The life-sustaining capacity of human polymerized hemoglobin when red cells might be unavailable.

Background: Human polymerized hemoglobin (PolyHeme, Northfield Laboratories, Evanston, IL) is a universally compatible, immediately available, disease-free, oxygen-carrying resuscitative fluid being developed as a red cell substitute for use in urgent blood loss. PolyHeme should be particularly useful when red cells may be temporarily unavailable. This article assesses survival at life-threatening RBC hemoglobin concentration ([Hb]) in massively bleeding patients who do not receive red cells.

Study Design: There were 171 patients who received rapid infusion of 1 to 20 units (1,000 g, 10 L) of PolyHeme in lieu of red cells as initial oxygen-carrying replacement in trauma and urgent surgery. The protocol simulated the unavailability of red cells, and the progressive fall in RBC [Hb] in bleeding patients was quantified. Thirty-day mortality was compared with a historical control group of 300 surgical patients who refused red cells on religious grounds.

Results: A total of 171 patients received rapid infusion of 1 to 2 units (n = 45), 3 to 4 units (n = 45), 5 to 9 units (n = 47), or 10 to 20 units (n = 34) of PolyHeme. Forty patients had a nadir RBC [Hb] < or = 3 g/dL (mean, 1.5 +/- 0.7 g/dL). But total [Hb] was adequately maintained (mean, 6.8 +/- 1.2 g/dL) because of plasma [Hb] added by PolyHeme. The 30-day mortality was 25.0% (10/40 patients) compared with 64.5% (20/31 patients) in historical control patients at these RBC [Hb] levels.

Conclusions: PolyHeme increases survival at life-threatening RBC [Hb] by maintaining total [Hb] in the absence of red cell transfusion. PolyHeme should be useful in the early treatment of urgent blood loss and resolve the dilemma of unavailability of red cells.