Flexible nasal bronchoscopy vs. Airtraq® videolaryngoscopy for awake tracheal intubation: a randomised controlled non-inferiority study

Videolaryngoscopy is a suitable alternative to flexible bronchoscopy to facilitate awake tracheal intubation. The relative effectiveness of these techniques in clinical practice is unknown. We compared flexible nasal bronchoscopy with Airtraq^® videolaryngoscopy in patients with an anticipated difficult airway scheduled for awake tracheal intubation. Patients were allocated randomly to flexible nasal bronchoscopy or videolaryngoscopy. All procedures were performed with upper airway regional anaesthesia blockade and a target-controlled intravenous infusion of remifentanil. The success rate with the allocated technique was the primary outcome. A non-inferiority analysis with a predefined limit of 8% was planned. Seventy-eight patients were recruited, allocated randomly and analysed. The rate of successful intubation was 97% and 82% in the flexible bronchoscopy and videolaryngoscopy groups, respectively, p = 0.032. The median (IQR [range]) time to tracheal intubation was shorter with the Airtraq, 163 (105–332 [40–1004]) vs. 217 (180–364 [120–780]) s, p = 0.030. There were no significant differences for complications found between the groups. The median visual analogue scale for ease of intubation was 8 (7–9 [0–10]) for Airtraq vs. 8 (7–9 [0–10]) for flexible bronchoscopy, p = 0.710. The median visual analogue scale for patient comfort for Airtraq was 8 (6–9 [2–10]) vs. 8 (7–9 [3–10]) for flexible bronchoscopy, p = 0.370. The Airtraq videolaryngoscope is not non-inferior to flexible bronchoscopy for awake tracheal intubation in a clinical setting when awake tracheal intubation is indicted. It may be a suitable alternative when judged on a case-by-case basis.     

Videolaryngoscopy vs. fibreoptic bronchoscopy for awake tracheal intubation: a systematic review and meta‐analysis

Awake fibreoptic intubation is often considered the technique of choice when a difficult airway is anticipated. However, videolaryngoscopes are being used more commonly. We searched the current literature and performed a meta‐analysis to compare the use of videolaryngoscopy and fibreoptic bronchoscopy for awake tracheal intubation. Our primary outcome was the time needed to intubate the patient's trachea. Secondary outcomes included: failed intubation; the rate of successful intubation at the first attempt; patient‐reported satisfaction with the technique; and any complications resulting from intubation. Eight studies examining 429 patients were included in this review. The intubation time was shorter when videolaryngoscopy was used instead of fibreoptic bronchoscopy (seven trials, 408 participants, mean difference (95%CI) ?45.7 (?66.0 to ?25.4) s, p < 0.0001, low‐quality evidence). There was no significant difference between the two techniques in the failure rate (six studies, 355 participants, risk ratio (95%CI) 1.01 (0.24–4.35), p = 0.99, low‐quality evidence) or the first‐attempt success rate (six studies, 391 participants, risk ratio (95%CI) 1.01 (0.95–1.06), p = 0.8, moderate quality evidence). The level of patient satisfaction was similar between both groups. No difference was found in two reported adverse events: hoarseness/sore throat (three studies, 167 participants, risk ratio (95%CI) 1.07 (0.62–1.85), p = 0.81, low‐quality evidence), and low oxygen saturation (five studies, 337 participants, risk ratio (95%CI) 0.49 (0.22–1.12), p = 0.09, low‐quality evidence). In summary, videolaryngoscopy for awake tracheal intubation is associated with a shorter intubation time. It also seems to have a success rate and safety profile comparable to fibreoptic bronchoscopy.     

A randomised clinical trial comparing the flexible fibrescope and the Pentax Airway Scope (AWS)® for awake oral tracheal intubation

We compared awake fibreoptic intubation with awake intubation using the Pentax Airway Scope^® in 40 adult patients. Sedation was achieved using a target‐controlled remifentanil infusion of 1–5 ng.ml^?1 and midazolam. The airway was anaesthetised with lidocaine spray and gargle. The total procedure time – a composite of sedation time, topical anaesthesia time and intubation time – was recorded. The operator's impression of the ease of the procedure and the patients' reported comfort were recorded on a 0–100 mm visual analogue scale. The median (IQR [range]) for total procedure time was 900 (739–1059 [616–1215]) s with the fibrescope and 651 (601–720 [498–900]) s with the Pentax Airway Scope (p = 0.0001). The median (IQR [range]) intubation time was 420 (283–480 [120–608]) s with the fibrescope and 183 (144–220 [107–420]) s with the Pentax Airway Scope (p = 0.0002). The median (IQR [range]) visual analogue scores for the operator's ease of intubation for the fibrescope and Pentax Airway Scope were 83.6 (72.0–98.0 [49.0–100.0]) and 86.8 (84.0–91.0 [61.0–100.0]), respectively (p = 0.3507). The median (IQR [range]) visual analogue score for patient comfort was 85.5 (81.0–97.0 [69.0–100.0]) and 79.4 (74.0–85.0 [59.0–100.0]) for the fibrescope and Pentax Airway Scope, respectively (p = 0.06). Total procedure time was significantly shorter with the Pentax Airway Scope compared with the fibrescope, with no difference in procedure difficulty or patient discomfort.     

Videolaryngoscopy vs. direct Macintosh laryngoscopy in tracheal intubation in adults: a ranking systematic review and network meta-analysis

Videolaryngoscopes are thought to improve glottic view and facilitate tracheal intubation compared with the Macintosh direct laryngoscope. However, we currently do not know which one would be the best choice in most patients undergoing anaesthesia. We designed this systematic review with network meta-analyses to rank the different videolaryngoscopes and the Macintosh direct laryngoscope. We conducted searches in PubMed and a further five databases on 11 January 2021. We included randomised clinical trials with patients aged ≥16 years, comparing different videolaryngoscopes, or videolaryngoscopes with the Macintosh direct laryngoscope for the outcomes: failed intubation; failed first intubation attempt; failed intubation within two attempts; difficult intubation; percentage of glottic opening seen; difficult laryngoscopy; and time needed for intubation. We assessed the quality of evidence according to GRADE recommendations and included 179 studies in the meta-analyses. The C-MAC and C-MAC D-Blade were top ranked for avoiding failed intubation, but we did not find statistically significant differences between any two distinct videolaryngoscopes for this outcome. Further, the C-MAC D-Blade performed significantly better than the C-MAC Macintosh blade for difficult laryngoscopy. We found statistically significant differences between the laryngoscopes for time to intubation, but these differences were not considered clinically relevant. The evidence was judged as of low or very low quality overall. In conclusion, different videolaryngoscopes have differential intubation performance and some may be currently preferred among the available devices. Furthermore, videolaryngoscopes and the Macintosh direct laryngoscope may be considered clinically equivalent for the time taken for tracheal intubation. However, despite the rankings from our analyses, the current available evidence is not sufficient to ensure significant superiority of one device or a small set of them over the others for our intubation-related outcomes.     

A new retrograde transillumination technique for videolaryngoscopic tracheal intubation

This single‐centre, prospective trial was designed to assess the efficacy of a new retrograde transillumination device called the ‘Infrared Red Intubation System’ (IRRIS) to aid videolaryngoscopic tracheal intubation. We included 40 adult patients, who were undergoing elective urological surgery under general anaesthesia. We assessed the ability to differentiate the transilluminated glottis from other structures and found a median (IQR [range]) larynx recognition time of 8 (5–14 [3–28]) s. The difference in laryngeal visibility on the screen between the deactivated vs. activated device expressed on a visual analogue scale was significant (6 (4–7 [2–10]) vs. 10 (8–10 [4–10]); p < 0.001). The number of laryngoscope insertions was 1 (1–2 [1–3]) and the device showed high values on a visual analogue scale ranging from 0 (lowest score) to 10 (highest score) for helpfulness (6 (5–7 [2–10])), credibility (10 (8–10 [5–10])) and ease of use (10 (9–10 [8–10])). Tracheal intubation with the system lasted 26 (16–32 [6–89]) s. No alternative technique of securing the airway was necessary. The lowest SpO₂ during intubation was 98 (97–99 [91–100])%. We conclude that this method of retrograde transillumination can assist videolaryngoscopy.     

Alternative techniques for tracheal intubation

Conventional direct laryngoscopy with the curved Macintosh blade is a fundamental skill for all anaesthetists and has been the cornerstone of airway management for many years. This technique relies upon the operator aligning the oro-pharyngo-laryngeal structures and inserting a tracheal tube into the trachea under direct vision. However, there is a recognized failure rate with this technique, thus alternative techniques for tracheal intubation are available and should be considered. Awake fibreoptic intubation remains the ‘gold standard’ method for securing the airway in an anticipated difficult airway. Advances in optical technology over recent years have led to the development of several rigid indirect devices, which improve glottic visualization by enabling the operator to ‘see around the corner’. With improved views at laryngoscopy these devices have emerged as important tools in airway management and are useful teaching and training aids.     

Alternative techniques for tracheal intubation

Conventional direct laryngoscopy with the curved Macintosh blade is a fundamental skill for all anaesthetists and has been the cornerstone of airway management for many years. This technique relies on the operator aligning the oro-pharyngo-laryngeal structures and inserting an endotracheal tube into the trachea under direct vision. There is a recognized failure rate with this technique and thus alternative techniques for tracheal intubation should be available for use in difficult situations. Awake fibreoptic intubation (AFOI) remains the ‘gold standard’ method for securing the airway in an anticipated difficult intubation. Advances in optical technology over recent years have lead to the development of several rigid indirect devices, which improve glottic visualization by enabling the operator to ‘see around the corner’. With improved views at laryngoscopy these videolaryngoscopes are emerging as important tools in airway management and useful teaching and training aids.     

Alternative techniques for tracheal intubation

Conventional direct laryngoscopy with the curved Macintosh blade is a fundamental skill for all anaesthetists and has been the cornerstone of airway management for many years. This technique relies on the operator aligning the oro-pharyngo-laryngeal structures and inserting an endotracheal tube into the trachea under direct vision. There is a recognized failure rate with this technique and thus alternative techniques for tracheal intubation should be available for use in difficult situations. Awake fibreoptic intubation (AFOI) remains the ‘gold standard’ method for securing the airway in an anticipated difficult intubation. Advances in optical technology over recent years have lead to the development of several rigid indirect devices, which improve glottic visualization by enabling the operator to ‘see around the corner’. With improved views at laryngoscopy these videolaryngoscopes are emerging as important tools in airway management and useful teaching and training aids.     

清醒气管插管气道局部麻醉技术的研究进展

对于术前评估为困难气道的患者应当采用清醒镇静表面麻醉下实施气管插管。实施清醒气管插管的关键技术是完善的气道局部麻醉。清醒气管插管是麻醉科医师必须掌握的技能之一。本文通过回顾近十年的文献,旨为麻醉科医师提供清醒气管插管气道局部麻醉技术相关理论参考。     

Alternative techniques for tracheal intubation

Alternative rigid blade intubation devices available in recent years include the Glidescope, Airtraq and Bonfils laryngoscopes. The Macintosh blade works by displacing the tongue to one side and into the submandibular space while the tip of the device sits in the vallecula lifting the hyoid and so the epiglottis forward to reveal the laryngeal inlet. Under less favourable intubating conditions, the tongue is not accommodated in the submandibular space and tends to be compressed downwards. As a result the vallecula is not accessible and the blade tip is less able to be drawn forward. The retro-molar Bonfils avoids this problem by starting from a posterior position in the mouth and approaching the larynx below and alongside the tongue. The Bonfils also serves as a rigid stylet inside the tracheal tube again producing minimal tongue displacement. Airtraq also compresses the tongue less and usually sits on the posterior pharyngeal wall where it maintains the laryngeal view with a minimum of effort. It houses the tracheal tube in a channel that delivers it into the device's field of view. While better optical systems have tended to improve visualization of the laryngeal inlet, this has not necessarily resulted in easier intubation conditions, shorter intubation times or improved overall success rates. Part of the problem has been that they have limited fields of view compared with the stereoscopic view of tube advancement down to the larynx as afforded by Macintosh.     

Difficult Airway Society guidelines for management of the unanticipated difficult intubation

Problems with tracheal intubation are infrequent but are the most common cause of anaesthetic death or brain damage. The clinical situation is not always managed well. The Difficult Airway Society (DAS) has developed guidelines for management of the unanticipated difficult tracheal intubation in the non-obstetric adult patient without upper airway obstruction. These guidelines have been developed by consensus and are based on evidence and experience. We have produced flow-charts for three scenarios: routine induction; rapid sequence induction; and failed intubation, increasing hypoxaemia and difficult ventilation in the paralysed, anaesthetised patient. The flow-charts are simple, clear and definitive. They can be fully implemented only when the necessary equipment and training are available. The guidelines received overwhelming support from the membership of the DAS. Disclaimer: It is not intended that these guidelines should constitute a minimum standard of practice, nor are they to be regarded as a substitute for good clinical judgement.     

Difficult paediatric intubation when fibreoptic laryngoscopy fails

We report an unusual problem with fibreoptic bronchoscopy in an 8-year-old girl with Negar syndrome. She had a history of difficult airway since birth, and had undergone mandibular distraction for severe obstructive sleep apnoea when she was aged 2 years. Nagar syndrome is a Treacher-Collins like syndrome with normal intelligence, conductive bone deafness and problems with articulation. The patients have malar hypoplasia with down slanting palpebral fissures, high nasal bridge, micrognathia, absence of lower eyelashes, low set posteriorly rotated ears, preauricular tags, atresia of external ear canal, cleft palate, hypoplasia of thumb, with or without radius, and limited elbow extension. Protracted attempts with a fibreoptic bronchoscope failed to visualize the glottis, and this was only possible when the tube was guided to the larynx by blind nasal intubation. Apparently, the healing of the wounds for the mandibular distraction in the mandibular space on the inside of the rami of the mandible had caused differential fibrosis on either side of the hyoid, leading to a triplane distortion of the larynx with a left shift, clockwise rotation to a 2-8 o'clock direction and a slight tilt towards the left pharyngeal wall. The large epiglottis overlying this had precluded a view of the larynx. Finally, the older technique of breathguided intubation facilitated fibreoptic bronchoscopy to achieve tracheal intubation.     

A prospective cohort study of awake fibreoptic intubation practice at a tertiary centre

Contemporary data are lacking for procedural practice, training provision and outcomes for awake fibreoptic intubation in the UK. We performed a prospective cohort study of awake fibreoptic intubations at a tertiary centre to assess current practice. Data from 600 elective or emergency awake fibreoptic intubations were collected to include information on patient and operator demographics, technical performance and complications. This comprised 1.71% of patients presenting for surgery requiring a general anaesthetic, with the majority occurring in patients presenting for head and neck surgery. The most common indication was reduced mouth opening (26.8%), followed by previous airway surgery or head and neck radiotherapy (22.5% each). Only five awake fibreoptic intubations were performed with no sedation, but the most common sedative technique was combined target‐controlled infusions of remifentanil and propofol. Oxygenation was achieved with high‐flow, heated and humidified oxygen via nasal cannula in 49.0% of patients. Most operators had performed awake fibreoptic intubation more than 20 times previously, but trainees were the primary operator in 78.6% of awake fibreoptic intubations, of which 86.8% were directly supervised by a consultant. The failure rate was 1.0%, and 11.0% of awake fibreoptic intubations were complicated, most commonly by multiple attempts (4.2%), over‐sedation (2.2%) or desaturation (1.5%). The only significant association with complications was the number of previous awake fibreoptic intubations performed, with fewer complications occurring in the hands of operators with more awake fibreoptic intubation experience. Our data demonstrate that awake fibreoptic intubation is a safe procedure with a high success rate. Institutional awake fibreoptic intubation training can both develop and maintain trainee competence in performing awake fibreoptic intubation, with a similar incidence of complications and success compared with consultants.     

Submandibular approach for tracheal intubation in patients with panfacial fractures

Background: The oral route for tracheal intubation can interfere with somemaxillofacial surgical procedures. At the same time, the nasalroute can be contraindicated or impossible. Tracheostomy isthe usual solution in these circumstances, but it carries ahigh incidence of complications. We tested the submandibularroute for tracheal intubation as an alternative to tracheostomyin such situations. Methods: The procedure was performed in 13 patients suffering from panfacialfractures associated with a fracture of skull base or a displacednasal fracture, and in one patient with post-caustic burn scaraffecting most of the face including the nose and requiringa full thickness skin flap surrounding the mouth. Results: The technique was found easy and satisfactory for both the surgeonand the anaesthetist. It allowed uninterrupted surgical techniquesand a secure airway. In six of the 13 patients, the submandibulartracheal tube was left in place for up to 44 h in the intensivecare unit after the operation without complications or difficulties.Accidental dislodgement of the tube to the right main bronchusoccurred in two patients while carrying out the procedure; itwas rapidly detected and corrected. In another two patients,postoperative superficial infection occurred that respondedwell to local treatment. No other complications were encountered. Conclusions: Submandibular tracheal intubation is a simple and effectivetechnique for upper airway management in some maxillofacialsurgical patients when both oral and nasal tracheal intubationsare not convenient.