Adult front of neck airway: a narrative review

Introduction

Anaesthetic airway management is undertaken to facilitate alveolar oxygenation and ventilation. Complications in airway management have long been recognised to occur with grave consequences, resulting in serious harm or death (1,2). As such, the anticipation of the difficult airway through pre-anaesthesia airway assessment (3-5) and meticulous airway planning in the both the anticipated (6,7) and unanticipated difficult airway (8) forms the mainstay of anaesthesia worldwide (9). All airway assessment techniques will have false-negative findings; so despite thorough pre-assessment an unexpected difficult airway can be encountered (4). Thus, it remains crucial that the management of a serious airway event is front and centre in every anaesthetist’s arsenal.

The Fourth National Airway Project (NAP4) showed that failure to achieve airway management by endotracheal intubation, supraglottic airway or face mask ventilation with a subsequent serious airway event occurred at least once in every 22,000 general anaesthetics and resulted in death or brain damage in one in 180,000 (10). Emergency front of neck airway (eFONA) occurred at a rate of at least one in 50,000 UK general anaesthetic cases (11). Forty-three of 133 serious airway complications were in patients with head, neck, or maxillofacial pathology and almost 75% of eFONA cases came from this group, particularly pertinent to readers of this journal. In support of these conclusions, Rosenstock et al. showed 85% of eFoNA occurred in patients with airway pathology or those undergoing head and neck surgery (11). Prior to 2011, the estimation of the rate of serious airway events focused on death certification (12,13) and litigation-based analysis (14,15). Thus, NAP4 informed airway management and shaped the formation of guidelines worldwide. This included the development of the British Difficult Airway Society (DAS) guidelines of the management of failed tracheal intubation in adults (16) (Figure 1). As a result of NAP4 there were suggestions in 2016 from the authors that the ‘safety gap’ in airway management and training had closed (17) but a study in 2022 by Cumberworth et al. concluded that the incidence of serious airway complications was at least as high as it was during NAP4 (18).

Figure 1 Overview of difficult intubation guidelines, reproduced with permission from ‘Unanticipated difficult intubation’ Difficult Airway Society 2015 (16). DAS, Difficult Airway Society; SAD, supraglottic airway device; CICO, can’t intubate can’t oxygenate.

Consequently, there remains an urgent, ongoing need to understand how we can reduce the incidence of serious airway events. This review will explore the role of front of neck access (FONA) in preventing harm from hypoxia resulting from airway complications in both the anticipated and unanticipated difficult airway.

FONA is defined as the approach to secure the airway by accessing the anterior neck either via the cricothyroid membrane or trachea (19). The scope of the British DAS ‘Unanticipated Difficult Airway’ 2015 guidelines describe eFoNA when other oxygenation measures have failed in a ‘can’t intubate, can’t oxygenate’ (CICO) scenario (16). The American Society of Anaesthesiologists (ASA) (9), the Australian and New Zealand College of Anaesthesiologists (ANZCA) (20,21) and the Canadian Airway Focus Group (CAFG) (22) have followed suit by recommending FoNA in CICO with updated guidance in the last 3 years. It should also be noted that the ASA have also recently recommended consideration of ECMO instead of eFONA in the unanticipated difficult airway (9).

FoNA is not isolated to emergent CICO cases. Access via the cricothyroid membrane or trachea can facilitate the application of local anaesthetics before awake intubation (23), retrograde awake intubation (24,25), awake placement of a cannula cricothyroidotomy (26), awake surgical cricothyroidotomy or tracheostomy (27) in those anticipated to have a difficult airway or for whom it is inevitable that oral or nasal endotracheal intubation would be futile. The authors also recognise that FoNA also takes place in pre-hospital, intensive care and in paediatric populations, but this lies beyond the scope of this review.

FONA is an uncommonly undertaken procedure with high stakes outcomes for patients (10). However there remains a deficit of data on the FONA near misses and delays in undertaking FONA that still result in morbidity and mortality (28). These patients are omitted from NAP4, death certification reviews and litigation-based analysis so the extent of the need for FONA is not truly understood. The Airway App seeks to capture front of neck experiences worldwide provide this unmet data set (29,30). Anaesthetists can experience a delay in making the decision to proceed to FONA. Knowledge gaps, high stress environments and system and technical failures when undertaking FONA which contribute to this unmet data (27). This review acts to summarise the indications, approaches, technical considerations, post insertion management, and human factors encountered when performing FoNA and the training and agreed standards of FoNA for anaesthetists worldwide. We present this article in accordance with the Narrative Review reporting checklist (available at https://joma.amegroups.com/article/view/10.21037/joma-23-43/rc).

Methods

A search of PubMed, Cochrane Library and UpToDate was performed in May 2024 to identify relevant publications on adult FONA. Papers not published in English, those with paediatric patients (aged <18 years) and FONA access in intensive care units and pre-hospital sites were excluded. Published titles and abstracts were reviewed and those deemed clinically relevant were included (Table 1). This narrative review did not include a full critical appraisal of the literature.

Emergency indications for FoNA

Can’t intubate, can’t oxygenate in the unanticipated difficult airway

During a can’t intubate, can’t oxygenate scenario, endotracheal intubation, supraglottic airway devices and facemask ventilation have failed to secure the airway. FoNA via a scalpel cricothyroidotomy represents ‘Plan D’ in the DAS difficult intubation guidelines (Figures 1,2) (16) and this is echoed in worldwide consensus agreements and national guidelines (9). FoNA, if successfully placed, provides a means of emergency oxygenation, ceasing the impending respiratory arrest and cardiovascular collapse. Depending on the device it may also facilitate alveolar ventilation to adequately clear carbon dioxide (31). These are high stress, unpredictable scenarios where the decision to proceed to FONA is often the rate limiting step for clinicians.

Figure 2 Failed intubation, failed oxygenation in the paralysed anaesthetised patient guidelines, reproduced with permission from ‘Unanticipated difficult intubation’ Difficult Airway Society 2015 (16). SAD, supraglottic airway device; CICO, can’t intubate can’t oxygenate.

Emergent post operative airway compromise

Airway compromise can occur after head and neck, maxillofacial, carotid, thyroid, anterior cervical spine, or free flap surgical procedures. The airway insult occurs via direct extrinsic compression by haematoma or by impaired venous return resulting in upper airway or free flap oedema (31). In many cases, evacuation of a haematoma, if present, can slow the progression or resolve airway compromise (32). Recent consensus agreement on the management of haematoma after thyroid surgery (33) from DAS, British Association of Endocrine and Thyroid Surgeons and the British Association of Otorhinolaryngology, Head and Neck Surgery recommend early recognition of airway compromise and involvement of senior surgeon and anesthetists, emergency haematoma evacuation and if airway compromise persists, intubation and ventilation following DAS guidance (33) (Figure 3). Therefore, eFONA remains ‘Plan D’ (Figure 1). Yet, contemporary case reports suggest a deviation from such guidance. Penston and colleagues (34) describe using eFONA as a ‘Plan A’ airway management technique in a patient after right selective neck dissection, right lateral partial glossectomy and radial forearm free flap reconstruction for squamous cell carcinoma of the tongue. They describe how eFONA was successfully performed through a new 10cm midline excision, despite significant tracheal deviation, as a ‘Plan A’ rapid sequence oral intubation was judged to be contraindicated due to the grossly swollen tongue and soft tissue flap and profound patient hypoxia. They highlight that DAS guidance was not designed for such anticipated difficult airways. As such, the authors undertook a pragmatic plan dictated by good clinical judgement and the patient’s pathology and current haemodynamic state.

Figure 3 The DAS, BAETS and ENT-UK management of haematoma after thyroid surgery. © DAS, BAETS, ENT-UK 2021. Reproduced with permission (33). DAS, Difficult Airway Society; BAETS, British Association of Endocrine and Thyroid Surgeons; ENT-UK, British Association of Otorhinolaryngology, Head and Neck Surgery; FONA, front of neck access.

Prehospital airway management

Though beyond the scope of this review the authors note the evolution of prehospital eFONA (35) particularly in austere settings (36). Prehospital eFONA is used as either a primary technique, for example, if a patient is trapped or has significant neck or maxillofacial injuries or as a rescue technique in a CICO failed intubation (37). The recommended is approach is via scalpel cricothyroidotomy, namely scapel-bougie-tube (38).

Elective indications for FONA

Anticipated difficult airway

Patients with known or suspected upper airway pathology for whom there is an anticipated difficult airway, pose challenges for anaesthetists. Associated comorbidities precipitating this presentation can include primary airway obstruction in advanced head and neck tumours and acquired obstruction from trauma, burns and oedema (39). Conventional pre-operative assessment may not determine the extent of difficulty of bag valve mask oxygenation, supraglottic device insertion or nasal/oral intubation and therefore anaesthetists or surgeons may elect to perform elective FONA (40). Advance airway assessment via nasendoscopy (41) has further progressed this decision making, as it has facilitated the differentiation of those lesions amenable to asleep intubation or awake fibre optic intubation, and those amenable only to FONA.

The predictability of these cases on elective lists or pre-alerts in the emergency department normally allow for prior planning, pre-oxygenation, and multidisciplinary team (MDT) cooperation (42) before FONA is undertaken. Elective FONA can form one or part of scalpel cricothyroidotomy, cannula cricothyroidotomy, percutaneous tracheostomy or surgical tracheostomy the techniques of which, are outlined below. Surgical and percutaneous tracheostomies make up the mainstay of these procedures by providing a definitive airway with one intervention (43).

Planned post operative airway management

Surgical anticipation of postoperative swelling, oedema or risk of haematoma prompts consideration of planned FONA. In most cases, this would include an early elective tracheostomy performed during surgery (44). Meier et al. showed that early tracheostomy in patients undergoing head and neck surgery reduced ventilation days, respiratory complications and delirium compared to those that received an endotracheal tube in isolation (45).

Transtracheal airway catheters and jet ventilation

Transtracheal airway catheters can be inserted through the cricothyroid membrane as a strategy for maintaining oxygenation in cases with difficult airway and to facilitate surgical access. Historically a primary tracheostomy had been the chosen technique (46). Transtracheal catheters have changed the field, providing a minimally invasive technique, facilitating a clear surgical access that can be initiated before the induction of general anaesthesia and maintained after emergence (47). Concern on barotrauma is not unfounded (48) but the use high frequency jet ventilation has reduced this risk in transtracheal delivery systems (49).

Retrograde intubation

Retrograde intubation describes the puncture of the cricothyroid or trachea with a needle and a catheter or wire is passed from the trachea to the mouth/nostrils. An endotracheal tube is then blindly passed over the wire or retrograde catheter, or the catheter is tied to the murphy’s eye of the endotracheal tube and pulled through (50). Historically this was useful if blood and secretions were anticipated to obscure the view during fibre optic intubation (51) but is not commonly used any more.

Topicalisation of the airway during awake fibre optic intubation

During awake tracheal intubation (ATI) topicalization of the nasopharynx, larynx and trachea can be achieved via several routes, for example nebulisation, atomisation, laryngeal nerve blocks, etc. (52). However, trans cricoid (53) or trans tracheal (54) airway access with a narrow-gauge needle and syringe can also allow tracheal anaesthesia by injecting lidocaine into the airway. There is insufficient evidence to recommend any particular topicalisation technique over any other (7). Though not an airway technique it may facilitate identification of the cricothyroid membrane or trachea in the event ATI failure. Pre-emptive cannula cricothyroidotomy has been postulated to be an option to secure oxygenation prior to induction in known difficult airways, preventing a CICO situation (55).

Emergency approach to FONA

The accepted approach to eFONA remains open to discussion. DAS recommend a scalpel cricothyroidotomy for anaesthetists advocating a scalpel-bougie-tube-approach (Figure 2) (16) after NAP4 showed increased failure rates with cannula cricothyroidotomy (11). However, ANZCA hold a more neutral stance, promoting the use of cannula cricothyroidotomy or scalpel cricothyroidotomy depending on the anaesthetist’s preference and experience (21). In a recent systematic review and meta-analysis, Duan et al. (56) concluded that scalpel cricothyroidotomies are significantly quicker, have fewer complications and a better first pass success rate when compared to cannula cricothyroidotomies. This challenges Rees et al. conclusions in 2019 (57), where a single centre observational study found cannula cricothyroidotomy advantageous supporting the ANZCA conclusions. Heard et al. (58) took this one step further finding scalpel-finger-cannula cricothyroidotomy preferrable to scalpel-finger-bougie in simulated impalpable anatomy.

This does assume the anaesthetist performs the eFONA. In the hands of a surgeon, a surgical tracheostomy may be preferable (59) but in 2016 an editorial, jointly published in Clinical Otolaryngology and the British Journal of Anaesthesia addressed the need for a common anaesthetic and surgical approach to emergency failed airway management (60). They concluded that for most anaesthetists, surgical trainees, and non-head and neck specialist surgical consultants, it may be more expedient to carry out a scalpel-bougie cricothyroidotomy when confronted by CICO.

So, who should perform eFONA? In 2011 during NAP4 almost all emergency surgical FONAs were performed by surgeons rather than anaesthetists. Groom et al. found in 2019 (61) that when comparing consultant head and neck surgeons, general surgeons and anaesthetists, anaesthetists who are regularly trained in emergency surgical FONA, function at levels comparable with head and neck surgeons, and should feel empowered to lead this procedure in the event of a CICO emergency (31). Given it is appropriate for anaesthetists to lead in a CICO eFONA scenario, and the readership of this journal, we will explore the eFONA approaches the cricothyroid membrane.

Correct identification of anterior neck anatomy facilitates swift and safe FONA. The laryngeal handshake, as described by Levitan (62), is recommended by DAS (16) for the identification of the cricothyroid membrane. It uses a three-step technique as shown in Figure 4. However, use of the laryngeal handshake remains controversial. In females the laryngeal handshake was more accurate compared with conventional digital palpation; but clinicians took longer to identify the cricothyroid membrane (63). Hung et al. found no significant differences in success rate between the laryngeal handshake and conventional palpation techniques in cricothyroid membrane identification in males and females (64).

Figure 4 Laryngeal handshake.

Identification of the cricothyroid membrane can be difficult and misplacement of the airway during FONA remains the most common cause for FONA failure (65). Misidentification of the cricothyroid membrane is more common in females (66) and those living with obesity (67). Ultrasound identification can assist in correctly locating the cricothyroid space (68). Ultrasound appears to be superior to palpation for cricothyroid membrane identification especially in those with difficult airway anatomy (69). As it objectively defines anatomy it can be used proactively in eFONA and elective FONA. Kristenson and Teoh in their editorial expand on this, recommending pre-induction cricothyroid ultrasound in all patients who on visual inspection and palpation do not with certainty have a locatable cricothyroid membrane (70). Interestingly there is evidence that second-generation laryngeal mask insertion improved cricothyroid membrane identification (71). Given that in a CICO scenario a supraglottic airway (Plan B, Figure 1) precedes eFONA, leaving the device in may confer a benefit.

During induction of anaesthesia patients should be positioned adequately to facilitate FONA should the need arise. FONA is best undertaken in full neck extension either by inserting a shoulder bolster, moving the patient to allow the head to extend off the end of the table or by lowering the head end of the operating table (72). Attempts at oxygenation either nasally or orally should continue throughout. Original recommendations suggested the clinician performing FONA stands on the patient’s left (if right-handed) to facilitate a left-handed laryngeal handshake and identification of the cricothyroid membrane with the left index finger (16). However, there was a lack of significant evidence to support this initial recommendation in 2015. Current prevailing opinion is that this is unlikely to significantly influence outcome, and ergonomically may be quite impossible in some anaesthetic room and operating theatre layouts or not suit surgical approaches (60). Access of the cricothyroid membrane is then undertaken using the techniques described below.

Elective approach to FONA

Elective FONA is primarily achieved using one of the three following techniques. Firstly, surgical tracheostomy for definitive airway management either in the anticipated difficult airway as ‘Plan A’ or to prevent post operative complications after operations to the head or neck (27,40,43,59). Secondly and thirdly, scalpel cricothyroidotomy or percutaneous tracheostomy can be used instead of surgical tracheostomy, less commonly, for the indications above. Finally, cannula cricothyroidotomy can be used to achieve jet ventilation, providing temporary, minimally invasive access to the airway below the obstruction or as an adjunct to other techniques, e.g., the application of local anaesthetic to the larynx in ATI or to assist asleep airway management during retrograde intubation (24,73).

FONA techniques

There are four techniques commonly undertaken when approaching FONA. These are cannula cricothyroidotomy, scalpel cricothyroidotomy, percutaneous tracheostomy and surgical tracheostomy. Equipment required, advantages and disadvantages of each are outlined in Table 2.

Cannula cricothyroidotomy

Cannula cricothyroidotomy describes the puncture of the cricothyroid membrane with a needle leaving a cannula in situ. This can be achieved using a wide bore (internal diameter ≥4 mm) or narrow bore (internal diameter <4 mm) cannula technique.

Wide bore cricothyroidotomy kits use a cannula over a guidewire (e.g., Melker Emergency Cricothyrotomy Catheter Set, Cook Group Incorporated, USA) and cannula over trochar (e.g., Surgicric 2, VBM Medical, Germany). In recent years, by and large, cannula over guidewire kits is not advocated. When compared to scalpel cricothyroidotomy Melker and Sugicric 2 caused more trauma to the posterior tracheal wall and were slower to insert (74).

Narrow bore cricothyroidotomy requires the catheter over needle assembly to be inserted through the cricothyroid membrane and the internal needle removed to leave a small diameter catheter in situ. Ventilation is achieved by using a high-pressure ventilation source or high-pressure oxygen supply. Historically, needle cricothyroidotomy and jet ventilation resulted in hypercarbia and respiratory acidosis because of inadequate ventilation (75) limiting its use to 30–40 minutes. Passive exhalation limits the accumulation of pulmonary pressure, thus limiting mean alveolar pressure and limiting the risk of barotrauma (76). As such, provided the correct exit for the injected gases via the patent upper airway is facilitated, the quality of the ventilation will depend on the settings of the jet ventilator (working pressure, inspiratory/expiratory ratio, frequency, etc.) (77). Ventrain (Dolphys Medical BV, Eindhoven, The Netherlands) is driven by a high-pressure oxygen source and facilitates expiration by suction thus functioning even when the upper airway is completely obstructed (78). It achieves an adult normal minute volume through a catheter 2 mm internal diameter.

Scalpel cricothyroidotomy

Scalpel cricothyroidotomy, known as ‘scalpel-bougie-tube’, describes incision through the cricothyroid membrane using a size 10-scalpel blade, bougie insertion and railroading of a size 6 endotracheal tube over the top. A transverse stab incision is made through the cricothyroid membrane. The blade is then turned 90 degrees with the sharp blade facing caudally. The tip of the bougie is slid along the scalpel blade into the trachea and a size 6.0 oral endotracheal tube is railroaded over the top. The cuff is inflated, and the position is confirmed.

The standardisation of the blade, bougie and tube is critical to success in scalpel cricothyroidotomies. A ‘size 10’ (10 mm) blade is chosen to minimise posterior tracheal wall trauma, provide an appropriate skin incision and to accommodate the external diameter of the size 6 endotracheal tube (8.8 mm) (79). A size 6.0 endotracheal tube is chosen to fit snugly with the cuff inflated within female and male tracheas (80). The familiar insertion of a normal bore cuffed tube allows for recognition with capnography, protection against gastric contents and for the reinstation of normal minute ventilation and expiration.

Patients living with obesity are more likely to require eFONA (81). During scalpel cricothyroidotomy a vertical incision of 8–10 cm is made in the front of the neck if the cricothyroid membrane cannot be located (16). This enables the soft tissues to be moved away from the cricothyroid membrane. In practice, clinicians were reluctant to perform an incision of 8–10 cm (55,82). There has since been encouragement for a ‘generous incision’ and data from 2019 suggests that the clinician was prepared to make incisions in excess of 8 cm which may be a reflection of having access to regular eFONA training (83).

Alongside the uptake of scalpel cricothyroidotomies in eFONA, innovative scalpel devices have been quick to come to the market. Recent analysis of ‘Cric-Guide’ (84) showed it was as effective as ‘scalpel-bougie-tube’ in accessing the cricothyroid membrane and had a higher first pass success rate with reduced false passage formation. This improvement is attributed to the ease of bougie insertion facilitated by the spoon shaped blade holding the membrane and tissues open. This is supported by Yeow et al. who demonstrated that using an introducer resulted in faster insertion times compared with the scalpel technique, with fewer false passages (85).

Surgical tracheostomy

Surgical tracheostomy involves careful open dissection in and around the thyroid isthmus and surrounding vessels down to the second and third tracheal rings where a tracheal window is opened under direct vision and a tracheostomy tube inserted (86). This can be performed under local or general anaesthetic. Given surgeons are often intimately involved in managing the airway of those requiring elective tracheostomies, outside of intensive care, they are considered best placed and practiced performing this procedure (60). However, we must not overlook the multi-speciality involvement in these cases, in an audit of surgical and anaesthetic tracheostomy experience, Lipton et al. found that elective tracheostomy under general anaesthetic represented the most common form of tracheostomy (87). Intubation of the airway by an anaesthetist prior to the tracheostomy had already occurred.

Percutaneous tracheostomy

The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) tracheostomy report, ‘On the right Trach?’ showed that 70% of tracheostomies in England and Wales are performed percutaneously (59). These are mostly undertaken by intensivists in intensive care. Those that are considered anatomically difficulty (e.g., patients living with obesity, altered neck anatomy, coagulopathy) are often referred to surgical colleagues (88) for an open approach. This suggests that surgical trainees are only exposed to ‘difficult’ tracheostomies and given surgical trainees are most often present out of hours this may impact emergency tracheostomy provision (60).

The approach to percutaneous tracheostomy was described by Ciaglia et al. in 1985 (89). The process involves a guide wire inserted through a cannula into the tracheal lumen. Tapered dilators follow the guide wire and a tracheostomy tube fitted over a dilator is then passed into the trachea (89). Though notably undertaken in intensive care there is also a described role for percutaneous tracheostomy for emergent airway control (90). Davidson et al. describe the use of percutaneous tracheostomy in airway oedema, anaphylaxis and trauma across hospital locations concluding that when performed by appropriately trained personnel that percutaneous tracheostomy provided an airway adjunct to other FONA approaches (90).

Post insertion management after emergency FONA

Once alveolar oxygenation has been re-established by emergency FONA in the anaesthetised patient clinicians must work to first stabilise and then plan ongoing care. Waveform capnography and endoscopic interrogation of the airway confirm correct tube placement (16). 100% oxygen should be provided until target saturations are achieved before being weaned as appropriate. Continued resuscitation following an A–E approach should continue with a chest X-ray to assess tube placement and rule out pneumothorax and pneumomediastinum. Consideration of whether to proceed with planned surgery is pertinent at this point.

Once stability is achieved, a plan for conversion to definitive airway should be made, if not already in situ. Most commonly this is via surgical tracheostomy (91), though retrograde intubation via the cricothyroid membrane is achievable to site an oral endotracheal tube (75). However, there is evidence if not required for long-term ventilation, cricothyroid access alone may be appropriate and that conversion to tracheostomy does not reduce the risk of subglottic stenosis (92). Despite this, in practice, most centres would prefer placement of a more definitive airway to avoid risks of losing the airway again. Following emergency FONA, transfer to an appropriate care facility, documentation, internal incident report logs, and debriefs should be undertaken (16). Communication with the patient and next of kin is followed by a formal referral to the DAS difficult airway register and alert card and letters sent to the patient, general practitioner and departmental lead (16).

Post-insertion management after elective FONA

After elective FONA, complications can arise (93). In the short-term, there is significant risk of oesophageal and pharyngeal trauma resulting in mediastinal infection, subcutaneous emphysema and pneumothorax and atelectasis. In the mid to longer term subglottic stenosis, tracheocutaneous fistula and tracheomalacia can result, requiring further intervention (94).

Human factors in emergency and elective FONA

Thankfully, FONA, anticipated or not, is relatively rare. Yet the effectiveness of a FONA strategy is dependent on a clinician’s willingness to implement it (55). Stress during FONA results in cognitive overload, impaired judgment, task fixation delaying the decision progress to FONA and difficult communication within the team (95). Stress contributes to fixation error and can delay identification of an incorrectly placed airway (96). As such, delay to FONA worsens hypoxia significantly contributing to resultant morbidity and mortality (97). Effective strategies to mitigate risk and reduce stress are those that ‘design out’ the error from occurring (98).

To combat this, the difficult airway trolley has been described. These trolleys consist of different drawers and compartments, each with different airway tools to meet the needs of each clinical airway plan. Over the last decade, a consultative approach with DAS and ANZCA (20) has refined the contents of the airway trolley and in doing so reduced the number of expected rescue techniques clinicians are expected to be technically proficient in (99). Integration of airway guidelines with trolley layout means that the trolley itself also becomes an aid memoir prompting the execution of Plan A to D (100). Clear packaging and arrangement in dedicated CICO kits allow the contents to be assessed prior to opening and to be present in one easily accessed location (101).

Cognitive aids such as The Association of Anaesthetists Quick Reference Handbook (102) can enhance fluidity of work and performance (103), particularly when implemented with standardised equipment and training (104). When cognitive aids, checklists and multidisciplinary teams are integrated into simulation and training situational awareness, decision-making improves (104,105). Yet in a systematic review by Nielson et al. simulation-based team training in airway management may help to improve participants perceived preparation but there is a dearth of data exploring whether this has a meaningful outcome on clinical performance or patient data (106).

The uptake of departmental airway leads across the UK, Ireland and New Zealand has been positive since it’s conception after NAP 4 (107). Implemented with the aim of improving institutional and individual airway preparedness, it sought to provide shared learning, shared simulation programmes and shared difficult airway databases (107,108). Anticipation of the difficult airway remains an imprecise science and despite the conception of the DAS airway database, the rate of unanticipated difficult airways remains high (109). Does this represent an undervalued airway assessment, lack of preparedness for airway complexity, the impact of human factors in stressful situations or have we not yet reached the crux of the airway issue?

Future of FONA

In an ever-changing population and anaesthetic environment, FONA remains the stalwart rescue technique. As the incidence of patients living with obesity increases and the survival with life-altering upper airway anatomy improves; more and more patients who are candidates for FONA will present for surgery.

There are technological advancements on the horizon with computational models and artificial intelligence investigating issues that are clinically problematic to address. Laviola et al. (110) have used computational modelling to look at narrow bore ventilation strategies for CICO situations maternal airway compromise and apnoeic oxygenation in subjects living with obesity. It remains to be seen whether the conclusions are clinically transferable. Since 2017, an open access template for a 3D printed cricothyroid model has been freely available reducing the barrier to FONA training for anaesthetists worldwide (111).

A group in the UK are looking into the novel role of voice-activated cognitive aid such as ‘Alexa’ in emergency FONA (112). The first arm of this study will introduce anaesthetists in training to the Alexa checklist in advance of performing the procedure during their annual eFONA refresher, whereas the second arm will not with aim to improve adherence to the DAS guidance in eFONA.

Over the last decade, airway management guidelines have been amended to include human factors. The concept of an ‘airway time out’ has generated good traction and in Edelman et al. novel systematic review, they concluded that human factors were well represented in the 26 guidelines reviewed (113). However, the specificity was lacking. Fifteen of the guidelines failed to provide an example cognitive aid or sterile communication (114), a process by which all bar non-essential communication is limited during airway intervention. Should human factors interventions equate to improved clinical outcomes then we should expect to see their inclusion in national guidelines going forward.

Ultimately, an international shared pathway for airway and FONA management may help to align management plans for anaesthetists worldwide. There has been an exponential increase in airway guidelines since 1993 when the ASA was first published, by 2021 38 were recorded (115). A standardised approach to airway emergencies, as seen in life support courses, may facilitate problem-solving during CICO (115).

Conclusions

With ongoing worldwide discussions on the best approach to eFONA, there will always remain a role for a clinician’s judgment and assessment of the situation. National guidelines act as a cognitive aid during high-stress situations or when planning the approach to a difficult airway. Training and simulation lessen the CICO cognitive burden and facilitate decision-making towards undertaking FONA. Yet ultimately, FONA should not distract from the simple task of providing safe and successful airway management for every patient to minimise the incidence of CICO events altogether.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, Journal of Oral and Maxillofacial Anesthesia for the series “Anaesthesia for Maxillofacial Surgery”. The article has undergone external peer review.

Reporting Checklist: The authors have completed the Narrative Review reporting checklist. Available at https://joma.amegroups.com/article/view/10.21037/joma-23-43/rc

Peer Review File: Available at https://joma.amegroups.com/article/view/10.21037/joma-23-43/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://joma.amegroups.com/article/view/10.21037/joma-23-43/coif). The series “Anaesthesia for Maxillofacial Surgery” was commissioned by the editorial office without any funding or sponsorship. C.J. serves as the unpaid Executive Editor-in-Chief of Journal of Oral and Maxillofacial Anesthesia from October 2023 to September 2025. C.J. also served as the unpaid Guest Editor of the series. The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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