Polymerized pyridoxylated hemoglobin: efficacy as an O2 carrier.

We have prepared a polymerized pyridoxylated hemoglobin solution (Poly SFH-P) with a normal [Hb] of 14 gm/dl and a normal COP of 20 torr. Although this normal [Hb] is a significant improvement over prior products, the P50 of 16-20 torr raises a concern about the ability of Poly SFH-P to effectively transport O2 in the presence of red cells with their normal P50 of 26 torr. This study quantitatively assessed the contribution of Poly SFH-P to total O2 delivery and consumption in the clinically relevant range of hematocrits. The results document that Poly SFH-P supports life at zero hematocrit, and makes significant contributions to total O2 delivery and consumption in the presence of red cells. Poly SFH-P permits a higher plasma [Hb], and has a longer intravascular persistence than any unpolymerized hemoglobin solution. Poly SFH-P is thus an effective O2 carrier, and offers greater potential than prior products as a clinically useful red cell substitute.