Background: Incubating blood with phosphoenolpyruvate decreases hemoglobin oxygen affinity (HOA). This study compared transfusion with phosphoenolpyruvate-treated blood and conventionally stored blood on oxygen consumption in acutely anemic dogs.

Methods: Dogs underwent isovolemic hemodilution (hematocrit = 10%). After 1 hour they were transfused to a hematocrit of 18% with control or phosphoenolpyruvate treated blood. Cardiac output, co-oxymetry, and hemoglobin P₅₀ measurements allowed calculation of oxygen consumption during anemia, and posttransfusion.

Results: Hemodilution doubled cardiac output. Transfusion with phosphoenolpyruvate-treated blood allowed greater O₂ consumption than control (8.31 ± 2.1 and 3.73 ± 0.11 cc/kg/mm). There were no differences in arterial or venous pO₂ or pH; there were marked differences in HOA, measured by posttransfusion P₅₀ (21 ± 3 versus 47 ± 4), and mixed venous O₂ saturation.

Conclusions: Decreased HOA results in increased O₂ consumption in dogs subjected to anemic hypoxia. Phosphoenolpyruvate-treated blood provides increased oxygen consumption at a similar hematocrit when compared with untreated banked blood.