Biophysical properties of resuscitation fluids

The preliminary results of this study indicate that the biophysical characteristics of stroma-free hemoglobin solution (SFH) make it an extremely suitable blood substitute. At the concentration that is currently being considered as an infusing solution (70 g/L), it is a Newtonian fluid having a viscosity very similar to that of plasma. At this concentration, SFH also has very favorable hemodilution properties, as well as potential oxygen transport ability, which most expanders lack. There seems to be little interaction between the plasma proteins and SFH, as indicated from viscosity measurements. The osmotic behavior of SFH indicates that it approaches an ideal polymer-solvent system as illustrated by the small value of the second virial coefficient, especially when compared to other plasma substitutes. In mixtures with whole blood at a series of hematocrits, SFH seems to be hyperosmotic. This biophysical property could certainly have significance in patients with severe shock. SFH maintains the integrity of whole blood and does not initiate erythrocyte aggregation. The investigations of the erythrocyte sedimentation rate (ESR) in this study with SFH indicate the potential usefulness of SFH in maintaining stability of these systems, particularly during the treatment of shock. The transport properties of the red cell membrane are apparently not effectively altered by the presence of SFH. This has been illustrated in the hemolytic malonamide kinetic and osmotic fragility studies. Although the results are preliminary, it should be stressed that SFH may offer protection against hemolysis when used as a transfusion solution.