Fluorinated blood substitutes and oxygen carriers

Perfluorochemicals (PFCs) are highly fluorinated, inert organic compounds that can dissolve large volumes of O2 and other respiratory gases. PFCs are unreactive in the body and excreted primarily as a vapour by exhalation. However, PFC liquids are immiscible with aqueous systems, including blood, but can be injected safely into the bloodstream as emulsions. Such emulsions are currently being assessed clinically as temporary, intravascular respiratory gas-carriers and tissue oxygenating fluids (so-called ‘blood substitutes’). One such emulsion, a commercial perflubron-based formulation, Oxygent™, is in advanced clinical trials as an alternative to allogeneic (donor) blood transfusion during surgery. Basic and clinical studies indicate that Oxygent™ can support O2 delivery to tissues during acute blood loss with no abnormal haemodynamic changes.