Oxygen transport by a modified haemoglobin solution (PPSFH) in a dog model of acute anaemia following hypovolaemia

Polymerised pyridoxylated stroma free haemoglobin (PPSFH) is a potential red cell substitute. We compared PPSFH to Succinylated Gelatin (SG) and autologous fresh blood (AFB) in a dog model. Three groups of dogs were subjected to a period of fluctuating hypovolaemia. Eight received AFB and had a final haematocrit (Hct) of 54% and total active haemoglobin level (WBod Hb) of 16.5 g/dl. Eight received SG, had a final Hct of 20% and WBod Hb of 5.6 g/dl. Eight received PPSFH, had a final Hct of 20% and a WBod Hb of 10.4 g/dl. Those dogs receiving AFB responded to the hypovolaemic stress by raising oxygen consumption by 27%, whereas in both those receiving SG and PPSFH, oxygen consumption fell by 15% (p=0.007). In the PPSFH group the PPSFH carried 43% of oxygen consumed. Thus, although PPSFH provided a higher circulating haemoglobin level than SG and carried a high proportion of oxygen consumed, it did not confer any advantage in terms of bulk oxygen transport.