Flexible bronchoscopic intubation through a supraglottic airway device: An evaluation of consultant anaesthetist performance

BACKGROUND

Few clinical studies investigate technical skill performance in experienced clinicians.

METHODS

We undertook a prospective observational study evaluating procedural skill competence in consultant anaesthetists who performed flexible bronchoscopic intubation (FBI) under continuous ventilation through a second-generation supraglottic airway device (SAD). Airway management was recorded on video and performance evaluated independently by three external assessors. We included 100 adult patients undergoing airway management by 25 anaesthetist specialists, each performing four intubations. We used an Objective Structured Assessment of Technical Skills-inspired global rating scale as primary outcome. Further, we assessed the overall pass rate (proportion of cases where the average of assessors' evaluation for every domain scored ≥3); the progression in the global rating scale score; time to intubation; self-reported procedural confidence; and pass rate from the first to the fourth airway procedure.

RESULTS

Overall median global rating scale score was 29.7 (interquartile range 26.0-32.7 [range 16.7-37.7]. At least one global rating scale domain was deemed 'not competent' (one or more domains in the evaluation was scored <3) in 30% of cases of airway management, thus the pass rate was 70% (95% CI 60%-78%). After adjusting for multiple testing, we found a statistically significant difference between the first and fourth case of airway management regarding time to intubation (p = .006), but no difference in global rating scale score (p = .018); self-reported confidence before the procedure (p = .014); or pass rate (p = .109).

CONCLUSION

Consultant anaesthetists had a median global rating scale score of 29.7 when using a SAD as conduit for FBI. However, despite reporting high procedural confidence, at least one global rating scale domain was deemed 'not competent' in 30% of cases, which indicates a clear potential for improvement of skill competence among professionals.

AuraGain™ versus i-gel™ for bronchoscopic intubation under continuous oxygenation: A randomised controlled trial

INTRODUCTION

After failed mask ventilation and tracheal intubation, guidelines issued by the Difficult Airway Society recommend placing a second generation supraglottic airway device to secure oxygenation. Ultimately, a secure airway can be obtained by tracheal intubation through the supraglottic airway device using a bronchoscope. In this randomised trial, we compared the AuraGain™ with the i-gel™ as conduit for bronchoscopic intubation under continuous oxygenation performed by a group of anaesthesiologists with variable experience in a general population of patients.

METHOD

We randomised one hundred patients who were equally allocated to flexible bronchoscopic intubation through the i-gel™ or the AuraGain™. In a random order, 25 anaesthesiologists each performed four intubations, two using the i-gel™ and two using the AuraGain™. Our primary outcome was 'total time for airway management'; i.e. total time from manually reaching the SAD to successful FBI confirmed at the end of the first inspiratory downstroke on the capnography curve.

RESULTS

In total, 87% (95% CI, 79%-92%) of the patients were successfully intubated through the allocated supraglottic airway device. There was no difference in total time for airway management between the i-gel™ and the AuraGain™ (199 vs. 227 s, p = .076). However, there was a difference in time for placement of the i-gel™, compared to the AuraGain™, (37 vs. 54 s, p < .001). There were nine failed intubations in the AuraGain™ group compared to four in the i-gel™ group (p = .147).

CONCLUSION

We found no difference in total time for airway management between using the i-gel™ and using the AuraGain™.

Rescue supraglottic airway devices at caesarean delivery: What are the options to consider?

Tracheal intubation is considered the gold standard means of securing the airway in obstetric general anaesthesia because of the increased risk of aspiration. Obstetric failed intubation is relatively rare. Difficult airway guidelines recommend the use of a supraglottic airway device to maintain the airway and to allow rescue ventilation. Failed intubation is associated with a further increased risk of aspiration, therefore there is an argument for performing supraglottic airway-guided flexible bronchoscopic intubation (SAGFBI). The technique of SAGFBI has a high success rate in the non-obstetric population, it protects the airway and it minimises task fixation on repeated attempts at laryngoscopic tracheal intubation. However, after failed intubation via laryngoscopy, there is a lack of specific recommendations or indications for SAGFBI in current obstetric difficult airway guidelines in relation to achieving tracheal intubation. Our narrative review explores the issues pertaining to airway management in these cases: the use of supraglottic airway devices and the techniques of, and technical issues related to, SAGFBI. We also discuss the factors involved in the decision-making process as to whether to proceed with surgery with the airway maintained only with a supraglottic airway device, or to proceed only after SAGFBI.

Awake supraglottic airway guided flexible bronchoscopic intubation in patients with anticipated difficult airways: a case series and narrative review

Awake intubation is indicated in difficult airways if attempts at securing the airway after induction of general anesthesia may lead to harm due to potential difficulties or failure in those attempts. Conventional awake flexible bronchoscopic intubation is performed via the nasal, or less commonly, oral route. Awake oral flexible bronchoscopic intubation (FBI) via a supraglottic airway device (SAD) is a less common technique; we refer to this as ‘supraglottic airway guided’ FBI (SAGFBI). We describe ten cases with anticipated difficult airways in which awake SAGFBI was performed. After sedation and adequate airway topicalization, an Ambu Auragain^TM SAD was inserted. A flexible bronchoscope, preloaded with a tracheal tube, was then inserted through the SAD. Finally, the tracheal tube was railroaded over the bronchoscope, through the SAD and into the trachea. The bronchoscope and the SAD were carefully removed, whilst keeping the tracheal tube in-situ. The technique was successful and well tolerated by all patients, and associated complications were rare. It also offered the advantages of performing an ‘awake test insertion’ of the SAD, an ‘awake look’ at the periglottic region, and an ‘awake test ventilation.’ In certain patients, awake SAGFBI offers advantages over conventional awake FBI or awake videolaryngoscopy. More research is required to evaluate its success and failure rates, and identify associated complications. Its place in difficult airway algorithms may then be further established.

Direct and indirect low skill fibre-optic intubation: A randomised crossover manikin study of six supraglottic airway devices

Background and Aims:

Fibre-optic intubation (FOI) through supraglottic airway devices (SADs) is useful in the management of the difficult airway. We compared two methods of FOI through seven SADs in a randomised crossover manikin study to assess each device's performance and discuss implications on SAD selection.

Methods:

Thirty anaesthetsiologists, 15 seniors and 15 juniors, each performed low skill FOI (LSFOI) with seven SADs using both 'direct' and 'indirect' methods. The order of method and device used were randomised. The primary end point was success rate of intubation; secondary end points were time taken for intubation, incidence of difficulties with direct and indirect LSFOI and operator device preference. Statistical analysis was with univariable analysis and comparison of proportions.

Results:

Data from six devices were analysed due to a protocol breach with one SAD. There was no difference in intubation success rate across all SADs and intubation methods. Intubation time was significantly shorter in AmbuAuragain than other SADs and shorter with the direct method of LSFOI than the indirect method (mean difference of 6.9 s, P = 0.027). Ambu Auragain had the least SAD and bronchoscope-related difficulties. Seniors had significantly shorter mean intubation times than juniors by 11.6 s (P = 0.0392). The most preferred SAD for both methods was AmbuAuragain.

Conclusion:

Low skill FOI consistently achieves a high intubation success rate regardless of experience, choice of method, or SAD used. SAD design features may significantly affect the performance of low skill FOI.

A cadaver study comparing three fibreoptic-assisted techniques for converting a supraglottic airway to a cuffed tracheal tube

After rescuing an airway with a supraglottic airway device, a method to convert it to a cuffed tracheal tube is often needed. The best method to do this has never been directly studied. We compared three techniques for conversion of a standard LMA^® Unique airway to a cuffed endotracheal tube using a fibrescope. The primary endpoint was time to intubation, with secondary endpoints of success rate, perceived difficulty and preferred technique. We also investigated the relationship between level of training and prior training and experience with the techniques on the primary outcome. The mean (95% CI) time to intubation using a direct tracheal tube technique of 37 (31-42) s was significantly shorter than either the Aintree intubation catheter technique at 70 (60-80) s, or a guidewire technique at 126 (110-141) s (p < 0.001). Most (13/24) participants rated the tracheal tube as their preferred technique, while 11/24 preferred the Aintree technique. In terms of perceived difficulty, 23/24, 21/24 and 9/24 participants rated the tracheal tube technique, Aintree technique and guidewire technique, respectively, as either very easy or easy. There was no relationship between prior training, prior experience or level of training on time to completion of any of the techniques. We conclude the tracheal tube and Aintree techniques both provide a rapid and easy method for conversion of a supraglottic airway device to a cuffed tracheal tube. The guidewire technique cannot be recommended.

A randomised comparison of free-handed vs air-Q assisted fibreoptic-guided tracheal intubation in children < 2 years of age

We prospectively compared free-handed and air-Q™ assisted fibreoptic-guided tracheal intubation in children < 2 years of age. Eighty healthy children were enrolled and randomly assigned to a technique (free-handed or air-Q assisted) and operator (trainee or attending). Time, number of attempts and manoeuvres required were assessed. There was no difference in median (IQR [range]) time to successful tracheal intubation between the free-handed (52.2 (34.8-67.7 [19.7-108.0]) s), and the air-Q assisted (60.3 (45.5-75.1 [28.1-129.0]) s; p = 0.13) groups, or the number of attempts needed. The air-Q assisted group required fewer manoeuvres to optimise the laryngeal view (median (IQR [range]) 0 (0-1 [0-2])) than the free-handed group (1 (1-1 [0-3]); p < 0.001). In conclusion, fibreoptic-guided tracheal intubation times were similar with and without the use of the air-Q, but supraglottic airway devices may be a consideration for their other practical advantages.

Equipment to manage a difficult airway during anaesthesia

Airway complications are a leading cause of morbidity and mortality in anaesthesia. Effective management of a difficult airway requires the timely availability of suitable airway equipment. The Australian and New Zealand College of Anaesthetists has recently developed guidelines for the minimum set of equipment needed for the effective management of an unexpected difficult airway (TG4 [2010] www.anzca.edu.au/resources/professionaldocuments). TG4 [2010] is based on expert consensus, underpinned by wide consultation and an extensive review of the available evidence, which is summarised in a Background Paper (TG4 BP [2010] www.anzca.edu.au/ resources/professional-documents). TG4 [2010] will be reviewed at the end of one year and thereafter every five years or more frequently if necessary. The current paper is reproduced directly from the Background Paper (TG4 BP [2010]).