Fluorocarbons

Abstract

SummaryThi.s article presents injormation on medical upplications of jluorocarhons. These inert chemicals have a high .solubility for the respiratory guse. 7 and, in emulstjiedform, are present Keg wordsPharmucology; fluorocarbons.The dcvclopmcnt of blood substitutes capable of carrying and delivering substantial amounts of oxygcn. has proceeded along two different lines. Stroma-free haemoglobin solutions suffer from a short half-life in the circulation (approximately 20 minutes) and a P s 0 Iowcr than normal blood. The latter will deereasc oxygen availability in the tissues, while the high osmotic pressure of haemoglobin solutions limits both the concentration that can be used and the total oxygen flux. These problems are being overcome in various ways. such as micro-encapsulation with synthetic cell membranes or polymerisation of the haemoglobin molecule.2The other approach to the production of oxygen-transporting plasma substitutes involves the use of fluorocarbons. These substances are often known as perfluorocarbons or. more correctly, perfluorochemicals (PFCs): this paper briefly describes thcir properties and possible clinical applications. Fluorocarbon-containing blood substitutesThe physiological availability of oxygen dissolved in PFCs was dramatically demonstrated by Clark and G~l l a n .~ who were able to show survival o f mice completely immersed in these liquids for extended periods of time.Fluorocarbons can dissolve more rhan 50 volumes percent of oxygen arid more than 400 volumes of carbon d i~x i d e ,~ but are immiscible with blood. To avoid cmbolic phcnornena emulsions are used, and the Grccn Cross Cor-