Anaesthesia Mask Circuit Contraption for Laryngo-bronchoscopy

Considering that specialised endoscopy masks facilitating endoscopy are not available in all markets/places/institutions,1-5 it may be deemed to devise an anaesthesia mask circuit contraption for laryngo-bronchoscopy to allow air-tight seal for non-diluted oxygenation with or without administration of anaesthesia gases during laryngo-bronchoscopy and with or without positive pressure ventilation during laryngo-bronchoscopy. This contraption becomes feasible with flex connectors6,7 as displayed in Figures 1 and 2 with red arrows because available blue-coloured swivel adapters8 for laryngo-bronchoscope are compatible to connect with invasive airway devices (endotracheal tubes, supraglottic airways and tracheostomy tubes) but are not compatible to connect with available anaesthesia masks.9 This incompatibility is overcome with flex connectors with anaesthesia mask head harnesses10 and anaesthesia circuit filters,11-13, ensuring the air-tight seal for the closed-circuit; however, flex connectors add dead-length a laryngo-bronchoscope has to traverse before reaching its destined target during laryngo-bronchoscopy. Herein, added manipulation may be required to negotiate laryngo-bronchoscope with possible safe loosening of air-tight seal of anaesthesia mask transiently before re-establishing that air-tight seal of anaesthesia mask after manipulation and negotiation of laryngo-bronchoscope via nose (transnasal) or via mouth (transoral). Interestingly, the feasibility of positive pressure ventilation across anaesthesia circuit filters with anaesthesia machine or with self-inflating bag due to air-tight seal feasibility with this contraption can safely allow transient episodes of loosened air-tight seal of anaesthesia mask during manipulation and negotiation of laryngo-bronchoscope. If specialised endoscopy masks facilitating endoscopy were available in all markets/places/institutions, it would have been interesting to compare whether positive pressure ventilation would have been equally possible with those specialised endoscopy masks, unless their self-sealing valves used to provide access to endoscopes would be interfering with air-tight seal across those specialised endoscopy masks. Interestingly, just like disposable laryngo-bronchoscopes,14 if and when detachable laryngo-bronchoscopes become available in the near future,15,16 this anaesthesia mask circuit contraption may allow advancing those detachable laryngo-bronchoscopes to the destined target before detaching laryngo-bronchoscopes’ insertion tubes from laryngo-bronchoscopes’ controls to allow removal of this contraption for railroading and threading endotracheal tubes across the detached insertion tubes and thereafter reattaching the controls of laryngo-bronchoscopes.Figure 1: (a-d) Simulation of anaesthesia mask circuit contraption for laryngo-bronchoscopy in: (a) long-view showing the whole setup with anaesthesia mask connected to swivel adapter via flex connector (marked by red arrow) with laryngo-bronchoscope passing across the contraption to display manikin’s glottis; (b) closeup-view showing manikin’s left nostril access for laryngo-bronchoscope simulation; (c) top-view and (d) side-view completing the wholesome view of the contraption secured in place with anaesthesia mask head harnessFigure 2: (a and b) Parts of anaesthesia mask circuit contraption, including green-rimmed anaesthesia circuit filter and black-coloured anaesthesia mask head harness in overall view (a) with closer view (b) of blue-coloured swivel adapter and clear-coloured anaesthesia mask to be connected via red-arrowed flex connectorAnyhow, in the interim, this anaesthesia mask circuit contraption can allow safely and securely providing (a) oxygenation even with a T-piece circuit,17 (b) anaesthesia obviously with an anaesthesia machine and (c) ventilation even with a manual ventilator/resuscitator during laryngo-bronchoscopy. Author contributions DG: Contributed to concept, simulation, manuscript preparation, manuscript editing and manuscript review; JP and SU: Contributed to concept, manuscript editing and manuscript review. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.