07-09-2006, 03:33 AM
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Due to the loss of 2,3 DPG which allows the blood to release 02, the 02 carrying capacity of stored blood is around 50% after 24 hours, whereas salvaged blood maintains almost full 02 carrying capacity - some references available:-
Quote:
Blood in cold storage contains glucose as a potential substrate for ATP production, but the glycolytic enzymes do not work well in the cold. Remember, DPG is produced as a byproduct of glycolysis. Thus, DPG levels decrease in refrigerated (stored) blood. Thus, if refrigerated whole blood is stored for too long, it becomes less efficient at O2 unloading, because it contains less DPG!
DPG decreases so much by the time the blood is 10 days old that the Hb affinity for O2 is actually increased such that less O2 is released from Hb which has been refrigerated for 10 days. For this reason, refrigerated blood is not normally stored beyond 21 days; if refrigerated blood older than 21 days is transfused, it picks up O2 at the lung but will not release the O2 at the tissues. Transfusion of blood older than 21 days actually impairs O2 transfer to the tissues. When older refrigerated blood is returned to the body, the levels of DPG present in the blood will gradually increase, but the initial decline in O2 carrying capacity following transfusion should be considered potentially dangerous.
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( THE HEMOGLOBIN PAGE )
Entrez PubMed
Chemical changes in stored blood, with observations on the effects of adenosine
2,3-diphosphoglycerate test
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