Blood substitutes: where are we?

Plasma volume expanders exist and are available. Balance salt solutions are preferred for initial resuscitation. Albumin should be avoided. Synthetic coagulation factors are not available. They exist because proper component therapy creates them to be stored for selective use. A substitute for the prime function of blood--oxygen delivery by the red cell--does not yet exist. Its clear that one is needed; the form is not yet identified. Fluorocarbon emulsions have a certain chemical cleanliness that makes them appealing, yet there are many unanswered questions, especially as to oxygen-carrying capacity and toxicity. Fluorocarbons have been pushed to clinical testing before their time. Chemically modified stroma-free hemoglobin continues to evolve and develop as a useful blood substitute. Most of the early problems seem to have been resolved and a third generation of molecules, the second set of modifications, is promising.