG-"stripped" blood.* Note: The maximum storage time for red cells has been doubled (21 to 42 days, with median time of 15 days) by changes in H+, phosphate and hexose sugar concentration, and by the addition of adenine. Although the content of 2,3-BPG was not greatly affected by these changes, ATP production was increased and improved RBC survival.* Transfusion of large volumes of stored blood, which has a low level of 2,3-BPG can lead to sudden hypoxia, since it can cause a left-shifted ODC.