Perfluorochemical-based artificial oxygen carrying red cell substitutes.

There has been rapid progress in research on artificial oxygen-carrying red blood cell substitutes composed of perfluorochemical emulsions (PFE). PFE are capable of delivering significant amounts of oxygen to tissues, but FDA approval is given for routine human use they must first overcome concerns regarding adverse effects and then clearly demonstrate efficacy in human trials. Infusion of the first commercial product used in humans, Fluosol-DATM, which contained a relatively low concentration of perfluorochemical, was associated with immediate adverse effects in some individuals and failed to demonstrate efficacy in a prospective clinical trial. A second generation PFE artificial oxygen carrier, Oxygent-HTTM, should be more effective since it carries five-fold more oxygen than Fluosol, does not require mixing, and is more stable. Initial clinical trials of this and other second generation PFE were accompanied by mild, transient flu-like side effects. PFE are also being investigated for regional organ perfusion, tumor oxygenation prior to radiotherapy, contrast imaging, and for liquid ventilation of infants with respiratory distress syndrome. The development of a safe, effective, artificial oxygen carrier at reasonable cost will have a major effect on transition practice. Since PFE have a brief intravascular survival they are unlikely to supplant the use of red blood cells in treatment of anemia.