Effect of prophylactic transfusion of stored RBCs on oxygen reserve in response to acute isovolemic hemorrhage in a rodent model.
BACKGROUND
The storage of RBCs results in a time-related decline in 2,3 DPG that may reduce the ability to unload oxygen (O(2)) to tissue. The objective of this study was to compare the effect that transfusion of stored 2,3 DPG-depleted rat blood (7 days in CPDA-1) had on the O(2) reserve in conscious rats, with that of the transfusion of fresh blood (<2-hour storage).


METHODS
Anemic rats (Hb, 80 g/L) received either fresh packed RBCs or stored RBCs to raise Hb levels to 140 g per L. They then underwent isovolemic hemorrhage mimicking surgical blood loss to the point of O(2) supply dependency (OSD). Critical O(2) delivery (DO(2)crit), Hb concentration, and O(2) extraction at OSD were measured in a metabolic chamber.


RESULTS
After transfusion, RBC DPG decreased by 50 percent in the stored-blood group, and the p50 value decreased by 5 mmHg (32.1 +/- 2.5 mmHg vs. 37.5 +/- 3.0). DO(2)crit was similar in the two groups (fresh blood: 2.79 +/- 0.44 mL/min x g(-1); stored blood, 2.99 +/- 0.76 mL/min x g(-1)). The critical Hb concentration at DO(2)crit was higher in the stored-blood group (44 +/- 4 g/L) than in the fresh-blood group (38 +/- 5 g/L); the cardiac index and O(2) extraction ratio in the two groups were not different. Under conditions of severe normovolemic anemia in rats, depletion of DPG and a decrease in p50 had only minor effects on the O(2) reserve. At OSD, under these conditions, O(2) consumption is not limited by diffusion.


CONCLUSIONS
The physiologic impact of DPG depletion in transfused stored blood on oxygen availability in normal rats appears to be small and may be clinically inconsequential.
d'Almeida
M S
MS
Department of Hematology, A.C. Burton Vascular Biology Laboratory, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario, Canada N6A 4G5.
Gray
D
D
Martin
C
C
Ellis
C G
CG
Chin-Yee
I H
IH
D000740:Anemia / Q000209:etiology; D000818:Animals; D016063:Blood Loss, Surgical / Q000517:prevention & control; D001793:Blood Preservation; D017707:Erythrocyte Transfusion; D006470:Hemorrhage / Q000097:blood; D000860:Hypoxia / Q000517:prevention & control*; D008297:Male; D010100:Oxygen / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley
D010100:Oxygen