[Biophysical mechanisms of toxicity of fluorocarbon emulsions]

Intravenous administration of emulsions of some perfluorochemicals (PFCs) are followed by lung gas-exchange alterations, lung inflation and animal death. The emulsion toxicity can be caused by both low aggregation stability of the emulsion in the blood stream and appearance of the additional gas pressure in alveoli as a result of difference in the rates of alveolar gas and PFC vapor diffusion. Theoretical and experimental analysis shows that (1) absence of emulsion particle aggregation into blood stream, (2) low pressure of saturated vapors of PFC phase and (3) relatively low rate of PFC expiration from the organism are essential conditions for the creation of a safe fluorocarbon blood substitutes.