key: cord-0754616-ujh02dn8
authors: Sorbello, Massimiliano; Hodzovic, Iljaz; Cusumano, Giacomo; Frova, Giulio
title: Tracheal introducers and airway trauma COVID-19. Comment on Br J Anaesth xxx
date: 2020-05-19
journal: Br J Anaesth
DOI: 10.1016/j.bja.2020.05.013
sha: a65d50f84be4e2b112e5f7b725e4cbe5515e7f01
doc_id: 754616
cord_uid: ujh02dn8

nan

the other was on 9 L min -1 facemask oxygen. Optimising oxygen delivery prior to intubation is likely to allow more controlled airway management and minimise the likelihood of an adverse airway event.

The authors 1 reported use of an intubating bougie in conjunction with direct laryngoscopy on both patients with grade IV Cormack-Lehane laryngeal views. The likelihood of successful tracheal bougie placement with a grade IV laryngeal view is quite low, whereas the risk of airway trauma due to blind bougie insertion is significant, so that use of a bougie in such a scenario is considered contraindicated 5 . The two reported cases substantiate this concept. Other factors could have contributed to the reported airway trauma.

Manikin studies suggest that single use bougies, depending on construction material, are variably more rigid and likely to cause airway trauma when compared to the Eschmann multiple-use introducer 6 . This may be exacerbated by the inflamed airway mucosa in COVID-19 patients which is likely to be frail and more prone to injury. The Chinese experience quotes a 5.9% incidence of pneumothorax during intubation in COVID-19 patients, but no association with bougie use is reported 7 . The authors did not state if signs for confirming tracheal bougie placement, such as hold-up or tracheal clicks, were used. It was not clear from the report if only the bougie was inserted and withdrawn in the absence of position confirmation, or if the tracheal tube was removed after being railroaded over the bougie in the absence of tracheal placement confirmation. Such a clarification would facilitate understanding of the airway trauma mechanisms in the two reported cases, which could be associated with the tube as well rather than with the bougie alone.

Should such airway trauma occur, multidisciplinary evaluation is recommended. A conservative approach would be preferable especially in critical COVID-19 patients when indicated (minor tracheal tears above the level of the tracheal tube cuff) 8 . A bougie-induced lesion of the cricothyroid membrane and how that resulted in pneumothorax and pneumomediastinum in the second patient is also difficult to understand.

Blind bougie advance against a resistance could explain it. We would advise even more caution than usual when using bougies in COVID-19 patients. It is critically important not to force the bougie advance, either when facing limited laryngeal views or when the bougie has passed the vocal cords. Any bougie advance past the carina carries a high risk of airway trauma 5 , hence it should not be inserted more than 8 cm past the vocal cords 5, 9 . These precautions might be even more relevant in COVID-19 patients, whose inflamed airways may be more prone to trauma.

The Eschmann angled-tip bougie is exclusively produced by Smiths-Portex (https://www.smithsmedical.com/products/airway-management/intubation-accessories/intubation-guides-andstylets/tracheal-tube-introducers-and-guides) and it is a reusable device, whereas Vygon produces a 10 .

MS has received paid consultancy from Teleflex Medical, Verathon Medical and DEAS Italia, is a patent coowner (no royalties) of DEAS Italia and has received lecture grants and travel reimbursements from MSD Italia and MSD USA. GF has received royalties from Cook Medical (Frova Introducer) and Teleflex Medical (Percutwist; Easycric) for his airway device inventions. IH and GC declare no competing interests.

Tracheal trauma after difficult airway management in morbidly obese patients with COVID-19

Obesity Task Force for the SIAARTI Airway Management Study Group. Perioperative and periprocedural airway management and respiratory safety for the obese patient: 2016 SIAARTI Consensus

and on behalf of The Società Italiana di Anestesia Analgesia Rianimazione e Terapia Intensiva (SIAARTI) Airway Research Group, and The European Airway Management Society. The Italian coronavirus disease 2019 outbreak: experiences and recommendations from clinical practice

Obesity as a risk factor for poor outcome in COVID-19 induced lung injury: the potential role of undiagnosed obstructive sleep apnoea

Frova introducer: neither a stylet nor simply an introducer

Evaluation of Frova, single-use intubation introducer, in a manikin. Comparison with Eschmann multiple-use introducer and Portex single-use introducer

Iatrogenic tracheobronchial ruptures: the debate continues

The traffic light bougie: a study of a novel safety modification

Effect of Use of a Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients With Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial

Note different tip curvatures/angles and construction materials. A: Boussignac

B: Venn Multiuse Introducer or reusable bougie

Single use bougie/introducer (Smiths-Portex

D: Frova Intubation Introducer