title: Potency of mixtures of general anaesthetic agents.
abstract: The anaesthetic potencies of binary mixtures of the gases argon (Ar), nitrous oxide (N2O) and sulphur hexafluoride (SF6) have been measured using mice. The mixtures SF6-N2O and N2O-Ar showed additive behaviour, whereas the constituents of the mixture SF6-Ar were non-additive, having a smaller total potency than expected. Further experiments on this mixture with Italian Great Newts and on the carbon tetrafluoride mixtures CF4-Ar and CF4-SF6 with mice suggested that the anomalous potencies may arise from specific pulmonary effects associated with the breathing of SF6 accompanied by a high pressure of some other gas.
mesh_terms: D000769:Anesthesia, Inhalation; D000818:Animals; D001128:Argon / Q000494:pharmacology*; D005617:Chlorofluorocarbons, Methane / Q000494:pharmacology; D004357:Drug Synergism; D005459:Fluorides / Q000494:pharmacology*; D005740:Gases / Q000494:pharmacology; D051379:Mice; D009609:Nitrous Oxide / Q000494:pharmacology*; D013455:Sulfur / Q000494:pharmacology; D014319:Triturus
chemical_list: D005617:Chlorofluorocarbons, Methane; D005740:Gases; D001128:Argon; D013455:Sulfur; D009609:Nitrous Oxide; D005459:Fluorides