title: Potential rapid solutions to maintain ventilation in the event of anaesthesia machine failure with no access to the patient's airway.
abstract: Anaesthesia machine failure requires rapid solutions to maintain ventilation and anaesthesia. During procedures with poor access to the patient's airway, it may not be possible to use a self-inflating mechanical ventilation device (SIMVD) for emergency ventilation, and alternative solutions are needed. We evaluated five methods for rescue ventilation using a patient simulator. In Method 1, we used the inspiratory and expiratory tubes and the alternative common gas outlet (ACGO) on the anaesthesia machine to produce a Mapleson E system. In Method 2, we used the tubes, ACGO and an open-ended reservoir bag to produce a Mapleson F system, controlling the bag to achieve ventilation. In Method 3, we attached a SIMVD to the inspiratory tube, and controlled occlusion of the expiratory tube. In Method 4, we used the tubes and ACGO in a Mapleson F configuration, replacing the open-ended bag with a SIMVD to facilitate manual ventilation. In Method 5, we attached a SIMVD to the expiratory tube and left the inspiratory tube attached to its mounting. We were able to achieve ventilation, maintain inhalational anaesthesia, and prevent expired gas rebreathing in Methods 1 and 2. In Method 3 ventilation was achieved with minimal rebreathing of expiratory gas, but with no inhalational agent. Methods 4 and 5 led to rebreathing. Our findings indicate that Methods 1 or 2 are the preferred rapid solutions to maintain ventilation and inhalational anaesthesia in the event of anaesthesia machine failure where there is poor airway access.
authors.affiliation: Dept of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore.
authors.forename: E H
authors.initials: EH
authors.lastname: Liu
authors.affiliation: Dept of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore.
authors.forename: Y
authors.initials: Y
authors.lastname: Tan
authors.affiliation: Dept of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore.
authors.forename: N H W
authors.initials: NH
authors.lastname: Loh
authors.affiliation: Dept of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore.
authors.forename: C
authors.initials: C
authors.lastname: Siau
mesh_terms: D000764:Anesthesia, Closed-Circuit / Q000295:instrumentation / Q000379:methods*; D000769:Anesthesia, Inhalation / Q000295:instrumentation / Q000379:methods*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D004630:Emergencies; D004868:Equipment Failure; D006801:Humans; D012121:Respiration, Artificial / Q000295:instrumentation / Q000379:methods*
chemical_list: D018685:Anesthetics, Inhalation
keywords: Mapleson E; Mapleson F; anaesthetic circuits; anaesthetic machine failure; emergency ventilation strategies