title: A modification of the Bain system for ambient air-oxygen inhalation.
abstract: In developing countries like Nepal, anaesthetic compressed gases, especially nitrous oxide, are expensive and in short supply and anaesthetic techniques must equally use oxygen and volatile anaesthetics sparingly. We have designed a non-rebreathing anaesthetic system which meets these requirements. An Ambu-E anaesthetic valve and self-inflating Ambu bag connected to a Bain system form a non-rebreathing system which uses ambient air to supplement a mixture of low flow oxygen and halothane. Over 100 patients have been anaesthetised with this system using a balanced anaesthetic technique. The oxygen flow was 2 l.min-1 and the average halothane consumption was 8 ml.h-1. The average inspired oxygen concentration was 34%, and the air:oxygen dilution ratio was 5:1. A graphical analysis of gas flow predicts that the system is almost 100% efficient, in that almost all of the oxygen and halothane will enter the alveoli. Our experience confirms that this is a safe, simple and economical method for inhalation anaesthesia. We recommend it for locations where anaesthetic machines and mechanical ventilators are lacking, and where medical oxygen is in short supply.
authors.affiliation: Department of Anaesthesia, University of Manitoba, Winnipeg, Canada.
authors.forename: B M
authors.initials: BM
authors.lastname: Shrestha
authors.forename: W A
authors.initials: WA
authors.lastname: Tweed
authors.forename: N B
authors.initials: NB
authors.lastname: Basnyat
authors.forename: B D
authors.initials: BD
authors.lastname: Lekhak
mesh_terms: D000388:Air; D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D003906:Developing Countries; D004867:Equipment Design; D006221:Halothane / Q000008:administration & dosage; D006801:Humans; D001239:Inhalation; D009390:Nepal; D010100:Oxygen / Q000008:administration & dosage*
chemical_list: D010100:Oxygen; D006221:Halothane