It does not come as a surprise that hemoglobin solutions improve oxygen delivery and consumption in severely anemic swine. However, changes in P-50 do not appear to modify oxygen dynamics over a large range of hematocrits. This is quite a surprise, considering the efforts taken by the manufacturers to produce a solution that possess the optimal characteristics of hemoglobin with respect to oxygen delivery. Thus, other mechanisms must be at play at the cellular level.

– J.-F. Hardy.