From evidence based on practice to evidence‐based practice: time for a difficult airway management research strategy

Abstract

In this edition of Anaesthesia, Thomsen et al. further examined data from the increasingly generalisable Danish Anaesthesia Database to explore the role of supraglottic airway devices (SAD) in difficult airway management [1, 2]. They found an incidence of difficult airway of 0.74%, and SADs were used as a rescue device in less than 5% of these occurrences. Supraglottic airway devices were used in multiple tracheal intubation attempts 10.8% of the time, in difficult facemask ventilation in 12.8% of incidents, while they were used in failed tracheal intubation in 35.1% of cases. Perhaps most alarmingly, only 18.9% of 'cannot intubate, cannot face-mask ventilate' cases received a SAD in the course of their management; and only 4.5% of cases that eventually resulted in emergency front-of-neck access had SAD insertion attempted. Nonetheless, when SADs were used in difficult airway cases as rescue devices, they were successful two-thirds of the time. Overall, Thomsen et al. report that, despite their importance in difficult airway management guidelines, SADs were underused but had a reasonable success rate [2].There remain many unanswered questions in the analysis and interpretation of this study, which is commonplace for retrospective studies. We are none the wiser regarding several markers of difficult airway in the specific cohort of patients included, nor do we know what the clinically important patient outcomes were. It also is unclear which exact SADs were used.A range of different SADs available were put into a single homogenous groupwe would not bundle together a range of videolaryngoscopes in a similar way, so can we do this with various SADs? The data leave further questions: were oropharyngeal airways used? What was the pharmacological strategy used in these patients? What were the relative rates of success or failure for trainees, consultants or nurse anaesthetists? Crucially, why were guidelines not adhered to and SADs so underutilised?Despite being left with perhaps as many questions as answers, retrospective data such as these may conceivably represent the highest level of evidence that we have in formulating guidelines for difficult airway management [3].There has been a recent increase in the number of anaesthetic practice guidelines, and the evidence base used to inform individual recommendations is highly heterogenous [4][5][6]. Guidelines for the management of patients with difficult airways in particular are highly clinically applicable and implemented in routine anaesthetic practice.Supraglottic airway devices are used in 56% of all general anaesthetics (although this number is likely to be higher in contemporary practice) [7], and their utilisation remains key to difficult airway algorithms. It is, therefore, high time to review the evidence for recommendations of SADs in guidelines for difficult airway management.In 2004, the Difficult Airway Society (DAS) published their first difficult tracheal intubation guidelinesthose most likely to have been implemented by Danish anaesthetists during the s...

Difficult Airway Society guidelines for awake tracheal intubation (ATI) in adults

“…For example, the use of SADs as a conduit to ATI or optical stylets in awake patients have not been well‐described but warrant future investigation as their role becomes more defined. Similarly, the lack of previously published specific guidelines means that research in ATI is disparate and inconsistent . However, we have sought and appraised the available evidence in ATI, and in its absence we have incorporated the practical and theoretical experience of international experts.…”

Dissemination of medical publications on social media – is it the new standard?

“…One possible explanation is that those delivering day‐to‐day patient care are not engaged with the academic literature. Another, is that this literature may fail to address the problems with the way in which care is delivered . We agree with Ng et al., that the way in which clinical staff access information at the bed‐side is much more amenable to videos, infographics and short headlines viewed on smartphones as compared with a full paper published in a journal and viewed on a hospital computer.…”

“…One possible explanation is that those delivering day-to-day patient care are not engaged with the academic literature. Another, is that this literature may fail to address the problems with the way in which care is delivered [15]. We agree with Ng et al, that the way in which clinical staff access information at the bed-…”

Difficult airway management algorithms: a directed review

“…Data establishing a direct causal relationship between the publication of algorithms and improved difficult airway practices and patient outcomes are not widely available in the literature. Therefore, robust, large‐scale, multicentre studies are required before a conclusion can be drawn on the overall effect of implementing airway algorithms .…”

“…Of the included studies, most are observational, contain small sample sizes and have a brief follow‐up . Furthermore, difficulties in conducting high‐quality studies on airway emergencies have led to the majority of algorithms being generated primarily on expert consensus, rather than evidence . Moreover, of those that claim to be evidence‐based, many do not categorise or detail the quality of the evidence sourced.…”