title: Performance of BOC Ohmeda Tec 3 and Tec 4 vaporisers following tipping.
abstract: The introduction of systems to facilitate the changing of vaporisers on the back bar of the anaesthetic machine has increased the risk of a vaporiser being tipped or inverted prior to attachment. The performance of three Ohmeda Tec 3 and three Ohmeda Tec 4 vaporisers following tipping to 30 degrees, 90 degrees and inversion to 180 degrees was measured using a calibrated Datex Capnomac AGM-103 analyser. Both types of vaporiser when switched off tolerated tipping and inversion without alteration of the anaesthetic concentration subsequently delivered. The same was true for the Tec 3 after tipping to 30 degrees and 90 degrees with the dial set at zero or above. However, after inversion of the Tec 3 vaporiser with the dial at zero or higher, the anaesthetic concentration delivered was much greater than shown on the dial, initially exceeding 12% for all agents. Should a Tec 3 vaporiser be inverted with the dial at any setting other than OFF, it is necessary to adequately flush it with fresh gas and check its output prior to use.
authors.affiliation: Department of Anaesthetics, St. Vincent's Hospital, Sydney, New South Wales.
authors.forename: D M
authors.initials: DM
authors.lastname: Scott
mesh_terms: D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D004737:Enflurane / Q000032:analysis; D004867:Equipment Design; D004868:Equipment Failure; D006221:Halothane / Q000032:analysis; D007530:Isoflurane / Q000032:analysis; D009330:Nebulizers and Vaporizers; D012212:Rheology; D012449:Safety; D013997:Time Factors
chemical_list: D004737:Enflurane; D007530:Isoflurane; D006221:Halothane