Fluorocarbon emulsions: methodology to assess efficacy

The fluorocarbon emulsion Fluosol-DA (20%) is an acellular O2 carrier that has potential as a red cell substitute. Clinical evaluation of efficacy requires knowledge of the ability of the perfluorochemical (pfc) phase to both load and unload O2. A method is described to measure the oxygen dissolved in the pfc and aqueous phases, and the oxygen chemically bound to hemoglobin, during use of this drug. These O2 contents are used to calculate the contribution of the pfc phase to total O2 delivery and O2 consumption (VO2) and the fractional extraction of O2 in the pfc phase. The technique requires a blood gas analyzer, a microhematocrit centrifuge, and a standard co-oximeter found in many blood gas laboratories. This technique appears to be simple and reliable, and should facilitate the evaluation of efficacy of fluorocarbon emulsions.