Dimensional compatibility and limitations of tracheal intubation through supraglottic airway devices: a mannequin-based in vitro study

Abstract

Background Flexible bronchoscope-guided tracheal intubation through supraglottic airway devices (SGAs) is a well-established element of difficult intubation algorithms. Success can be limited by dimensional incompatibilities between tracheal tubes (TTs) and SGAs. Methods In this in vitro study, we tested the feasibility of TT passage through SGAs, removal of SGAs over TTs, and the ability to guide the flexible bronchoscope with 13 TT brands (internal diameter, 6.5-8.0 mm) and ten different SGAs (#4 and #5) in an intubation mannequin. Results We tested 1,040 combinations of SGAs and TTs. Tracheal tube passage failed in 155 (30%) combinations of the five tested first-generation SGAs (117 [46%] with SGA Electronic supplementary material The online version of this article (

What is new in airway management

“…Intubation success can be limited by dimensional incompatibilities between devices and even the help of a fibreoptic bronchoscope does not always guarantee a good result. Moser et al studied the feasibility of intubation and extubation in an airway head manikin and tested more than 1000 combinations [ 15 ]. Often the narrow diameter of the ventilation tube of first-generation SADs prevented ETT passage [ 15 ].…”

“…Moser et al studied the feasibility of intubation and extubation in an airway head manikin and tested more than 1000 combinations [ 15 ]. Often the narrow diameter of the ventilation tube of first-generation SADs prevented ETT passage [ 15 ]. However, almost all combinations with second-generation SADs permitted passage of the ETT [ 15 ].…”

“…Often the narrow diameter of the ventilation tube of first-generation SADs prevented ETT passage [ 15 ]. However, almost all combinations with second-generation SADs permitted passage of the ETT [ 15 ]. Removal of the SADs over the ETT was often impossible or not ideal because of the ETT connector that is firmly attached to most reinforced ETTs [ 15 ].…”

Editors’ note: 2021 Special Issue on airway management

“…from Austria report their findings from a painstaking investigation of 1,040 combinations of endotracheal tubes and SGAs, illustrating the possible problem of dimensional incompatibility and its downstream implications. 9 In other words: size does indeed matter.…”

“…rapportent les résultats de leur évaluation rigoureuse de 1040 combinaisons de tubes endotrachéaux et de DSG, illustrant le problème potentiel d’une incompatibilité dimensionnelle et ses implications en aval. 9 Autrement dit : la taille est effectivement importante.…”