Airway management: Overview

Abstract
Anaesthetic airway incidents persist as a significant concern in patient safety and, despite extensive investigations, continue to cause patient harm. Traditional safety investigations predominantly adhere to Safety-I principles, focusing on identifying and rectifying errors, often yielding limited new findings. In this analysis conducted within the webAIRS database, the focus shifted towards Safety-II principles. The aim of this study was to identify factors contributing to airway management safety by examining incidents that did not result in adverse patient outcomes. Incidents categorised as 'difficult intubation' or 'failed intubation' without causing harm to the patient and reported to webAIRS between 2016 and 2022, were included in the analysis.An inductive qualitative content analysis of narrative data from 129 such incidents revealed that the majority of reported events depicted scenarios deviating from controlled and planned circumstances. During the analysis four themes were identified: patient factors, system factors, individual anaesthetist factors and airway management strategy. Within the first three themes, multiple factors were linked to airway management strategies. The findings of this qualitative analysis show that 'Work as done' often differs from 'Work as imagined'.This qualitative analysis highlighted the dynamic nature of human management, as individuals respond to unplanned or unexpected events, showcasing adaptability and positive contributions to incident performance. Expanding the understanding of patient safety to also include Safety-II principles, provides a deeper and wider understanding of airway management safety.

Abstract in English, French
Purpose: When difficulty with laryngoscopy is encountered, confirmation of endotracheal access can be confirmed using the tactile feedback (i.e., tracheal clicks) of a tracheal tube introducer (bougie). There is anecdotal evidence that a bougie placed in the esophagus may have a unique, tactile "boggy" resistance. In this study, we aimed to elucidate the sensitivity and specificity of clicks and boggy resistance for infrequent airway providers in cadaveric airways.

Methods: We conducted a prospective observational study using descriptive statistics to examine the diagnostic accuracy of clicks and boggy resistance for bougies placed in cadaveric airways. We recruited prehospital providers from within Atlantic Canada who then underwent a brief formal training protocol. Cadavers were equipped with a static laryngoscope and bougie (placed either in the trachea or esophagus). Each participant, blinded to bougie placement, was then tested on two separate cadavers and asked whether they felt clicks and/or boggy resistance.

Results: Thirty-seven paramedics participated in the study (32 advanced care paramedics, five critical care paramedics) and were randomized to perform 74 bougie assessments on cadaveric airways. For tracheal clicks, we calculated an overall sensitivity of 86% (95% confidence interval [CI], 75 to 98) and an overall specificity of 81% (95% CI, 68 to 94). Sensitivity for the esophageal boggy resistance test was 78% (95% CI, 65 to 92) while specificity was 86% (95% CI, 75 to 98).

Conclusion: Following a brief training session, prehospital providers who intubate infrequently seemed to show a relatively high degree of accuracy using tracheal clicks and esophageal boggy resistance to confirm bougie placement in cadaveric airways.

Abstract
Before completion of this study, there was insufficient evidence demonstrating the superiority of videolaryngoscopy compared with direct laryngoscopy for elective tracheal intubation. We hypothesised that using videolaryngoscopy for routine tracheal intubation would result in higher first-pass tracheal intubation success compared with direct laryngoscopy. In this multicentre randomised trial, 2092 adult patients without predicted difficult airway requiring tracheal intubation for elective surgery were allocated randomly to either videolaryngoscopy with a Macintosh blade (McGrath™) or direct laryngoscopy. First-pass tracheal intubation success was higher with the McGrath (987/1053, 94%), compared with direct laryngoscopy (848/1039, 82%); absolute risk reduction (95%CI) was 12.1% (10.9-13.6%). This resulted in a relative risk (95%CI) of unsuccessful tracheal intubation at first attempt of 0.34 (0.26-0.45; p < 0.001) for McGrath compared with direct laryngoscopy. Cormack and Lehane grade ≥ 3 was observed more frequently with direct laryngoscopy (84/1039, 8%) compared with McGrath (8/1053, 0.7%; p < 0.001) No significant difference in tracheal intubation-associated adverse events was observed between groups. This study demonstrates that using McGrath videolaryngoscopy compared with direct laryngoscopy improves first-pass tracheal intubation success in patients having elective surgery. Practitioners may consider using this device as first choice for tracheal intubation.