Solubility of volatile anesthetics in plasma substitutes,albumin, intravenous fat emulsions,perfluorochemical emulsion,and aqueous solutions

Using the gas chromatographic headspace sampling technique, we determined the solubility of volatile anesthetics (halothane, enflurane, isoflurane, and sevoflurane) in plasma substitutes, albumin solution, intravenous fat emulsions, perfluorochemical FC-43 emulsion, and aqueous solutions at 37°C. The order of magnitude of λ value (liquid/gas partition coefficients) was halothane >enflurane>isoflurane> sevoflurane in all the parenteral infusion fluids except the perfluorochemical emulsion (FC-43). The FC-43/gas partition coefficients of the volatile anesthetics were almost the same at 5.5. The partition coefficients were affected by the osmolarity of solutions, hydrophobicity, and the structure of solutes. Also, the blood/gas partition coefficients in intravenous fat emulsions and FC-43 were calculated. It is suggested that fluid therapy, especially with intravenous fat emulsions or FC-43, may influence the blood/gas partition coefficients of anesthetics, and affect the induction of anesthesia.