Transtracheal jet oxygenation: Comparing the efficacy and safety of two self‐made Y‐connector devices with the ENK oxygen flow modulator™ in an infant animal model

Abstract

Background: Self-made Y-connector jet-oxygenation devices with wide-bore expiratory port have been described but not evaluated in infant models. Little is known about the effect of oxygen flow rates on jet oxygenation via transtracheal cannula. Aims:The aim of this study was to compare two self-made Y-connector jet-oxygenation devices against the ENK oxygen flow modulator™, and the effects of three different oxygen flow rates based on body weight, in both unobstructed and obstructed airways, on the time to re-oxygenate in a rabbit infant model. The aim was also to assess the effectiveness of an oxygen flow rate of 1 L/min, for re-oxygenation using ENK oxygen flow modulator™.Methods: Nine rabbits were grouped in threes: Group 1 had a Y-connector attached to an intravenous infusion tubing, Group 2 the same Y-connector attached to a perfusion oxygenator tubing and Group 3, ENK oxygen flow modulator™. From oxygen saturations of 75%, the rabbits were jet oxygenated using their assigned device for 10 minutes at each flow rate of 1 L/kg/min, 1.5 L/kg/min and 2 L/kg/min with their airways unobstructed and later, obstructed. Group 3 had additional experiments involving an absolute oxygen flow rate of 1 L/min. Results:All devices resulted in rapid re-oxygenation within 40 seconds at flow rates of 1 L/kg/min. Oxygen flow rates beyond 1 L/kg/min in obstructed airways resulted in high airway pressures. All rabbits in Group 3 with obstructed airways died from barotrauma when jet oxygenated at a flow rate of 1.5 L/kg/min. When an oxygen flow rate of 1 L/min was used in Group 3, there was a failure to re-oxygenate to SpO 2 90% within 120 seconds in some rabbits.Conclusion: Our animal model results suggest that self-made Y-connector jet-oxygenation devices with wide-bore expiratory port are efficacious and perhaps safer than ENK oxygen flow modulator™ in obstructed airways, and jet oxygenation with minimal oxygen flow rates starting at 1 L/kg/min or (age [years] + 4) L/min, whichever lower, should be considered.

Rehearsing for a rare event—one small step in the right direction?

“…In this edition of the Journal, Lim and colleagues have used a well‐selected animal model to examine this topic in depth . They have commented on methods of access and their inherent hazards examined various ventilation strategies and flow rate algorithms and tempered it all with a wonderfully sensible and succinct summary: if in doubt, start gently and be guided by the chest's rise and fall.…”

“…In this edition of the Journal, Lim and colleagues have used a well-selected animal model to examine this topic in depth. 2 They have commented on methods of access and their inherent hazards examined various ventilation strategies and flow rate algorithms and tempered it all with a wonderfully sensible and succinct summary: if in doubt, start gently and be guided by the chest's rise and fall. Like all good studies, it not only answers questions but generates more: who is the ideal target audience for this article, and where does tracheal cannulation and ventilation of an infant sit in the pediatric anesthetist's armamentarium?…”