2025+DAS指南：成人未预料困难气管插管的管理

Summary

Advances in our understanding and practice of airway management necessitate contemporary guidelines for tracheal intubation. The Difficult Airway Society (DAS) therefore produced recommendations to improve the efficacy and safety of tracheal intubation. We conducted a systematic review and a three-round Delphi process to formulate multidisciplinary, evidence-based, expert consensus recommendations. We invited 20 external experts to guide recommendations on emergency front-of-neck airway and engaged DAS members and 16 international airway experts to provide feedback. Twelve members of the guidelines group participated in 65 meetings over 3 years, and 1241 papers were included after a systematic review. Sixty-five recommendations were made in relation to tracheal intubation. These included airway assessment and planning; peroxygenation; postintubation care; rapid sequence induction and intubation; the physio-logically difficult airway; obesity; human factors; point-of-care ultrasound; documentation; and education and training.We maintain the concept of a linear algorithm encompassing tracheal intubation (Plan A); supraglottic airway device ventilation (Plan B); facemask ventilation (Plan C); and emergency front-of-neck airway (Plan D). The recommendations prioritise continuous oxygen delivery throughout airway management; maximising the likelihood of successful tracheal intubation at the first attempt; confirmation of ventilation with waveform capnography; progressing through the algo-rithm in the event of failure; multidisciplinary teamwork; and ongoing education and training. These guidelines are designed to support clinicians in delivering airway management that prioritises efficacy and safety. Overall, we emphasise the importance of maximising the chances of success, rather than the avoidance and management of failure,to improve outcomes for patients undergoing airway management.

Keywords: airway management; emergency front-of-neck airway; laryngoscopy; tracheal intubation; ventilation

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Editor's key points

● Advances in airway management since the last Difficult Airway Society(DAS) guidelines from 2015 necessitate updated guidelines for tracheal intuba-tion in adults. This need for updated guidelines was addressed using a modified Delphi process by multidisciplinary international experts.

● The recommendations maintain the concept of a linear algorithm from tracheal intubation(Plan A), to supraglottic airway device ventilation(Plan B), to facemask ventilation(Plan C), and to emergency front-of-neck airway(Plan D).

● Recommendations include continuous oxygen de-livery throughout airway management, confirmation of ventilation with waveform capnography, multi-disciplinary teamwork, and ongoing education and training.

● The emphasis is on maximising the likelihood of successful tracheal intubation at the first attempt,rather than avoidance and management of failure.

Guidelines for the management of the difficult airway have now existed for more than 30 years, ${}^{1}$ and the first Difficult Airway Society (DAS) guidelines on management of unantici-pated difficult intubation were published in 2004. ${ }^{2}$ Despite these and numerous other guidelines from various airway societies and organisations around the world, ${ }^{3-13}$ the 7th Na-tional Audit Project of the Royal College of Anaesthetists(NAP7) reported that airway and breathing complications remain an important cause of perioperative cardiac arrest. ${ }^{14,15}$ The 2015 guidelines responded to the findings of NAP4, 9,16 with a particular emphasis on managing failure. They incorporated concepts of human factors in airway management, ${ }^{17}$ and supported the implementation of developing technology such as videolaryngoscopy, second-generation supraglottic airway devices (SADs), and high-flow nasal oxygen (HFNO). They also encouraged a significant change in emergency front-of-neck airway (eFONA) techniques from cannula to scalpel ap-proaches. It is likely that those guidelines improved airway management safety.

In the ensuing years, clinical practice and evidence have evolved. Patients requiring airway management are increas-ingly complex,18 data demonstrating safety and efficacy of airway management techniques have emerged, and under-standing of risks such as unrecognised oesophageal intubation have become apparent.19-30 Evidence on the benefits of tools such as videolaryngoscopy,20,23,31 point-of-care ultra-sound,32-34 and HFNO25 have also been established. The con-cepts of peroxygenation and physiologically difficult airways have subsequently been introduced.10,19,25,35 Recent years have also seen a number of other specific guidelines for safe airway management, such as the critically ill patient,10 awake tracheal intubation(ATI)3 and COVID-19.6 The accumulation of all of these changes and developments warranted updated guidelines on the management of unanticipated difficult tracheal intubation.

We therefore developed these guidelines using the best available evidence to support expert consensus recommen-dations. In addition to specific and technical

recommendations following a linear algorithm, we highlight several key themes to maximise the likelihood of successful tracheal intubation, rather than the avoidance and manage-ment of failure, to improve outcomes for patients undergoing airway management.

Methods

These guidelines followed the Appraisal of Guidelines for Research And Evaluation 2(AGREE 2) reporting checklist.36 We convened a multidisciplinary group from across the UK and Ireland, including anaesthetists from both teaching and dis-trict general hospitals with a range of areas of expertise, a surgeon, a resident doctor, an operating department practi-tioner, and a lay representative. To support the development of recommendations, we conducted a systematic review adhering to the Preferred Reporting Items for Systematic Re-views And Meta-Analyses(PRISMA) recommendations. ${}^{37}$ Given the need to assess contemporary evidence since the DAS 2015 guidelines, we only sought studies published after completion of that initial search(2012 onwards). ${}^{9}$ Full results and details of the review are shown in Supplementary File 1.

Data from included studies were synthesised, and consensus from all 12 members of the guideline group was sought to formulate guideline recommendations using a three-round Delphi method. The first round entailed an initial pro-posed long list of recommendations, which were each reviewed and rated for content and clarity. Recommendations with which≥70% of the guideline group agreed were included unchanged, and those with 50-69% agreement were revised or harmonised based on comments from all members. Recom-mendations with<50% agreement were excluded. A second Delphi round of rating was then conducted using the same methodology, with all members receiving fully anonymised results and comments from the first round. Finally, a third round involving discussion and further revision was under-taken. The level of evidence used to make each recommenda-tion was based on a modified Oxford Centre for Evidence-Based Medicine system(A-D).3 Full results and levels of evidence for all recommendations are shown in Supplementary File 2.

Given the uncertainty regarding eFONA techniques, an expert panel process was conducted to help inform recom-mendations made by the DAS intubation guidelines group.Aneasthetists, intensivists, and surgeons experienced in eFONA and related procedures were invited to participate.After distribution of specific clinical practice proposals, two discussion panel meetings were held in which members of the DAS intubation guidelines group did not participate. This process adhered to the Scientific Evaluation and Review of Claims in Health Care(SEaRCHTM) recommendations.38 In to-tal,20 experts were invited, of which 17(85%) attended the first meeting and 11(55%) attended the second.

Over the 3 years of guideline development, the group met 35 times for in-person all-day meetings and 30 times for vir-tual meetings. In October 2022, we invited DAS members and followers of the DAS social media accounts to provide feed-back regarding the 2015 guidelines, receiving 94 responses that informed recommendations. Elements of the guidelines were also presented at the DAS Annual Scientific Meetings in 2023 and 2024, and key principles of the final recommendations were presented virtually to the DAS members for comment.The draft manuscript was also reviewed by 16 international experts with clinical or academic experience related to

DAS tracheal intubation guidelines 2025| 3

difficult airway management. All comments were reviewed by the guideline group. The final draft was then reviewed by the DAS committee for ratification.

Disclaimer

These guidelines are not intended to represent a minimum standard of practice, nor are they to be regarded as a substitute for good clinical judgement. They are also not expected to account for all possible clinical scenarios, but aim to provide a framework for decision-making. In this document,‘airway manager' is any clinician responsible for tracheal intubation,including anaesthetists, intensive care physicians, and emer-gency and pre-hospital physicians.

Airway assessment

Assessment is essential to airway management, enabling identification of patients with potentially difficult facemask ventilation, SAD insertion or ventilation, tracheal intubation,or eFONA.16 Although data suggest that anticipating difficult airway management remains challenging.39,40 history, exam-ination, and appropriate investigations can help identify a potential difficult airway, and facilitate the formulation of an individualised airway strategy(a series of plans). This should also account for the context of airway management such as urgency,timing,location, equipment availability,staffing, and access to appropriate help.41 Crucially, findings of the airway assessment need to be acted upon, and the earlier airway assessment is performed, the more time there is for the strategy to be formulated, equipment to be obtained, and multidisciplinary communication to occur.

Numerous bedside screening tests have been used to facil-itate risk assessment of difficult airway. In general, bedside assessments alone have been shown to be poor screening tools to rule out difficulty, but of these, the upper lip bite test appears to have the greatest diagnostic accuracy.42,43 Combining mul-tiple bedside tests will likely improve the sensitivity of pre-dicting difficulty.44 A history of obstructive sleep anponea and snoring appear to be more reliable predictors of difficult airway management.45-47 There remains uncertainty if obesity in isolation is an independent risk factor, 46 although people living with obesity were over-represented in airway complications in NAP4 and NAP7.14.16 Perhaps the most reliable predictor is a previous history of difficult airway management.48 Patients might carry difficult airway alert cards, but medical records should be reviewed for further information.48 Identification of the cryothroid membrane by visual assessment, palpation, or ultrasound should be conducted during airway assessment,ideally with the neck in a fully extended position, to facilitate decision-making before an eFONA scenario arises. This should inform the eFONA technique.

Investigations reportedly have a potential value in pre-dicting difficulty and guiding airway management,including point-of-care ultrasound,34,49-51 virtual endoscopy,52 nasen-doscopy,53,54 awake videolaryngoscopic assessment,55 computed tomography,56 and three-dimensional printing.57 These tools are not available to all clinicians or for all patients,and therefore they are rarely relied on exclusively in current clinical practice. Nasendoscopy, in particular, has significant potential to help guide airway management.58 It can be rapidly, safely, and easily performed, and clinicians should consider gaining further skills in this technique.

Ultrasound assessment of airway parameters has increas-ingly been shown to help risk stratify airway management difficulty.59-65 Although the evidence is favourable, we recognise this might not be deliverable in practice currently.Widespread use of this technique can be seen as aspirational,requiring validated educational training programmes.

Assessment also includes screening for a physiologically difficult airway,19 which accounts for an increased risk of complications from airway management, such as hypoxaemia and pulmonary aspiration, and also haemodynamic complications.

In specific circumstances, airway assessment scoring sys-tems have been shown to be of particular value. This includes the HEAVEN criteria in pre-hospital care66,67 and the MACO-CHA score in critical care(Supplementary File 3).68

Recommendations

● Airway assessment should be performed before induction of anaesthesia.

● Assessment should include history, examination with bedside tests, and, when appropriate, review of relevant investigations. The physiologically difficult airway should also be considered.

Planning and strategy

A preformulated airway strategy is fundamental to airway management, and should take into account the findings of the airway assessment.16 Failure to do so may be associated with adverse outcomes.16,48,69-71 The strategy should consider any anticipated difficulty in facemask ventilation, SAD insertion or ventilation, tracheal intubation, eFONA, and physiological status(Fig. 1). Consideration should also be given to patient positioning, equipment, personnel, location, timing, plans for failure of any of the proposed techniques, and communication with the wider team. Specific plans should be shared with the anaesthetic assistant, and any concerns discussed at the team brief.

Compared with asleep techniques, ATI is associated with lower failure and complication in patients with anticipated difficult airway management.72,73 In planning airway man-agement, any predicted difficulty should alert clinicians to consider performing ATI with a flexible bronchoscope or vid-olerangynoscope, or a tracheostomy(Fig.2).3

Airway management performed out of hours or in the nonoperating theatre environment is associated with increased risk.14 Planning in these scenarios should account for clinical urgency, timing, and location(moving the patient to an anaesthetic room or operating theatre, or not trans-ferring from their current location). Senior input should be sought early given the recognised risks.14 Checklists can be useful in these settings to improve guideline adherence,reduce the number of tasks that are omitted, and optimise teamworking.74-77

Recommendations

● The airway management strategy should address any anticipated difficulty in A) tracheal intubation; B) SAD insertion or ventilation; C) facemask ventilation; and D)emergency front-of-neck airway.

● The airway management strategy should be guided by any history of previous difficulty.

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 Fig 1. Management of unanticipated difficult tracheal intubation. eFONA, emergency front-of-neck airway; FONA, front-of-neck airway;SAD, supraglottic airway device.

● If any difficulty is anticipated in Plans A, B, C, or D, awake tracheal intubation should be considered.

● The airway management strategy should be clearly communicated with the anaesthetic assistant.

● Airway management should be discussed as part of the theatre team briefing.

● Patient position should be optimised before pre-oxygena-tion and for tracheal intubation.

● Equipment for delivering Plans A-D must be immediately available in all areas where airway management is performed.

● Out-of-hours airway management is associated with increased risks; teams should plan accordingly.

● Optimal location for airway management should be considered.

● Consider a checklist when performing emergency tracheal intubation.

Monitoring

Patient monitoring is essential in the provision of safe anaesthesia. The Association of Anaesthetists has published recommended standards for monitoring during anaesthesia and recovery.78 In addition to minimum monitoring(pulse oximetry, noninvasive blood pressure, electrocardiography,and temperature), patients undergoing general anaesthesia require inspired and expired oxygen monitoring, and wave-form capnography.

Pre-oxygenation is important to maximise the safety of airway management. During this process, clinicians can ach-ieve two objectives: assess the efficacy of pre-oxygenation by targeting an end-tidal oxygen fraction(ETO2);35 and check that

waveform capnography is working and correctly interpretable.Efficacy of pre-oxygenation is generally tested by targeting an ETO2 of≥0.9 when using a facemask,79 but with use of HFNO techniques, this monitoring method can be less reliable.25 Waveform capnography is the gold standard airway monitor,however cases of both misinterpretation of the monitor and monitoring failure have been reported,80,81 which were asso-ciated with devastating consequences.

After induction of anaesthesia, uninterrupted waveform capnography is essential to demonstrate effectiveness of facemask ventilation, and is the most sensitive and specific monitor to exclude oesophageal intubation.22 When used in isolation, clinical tests(e.g. tube misting, chest rise, or auscultation) are unreliable.82,83 Repeated evidence of serious consequences of unrecognised oesophageal intubation un-derscores the importance of functioning and continuous monitoring of waveform capnography.14,84 Confirmation of tracheal intubation requires more than one variable to be assessed: 1) waveform capnography; and 2) visualisation of the tracheal tube entering or in the trachea, where possible.Although there are data to support the accuracy of ultrasound for confirming tracheal intubation,85,86 it is potentially time-consuming and impractical, requires training, and could distract from immediate clinical care.

Task fixation and loss of situational awareness are recognised risks in airway emergencies.87 Starting a timer when administering neuromuscular block can help cli-nicians appropriately time tracheal intubation and prompt transition through the algorithm in the event of unsuccessful attempts.17 Audible triggers or alarms, particularly for oxygen saturation(Spoo2), might further reduce the risk of task fixation.17

DAS tracheal intubation guidelines 2025 | 5

 Fig 2.Preparation and planning for tracheal intubation.ATI,awake tracheal intubation;RSI,rapid sequence induction and intubation.

The Association of Anaesthetists recommend quantitative neuromuscular monitoring before tracheal intubation. ${}^{78}$ This can guide appropriate timing of tracheal intubation attempts,and also reduce the risk of complications during maintenance and after extubation.

Recommendations

● Waveform capnography should be checked before induction of anaesthesia.

● Audible Spo2 tones should be enabled before induction of anaesthesia.

● Continuous, uninterrupted waveform capnography should be used throughout all phases of airway management.

● Quantitative neuromuscular monitoring should be used to confirm adequate neuromuscular block before tracheal intubation attempts, when feasible.

● Institutions should provide equipment that enables patient monitoring in accordance with current Association of Anaesthetists recommendations.

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Drugs

Successful airway management can be affected by the choice of anaesthetic induction agent, dosing, administration method, and anticipated adverse effects. Propofo is the most widely used induction agent, providing favourable conditions for airway management. However, it can be associated with haemodynamic instability and aggravating physiologically difficult airway management.14,19,88 Other drugs or combina-tions of agents can have a more favourable cardiovascular profile for induction of anaesthesia,89-91 but it is useful for clinicians to prepare for haemodynamic instability regardless of induction agent.

A single bolus dose of propofol might be insufficient to maintain general anaesthesia during difficult airway man-agement, posing a potential risk of accidental awareness un-der general anaesthesia in these settings. ${}^{92}$

Historically, inhalation induction of anaesthesia in adults was thought to be a viable option when difficult airway man-agement was anticipated. However, this technique is associ-ated with substantial risks, and data suggest that it is not reliable in adults.93

Neuromuscular block is known to improve the effective-ness of facemask ventilation, 94,95 and is superior to alternative strategies for successful tracheal intubation without compli-cations.96,97 Each neuromuscular blocking agent has its own characteristics that must be considered. Although there is high-quality evidence that suaxhamonium can provide better intubating conditions than rouronium,98 this should be balanced against the side-effect profile of suaxethonium.Moreover, data suggest that suxamethonium can be associ-ated with an increased risk of postoperative pulmonary com-plications.99 Rocuronium is used increasingly, possibly owing to the greater availability of sugammadex for reversal.Although there are cases in which sugammadex was used to antagonise neuromuscular block during‘cannot intubate,cannot oxygenate'(CICO) scenarios, 100 this is not a reliable strategy in failed tracheal intubation. 101 This is because it can be associated with significant risks(e.g. laryngospasm or pulmonary aspiration), does not guarantee a patent and manageable upper airway, and potentially might distract cli-nicians from immediate airway management(e.g. time taken to obtain and draw up enough sugammadex for full reversal of neuromuscular block). Regardless, the importance of effective neuromuscular block during tracheal intubation and throughout airway management cannot be understated.Neuromuscular block improves the likelihood of successful tracheal intubation, SAD ventilation, facemask ventilation,and eFONA.102-104

Recommendations

● Neuromuscular blocking agents should be routinely used to facilitate tracheal intubation.

Peroxygenation

Peroxygenation is the process of continuous oxygen delivery from before induction of anaesthesia(pre-oxygenation), dur-ing apnoea(apoieic oxygenation), and throughout attempts at airway management(e.g. laryngoscopy) until the airway is secured.35

Pre-oxygenation is essential to prolong the safe apnoe time after induction of anaesthesia.105 It increases the oxygen

reserve, delays the onset of hypoxaemia, and allows more time for laryoscopy, tracheal intubation, and airway rescue should intubation fail.105 Pre-oxygenation requires consider-ation of:(1) devices(e.g. facemask, HFNO, noninvasive venti-lation);(2) patient positioning(e.g. supine, head up);(3)breathing technique(e.g.tidal volume, vital capacity breath-ing;(4) oxygen flow rates; and(5) pressures applied(e.g.pressure support, PEEP).

The head-up position and positive pressure during pre-oxygenation increases functional residual capacity and, thus,the total volume of oxygen available during apnoea and laryngoscopy.105 Therefore, the most effective strategy for pre-oxygenation involves using a positive pressure technique in the head-up position, either with HFNO, noninvasive ventila-tion, or facemask with continuous positive airway pressure.25,106-108

After induction of anaesthesia, oxygen delivery should continue through facemask ventilation. During attempts at laryngoscopy, facemask ventilation is not possible, but continuous oxygen delivery can still be achieved with nasal cannulae(low or high flow). This can further prolong safe apnoe time; however, a patent airway is essential. When using some high-flow cannulae, further attempts at facemask ventilation might require removal of the cannulae to allow for an effective seal.35,109 HFNO involves an oxygen flow rate that exceeds peak inspiratory flow rate(typically>30 L min-1).HFNO has a growing evidence base and has been used for prolonged safe apnoe in numerous settings.110 Apnoeic oxygenation, ideally with HFNO, is particularly important in patients at risk of having a physiologically or anatomically difficult airway, as they can have rapid desaturation or pro-longed tracheal intubation attempts.110 If difficult airway management is encountered whilst HFNO is being used, it should be continued and requires maintenance of a patent airway. However, clinicians should beware that HFNO has limitations, might not prevent hypoxaemia(though might delay it),111 and should not be started as a rescue technique when facemask ventilation has failed.

Recommendations

● All patients should be pre-oxygenated before induction of general anaesthesia.

● Pre-oxygenation should be performed in the head-up posi-tion and with a technique allowing positive pressure, where feasible.

● In patients with a risk of difficult airway management,peroxygenation should be used, ideally with high-flow nasal oxygen.

Plan A: Tracheal intubation

The essence of Plan A remains to ensure successful(confirmed with waveform capnography) tracheal intubation at the first attempt without complications, limiting the number and duration of attempts at tracheal intubation whilst maintaining oxygenation(Fig. 3).

Laryngoscopy

Videolaryngoscopy improves the safety and efficacy of tracheal intubation compared with direct laryngoscopy across a range of patients, settings, and operators.20,23,31,112 There-fore, a videolaryngoscope should be used first line to facilitate

DAS tracheal intubation guidelines 2025| 7

 Fig 3. Plan A: Tracheal intubation. eFONA, emergency front-of-neck airway; SAD, supraglottic airway device.

tracheal intubation whenever possible. There are a variety of videolaryngoscopes available and evidence suggests they are effective at increasing first-attempt success, reducing hypo-xaemia, and reducing the risk of oesophageal intubation compared with direct laryngoscopes. 20,31 There is currently no strong evidence to recommend one blade design over another.20 Specific blade types(e.g. hyperangulated, Macin-tosh type) require different techniques to facilitate successful tracheal intubation. 113,114 Local provision will be influenced by various factors(e.g. widespread availability)115 and should be supported by training and regular use.116 Tracheal intubation can also be achieved with a range of other devices, such as optical styles,117 although their effective use requires training.118

Tracheal tube introducers

Bougies(static or dynamic) and stylets are tracheal tube in-troducers that can facilitate more effective tracheal tube de-livery. They can be used routinely in a range of settings, such as with a reinforced tracheal tube or during rapid sequence induction and intubation. They can also facilitate tracheal intubation when unexpected difficulty is encountered. The evidence for efficacy and safety of one introducer over the other is unclear.29,30,119-124 In particular, when using a video-laryngoscope with a hyperangulated blade, a stylet, bougie, or flexible bronchoscope should be used. Introducers should be shaped appropriately before use.120,125 There is a potential risk of airway trauma from the use of either a bougie or stylet,°30 but this must be balanced against the benefit of increased likeli-hood of successful tracheal intubation.120

Blind(Cormack-Lehane grade 3 or 4 view of the glottis)bougie insertion can be associated with trauma or device

misplacement and should be avoided. The‘hold-up’sign can indicate passage of the bougie into the bronchial tree,128 but can be associated with risk of airway perforation and trauma and should be avoided.127

External laryngeal manipulation

External laryngeal manipulation can be performed by a trained assistant to improve the glottic view. Manual displacement of the larynx with backward, upward, rightward pressure(BURP) on the thyroid cartilage manoeuvre can improve the glottic view.129,130 It is possible that the shared visibility of the glottis with videolaryngoscopy might make the effectiveness of external laryngeal manipulation greater,although there are currently no studies to support this.

Attempts

Tracheal intubation requires successful laryngoscopy and successful insertion of a tracheal tube. A successful attempt is defined as a tube placed in the trachea after instrumentation with a device, introducer, or both, confirmed with waveform capnography and visualisation131 when possible.

Each successive attempt at tracheal intubation increases the risk of complications, including airway trauma, and re-duces the likelihood of successful intubation.72 This un-derscores the importance of making the first attempt the best attempt. A suboptimal attempt is a wasted attempt. These guidelines maintain the principle of 3+1 attempts: a maximum of three attempts at intubation, with a fourth and final attempt only being undertaken by a more experienced colleague. Each subsequent attempt should involve a change to increase the likelihood of success. Any change should be informed by previous attempts, such as adjusting positioning; change of

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laryngoscope or blade; use or change of an introducer; change of operator; external laryngeal manipulation or airway such-tion; removal of cricoid force if applied; or optimising neuro-muscular block.132 If hypoxaemia occurs at any time during intubation, the attempt should be abandoned and oxygenation prioritised with facemask ventilation. Oxygenation with facemask ventilation should continue between tracheal intu-bation attempts, and anaesthesia maintained.

Failure of Plan A can be declared at any time, even after the first attempt at tracheal intubation. This decision can be made when clinicians cannot identify any changes to improve the likelihood of success (e.g. impossible laryngoscopy despite optimal conditions) or if further attempts may lead to com-plications (e.g. airway obstruction or failure of facemask ventilation). At this stage, a decision can be made to discon-tinue anaesthesia, but this requires either insertion of a SAD or effective facemask ventilation until full reversal of neuro-muscular block and emergence from anaesthesia.

In the event of unsuccessful tracheal intubation after the maximum 3+1 attempts, the operator should declare 'failed intubation', move onto Plan B, and ensure the eFONA kit is immediately accessible (priming). Appropriate assistance must be summoned.

Confirmation of tracheal intubation

A two-point check has been advocated to confirm tracheal tube placement, where the tube is seen to pass through the vocal cords and confirmed by the presence of sustained exhaled carbon dioxide on waveform capnography.22,24 Although sustained exhaled carbon dioxide can exclude oesophageal intubation, it does not confirm correct placement of the tube in the trachea when used in isolation, as the tube can be in the bronchus or in the pharynx.133-135 Thus, visu-alisation of the tracheal tube passing through the cords or within the trachea is important. A two-person check has also been suggested, but warrants further research.24

Recommendations

● A videolaryngoscope should be used for tracheal intubation whenever possible.

● Airway managers should be aware of the differences in videolaryngoscope blade types and techniques.

● Airway managers should attain and maintain competence in the use of videolaryngoscopes available in their department.

● The number of intubation attempts should be limited to a maximum of three, plus one final attempt by a more expe-rienced colleague(3+1).

● A stylet, bougie, or flexible bronchoscope should be used with a hyperangulated videolaryngoscope blade.

● Successful tracheal intubation ideally should be confirmed with a two-point check: sustained exhaled carbon dioxide and visualisation of the tracheal tube through the vocal cords.

● In the event of a poor glottic view during laryngoscopy,consider use of external laryngeal manipulation.

● When difficulty with laryngoscopy or tracheal intubation occurs:

a. Continue oxygenation throughout

b. Maintain anaesthesia

c. Optimise head and neck position; optimise blade size and type; consider adjuncts; optimise tube size and type;external laryngeal manipulation; remove cricoid force;optimise neuromuscular block; change operator; suction;and optimise ergonomics

Facemask ventilation

Facemask ventilation is a core airway skill that is required in all stages of the algorithm. Effective performance requires training and experience to maximise the likelihood of success,particularly in difficult airway management scenarios. When facemask ventilation is difficult, the risk of failed tracheal intubation increases more than 10-fold.2,136

Prediction of difficult facemask ventilation is generally poor,48 however, an assessment should still be made. Features associated with difficult facemask ventilation include a pre-vious history of difficulty; obstructive sleep apnoea; radio-therapy; high BMI; increased neck circumference; Mallampati 3/4; and male sex. Scoring systems can also predict difficult facemask ventilation.137,138

Neuromuscular block improves ease of facemask ven-tilation.103,139-141 After pre-oxygenation, induction of anaes-thesia, and administration of neuromuscular block, facemask ventilation with 100% oxygen should be commenced. Clini-cians should not delay administration of neuromuscular block to confirm facemask ventilation. If HFNO is used, effective facemask ventilation should still be confirmed.

Effectiveness of facemask ventilation should be confirmed with waveform capnography, and ease can be classified using the Lim and Nielsen scoring system(Supplementary File 4).142 Facemask ventilation can be improved by techniques and adjuncts. Techniques include ensuring a correctly sized mask with an airtight seal, increasing fresh gas flow,chin lift and jaw thrust, two-person technique, and correct hand positioning. Although data are limited, there is evidence that the VE two-handed grip is more effective than the CE two-handed technique.143 Adjuncts such as oropha-ryngeal and nasopharyngeal airways can also improve the effectiveness of facemask ventilation, but must be sized appropriately.

Ease or effectiveness of facemask ventilation may change throughout the process of airway management. Subtle changes(e.g. increased airway pressure, reduced tidal volume,loss of facemask seal, deteriorating capnography trace, or increasing operator effort) may be early indicators of pro-gressive airway difficulty or pending failure of Plans A-C.These changes should be verbalised to the team, help should be sought immediately, and the airway strategy adjusted appropriately.

Recommendations

● Do not delay administration of neuromuscular block to check facemask ventilation.

● Facemask ventilation should be used to maintain oxygen-ation between attempts at airway instrumentation.

● Airway manoeuvres, adjuncts, or both can be used to improve ease of facemask ventilation where required.

● When facemask ventilation is difficult, this should be ver-balised to the team, help should be sought immediately, and the airway strategy adjusted appropriately.

DAS tracheal intubation guidelines 2025| 9

Plan B: Supraglottic airway device

The principle of Plan B is that ongoing oxygenation should be maintained using a SAD as the initial plan for tracheal intu-bation has failed(Fig. 4). Effective oxygenation through a SAD gives the opportunity to stop, think and communicate the next steps with the team. The default decision should be to dis-continue anaesthesia. Other options are high-risk and should only be considered with senior input(e.g. a more experienced anaesthet or surgeon). These options include: continue with SAD in situ(without intubating the trachea), intubate the tra-chea via SAD, or perform a FONA(tracheostomy or cricothyroidotomy).

Second-generation SADs offer important benefits over first-generation devices. Second-generation SADs are designed to reduce risk of aspiration. They generally have a higher pharyngeal seal, they can have a drainage port, and many are better suited as a conduit for intubation than first-generation devices.144,145 Among second-generation SADs, current cuffed devices have higher oropharyngeal leak pressure and allow adjusting cuff pressures.146 Insertion success rates do not appear significantly affected by design.145 There is insufficient high-quality evidence in clinically relevant insertion time differences between cuffed and uncuffed second-generation SADs. It is clear that second-generation SADs should be used ahead of first-generation devices. There is currently insuffi-cient evidence to recommend any particular second-genera-tion device or design, but cuffed devices can have potential benefits.146 Airway managers should attain and maintain competence in the use of the second-generation SADs avail-able in their department.

Most evidence for the use of SADs involves their use as a primary airway device in elective settings, and extrapolation of these data warrants cautious interpretation. The limited evidence suggests that SADs can rescue difficult or failed tracheal intubation in 60-65% of cases, but are underutilised as a rescue technique.113,147 There is little evidence on a safe maximum number of insertion attempts for effective

oxygenation with SADs in Plan B. Extrapolation of evidence suggests that as the number of attempts increases, the likeli-hood of successful oxygenation with a SAD decreases. ${}^{72}$ Repeated attempts can lead to more airway trauma, making ventilation more challenging, and could delay timely transi-tion to Plan C. Therefore, limiting the number of attempts to a maximum of three is recommended. Each subsequent attempt should involve a change to increase the likelihood of success,such as changing the size or using an alternative SAD, and ensuring full neuromuscular block. Oxygenation with face-mask ventilation should continue between SAD insertion attempts.

Stop, think, and communicate

Successful ventilation and oxygenation through a SAD should be confirmed with waveform capnography and pulse oxime-try. The next steps should be guided with senior input. Many factors will influence the decision on which option is most appropriate such as operator skill, urgency of surgery, loca-tion, equipment availability, and patient condition, but maintaining oxygenation and ventilation should take precedence.

Discontinue anaesthesia

After effective oxygenation through a SAD, the default deci-sion should be to discontinue anaesthesia and wake the pa-tient up, unless proceeding is essential. Compared with the other three options, emergence from anaesthesia is likely the safest way to maintain airway control and allow return of spontaneous ventilation. There is limited evidence, but data suggest that it is usually a viable option.15,72 However, this is not without risk. Vigilance is required for the potential risk of airway complications on emergence, such as laryngospasm.Considerations include quantitative neuromuscular moni-toring to guide full reversal and controlled emergence from anaesthesia.

 Fig 4. Plan B: Supraglottic airway device. eFONA, emergency front-of-neck airway; FONA, front-of-neck airway; SAD, supraglottic airway device

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Proceed with surgery using a supraglottic airway device

This should be considered as a high-risk option reserved for specific or immediately life-threatening situations and should involve input from senior clinicians. The airway might already be traumatised from several unsuccessful attempts at intubation and might deteriorate during the course of surgery because of device dislodgement, regurgitation,airway swelling, or surgical factors. Rescue options are limited given that tracheal intubation has already failed. Despite the good evidence supporting use of SADs in a range of surgical procedures,28,117,148 there is little evidence in the rescue scenario.

If proceeding with surgery is agreed by the team, effective oxygenation and ventilation must be continually confirmed.Before proceeding with a SAD, all techniques to maximise the likelihood of success should be considered, including opti-mising cuff pressure where relevant, passing a nasogastric tube to decompress the stomach, and optimising head and neck position and neuromuscular block.149 Consideration should also be made regarding expediting safe surgery and plans for device failure.

Intubation through a supraglottic airway device

This should be considered an advanced technique and a high-risk option that can fail. If tracheal intubation is essential,consider one attempt at intubation through a well-functioning SAD if the patient is stable, oxygenation is adequate, and the airway manager and assistant are trained in the technique.150 Tracheal intubation through a SAD that allows this technique can be performed with or without an Aintree Intubation Catheter ${}^{TM}$ , but it must always be performed under visual-isation(e.g. with flexible bronchoscopy). Blind techniques should not be performed.

Front-of-neck airway

In rare circumstances, even when it is possible to ventilate through a SAD, it might be appropriate to secure the airway with a tracheostomy or cricothyroidotomy(FONA). This is a more controlled scenario than an eFONA, but is complex and requires senior surgical and anaesthetic presence.

In the event of unsuccessful oxygenation and ventilation after three attempts or at any point during Plan B, the operator should declare failed SAD ventilation, move on to Plan C, and open the eFONA kit. Appropriate assistance must be sum-moned immediately. Clinicians should recognise that the need for eFONA is increasingly likely at this point.

Recommendations

● If tracheal intubation fails(Plan A), a second-generation supraglottic airway device should be used to attempt rescue.

● Airway managers should attain and maintain competence in the use of the second-generation supraglottic airway devices available in their department.

● The number of supraglottic airway device insertion at-tempts should be limited to a maximum of three.

● Once effective oxygenation is established with a supra-glottic airway device, stop, think and communicate.

● If proceeding is not essential, wake the patient up.

● If proceeding is essential and ventilation through the supraglottic airway device is satisfactory, consider continuing with the supraglottic airway device.

● If tracheal intubation is essential, consider one attempt at intubation through the supraglottic airway device using a flexible bronchoscope or perform a front-of-neck airway(tracheostomy or cricothyroidotomy).

● Blind tracheal intubation through a supraglottic airway device is not recommended.

● If supraglottic airway device ventilation is difficult, start priming for emergency front-of-neck airway.

Plan C: Final attempt at facemask ventilation

Plan C is the final attempt at facemask ventilation after failed tracheal intubation and SAD ventilation(Fig. 5). Up until this point, facemask ventilation might have been possible, but airway trauma and oedema from repeated instrumentation can contribute to increased difficulty. Therefore, every effort must be made to maximise the likelihood of successful oxygenation.This includes ensuring full neuromuscular block;adequate depth of anaesthesia; optimising patient posi-tioning; using an oropharyngeal airway, nasopharyngeal airway, or both; and using a two-person mask ventilation technique. Clinicians should be aware that rapid progression to Plan D might be necessary at this point.

Successful facemask ventilation is demonstrated by a waveform capography trace and either maintenance or improvement in arterial oxygen saturations. If facemask ventilation is successful, stop, think and communicate with senior clinicians to determine the most appropriate option.This is a complex clinical scenario. If the airway team decides to discontinue anaesthesia, full reversal of neuromuscular block and careful emergence of anaesthesia should be per-formed. Emergence in this scenario can be associated with risks of further deterioration or complications.150 Reversal of neuromuscular block could worsen airway obstruction or make facemask ventilation more difficult.101,151-153 Even if facemask ventilation is successful, proceeding to FONA might be considered.

If facemask ventilation is unsuccessful, declare a CICO scenario, allocate roles to team members, and immediately proceed to Plan D to perform an eFONA.

Recommendations

● When tracheal intubation and ventilation through a supraglottic airway device have failed, a final attempt at oxygenation by facemask ventilation should be made.

● For this final rescue attempt at facemask ventilation:

a. Ensure adequate neuromuscular block

b. Ensure patient positioning is optimised

c. Use airway adjuncts

d. Use a four-handed (two-person) technique

e. Ensure adequate depth of anaesthesia

Plan D: Emergency front-of-neck airway

Plan D arises when the ability to oxygenate the patient has failed by all other means(Plans A-C), leading to a CICO sce-nario(Fig. 6). Unless immediate intervention to establish an

DAS tracheal intubation guidelines 2025| 11

 Fig 5. Plan C: Final attempt at facemask ventilation.*At this point, clinical signs might be the only available marker of effective oxygenation.eFONA, emergency front-of-neck airway; FONA, front-of-neck airway.

eFONA and deliver oxygen is achieved, hypoxic brain injury or death will ensue.

Despite the fundamental importance of eFONA,evidence in this area remains limited owing to its rarity and being subject to reporting bias. Data are limited to nonclinical154-156 or retrospective studies.157-160 Therefore, pragmatic recommen-dations are required to optimise decision-making and perfor-mance of eFONA. Of note, there is some evidence to support the first-line use of scalpel techniques.161,162

Decision-making

There is evidence that choice in an emergency hinders per-formance.163,164 Decision-making in crises is almost solely based on previous experiences; in CICO situations this is usually from simulated scenarios. Clinicians should under-take repeated experience of skills training under stress and time pressure in a single technique that will be successful in most situations. ${}^{165}$ The choice of approach in the DAS 2015 guidelines was between a transverse stab incision for a palpable crothyroid membrane or a vertical skin incision for an impalpable crothyroid membrane. ${}^{9}$ However,locating the crothyroid membrane by palpation is unreli-able, even in elective settings.166 A vertical skin incision is suitable for both palpable and impalpable crothyroid membranes, but a transverse stab incision is only suitable for those in whom the crothyroid membrane is correctly identifiable by palpation or has been previously marked after ultrasound. ${}^{167}$ Furthermore, a vertical skin incision should make it easier to identify the crothyroid membrane. The decision regarding crothyroid membrane palpability should have been made during airway assessment and ver-balised by the end of Plan A. However, if this has not been explicitly assessed and determined, or if there is uncertainty regarding palpability of the crothyroid membrane, we recommend that a vertical skin incision should be performed for eFONA as a default.

Performance

Once CICO has been declared and help has been summoned,the senior member of the team should rapidly allocate roles for the most appropriate person to perform the eFONA, the operator's assistant, and an individual attempting to deliver oxygen by the upper airway if possible. An eFONA should not be attempted without full neuromuscular block. If sugarma-dex has already been administered, a neuromuscular blocking agent other than rocururonium or vecuronium will likely be required.168,169 Maximal neck extension is critical to success-fully performing eFONA, usually by pushing a pillow beneath the shoulders or extending the head of the bed.

Oxygen should be applied to the upper airway throughout.This can be achieved using a SAD, a facemask, or nasal can-nula. There can be advantages to using a SAD in this scenario,including optimal utilisation of staff and easier identification of the crothyroid membrane.170

Equipment(scalpel-bougie-tube)

The required equipment for eFONA are: a scalpel with a number 10 blade, a bougie, and a size 6.0 tracheal tube. Suction is likely to be needed.

Technique

CICO scenarios are variable, but regular training improves the likelihood of success. However, anecdotally, technical varia-tion is common. Surgical technique suggests that a right-to-right position(right-hand dominant operator standing on the right side of the patient) and a vertical incision starting at the thyroid cartilage, cephalad to caudad, can be advantageous.However, there is currently little evidence for this approach and many of the steps in the eFONA technique. Although we propose a specific technique, clinicians must be responsive to the clinical scenario, use approaches most likely to be suc-cessful in their hands, and train regularly in their preferred

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 Fig 6. Plan D: Emergency front-of-neck airway (eFONA).

technique. Regardless of the technique, fundamental princi-ples are that the scalpel should be held in the dominant hand and incisions made away from the operator's nondominant hand.

The vertical eFONA technique below remains largely un-changed from the DAS 2015 guidelines(Fig. 7). However,alternative scalpel-bougie-tube techniques are also accept-able, such as those presented in Supplementary File 5. More than one attempt might be required.

(1) Stand on the patient's left-hand side if right handed(reverse if left handed).

(2) Attempt to identify laryngeal anatomy in maximum neck extension and locate the midline with the nondominant hand.

(3) Apply tension to the skin and stabilise the larynx with the nondominant hand.

(4) Make a midline vertical skin incision up to 8 cm in length,caudad to cephalad(bottom to top).

(5) Use blunt dissection with fingers of both hands to sepa-rate tissues and identify and stabilise larynx with the nondominant hand.

(6) Use the nondominant hand index finger to identify the cricothyroid membrane.

(7) Hold the scalpel in the dominant hand, make a transverse stab incision through the cricothyroid membrane with the cutting edge of the blade facing towards you.

(8) Keep the scalpel perpendicular to the skin and turn it through 90 degrees so that the sharp edge points caudally(towards the feet).

(9) Swap hands; hold the scalpel with your nondominant hand.

(10) Maintain gentle traction, pulling the scalpel towards you(laterally) with the nondominant hand, keeping the scalpel handle vertical to the skin(not slanted).

(11) Pick the bougie up with your dominant hand.

(12) Slide the coudé tip of the bougie down the side of the scalpel blade into the trachea.

(13) Rotate and align the bougie with the trachea and advance gently to 10-15 cm.

(14) Remove the scalpel.

(15) Stabilise the trackhea, apply tension to the skin, and hold the bougie with the nondominant hand.

(16) Railroad a size 6.0 mm cuffed tracheal tube over the bougie with the dominant hand. Rotate the tube as it is advanced.

(17) Remove the bougie.

(18) Inflate the cuff, ventilate with 100% oxygenation, and confirm ventilation with waveform capnography.

(19) Secure the tube.

After emergency front-of-neck airway

After successful eFONA and stabilisation of the patient, com-plications such as bronchial intubation and pneumothorax should be excluded. Review by a suitable surgeon is required to determine the most appropriate next steps for airway management. ${}^{171,172}$

Reflection after a significant airway event is important to determine what process and procedural elements can be improved. It is recognised there is a significant psychological impact on those involved in eFONA scenarios extending beyond the individual performing the procedure. ${}^{173}$ Debriefing and signposting those involved to support services is encour-aged after events. ${}^{174}$

In the event of an unsuccessful eFONA attempt, consider extending the incision, performing more blunt dissection down to the cricothyroid membrane, changing position of the patient or operator, changing operator, or changing to a smaller tube. However, we recognise that the situation at this stage is likely catastrophic.

DAS tracheal intubation guidelines 2025|13

 Fig 7. Emergency front-of-neck airway technique.

Recommendations

● Where Plans A, B, and C have failed, and a‘cannot intubate,cannot oxygenate' scenario exists, an emergency front-of-neck airway(Plan D) must be performed.

● Ensure maximal neck extension before performing an emergency front-of-neck airway, where feasible.

● Give a full dose of neuromuscular blocking agent before performing an emergency front-of-neck airway.

● Psychological support should be available to those who have been involved in an emergency front-of-neck airway scenario.

Rapid sequence induction and intubation

Rapid sequence induction and intubation(RSI) is used in pa-tients who are identified as being at increased risk of pulmo-nary aspiration after induction of anaesthesia and before securing a cuffed tracheal tube. Although the same general principles of airway management apply in this setting, there

are some specific considerations in patients requiring RSI(Table 1, Supplementary File 6).

Clinicians should consider that these patients might also have a physiological difficult airway and manage this appropriately.

Cricoid force aims to reduce the risk of pulmonary aspira-tion before tracheal intubation. Classically defined, it involves the application of 10 N of force before induction followed by 30 N once consciousness is lost.175 There is variation in the use of cricoid force across specialties and globally176-179 because of uncertainty in both safety and efficacy.180 In particular, there are concerns that cricoid force might worsen the view at laryngoscopy,reduce successful tracheal intubation,181 reduce lower oesophageal sphincter tone.182 and might not reduce the risk of pulmonary aspiration.

These concerns are not founded in robust contemporary evidence, with unreliable data on the safety and efficacy of cricoid force.183 There is increasing evidence that localisation of the cricoid cartilage and nearby anatomical structures is likely

14| Ahmad et al.

Table 1 Considerations for rapid sequence induction and intubation.

|Risk assessment|History,examination, and investigations,including point-of-care gastric ultrasound Prokinetics and antacids| |---|---| |Nasogastric tube management|Consider risks/benefits Suction if present; consider insertion if not| |Suction|On and at hand| |Head-up position|≥30 degrees| |Pre-oxygenation|ETO2 ≥0.9 where possible; consider high-flow nasal oxygen| |Rapid onset of anaesthesia|Dosing to consider physiology| |Rapid onset of neuromuscular block|No latency between induction agent and neuromuscular blocking agent.| ||Ensure sufficient dosing(e.g.1.2 mg kg-1 rocururonium;1.5 mg kg-1 suamethonium)| |Cricoid force|Correct localisation and correct force, performed by a trained assistant| |Gentle mask ventilation or apnoecic|Low-pressure mask ventilation if required| |oxygenation|| |Videolaryngoscopy|Optimise ergonomics for a shared view| |Tracheal tube introducers|Bougie or stylet prepared|

inaccurate unless performed with ultrasound.50,51,184-186 Furthermore, the correct application of force is variable unless the operator undergoes regular training. ${}^{187,188}$ First-attempt and overall intubation success with videolaryngoscopy is not hampered by the use of cricoid force. ${}^{189}$ though it could reduce the ease of tracheal tube advancement. ${}^{190}$ Finally, despite high-quality data, there is no evidence that cricoid force either in-creases the risk of failed tracheal intubation or reduces the risk of pulmonary aspiration. ${}^{189,191}$ Therefore, given the dearth of definitive evidence, pragmatic recommendations are required.In patients at particularly high risk of pulmonary aspiration,cricoid force should be used. If inserting a SAD in Plan B, or dif-ficulty with laryngoscopy or tracheal intubation is encountered,or active vomiting occurs, cricoid force should be removed.

Recommendations

● If cricoid force is used and the view at laryngoscopy is poor,it should be removed in an attempt to improve the view.

● Assistants providing cricoid force should receive regular training in correct application.

Physiologically difficult airway

In addition to anatomical factors, airway managers must also consider risks of physiological(e.g. old age, pregnancy) and pathophysiological(e.g. sepsis, cardiac failure) alterations including hypoxaemia, haemodynamic instability and com-plications on transition to positive pressure ventilation.19 These alterations could decrease the effectiveness of perox-yagenation and precipitate or worsen cardiovascular instability,which can contribute to cognitive overload and impact patient outcomes. Although anatomically or physiologically difficult airways can occur independently, they are particularly haz-ardous in combination. ${}^{192}$

Haemodynamic instability is the most common life threatening complication of tracheal intubation in critically ill adults,193 but is often predictable and preventable. Therefore,assessment and optimisation before induction of anaesthesia is vital.194,195 This includes appropriate fluid resuscitation and management, use of vasopressors and choice of induction agent.88,196,197 Designating a team member to monitor and independently manage haemodynamic status allows the airway manager to focus on tracheal intubation.

Physiological alterations can impair oxygen uptake and delivery, underscoring the importance of pre-oxygenation with a positive pressure technique,25,26 and of continuing

oxygen delivery throughout airway management(i.e. perox-ygenation). Multiple attempts at tracheal intubation signifi-cantly increase the rate of adverse events in patients with physiologically difficult airways,193 making first-attempt suc-cess particularly important.

Propofol can contribute to haemodynamic instability, high-lighting the importance of careful dosing. 88,193 There can also be a role for alternative induction agents such as ketamine, eto-midate, and remimazolam in these high-risk patients. 89,198,199

Recommendations

● Haemodynamic status should be optimised before induc-tion of anaesthesia, and those at risk of ongoing haemody-namic instability should have a team member nominated to manage this.

Obesity

Obesity is associated with an increased risk of airway com-plications, as highlighted in NAP4 and NAP7.16,71,200 People living with obesity are more likely to be difficult to ventilate with a facemask or SAD. Excess adiposity can make tracheal intubation and FONA more difficult. These risks are com-pounded by higher basal metabolic rate and reduced func-tional residual capacity, increasing the risk of rapid haemoglobin oxygen desaturation after induction of anaes-thesia.Therefore,ATI,HFNO for peroxygenation, and early use of a SAD should be considered. Recent guidelines from the Society for Obesity and Bariatric Anaesthesia(SOBA) describe how the risks of adverse events might be mitigated in this population; however, it is important to acknowledge that this involves a comprehensive package of measures to create a safe airway strategy.201 It is vital to optimise patient posi-tioning throughout. The head-up position(≥30 degrees) in-creases the effectiveness of pre-oxygenation, facemask ventilation, and tracheal intubation.202,203

Calling for help should be considered earlier for this group of patients.

Recommendations

● Consider awake tracheal intubation in people living with obesity.

● Patients should be pre-oxygenated in a head-up position(≥30 degrees).

DAS tracheal intubation guidelines 2025| 15

● Consider performing airway management in the operating theatre.

● Consider use of high-flow nasal oxygen for peroxygenation.

● Consider early use of a second-generation supraglottic airway device for ventilation if facemak ventilation is suboptimal.

Human factors

The science of human factors and ergonomics is central to airway management.87,204,205 Although technical and nontechnical skills are considered and taught independently,they are complementary and interdependent.206 Education and training are reported as the least effective control to improve patient safety.17 Mitigations, barriers, and design changes are more effective, and specific examples can be seen in Supplementary File 7.

Priming

In these guidelines, priming is the process of preparing for eFONA in parallel to Plans A to C. It aims to ensure immediate availability of necessary equipment, and that appropriately skilled staff are present and cognitively prepared. After declared failure at tracheal intubation, the operator and assistant should ensure the eFONA kit is immediately accessible, declaring clearly who is the most appropriately skilled individual to perform eFONA. After a maximum of three attempts at oxygenation through a SAD, the assistant should open the eFONA kit.

Transitioning

Transitioning is recognising that Plan A, B, or C has failed and immediately moving on to the next step of the algorithm. As part of airway crisis management, this is often poorly executed owing to task fixation or excessive efforts at failing techniques, potentially leading to airway trauma and pro-gression to CICO. ${}^{136}$ Each transition should be declared clearly to the whole team and should trigger seeking appropriate help.The need to end attempts at a plan and move on can be prompted by the assistant or another member of the team.

Cardiac arrest algorithms effectively use time-based tran-sitioning,207 which is not always practical in airway manage-ment crises. However, triggers such as number of attempts at a technique, time taken, and physiological response are feasible alternatives to guide transitioning. ${}^{136}$

Calling for help

Integral to these guidelines is the need to call for help when-ever any difficulty is encountered. This should not be related to seniority or role(progression through the algorithm places increasing demand on the airway assistant), and should be determined by the clinical scenario. Who seeks this help, and how, will be dependent on institution, location, scenario, and time. If difficulty is anticipated, airway teams should discuss during the team brief who they will ask for help, and allocate a member of the team(not the airway assistant) to this task.

Airway assistant

The airway assistant plays an integral role in technical and nontechnical aspects of safe airway management. They should be appropriately trained and empowered to confirm sustained

exhaled carbon dioxide on waveform capnography, have situ-ational and time awareness, prompt transitioning after the maximum number of attempts, and know when to seek appropriate help. ${}^{208}$ Graded assertiveness tools can be used to facilitate communication with the airway manager. ${}^{209,210}$

Point-of-care ultrasound

Point-of-care ultrasound has an increasing evidence base in airway management for airway assessment, preprocedural anatomical localisation, and pulmonary aspiration risk assessment. Airway assessment to predict a difficult airway is possible using a number of sonographic measurements and assessments.59-65 Although this is now well-validated in research settings, 211 its current role and application in clinical practice is unclear and limited.

Airway ultrasound can be used for preprocedural local-isation of the cricoid cartilage and the cricothyroid membrane.Manual palpation is often inaccurate for localisation of the cricoid cartilage, with pre-induction sonography proving significantly more accurate for both cricoid cartilage and cri-cothyroid membrane.50 In patients in whom difficult airway management is anticipated, pre-induction sonographic identi-fication and marking is beneficial for asleep and awake tech-niques.166 This should ideally be done with the neck extended.

Pulmonary aspiration risk assessment with point-of-care gastric ultrasound can influence airway management de-cisions, ${}^{212,213}$ and is increasingly recognised as a skill anaestheists should acquire. ${}^{214-216}$ It can be readily learned with supervision, and performed quickly by competent clini-cians. ${}^{217,218}$ Despite the challenges in widespread training, this is likely to become as a more commonly used skill for clini-cians in the future.

Ultrasound skills are important to advancing practice but they currently lack validated training programmes and rely heavily on enthusiasts to share knowledge and provide teaching.

Documentation

Clear, concise documentation is vital to provide a reference for current and future airway management and to inform case reviews. No minimum standards for documentation of airway management currently exist. However, airway assessment,techniques and equipment used,difficulties encountered,and outcomes should be documented and communicated with staff involved in the patient's immediate and ongoing care(e.g. PACU, ward, or critical care staff). A distinction should be made when a technique has been used purely for training(e.g.intubation through SAD) or when it has been used because of anticipated or actual difficulty. ${}^{219}$

When airway management has been considered to be difficult, in addition to documentation in the patient's record,this should be communicated verbally and in writing to the patient, and also to their primary care provider using appro-priate diagnostic coding(e.g. SNOMED CT 718446005).220 These details can also be entered into a national registry(e.g. DAS Difficult Airway Registry or DAS eFONA Registry),48 and recorded using theatre coding systems.

Recommendations

● Individuals have a professional responsibility to document airway management as provided by their institution.

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Education, training, and institutional responsibility

Education and training in all aspects of airway management are fundamental for the effective delivery of Plans A-D. This must not be limited to device skill acquisition, but should also include other elements such as decision-making, communi-cation, human factors, and guideline implementation. Recog-nising that airway managers do not work alone, training opportunities should include all members of the multidisci-plinary airway team (Supplementary File 8).

Institutional and individual responsibilities

Institutions and individuals have a shared responsibility to ensure effective training. Institutions have a responsibility to provide access to and encourage regular use of any equipment required in Plans A-D. Individuals must ensure that they avail of such clinical training opportunities in an ethically appro-priate way.219 Demonstrable improvement in skill can be shown with relatively few uses of a device; however to achieve reliable first-attempt success without complications requires regular and ongoing training for all grades of airway man-agers.114,188,221,222 Airway leads are ideally placed to determine local device choice and facilitate the necessary institutional airway training programmes.223,224 Mandatory training might be introduced in the coming years,225 and the responsibility for implementation of this should be shared. Confidential en-quiries across the UK'(MBRRACE-UK) reports,226 might have future aspiration.227

Team-based training

Effective delivery of multidisciplinary team training requires institutional direction and support to ensure staff can attend.Training as a team develops a shared approach and under-standing. This enables teams to practise the roles of leader-ship and followership,228,229 consider how they can optimise human factors, ergonomics, ${}^{17}$ and practise challenging hier-archies in emergency situations. ${}^{230,231}$ This will help promote a culture of psychological safety amongst the multidisciplinary team. ${}^{232}$ However, it is important to understand the need for clear leadership in emergency situations. ${}^{233}$

Educational opportunities

We recognise that although certain aspects of clinical pro-cedures can be rehearsed (e.g. cricothyroid membrane palpa-tion), practising the complete eFONA technique is usually manikin-based. Manikin and simulation-based training has an important role in skill development, ${}^{234}$ which along with tea trolley training, ${}^{235}$ airway courses and workshops and con-ferences should be regarded as a foundation for clinical prac-tice. The COVID-19 pandemic demonstrated the potential benefits of learning through webiners and virtual classrooms,and these continue to be an important source of airway education. ${}^{236}$

Learning from adverse events

Adverse airway events and near misses should be reviewed at departmental morbidity and mortality meetings, ideally

<EndOfPara>moderated by airway leads. This should focus on learning outcomes for individuals and the institution to ensure the prevention of future events and implementation of these guidelines. The airway leads network is an important resource for the sharing of such incidents and their learning nationally 224

Training in laryngoscopy

Despite the evidence and availability of videolaryngoscopy,routine use of videolaryngoscopy for tracheal intubation has yet to be achieved in many countries.39 One barrier might be a fear of loss of skill in direct laryngoscopy. Evidence now sup-ports the effective teaching of both direct and indirect (video)laryngoscopy with a videolaryngoscope. ${}^{237}$

Capnography interpretation

All members of the multidisciplinary team should be trained in recognising and verbalising the presence of appropriate waveform capography(sustained exhaled carbon dioxide).24

Recommendations

● Institutions should support and facilitate individuals at all levels to train and maintain competencies in airway man-agement with clinical and nonclinical multidisciplinary training.

● Institutions should support clinicians to train with new equipment or guidelines.

● Airway leads should reinforce familiarity with the Plan A-D approach amongst airway managers and assistants.

● Human factors and team performance under stress should be included in training.

● All individuals involved in airway management should have training in capnography interpretation.

● All airway managers should be regularly trained in per-forming an emergency front-of-neck airway.

● Every failed intubation and emergency front-of-neck airway should be reviewed and discussed at morbidity and mor-tality meetings.

● Evidence of airway training can be used to support annual performance assessments, such as appraisal.

Discussion

These guidelines emphasise the importance of maximising the likelihood of successful tracheal intubation at the first attempt; continuous oxygen delivery throughout airway management; confirmation of ventilation with capnography;multidisciplinary team working; and ongoing education and training. We encourage clinicians to prioritise improving the likelihood of successful airway management rather than management of failure whilst being prepared for all eventu-alities. Importantly, we advocate for early recognition that an attempt at any technique is unsuccessful, learning from this failure for subsequent attempts, and promptly moving on to the next step of the algorithm(Fig. 1).

In keeping with previous iterations(Supplementary File 9),these guidelines are designed to manage unanticipated diffi-culty when the primary airway plan is tracheal intubation.However, we recognise that elements of these plans will be relevant to any airway management strategy regardless of the

DAS tracheal intubation guidelines 2025|17

starting point. Adherence to these guidelines should reduce the risk of unanticipated difficulty occurring and increase the likelihood of success if difficulty is encountered.

Where the primary airway management plan is a SAD,14,16 failure requiring subsequent tracheal intubation necessitates entry into the algorithm at Plan A. However, progression through the algorithm should be informed by previous un-successful SAD ventilation attempts. If initial attempts at effective oxygenation with a SAD were unsuccessful, it would be futile to repeat these steps, and rapid progression to Plan C might be necessary.

The DAS 2015 guidelines generated debate around eFONA given the recommendations to primarily focus on a scalpel rather than cannula technique.9 We had similar uncertainties regarding technical elements of the scalpel eFONA approach(e.g. operator positioning, palpable vs nonpalpcricity-roid membrane, transverse stab us vertical incision) owing to a paucity of evidence. We therefore used an expert consensus process to help inform the recommendations for this tech-nique. Given the dearth of evidence, clinicians should choose which scalpel eFONA approach is most likely to be successful in their hands, and train in that technique. Another technical change was the removal of decision-making about a trans-verse stab vs vertical incision depending on crichyroid membrane palpability in Plan D, but encouraging its consid-eration earlier in the algorithm. This change was guided by human factors theory, suggesting that decision-making in a crisis can hamper performance.238 It remains to be seen whether this will improve outcomes in eFONA. Although the eFONA Registry might improve our understanding and lead to changes in technical recommendations, 239 data demonstrate that decision-making throughout airway management con-tinues to be delivered poorly, leading to airway complica-tions.14,48,71 This highlights that the technical specifics of procedures might be less important than decision-making around eFONA.

There have been advancements in clinical practice since the previous iterations of these guidelines. In the coming years, artificial intelligence will likely play an increasing role in airway management, from education to airway assess-ment and tracheal intubation. Similarly, technology such as combined videolaryngoscope/endoscope devices or novel introducer designs might become more widely available.There have also been changes in the characteristics of pa-tients requiring airway management. For example, obesity has become increasingly prevalent, surgery in the older pa-tient is more common,14,15,18 use of TIVA is widespread, and introduction of drugs such as glucagon-like peptide-1(GLP-1)receptor agonists have all influenced clinical practice. These have affected decision-making and the role of techniques such as cricoid force application, rapid sequence induction and intubation, use of point-of-care gastric ultrasound, and management of physiologically difficult airways. Regardless of the technological and clinical practice changes, the fundamental principles of all airway management strategies are likely to remain, including having a strategy and prepa-ration for failure.

Effective implementation of these guidelines relies on the provision and delivery of suitable education material to sup-port educators and learners. As such, we have developed a multimodal educational package to be used in conjunction with these guidelines to allow multidisciplinary, standardised,

and consistent training for the effective delivery of airway management(Supplementary File 8).

There are limitations to these guidelines including evolving techniques and their associated literature base; the lack of RCTs in some areas; and the limitations of trials and meta-analyses. We eagerly await evidence from a number of studies,including the eFONA Registry, and updated analyses of the Difficult Airway Registry, although we recognise the limita-tions of cohort studies. The recommendations are pragmatic but might not necessarily apply to all scenarios or all airway managers, because of the complexity and heterogeneity of clinical practice. Changes made from the previous guidelines were often based on expert opinion. Finally, some elements of these recommendations might not be applicable to low-resource environments.

In conclusion, these guidelines are designed to support clinicians in delivering airway management that prioritises efficacy and safety. Overall, we emphasise the importance of maximising the chances of success rather than the avoidance and management of failure, to improve outcomes for patients undergoing airway management.

Authors' contributions

Guidelines development: all authors Manuscript drafting: IA, KE, HI, AFM Revision and final approval: all authors

Chair: IA

Secretary:KE

Deputy secretary: HI

Acknowledgements

We thank F. Kelly, Royal United Hospitals Bath NHS Founda-tion Trust(Bath, UK) for her significant contributions to the early development of these guidelines. We thank the NHS Wales librarians J. Roe, Cardiff and Vale University Health Board(Cardiff, UK); K. Osbourne, Aneurin Bevan University Health Board(Cwmbran, UK); R. Whelan, Swansea Bay Uni-versity Health Board(Swansea, UK); and B. Sharif, Cardiff and Vale University Health Board(Cardiff, UK) for their assistance in the literature review. We thank B. McGrath, Manchester University NHS Foundation Trust(Manchester, UK); C. McCaul,Rotunda Hospital(Dublin, Ireland); C. Mendonca, University Hospitals Coventry and Warwickshire NHS Trust(Coventry,UK); T. Cook, Royal United Hospitals Bath NHS Foundation Trust(Bath, UK); D. Lockey, North Bristol NHS Trust(Bristol,UK); T. Tatla, London North West University Healthcare NHS Trust(London, UK); S. Khan, Oxford University NHS Founda-tion Trust(Oxford, UK); K. Kapoor, Surrey and Sussex NHS Trust(Redhill, UK); S. Sudan, University Hospitals Sussex NHS Foundation Trust(Bighton, UK); C. Frerk, Northampton Gen-eral Hospital NHS Trust(Northampton, UK); V. Mitchell, Uni-versity College London Hospitals NHS Foundation Trust(London, UK); B. McGuire, NHS Tayside(Dundee, UK); B. Patel,Royal Surrey NHS Foundation Trust(Guilford, UK); T. Kitchen,Cardiff and Vale University Health Board(Cardiff, UK); P. Ward,NHS Lothian(Edinburgh, UK); G. Sandu, Imperial College Healthcare NHS Trust(London, UK); and R. Bhagrath, Barts Health NHS Trust(London, UK) for their contributions to the eFONA expert panel. We thank T. Asai, Dokkyo Medical Uni-versity(Mibu, Japan); C. McCaul, Rotunda Hospital(Dublin,

18| Ahmad et al.

Ireland);B. Patel, Royal Surrey NHS Foundation Trust(Guilford,UK); P. Baker, University of Auckland (Auckland, New Zea-land); V. Mitchell, University College London Hospitals NHS Foundation Trust(London, UK); B. McGrath, Manchester Uni-versity NHS Foundation Trust(Manchester, UK); S. Jagana-than, Phoenix Children's Hospital (AZ, USA); C. Frerk,Northampton General Hospital NHS Trust(Northampton,UK);L.Beckmann, Royal Brisbane and Women's Hospital (Brisbane,Australia); A. Fuchs, University Hospital Bern(Bern;Switzerland); B. McGuire, NHS Tayside(Dundee, UK); M.Parotto, Toronto General Hospital(Toronto, ON, Canada); F.Undaneta, University of Florida Health(FL, USA); M. Sorbello,policlinico San Marco(Catania, Italy); T. Cook, Royal United Hospitals Bath NHS Foundation Trust(Bath, UK); and S.Marshall, Alfred Health(Melbourne, Australia) for their expert review of the manuscript. We thank Yen Chow and Marios Hadjvisvas for their development of graphics. We thank the DAS committee and members who contributed comments that helped shape the recommendations. We thank H. Smith,University College London Hospitals NHS Foundation Trust(London, UK) for her contributions to film production of the educational package. We thank the Department of Anaes-thesia at Guy's Hospital for the use of the department for all in-person meetings.

Funding

These guidelines were funded by the Difficult Airway Society.The educational material was funded by the Difficult Airway Society and the British Journal of Anaesthesia.

Declarations of interest

IA has received funding from Fisher and Paykel Healthcare,IA has received funding from Fisher and Paykel Healthcare,GE Health Care, and PAION. FM has received honoraria from Fisher and Paykel Healthcare. EPO has received honoraria from Med-tronic. AP as received support for lectures, consulting, and research funding from Fisher and Paykel Healthcare. SARN has received honoraria from Fisher and Paykel Healthcare and Pentax. AFM has received honoraria from Fisher and Paykel Healthcare and is on the speakers' bureau for Medtronic. The other authors declare no conflict of interest.

Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.org/10.1016/j.bja.2025.10.006.

Supplementary File S1. Systematic review methodology and results.

Supplementary File S2. Recommendations and level of evidence.

Supplementary File S3. HEAVEN and MACOCHA criteria.

Supplementary File S4. Lim and Nielsen scoring system for facemask ventilation.

Supplementary File S5. Emergency front-of-neck airway techniques.

Supplementary File S6. Emergency tracheal intubation checklist.

Supplementary File S7. Example human factors consider-ations in Plans A-D.

Supplementary File S8. Educational resources for the 2025 DAS Guidelines.

Supplementary File S9. Overview of key changes to the DAS 2025 Guidelines from DAS 2015 Guidelines.

References

1. Practice guidelines for management of the difficult airway. A report by the American Society of Anesthesi-ologists Task Force on Management of the Difficult Airway. Anesthesiology 1993; 78: 597-602

2. Henderson JJ, Popat MT, Latto IP, Pearce AC. Difficult Airway Society guidelines for management of the unanticipated difficult intubation. Anaesthesia 2004; 59:675-94

3. Ahmad I, El-Boghdadly K, Bhagrath R, et al. Difficult Airway Society guidelines for awake tracheal intubation(ATI) in adults. Anaesthesia 2020;75:509-28

4. Apfelbaum JL, Hagberg CA, Connis RT, et al. American Society of Anesthesiologists practice guidelines for management of the difficult airway. Anesthesiology 2022;136:31-81.2022

5. Petrini F, Accorsi A, Drario E, et al. Recommendations for airway control and difficult airway management.Minerva Anestesiol 2005; 71:617-57

6. Cook TM, El-Boghaddydly K, McGuire B, McNarry AF,Patel A, Higgs A. Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetist. Anaes-thesia 2020;75:785-99

7. Law JA, Duggan LV, Asselin M, et al. Canadian Airway Focus Group updated consensus-based recommendations for management of the difficult airway: part 1. Difficult airway management encountered in an unconscious pa-tient Can J Anesth Can J Anaesth 2021;68:1373-404

8. Wiles MD, Iliff HIA, Brooks K, et al. Airway management in patients with suspected or confirmed cervical spine injury. Anaesthesia 2024; 79: 856-68

9. Frerk C, Mitchell VS, McNarry AF, et al. Difficult Airway Society 2015 guidelines for management of unantici-pated difficult intubation in adults. BrJ Anaesth 2015;115:827-48

10. Higgs A, McGrath BA, Goddard C, et al. Guidelines for the management of tracheal intubation in critically ill adults.Br J Anaesth 2018; 120:323-52

11. Langeron O, Bourgain JL, Francon D, et al. Difficult intu-bation and extubation in adult anaesthesia. Anaesth Crit Care Pain Med 2018; 37: 639-51

12. Piepho T. German guidelines for airway management 2023.Anaesthesiologie May 16, 2024. https://doi.org/10.1007/s00101-024-01413-5. Advance Access published on

13. Myatra S, Shah A, Kundra P, et al. All India Difficult Airway Association 2016 guidelines for the management of unanticipated difficult tracheal intubation in adults.Indian J Anaesth 2016; 60: 885

14. Cook TM, Oglesby F, Kane AD, Armstrong RA,Kursumovic E, Soar J. Airway and respiratory complica-tions during anaesthesia and associated with peri-oper-ative cardiac arrest as reported to the 7th National Audit Project of the Royal College of Anaesthetists. Anaesthesia 2024;79:368-79

15. Kane AD,Cook TM,Armstrong RA,et al.The incidence of potentially serious complications during non-obstetric

DAS tracheal intubation guidelines 2025| 19

anaesthetic practice in the United Kingdom: an analysis from the 7th National Audit Project(NAP7) activity sur-vey. Anaesthesia 2024;79:43-53

16. Cook TM, Woodall N, Frerck C. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaes-thetics and the Difficult Airway Society. Part 1: Anaes-thesia. Br J Anaesth 2011; 106: 617-31

17. Kelly FE, Frék C, Bailey CR, et al. Implementing human factors in anaesthesia: guidance for clinicians, de-partments and hospitals. Anaesthesia 2023; 78: 458-78

18. Kane AD, Soar J, Armstrong RA, et al. Patient character-istics, anaesthetic workload and techniques in the UK:an analysis from the 7th National Audit Project(NAP)activity survey. Anaesthesia 2023;78:701-11

19. Karamchandani K,Nasa P,Jarzebowski M,et al.Tracheal intubation in critically ill adults with a physiologically difficult airway. An international Delphi study. Intensive Care Med 2024; 50: 1563-79

20. de Carvalho CC, Guedes IHL, Dantas MVM, et al. Video-laryngoscope designs for tracheal intubation in adults: a systematic review with network meta-analysis of rand-omised controlled trials. Anaesthesia 2025; 80:823-33

21. von Hellmann R, Fuhr N, Ward A, Maia I, et al. Effect of bougie use on first-attempt success in tracheal in-tubations: a systematic review and meta-analysis. Ann Emerg Med 2024;83:132-44

22. Chrimes N, Higgs A, Hagberg CA, et al. Preventing unrecognised oesophageal intubation: a consensus guideline from the Project for Universal Management of Airways and international airway societies. Anaesthesia 2022; 77: 1395-415

23. de Carvalho CC, Guedes IHL, Dantas MVM, El-Boghdadly K. Videolaryngoscopy vs direct laryngoscopy for tracheal intubation by experienced anaesthetists: a meta-analysis and trial sequential analysis of rando-mised controlled trials. Anaesthesia 2024; 79: 1371-3

24. Cloke T, Ross C, Joy P,et al. A two-person verbal check to confirm tracheal intubation: evaluation of practice changes to prevent unrecognised oesophageal intuba-tion. Br J Anaesth 2024; 133: 1307-17

25. Cristian de Carvalho C, Iliff H, Santos Neto JM, et al.Effectiveness of preoxygenation strategies: a systematic review and network meta-analysis. Br J Anaesth 2024;133:152-63

26. Pitre T, Liu W, Zeraatkard et D, et al. Preoxygenation stra-tegies for intubation of patients who are critically ill: a systematic review and network meta-analysis of rando-mised trials. Lancet Respir Med 2025; 13: 585-96

27. de Carvalho CC,Kapsokalyvas I,El-Boghaddyad K. Second-generation supraglottic airway devices versus endotra-cheal intubation in adults undergoing abdominopercel surgery: a systematic review and meta-analysis. Anesth Analg 2025; 140:265-75

28. Sanganee U,Jansen K,Lucas N,Van de Velde M.The role of supraglottic airway devices for caesarean section un-der general anaesthesia. A scoping literature review with a proposed algorithm for the appropriate use of supra-glottic airway devices for caesarean sections. Eur J Anaesthesiol 2024;41:668-76

29. Driver BE, Semler MW, Self WH, et al. Effect of use of a bougie vs endotracheal tube with stylet on successful intubation on the first attempt among critically ill patients undergoing tracheal intubation. JAMA 2021;326: 2488

30. Boulton AJ, Smith E, Yasin A, Moreton J, Mendonca C.Tracheal tube introduce-associated airway trauma: a systematic review. Anaesthesia 2024; 79: 1091-101

31. Hansel J, Rogers AM, Lewis SR, Cook TM, Smith AF.Videolaryngoscopy versus direct laryngoscopy for adults undergoing tracheal intubation. Cochrane Database Syst Rev 2022; 4: CD011136

32. Koundal V, Rana S, Thakur R, Chauhan V, Ekke S,Kumar M. The usefulness of point of care ultrasound(POCUS) in preanaesthetic airway assessment. Indian J Anaesth 2019; 63: 1022

33. Austin DR, Chang MG, Bittner EA. Use of handheld point-of-care ultrasound in emergency airway management.Chest 2021; 159: 1155-65

34. Perlas A, Arzola C, Van de Putte P. Point-of-care gastric ultrasound and aspiration risk assessment: a narrative review. Can J Anesth 2018; 65: 437-48

35. Patel A, El-Ohhdadly K. Facemask or high-flow nasal oxygenation: time to switch? Anaesthesia 2022;77:7-11

36. Brouwers MC, Kho ME, Browman GP, et al. AGREE II:advancing guideline development, reporting and evaluation in health care. J Clin Epidemiol 2010; 63:1308-11

37. Page MJ, McKenzie JE, Bossuyt PM, et al. Updating guid-ance for reporting systematic reviews: development of the PRISMA 2020 statement. J Clin Epidemiol 2021; 134:103-12

38. Coulter I, Effenbaum P,Jain S, Jonas W. SEaRCHTM expert panel process: streamlining the link between evidence and practice. BMC Res Notes 2016; 9: 16

39. Narskov AK, Rosenstock CV, Wetterssley J, Astrup G,Afshari A, Lundstrom LH. Diagnostic accuracy of anaes-thesologists' prediction of difficult airway management in daily clinical practice: a cohort study of 188 064 pa-tients registered in the Danish Anaesthesia Database.Anaesthesia 2015; 70: 272-81

40. Cattano D,Killoran PV,Iannucci D,et al. Anticipation of the difficult airway: preoperative airway assessment, an educational and quality improvement tool. Br J Anaesth 2013;111:276-85

41. Lamperti M, Romero CS, Guarracino F,et al. Preoperative assessment of adults undergoing elective noncardiac surgery. Eur J Anaesthesiol 2025; 42: 1-35

42. Roth D, Pace NL, Lee A, et al. Airway physical examina-tion tests for detection of difficult airway management in apparently normal adult patients. Cochrane database Syst Rev 2018; 5 CD008874

43. Faramarzi E, Soleimanpour H, Khan ZH,Mahmoodpo A, Sanaie S. Upper lip bite test for pre-diction of difficult airway: a systematic review. Pakistan J Med Sci 2018; 34: 1019-23

44. Wang Z, Jin Y, Zheng Y, Chen H, Feng J, Sun J. Evaluation of preoperative difficult airway prediction methods for adult patients without obvious airway abnormalities: a systematic review and meta-analysis. BMC Anesthesiol 2024;24:242

45. Aydin BG, Küçukosman G, Piskin O, Okyay RD, Ayoglu H.Difficult mask ventilation in obese patients: new pre-dictive tests? Haseki Tip Bul 2019; 57: 15-9

46. Mahmoud M, Hasanin AM, Mostafa M, Alhamade F,Abdelhamid B, Elsherbeeny M. Evaluation of super-obesity and super-super-obesity as risk factors for diffi-cult intubation in patients undergoing bariatric surgery.Surg Obes Relat Dis 2021; 17: 1279-85

20| Ahmad et al.

47. Nagappa M, Wong DT, Cozowicz C, Ramachandran SK,Memtsoudis SG, Chung F. Is obstructive sleep apnea associated with difficult airway? Evidence from a sys-tematic review and meta-analysis of prospective and retrospective cohort studies. PLoS One 2018; 13:1-15

48. Sajayan A, Nair A, McNarry AF, Mir F, Ahmad I, El-Boghaddy K. Analysis of a national difficult airway database. Anaesthesia 2022;77:1081-8

49. Lyons C, El-Boghaddly K. Point-of-care gastric ultra-sound: food for thought. Anaesthesia 2024; 79: 123-7

50. Lee D, Czech AJ, Elriedy M, Nair A, El-Boghdadly K,Ahmad I. A multicentre prospective cohort study of the accuracy of conventional landmark technique for cricoid localisation using ultrasound scanning. Anaesthesia 2018;73:1229-34

51. You-Ten KE, Desai D, Postonogova T, Siddiqui N. Accu-racy of conventional digital palpation and ultrasound of the cricothyroid membrane in obese women in labour.Anaesthesia 2015; 70: 1230-4

52. El-Boghdadly K, Onwochei DN, Millhoff B, Ahmad I. The effect of virtual endoscopy on diostatic accuracy and airway management strategies in patients with head and neck pathology: a prospective cohort study. Can J Anesth 2017;64:1101-10

53. Sasu PB, Pansa JI, Stadlhofer R, et al. Nasendoscopy to predict difficult videoryngoscopy: a multivariable model development study. J Clin Med 2023; 12: 3433

54. Barclay-Stuart A,Grohbenhig HL,Sasu P,et al. Transnasal video endoscopy for preoperative airway risk stratification: development and validation of a multivariable risk pre-diction model. Anesth Analg 2023; 136: 1164-73

55. Orrock JL, Ward PA, McNarry AF. Advancing the utility of bedside airway assessment. Eur J Anaesthesiol 2025; 42:186-7

56. Gutierrez JC,Merino S,de la Calle P, Perrino C,Represa M,Moral P. Correlation of preoperative findings in computed axial tomography with the presence of diffi-cult airway in patients undergoing head and neck otorhinolaryngological surgery. Rev Esp Anestesiol Reanim 2018;65:252-7

57. Iliff HA, Ahmad I, Evans S, Ingham J, Rees G, Woodford C.Utilising 3D printing in assessment of anticipated diffi-cult airways. Anaesth Rep 2023; 11,e12232

58. Rosenblatt W, Ianus AI, Sukhupragarn W, Fickenscher A,Sasaki C. Preoperative endoscopic airway examination(PEAE) provides superior airway information and may reduce the use of unnecessary awake intubation. Anethag Analg 2011;112:602-7

59. Benavides-Zora D, Jaramillo MC, Townsley MM, et al.Diagnostic performance of airway ultrasound for the assessment of difficult laryngoscopy: a systematic re-view and meta-analysis. J Cardiothorac Vasc Anesth 2023;37:1101-9

60. Falctetta S, Cavallo S, Gabbanelli V, et al. Evaluation of two neck ultrasound measurements as predictors of difficult direct laryngoscopy. Eur J Anaesthesiol 2018; 35:605-12

61. Carsetti A, Sorbello M, Arradio E, Donati A, Falctetta S,Airway ultrasound as predictor of difficult direct laryn-goscopy: a systematic review and meta-analysis. Anesth Analg 2022; 134:740-50

62.Yao W,Wang B. Can tongue thickness measured by ul-trasonography predict difficult tracheal intubation? Br J Anaesth 2017;118:601-9

63. Wang L, Feng YK, Hong L, et al. Ultrasound for diag-nosing new difficult laryngoscopy indicator: a prospec-tive, self-controlled, assessor blinded, observational study.Chin Med J(Engl) 2019; 132: 2066-72

64. Wu H, Wang H. Diagnostic efficacy and clinical value of ultrasonography in difficult airway assessment: based on a prospective cohort study. Contrast Media Mol Imaging 2022;2022,4706438

65. Bhargava V, Rockwell NA, Tawfik D, Haileselassie B,Petrisor C,Su E. Prediction of difficult laryngoscopy using ultrasound: a systematic review and meta-analysis. Crit Care Med 2023; 51: 117-26

66. Nausheen F, Niknafs NP, MacLean DJ,et al.The HEAVEN criteria predict laryngoscopic view and intubation suc-cess for both direct and video laryngoscopy: a cohort analysis. Scand J Trauma Resusc Emerg Med 2019; 27:50

67. Kuzmack E, Inglis T, Olvera D, Wolfe A, Seng K, Davis D.A novel difficult-airway prediction tool for emergency airway management: validation of the HEAVEN criteria in a large air medical cohort.J Emerg Med 2018; 54: 395-401

68. De Jong A, Molinari N, Terzi N, et al. Early identification of patients at risk for difficult intubation in the intensive care unit: development and validation of the MACOCHA score in a multicenter cohort study. Am J Respir Crit Care Med 2013; 187: 832-9

69. Endlich Y, Lee J, Culwick MD. Difficult and failed intu-bation in the first 4000 incidents reported on webAIRS.AnaethSntensive Care 2020; 48:477-87

70. Endlich Y, Beckmann LA, Choi SW, Culwick MD.A prospective six-month audit of airway incidents dur-ing anaesthesia in twelve tertiary level hospitals across Australia and New Zealand. Anaesth Intensive Care 2020;48:389-98

71. Cumberworth A, Lewith H, Sud A, Jefferson H,Athanassoglou V, Pandit JJ. Major complications of airway management: a prospective multicentre obser-vational study. Anaesthesia 2022;77:640-8

72.Yang IT, Tung A, Flores KS, Berenhout KS, Choi JA,Bryan YF. Clinical decision-making and process compli-cations during anticipated difficult airway management for elective surgery. Anesth Analg 2025; 140: 295-305

73. Law JA, Thana A, Milne AD. The incidence of awake trachealt intubation in anesthetic practice is decreasing: a historical cohort study of the years 2014-2020 at a single tertiary care institution. Can J Anesth 2023;70:69-78

74. Chowdhury R, Orishchak O, Mascarella MA, et al. Emer-gency airway management: a systematic review on the effectiveness of cognitive aids in improving outcomes and provider performance. Clin Pract 2025; 15: 13

75. Erikson EJ, Edelman DA, Brewster FM, et al. The use of checklists in the intensive care unit: a scoping review.Crit Care 2023; 27:468

76. Zeuchner J, Graf J, Elander L, Frisk J, Fredrikson M,Chew MS. Introduction of a rapid sequence induction checklist and its effect on compliance to guidelines and complications. Acta Anaesthesiol Scand 2021;65:1205-12

77.Fuchs A, Frick S, Huber M, et al. Five-year audit of adherence to an anaesthesia pre-induction checklist.Anaesthesia 2022;77:751-62

78. Klein AA, Meek T, Allcock E, et al. Recommendations for standards of monitoring during anaesthesia and recov-ery 2021. Anaesthesia 2021;76:1212-23

79. Tanoubi I, Drolet P, Donati F. Optimizing preoxygenation in adults. Can J Anesth 2009; 56: 449-66

DAS tracheal intubation guidelines 2025| 21

80. Safe Anaesthesia Liaison Group. Death related to CO2 monitor not working. Patient Safety Update July-September 2023. https://www.alsg.ac.uk/salg-publications/patient-safety-update/patient-safety-update-july-september-2023/reports-from-the-coroner/

81. Cummings S. Glenda Logsdail: Prevention of future deaths report. Courts and Tribunals judiciary 2021

82. Hansel J, Law JA, Chrimes N, Higgs A, Cook TM. Clinical tests for confirming tracheal intubation or excluding oesophageal intubation: a diagnostic test accuracy sys-tematic review and meta-analysis. Anaesthesia 2023; 78:1020-30

83. Hansel J, Higgs A, Cook TM. Unrecognised oesophageal intubation: a sequential Bayesian exploration of clinical signs. Anaesthesia 2024;79:325-6

84. Cook TM, Hansel J, Chrimes N. More on deaths from unrecognised oesophageal intubation. Anaesthesia 2023;78:1519-20

85. Sahu AK, Bhoi S, Aggarwal P, et al. Endotracheal tube placement confirmation by ultrasonography: a system-atic review and meta-analysis of more than 2500 pa-tients.J Emerg Med 2020; 59:254-64

86. Chen WT, Wang MY, Jiang TT, et al. Transtracheal ul-trasound for confirmation of endotracheal tube place-ment in the intensive care unit: a systematic review and meta-analysis. Eur Rev Med Pharmacol Sci 2022; 26:8224-33

87. Kelly FE, Frk C, Bailey CR, et al. Human factors in anaesthesia: a narrative review. Anaesthesia 2023; 78:479-90

88. Russotto V, Tassiro E, Myra SN,et al.Peri-intubation cardiovascular collapse in patients who are critically ill:insights from the INTUBE study. Am J Respir Crit Care 2022;206:449-58

89.Fechner J,El-Boghdadly K, Spahn DR, et al. Anaesthetic efficacy and postinduction hypotension with remima-zolam compared with propofool: a multicentre rando-mised controlled trial. Anaesthesia 2024; 79:410-22

90. Li J, Wang Z, Wang A, Wang Z. Clinical effects of low-dose ketamine for anaesthesia in anaesthesia in induction in the elderly: a randomized controlled trial. J Clin Pharm Ther 2022;47:759-66

91. Ongewe A, Mung'ayi V, Bal R. Effect of low-dose keta-mine versus fantenyl on attenuating the haemodynamic response to laryngosopy and endotracheal intubation in patients undergoing general anaesthesia: a prospective,double-blinded, randomised controlled trial. Afr Health Sci 2019; 19: 2752-63

92. Pandit JJ, Andrade J, Bogod DG, et al. 5th National Audit Project(NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors.Br J Anaesth 2014; 113: 549-59

93. Kuo AS, Vijieswarapu MA, Philip JH. Incomplete sponta-neous recovery from airway obstruction during inhaled anesthesia induction. Anesth Analg 2016; 122:698-705

94. Ide A, Nozaki-Taguchi N, Sato S, Saito K, Sato Y, Ionso S.Rocuronium versus saline for effective facamask venti-lation during anesthesia induction: a double-blinded randomized placebo-controlled trial. BMC Anesthesi 2022;22: 273

95. El-Boghaddly K, Aziz MF. Face-mask ventilation: the neglected essentials? Anaesthesia 2019; 74:1227-30

96. Grillot N, Lebuffe G, Huet O, et al. Effect of remifantani vs neuromuscular blockers during rapid sequence intubation

on successful intubation without major complications among patients at risk of aspiration. JAMA 2023; 329:28

97. Sabale P, Deshmhukh P, Meshram S, Bankar N,Choudhary A. Intubating conditions comparison, after administration of propofol with muscle relaxant and profool without muscle relaxant-an observational study. Indian J Forensis Med Toxicol 2020; 14: 6286-91

98. Tran DTT,Newton EK, Mount VAH,et al. Rocuronium vs.succinylcholine for rapid sequence intubation: a Cochrane systematic review. Anaesthesia 2017;72:765-77

99. Schaefer MS, Hammer M, Santer P, et al. Succinylcholine and postoperative pulmonary complications: a retro-spective cohort study using registry data from two hos-pital networks. Br J Anaesth 2020; 125: 629-36

100.Chambers D, Paulden M, Paton F, et al. Sugammadex for reversal of neuromuscular block after rapid sequence intubation: a systematic review and economic assess-ment. Br J Anaesth 2010; 105: 568-75

101. Curtis R, Lomax S, Patel B. Use of sugammadex in a'can't intubate, can't ventilate' situation. Br J Anaesth 2012; 108:612-4

102. Cho CK, Change M, Lee SJ, Sung TY. Effects of neuro-muscular blocking agents on the clinical performance of i-gel® and surgical condition in elderly patients under-going hand surgery: a prospective randomized controlled trial. Int J Med Sci 2021; 18: 2381-8

103. Soltész S,Alm P,Mathes A,Hellmich M,Hinkelbein J.The effect of neuromuscular blockade on the efficiency of facemask ventilation in patients difficult to facemask ventilate: a prospective trial. Anaesthesia 2017;72:1484-90

104. Lundstram LH, Duez CHV, Nerskov AK, et al. Effects of avoidance or use of neuromuscular blocking agents on outcomes in tracheal intubation: a Cochrane systematic review. Br J Anaesth 2018; 120: 1381-93

105. Nimmagada U, Salem MR, Crystal GJ. Preoxygenation:physiologic basis, benefits, and potential risks. Anesth Analg 2017; 124: 507-17

106. Zhong M, Xia R, Zhou J, Zhang J, Yi X, Yang A. The comparison of preoxygenation methods before endotra-cheal intubation: a network meta-analysis of random-ized trials. Front Med 2024; 11, 1379369

107. Chiang TL, Tam KW, Chen JT, et al. Non-invasive venti-lation for preoxygenation before general anesthesia: a systematic review and meta-analysis of randomized controlled trials. BMC Anesthesiol 2022; 22: 306

108. Gibbs KW, Semler MW, Driver BE, et al. Noninvasive ventilation for preoxygenation during emergency intu-bation. N Engl J Med 2024; 390: 2165-77

109. Thompson L, Ward P, Nixon IJ, Milligan P, McNarry AF.OptiflowTM Switch: a design modification that can extend safe anoieic oxygenation(THRIVE) time for tubeless airway surgery. A case series. Clin Otolaryngol 2023;48:83-7

110. Lyons C, Jonsson Fagerlund M, Patel A. High-flow nasal oxygen: physiology and clinical applications. Int Anes-thesiol Clin 2024; 62: 72-81

111. White LD, Vlok RA, Thang CY, Tian DH, Melhuish TM.Oxygenation during the apnoelic phase preceding intu-bation in adults in prehospital, emergency department,intensive care and operating theatre environments.

112. Goh ZJ, Ang A, Ang SN, et al. Videolaryngoscopy vs. direct laryngoscopy in class 2 and 3 obesity: a systematic re-view, meta-analysis and trial sequential analysis of

22| Ahmad et al.

randomised controlled trials. Anaesthesia 2025; 80:684-93

113. Kohl V, Wünsch VA, Müller M, et al. Hyperangulated vs.Macintosh videolaryngoscopy in adults with anticipated difficult airway management: a randomised controlled trial. Anaesthesia 2024; 79:957-66

114. Ott S, Müller-Wirtz LM, Bustamante S, et al. Learning tracheal intubation with a hyperangulated video-laryngoscopy blade: sub-analysis of a randomised controlled trial. Anaesthesia 2025; 80: 395-403

115. Kelly FE, Scholz A, Mayer J, Groom P, McGuire B, Cook TM. Implementation of default videolaryngoscopy instead of direct laryngoscopy for tracheal intubation: a narrative review of evidence and experiences. Anaes-thesia Advance Access published on August 22, 2025, doi:10.1111/anae.16731.

116. Taboada M, Fernández J, Bermudez M, et al. Universal videolaryngoscopy for tracheal intubation in the oper-ating theatre: a prospective non-randomised clinical trial. Anaesthesia 2025; 80: 1045-56

117. Chen IW, Li YY, Hung KC, et al. Comparison of video-stylet and conventional laryngoscopore for endrackal intubation in adults with cervical spine immobilization: a PRISMA-compliant meta-analysis. Medicine(Baltimore)2022; 101,e30032

118. Fu D, Li W, Li W, Han Y. Improved skill for tracheal intubation using optical stylets through remote training model: a before and after interventional study. BMC Med Educ 2022; 22: 668

119. Eum D, Ji YJ, Kim HJ. Comparison of the success rate of tracheal intubation between stylet and bougie with a hyperangulated videolaryngoscope: a randomised controlled trial. Anaesthesia 2024;79:603-10

120. Taboada M, Carinena A, Estany-Gestal A, et al. Flexible-tip bougie vs. stylet for tracheal intubation with a hyperangulated videolaryngoscope in critical care: a randomised controlled trial. Anaesthesia 2025; 80:790-8

121. Seitz KP, Spicer AB, Casey JD,et al. Individualized treat-ment effects of bougie versus stylet for tracheal intuba-tion in critical illness. Am J Respir Crit Care Med 2023; 207:1602-11

122. Sheu YJ, Yu SW, Huang TW, Liu FL, Lin YK, Tam KW.Comparison of the efficacy of a bougie and stylet in pa-tients with endotracheal intubation: a meta-analysis of randomized controlled trials. J Trauma Acute Surg 2019;86:902-8

123. Driver BE, Prekerke ME, Klein LR, et al. Effect of use of a bougie vs endotracheal tube and stylet on first-attempt intubation success among patients with difficult air-ways undergoing emergency intubation. JAMA 2018; 319:2179

124. Dallyn B, Hanratty R, Hillier M, Ainsworth M, Hansel J,Cook TM. Evaluation of five static or dynamic tracheal tube introduces during standard and difficult in-tubations with C-MAC® D-blade videolaryngoscopy in a manikin. Anaesthesia 2025; 80:1074-82

125. Hanratty R, Dallyn B, Hansel J, Cook TM. Through and through the airway: optimising airway introducer use with videolaryngoscopy. Anaesthesia Advance Access published on September 28, 2025, doi: 10.1111/anae.70001.

126. Arndt GA, Cambray AJ, Tomasson J. Intubation bougie dissection of tracheal mucosa and intracheal airway obstruction. Anesth Analg 2008; 107: 603-4

127. Marson BA, Anderson E, Wilkes AR, Hodzovic I. Bougie-related airway trauma: dangers of the hold-up sign.Anaesthesia 2014; 69: 219-23

128. Kidd JF, Dyson A, Latto IP. Successful difficult intubation:use of the gum elastic bougie. Anaesthesia 1988; 43:437-8

129. Yu T, Wu RR, Longhini F, et al. The“BURP” maneuver improves the glottic view during laryngoscopy but re-mains a difficult procedure. J Int Med Res 2020; 48,300060502925325

130. Hwang J, Park S, Huh J, et al. Optimal external laryngeal manipulation: modified bimanual laryngoscopy. Am J Emerg Med 2013;31:32-6

131. Hansel J, Fuchs A, Cornwell B, et al. A core outcome set for airway management research. Anaesthesia 2025.https://doi.org/10.1111/anae.70026. Pubilication date 07 November 2025

132. Hillier M, Thorne CJ, Penders R, Kelly F, Cook TM.Assessing the incidence of‘can see, cannot intubate easily' during routine use of C-MAC videolaryngoscopy.Anaesthesia 2025; 80: 1152-4

133. Markenborg ML, Kristensen MS. Tube tip in pharynx-a conduit for awake oral intubation in patients with extremely restricted mouth opening. Can J Anesth 2022;69:504-8

134. Ellefsen S, Stubager AB, Kristensen MS. Tube tip in phar-ynx(TTIP) ventilation-a simple rescue technique in limited resource settings. Wilderness Environ Med 2025; 36:126-9

135. Markham T, Alfarra AS, Tejani M, et al. Effectiveness of ventilation via an endotracheal tube in pharynx versus a facemask in patients with potentially difficult airway: a randomized, crossover, and blind trial. Anesth Analg 2025;140:280-9

136. Cook TM. Strategies for the prevention of airway complications- a narrative review. Anaesthesia 2018; 73:93-111

137. Lundstrom LH, Rosenstock CV, Wetterslev J, Norskov AK.The DIFFMASK score for predicting difficult facemask ventilation: a cohort study of 46,804 patients. Anaesthesia 2019;74:1267-76

138. Cattano D, Killoran PV, Cai C, Katsiampoura AD,Corso RM, Hagberg CA. Difficult mask ventilation in general surgical population: observation of risk factors and predictors. F1000Res 2014;3:204

139. Joffe AM, Ramaiah R, Donahue E, et al. Ventilation by mask before and after the administration of neuromus-cular blockade: a pragmatic non-inferiority trial. BMC Anesthesiol 2015; 15: 134

140. Sachdeva R, Kanan TR, Mendonca C, Patteril M. Evalu-ation of changes in tidal volume during mask ventilation following administration of neuromuscular blocking drugs. Anaesthesia 2014; 69: 826-31

141. Warters RD,Szabo TA, Spinale FG,DeSantis SM,Reves JG.The effect of neuromuscular blockade on mask ventila-tion. Anaesthesia 2011;66:163-7

142. Lim KS, Nielsen JR. Objective description of mask venti-lation. Br J Anaesth 2016; 117: 828-9

143. Fei M,Blair JL,Rice MJ,et al. Comparison of effectiveness of two commonly used two-handed mask ventilation techniques on unconscious apnoiec obese adults. Br J Anaesth 2017; 118: 618-24

144. Yoon SW, Kang H, Choi GJ, et al. Comparison of supra-glottic airway devices in laparoscopic surgeries: a network meta-analysis. J Clin Anesth 2019; 55: 52-66

DAS tracheal intubation guidelines 2025| 23

145. Lai CJ, Yeh YC, Tu YK, Cheng YJ, Liu CM, Fan SZ. Com-parison of the efficacy of supraglottic airway devices in low-risk adult patients: a network meta-analysis and systematic review. Sci Rep 2021; 11, 15074

146. Kanakaraj M, Bhat AD, Singh NP, et al. Choice of supra-glottic airway devices: a network meta-analysis of rando-mised controlled trials. Br J Anaesth 2024; 133: 1284-306

147. Thomsen JLD, Norskov AK, Rosenstock CV. Supraglottic airway devices in difficult airway management: a retro-spective cohort study of 658,104 general anaesthetics registered in the Danish Anaesthesia Database. Anaes-thesia 2019; 74: 151-7

148. Yang LQ, Zhu L, Shi X, et al. Postoperative pulmonary complications in older patients undergoing elective sur-gery with a supraglotic airway device or tracheal intu-bation. Anaesthesia 2023; 78:953-62

149. Kim MS, Park JH, Lee KY, et al. Influence of head and neck position on the performance of supraglottic airway devices: a systematic review and meta-analysis. PLoS One 2019; 14, e0216673

150. Svendsen CN, Rosenstock CV, Glargard GL, Strm C,Lange KHW, Lundstrom LH. AuraGainTM versus i-gelTM for bronchoscopic intubation under continuous oxygen-ation: a randomised controlled trial. Acta Anaesthesiol Scand 2022; 66: 589-97

151. Curtis RP. Persistent'can't intubate, can't oxygenate' crisis despite reversal of rocurium with sugammadex: the importance of timing. Anaesth Intensive Care 2014; 40: 722

152. Desorges JCW, McDonnell NJ. Sugammaxad in the management of a failed intubation in a morbidly obese patient. Anaesth Intensive Care 2011; 39:763-4

153. Barbosa FT, da Cunha RM. Reversal of profound neuro-muscular blockade with sugammadex after failure of rapid sequence endotracheal intubation: a case report.Brazilian J Anesthesiol 2012; 62:281-4

154. Heard A, Gordon H, Douglas S, et al. Front-of-neck airway rescue with impalpable anatomy during a simulated cannot intubate, cannot oxygenate scenario: scal-pel-finger-cannula versus scalpel-finger-bougie in a sheep model. Br J Anaesth 2020; 125: 184-91

155. Rees K,Wawryk J,O'Halloran L,Cameron E,Woonton H.Time to oxygenation for cannula- and scalpel-based techniques for emergency front-of-neck access: a wet lab simulation using an ovine model: a reply. Anaesthesia 2020;75:132-3

156. Abdelhamid A, Sapra S. Comparing the scalpel-bougie tube emergency front-of-neck airway(eFONO) tech-nique on conventional manikins and ovine larynges:evaluating cost,realism, and performance in anaesthetic trainees. Cureus 2023; 15, e40040

157. Duggan LV, Lockhart SL, Cook TM, O'Sullivan EP, Dare T.Baker PA. The Airway App: exploring the role of smart-phone technology to capture emergency front-of-neck airway experiences internationally. Anaesthesia 2018;73:703-10

158. Offenbacher J, Nikolla DA, Carlson JN, et al. Incidence of rescue surgical airways after attempted orotracheal intubation in the emergency department: a National Emergency Airway Registry(NEAR) study. Am J Emerg Med 2023;68:22-7

159. Alkhouri H, Richards C, Miers J, Fogg T, McCarthy S. Case series and review of emergency front-of-neck surgical airways from The Australian and New Zealand

Emergency Department Airway Registry. Emerg Med Australas 2021;33:499-507

160. Heard AM, Lacquiere DA, Gordon HL, Douglas SG, Avis HJ.A case series of the Royal Perth Hospital cannula-first approach in the‘can’t intubate, can’t oxygenate’ sce-nario. Anaesth Intensive Care 2024; 52:159-67

161. Morton S,Avery P,Kua J,O'Meara M. Success rate of prehospital emergency front-of-neck access(FONA): a systematic review and meta-analysis. Br J Anaesth 2023;130:636-44

162. Helm M, Hossfeld B, Jost C, Lampl L, Bockers T.Emergency cricothyroidotomy performed by in-experienced clinicians-surgical technique versus indicator-guided puncture technique. Emerg Med J 2013;30:646-9

163. Schwartz B. The Paradox of Choice. New York, NY: Harper Perennial;2004

164. Schnittker R, Mashshall S, Horberry T, Young K, Lintern G.Exploring decision pathways in challenging airway management episodes. J Cogn Eng Decis Mak 2017; 11:353-70

165. Cassidy J, Reynolds J, Miller T, et al. Enhancing emer-gency front-of-neck airway training: a mixed methods study on the impact of external noise and startle stressors. Anaesthesia 2025; 80: 1216-25

166. Rai Y,You-Ten E,Zasso F,De Castro C,Ye XY,Siddiqui N.The role of ultrasound in front-of-neck access for crico-thyroid membrane identification: a systematic review.J Crit Care 2020;60:161-8

167. Fennessy P, Alslani A, Campbell M, Husarova V,Duggan M, McCaul CL. Theoretical optimal cricothy-oidotomy incisidion length in female subjects, following identification of the cricothyroid membrane by digital palpation. Int J Obstet Anesth 2018; 36: 42-8

168. Iwasaki H, Sasakawa T, Takahoko K, et al. A case series of re-establishment of neuromuscular block with rocururonium after sugammadex reversal. J Anesth 2016;30:534-7

169.Cammu G,de Kam PJ,De Graeve K,et al.Repeat dosing of rocururonium 1.2 mg kg-1 after reversal of neuromuscular block by sugamradex 4.0 mg kg-1 in anaesthetized healthy volunteers: a modelling-based pilot study. Br J Anaesth 2010;105:487-92

170. Drew T, Khan W, McCaul C. The effect of i-gel® insertion on the accuracy of cricothyroid membrane identification in adult females: a prospective observational study. Br J Anaesth 2019; 123: 392-8

171. Choi, Anderson TN, Sheira D, et al. The need to routinely convert emergency cricothyroidotomy to tra-cheostomy: a systematic review and meta-analysis.J Am Coll Surg 2022; 234: 947-52

172. Drew T, Radwan MA, McCaul CL. In the nick of time-emergency front-of-neck airway access. Int Anesthesiol Clin 2024; 62: 101-14

173. Samuels JD, Greif R, Perera S, Lui B, McGuire B,Hagberg CA. Second victim response in airway practi-tioners following difficult airway management: an in-ternational survey.J Clin Anesth 2022;78,110616

174. Johnson TJ, Millinchamp FJ, Kelly FE. Use of a team im-mediate debrief tool to improve staff well-being after potentially traumatic events. Anaesthesia 2021;76:1001-2

175. Vanner RG, Asai T. Safe use of cricoid pressure. Anaes-thesia 1999;54:1-3

24| Ahmad et al.

176. Klucka J, Kosinova M, Zacharowski K, et al. Rapid sequence induction: an international survey. Eur J Anaesthesiol 2020; 37:435-42

177. Mistry R, Frei DR, Badenhorst C, Broadbent J. A survey of self-reported use of cricoid pressure amongst Australian and New Zealand anaesthetists: attitudes and practice.Anaesth Intensive Care 2021; 49: 62-9

178. Sajayan A, Wicker J, Ungureanu N, Mendonca C,Kimani PK. Current practice of rapid sequence induction of anaesthesia in the UK- a national survey. Br J Anaesth 2016;117: i69-74

179. Zdrvkovic M, Berger-Estilita J, Sorbello M, Hagberg CA.An international survey about rapid sequence intubation of 10,003 anaesthetists and 16 airway experts. Anaes-thesia 2020;75:313-22

180.Desai N, Wicker J, Sajayan A, Mendonca C. A survey of practice of rapid sequence induction for caesarean sec-tion in England. Int J Obstet Anesthes 2018; 36:3-10

18.Zdravkovic M, Rice MJ, Brull SJ. The clinical use of cricoid pressure: first, do no harm. Anesth Analg 2021; 132:261-7

182. Tournadre JP, Chassard D, Berrada KR, Bouletrau P.Cricoid cartilage pressure decreases lower esophageal sphincter tone. Anesthesiology 1997; 86:7-9

183. Sotiriou A, Ahmad I, El-Boghdadly K. Cricoid force:anatomic, physiologic, and clinical concepts. Anesthesi-ology 2025; 143: 1090-110

184. Qasem F, Khalaf R, Sebbag I, Lavi R, Jones P, Singh S. Effi-cacy of surface landmark palpation for identification of the cricoid cartilage in obstetric patients: a prospective observational study. J Anaesthesiol Clin Pharmacol 2019; 35:335

185. Lavelle A, Drew T, Fennessy P, McCaul C, Shannon J.Accuracy of cricroid thyroid membrane identification using ultrasound and palpation techniques in obese obstetric patients: an observational study. Int J Obstet Anesth 2021;48, 103205

186. You-Ten KE, Wong DT, Ye XY, Arzola C, Zand A,Siddiqui N. Practice of ultrasound-guided palpation of neck landmarks improves accuracy of external palpation of the cricothyroid membrane. Anesth Analg 2018; 127:1377-82

187. Johnson RL, Cannon EK, Mantilla CB, Cook DA.Cricoid pressure training using simulation: a sys-tematic review and meta-analysis. Br J Anaesth 2013; 111:338-46

188. Beckford L, Holly C, Kirkley R. Systematic review and meta-analysis of cricoid pressure training and education efficacy. AORN J 2018; 107: 716-25

189. Hung KC, Hung C, Poon Y, et al. The effect of cricoid pressure on tracheal intubation in adult patients: a sys-tematic review and meta-analysis. Can J Anesth 2021; 68:137-47

190. Komasawa N, Kido H, Miyazaki Y, et al. Cricoid pressure impedes tracheal intubation with the Pentax-AWS Air-wayscope: a prospective randomized trial. Br J Anaesthes 2016;116:413-6

191. Birenbaum A, Hajage D, Roche S, et al. Effect of cricoid pressure compared with a sham procedure in the rapid sequence induction of anesthesia: the IRIS randomized clinical trial. JAMA Surg 2019; 154: 9-17

192. Nikolla DA, Offenbacher J, Smith SW,et al. First-attempt success between anatomically and physiologically diff-cult airways in the National Emergency Airway Registry.Anesth Analg 2024; 138: 1249-59

193. Russotto V, Myatra SN, Laffey JG, et al. Intubation prac-tices and adverse peri-intubation events in critically ill patients from 29 countries. JAMA 2021; 325: 1164

194. Kornas RL, Owyang CG, Sakles JC, Foley LJ, Mosier JM.Evaluation and management of the physiologically difficult airway: consensus recommendations from So-ciety for Airway Management. Anesth Analg 2021; 132:395-405

195. De Jong A, Myatra SN, Roca O, Jaber S. How to improve intubation in the intensive care unit. Update on knowl-edge and devices. Intensive Care Med 2022; 48: 1287-98

196. Russell DW, Casey JD, Gibbs KW, et al. Effect of fluid bolus administration on cardiovascular collapse among critically ill patients undergoing tracheal intubation.JAMA 2022;328:270

197. Janz DR, Casey JD, Semler MW, et al. Effect of a fluid bolus on cardiovascular collapse among critically ill adults undergoing tracheal intubation(PrePARE): a randomised controlled trial. Lancet Respir Med 2019; 7:1039-47

198. Takaki R, Yokose M, Mihara T, et al. Hypotension after general anaesthesia induction using remimazolam or propofol in geriatric patients undergoing seovflurane anaesthesia with remifentanil: a single-centre, double-blind, randomised controlled trial. Br J Anaesth 2024; 133:24-32

199. Wu X,Wang C,Gao H,et al.Comparison of remimazolam and propofol about safety outcome indicators during general anesthesia in surgical patients: a systematic re-view and meta-analysis. Minerva Anestesiol 2023; 89:553-64

200. Shaw M, Waiting J,Braaclough L,Ting K,Jeans J,Black B.Airway events in obese vs. non-obese elective surgical patients: a cross-sectional observational study. Anaes-thesia 2021; 76: 1585-92

201.McKechnie A, Iliff HA, Black R,et al. Airway management in patients living with obesity: best practice recommen-dations from the Society for Obesity and Bariatric Anaesthesia. Anaesthesia 2025; 80: 1103-14

202. Lee S, Jang EA, Hong M, Bae HB, Kim J. Ramped versus sniffing position in the videolaryngoscopy-guided tracheal intubation of morbidly obese patients: a pro-spective randomized study. Korean J Anesthesiol 2023; 76:47-55

203. Hung Tsan SE, Viknaswaran NL, Lau J, Cheong CC,Wang CY. Effectiveness of preoxygenation during endo-tracheal intubation in a head-elevated position: a sys-tematic review and meta-analysis of randomized controlled trials. Anaesthesiol Intensive Ther 2022; 54:413-24

204.Edelman DA, Duggan LV, Lockhart SL, Marshall SD,Turner MC, Brewster DJ. Prevalence and commonality of non-technical skills and human factors in airway man-agement guidelines: a narrative review of the last 5 years. Anaesthesia 2022; 77: 1129-36

205. Flin R, Fioratou E, Frerk C, Trotter C, Cook TM. Human factors in the development of complications of airway management: preliminary evaluation of an interview tool. Anaesthesia 2013;68:817-25

206. Radhakrishnan HB, Katikar MD, Myatra SN, Gautam PL,Vinayagam,Saroa R. Importance of non-technical skills in anaesthesia education. Indian J Anaesth 2022;66:64-9

207. Greif R, Bray JE, Djarv T,et al. International consensus on cardiopulmonary resuscitation and emergency

DAS tracheal intubation guidelines 2025| 25

cardiovascular care science with treatment recommen-dations: summary from the basic life support; advanced life support; pediatric life support; neonatal life support;education,implementation,and teams; and first aid task forces.Circulation 2024; 150: e580-687.2024

208. Association of Anaesthesists. The Anaesthesia Team.Available from 2018. London, https://anaesthesists.org/Home/Resources-publications/Guidelines/The-Anaesthesia-Team-2018.[Accessed 20 October 2025]

209. McCoy L, Lewis JH, Simon H, et al. Learning to speak up for patient safety: interprofessional scenarios for training future healthcare professionals.J Med Educ Curric Dev 2020;7,2382120520935469

210. Yianni L, Rodd I. G236(P) Pace-‘probe, alert challenge,escalate' model of graded assertiveness used in paedi-atic resuscitation. Arch Dis Child 2017; 102. A93 LP-A93

211. Soni VM, Pappu A, Zarabi S, et al. Point-of-care ultra-sound of the upper airway in difficult airway manage-ment: a systematic review and meta-analysis.Anaesthesia Advance Access published on September 2,2025, doi: 10.1111/anae.16751.

212. van de Putte P, van Hoonacker J, Perlas A. Gastric ultra-sound to guide anesthetic management in elective surgical patients non-compliant with fasting instructions: a retro-spective cohort study. Minerva Anestiosel 2018; 84: 787-95

213. Alakkad H, Kruisselbrink R, Chin KJ, et al. Point-of-care ultrasound defines gastric content and changes the anesthetic management of elective surgical patients who have not followed fasting instructions: a prospective case series. Can J Anesth 2015; 62: 1188-95

214. El-Boghdlyad K, Deshi J, Fabb P, et al. Elective peri-operative management of adults taking glucagon-like peptide-1 receptor agonists, glucose-dependent insuli-notropic peptide agonists and sodium-glucose cotrans-porter-2 inhibitors: a multidisciplinary consensus statement. Anaesthesia 2025; 80: 412-24

215. Godschalx V, Vanhoof M, Soetens F, et al. The role of gastric ultrasound in anaesthesia for emergency surgery.Eur J Anaesthesiol Intensive Care 2023; 2, e0027

216. Frykholm P, Disma N. Andersson H, et al. Pre-operative fasting in children. Eur J Anaesthesiol 2022; 39: 4-25

217. Filipovic MG, Baettig SJ, Hebeisen M, Meierhans R,Ganter MT. Gastric ultrasound performance time and difficulty: a prospective observational study. Anaesthesia 2025;80:161-9

218. Baettig SJ, Filipovic MG, Hebeisen M, Meierhans R,Ganter MT. Pre-operative gastric ultrasound in patients at risk of pulmonary aspiration: a prospective observa-tional cohort study. Anaesthesia 2023; 78: 1327-37

219. McGuire B, Crawley S, Dill N, et al. Ethical decision making in airway management: a Difficult Airway Soci-ety position statement on good practice. BJA Open 2025;15, 100416

220. NHS Digital. NHS Digital SNOMED CT Browser 2025.https://ternbrowser.nhs.uk

221. Nakanishi T, Sakamoto S, Yoshimura M, Toriumi T.A learning curve of LMA® ProSealTM insertion: a pro-spective analysis of cumulative sum method. J Anesth 2020;34:554-60

222.Theiler L, Greif R, Bütikofer L, Arheart K, Kleine-Brueggeney M. The skill of tracheal intubation with rigid

scopes - a randomised controlled trial comparing learning curves in 740 intubations. BMC Anesthesiol 2020; 20: 263

223. Baker PA, Behringer EC, Feinleib J, et al. Formation of an Airway Lead Network: an essential patient safety initia-tive. Br J Anaesthes 2022; 128: 225-9

224. McNarry AF, Cook TM, Baker PA, O'Sullivan EP. The Airway Lead: opportunities to improve institutional and personal preparedness for airway management. Br J Anaesth 2020;125:e22-4

225. Nathanson MH, Bogod DG, Harrop-Griffiths W. Manda-tory training for rare anaesthetic events. Anaesthesia 2024;79:1145-7

226. Freedman RL, Lucas DN. MBRRACE-UK: saving lives,improving mothers' care- implications for anaesthe-tists.Int J Obstet Anesth 2015; 24: 161-73

227. Ahmad I, El-Boghdadly K. Time for confidential enquiries into airway complications? Anaesthesia 2024;79:349-52

228. Howarth D. Team in working in airway crisis: role of oper-ating department practitioner in management of failed intubations. Br J Anaesth 2016; 117: 553-7

229. Brewster DJ, Butt WW, Gordon LJ, Sarkar MA, Begley JL,Rees CE. Leadership during airway management in the intensive care unit: a video-reflexive ethnography study.Front Med 2023; 10, 1043041

230. Pattni N, Arzola C, Malavade A, Varmani S, Krimus L,Friedman Z. Challenging authority and speaking up in the operating room environment: a narrative synthesis.Br J Anaesth 2019; 122: 233-44

231. Friedman Z, Hayter MA, Everett TC, Matava CT,Noble LMK, Bould MD. Power and conflict: the effect of a superior's interpersonal behaviour on trainees' ability to challenge authority during a simulated airway emer-gency. Anaesthesia 2015; 70: 1119-29

232. O'Donovan R, McAuliffe E. A systematic review of factors that enable psychological safety in healthcare teams. Int J Qual Heal Care 2020; 32: 240-50

233. Janssens S, Simon R, Beckmann M, Marshall S. Shared leadership in healthcare action teams: a systematic re-view.J Patient Saf 2021; 17: e1441-51

234. Bisgaard CH, Rubak SLM, Rodt SA, Petersen JAK,Musaeus P. The effects of graduate competency-based education and mastery learning on patient care and re-turn on investment: a narrative review of basic anes-thetic procedures. BMC Med Educ 2018; 18: 154

235. O'Farrell G, McDonald M, Kelly FE. 'Tea trolley' difficult airway training. Anaesthesia 2015; 70: 104. 104

236. Hickman J, McNarry AF, Kelly FE. Practical strategies for delivering airway training in the COVID-19 era. Br J Anaesth 2021; 127: 188-91

237. Gunning SGS, Urwin D, Cook TM, Hansel J. Video-laryngoscopy versus direct laryngoscopy for teaching direct laryngoscopy skills: a systematic review and meta-analysis. Br J Anaesth Advance Access published on July 8,2025, doi:10.1016/j.bja.2025.05.034.

238. Reale C, Salwei ME, Militello LG, et al. Decision-making during high-risk events: a systematic literature review.J Cogn Eng Decis Mak 2023; 17: 188-212

239. Royal College of Anaesthets.eFONAr: Emergency Front of Neck Airway Registry. Available from, https://www.rcoa.ac.uk/research/research-projects/efonar-emergency-front-neck-airway-registry.[Accessed 20 October 2025]

Handling Editor: Hugh C Hemmings Jr