A stable liquid nanoemulsion of a volatile gas anesthetic, such as, isoflurane or sevoflurane, is disclosed which is effective in inducing and maintaining a state of anesthesia and/or general anesthesia in a patent. A method of preparation of stable liquid formulations of volatile gas anesthetics is presented, as well as a method for directly testing the concentration of a volatile gas anesthetic in a stable liquid formulation. A kit comprising an amount of a stable liquid formulation of a volatile gas anesthetic, and the non-specialized equipment for administration of the same to a patient, either in an operating room environment or in the field, is also described herein.