title: [Pollution and retro-pollution by the distribution system of medical gases].
abstract: The anaesthetic machine, the recovery room or the ICU ventilator as well as any other simple oxygenation device can be accidentally supplied with a "wrong" gas, or a mixture of "wrong" and "true" gases, or a gas containing chemical impurities, as a result of one of the following causes: a) the source of the medical gas pipeline supply contains a "wrong" gas or impurities; b) the gas pipeline is polluted by a "wrong" gas or solvents, introduced during the installation or maintenance of the pipeline; c) the pipeline is polluted by a wrong gas at a point of inter-connection or cross-connection of two pipelines; d) supply of a "wrong" gas through wrong quick couplers connected to the pipeline; e) back flow of a gas in another pipeline supply through a defective gas mixer, which is today the most common cause of pipeline contamination or retropollution. It occurs with some types of mixers in case of absence or malfunction of non-return valves, associated with a pressure difference between the two gas lines. The means of prevention, recognition and emergency treatment of these events include: a) systematic removal of mixers and flowmeter-mixers from supplies when not in use; b) periodical checking of these devices for an accidental communication between the gases to be mixed; c) systematic use of an oxygen analyser for a continuous measurement of FIO2, especially when the machine is connected to the N2O pipeline supply; d) the presence of a reserve cylinder of oxygen connected to every anaesthetic machine.
authors.affiliation: Service d'Anesthésie-Réanimation Chirurgicale, CHU de Hautepierre, Strasbourg.
authors.forename: J C
authors.initials: JC
authors.lastname: Otteni
authors.forename: J
authors.initials: J
authors.lastname: Ancellin
authors.forename: J B
authors.initials: JB
authors.lastname: Cazalaà
authors.forename: F
authors.initials: F
authors.lastname: Clergue
mesh_terms: D000388:Air; D000769:Anesthesia, Inhalation / Q000295:instrumentation; D004868:Equipment Failure; D004869:Equipment Safety; D006801:Humans; D009609:Nitrous Oxide / Q000008:administration & dosage*; D010100:Oxygen / Q000008:administration & dosage* / Q000032:analysis; D012122:Ventilators, Mechanical
chemical_list: D009609:Nitrous Oxide; D010100:Oxygen
vernacular_title: Pollution et rétropollution du réseau de distribution d'un gaz médical.