title: [The closed system (author's transl)].
abstract: It is appropriate to consider dose-regulated or quantitative closed-circuit anesthesia in terms of uptake of inhalation anesthetics from a reservoir bag which is never allowed to fill completely. The method which the authors have used routinely for 8 years requires reduction of the dose as a function of the inverse square root of elapsed anaesthesia time. Nitrogen does not accumulate because there is an inevitable loss of 20 to 100 ml/min between cuff and trachea. A simpler method, which has been well received, is that of "minimal flow" anesthesia (Virtue) with a constant fresh gas flow of 300 ml/min O2 and 200 ml/min N2O. "Low-flow" techniques typically entail use of 500 ml each of O2 and N2O per min.
mesh_terms: D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D000777:Anesthetics / Q000097:blood; D006801:Humans; D008433:Mathematics; D008722:Methods; D009584:Nitrogen; D012121:Respiration, Artificial; D013997:Time Factors
chemical_list: D000777:Anesthetics; D009584:Nitrogen
vernacular_title: Das geschlossene System.