Abstract: Perfluorinated alkylcyclohexane and alkyl cyclopentane derivatives of the empirical formula C10F20 boil at atmospheric pressure in the range of 144-146° C. and are utilized as mediums for gas transport in liquid ventilation and in artificial blood. Compounds of the C10F20 formula which can exist only as a single stereoisomer are preferred as mediums for gas transport.

Abstract: Perfluorotetramethylcyclohexane shows improved properties for use in biological gas exchange, both as a blood substitute and as perfluorocarbon for intra-pulmonary applications. The material has an adequately low vapor pressure to completely avoid causing hyperinflated lung damage and to increase the interval between required applications. However, the compound has a sufficiently high vapor pressure to produce acceptably brief residence time within the body. A method has been developed for using this novel compound to accelerate the exhalation of very low vapor pressure compounds such as perfluorophenanthrene from the lungs. The addition of perfluorotetramethylcyclohexane, along with perfluorophenanthrene, greatly increases the rate at which the perfluorophenanthrene is exhaled.

Abstract: A method of assisting a mammal having a lung disorder to breathe ambient gas normally, i.e., without the assistance of a ventilator. The method includes providing an animal having a lung disorder, such as surfactant deficiency, stiff lung, or hyperinflated lung syndrome, and instilling a minimum effective dose of a perfluorochemical liquid or emulsion through the trachea for coating the alveolar sacs of a lung of the mammal. The preferred perfluorochemicals have a very low vapor pressure to avoid inducing hyperinflated lung syndrome and are supplied in a minimum effective dosage sufficient to coat the inner lung surfaces. The perfluorochemicals are permeable to the ambient gas and reside substantially permanently within the alveolar sacs without inducing hyperinflated lung syndrome. The liquid is instilled in an amount sufficient to enable the animal to breathe the ambient gas normally with O.sub.2 /CO.sub.2 blood gas exchange. Effective coating of the lungs with a small (generally <0.

Abstract: A method of assisting a mammal having a lung disorder to breathe ambient gas normally, i.e., without the assistance of a ventilator. The method includes providing an animal having a lung disorder, such as surfactant deficiency, stiff lung or hyperinflated lung syndrome, and instilling a perfluorochemical liquid into the trachea for administration in the alveolar sacs of a lung of the animal. The perfluorochemical is permeable to the ambient gas and resides substantially permanently within the alveolar sacs without inducing hyperinflated lung syndrome. The liquid is instilled in an amount sufficient to enable the animal to breathe the ambient gas normally with O.sub.2 /CO.sub.2 blood gas exchange. In another aspect of the invention, the method further includes the step of alleviating the lung disorder without inducing hyperinflated lung syndrome.