First-attempt awake tracheal intubation success rate using a hyperangulated unchannelled videolaryngoscope vs. a channelled videolaryngoscope in patients with anticipated difficult airway: a randomised controlled trial.

INTRODUCTION: There is uncertainty about the optimal videolaryngoscope for awake tracheal intubation in patients with anticipated difficult airway. The use of channelled and unchannelled videolaryngoscopy has been reported, but there is a lack of evidence on which is the best option. METHODS: We conducted a randomised clinical trial to compare the efficacy of the C-MAC D-Blade® vs. Airtraq® in adult patients (aged ≥ 18 y) scheduled for elective or emergency surgery under general anaesthesia with anticipated difficult airway who required awake tracheal intubation under local anaesthesia and conscious sedation. The primary endpoint was the first-attempt tracheal intubation success rate. Secondary outcomes included the overall success rate; number of tracheal intubation attempts; Cormack and Lehane glottic view; level of difficulty (visual analogue score); patient discomfort (visual analogue score); and incidence of complications. RESULTS: Ninety patients (70/90 male (78%); mean (SD) age 65 (12) y) with anticipated difficult airways were randomly allocated to C-MAC D-Blade or Airtraq videolaryngoscopy. First-attempt successful tracheal intubation rate was higher in patients allocated to the C-MAC D-Blade group compared with those allocated to the Airtraq group (38/45 (84%) vs. 28/45 (62%), respectively; p = 0.006). The proportion of patients' tracheas that were intubated at the second and third attempt was 4/45 (9%) and 3/45 (7%) in those allocated to the C-MAC D-Blade group compared with 14/45 (31%) and 1/45 (2%) in those allocated to the Airtraq group (p = 0.006). There was no significant difference in overall tracheal intubation success rate (C-MAC D-Blade group 45/45 (100%) vs. Airtraq group 43/45 (96%), p = 0.494). DISCUSSION: In patients with anticipated difficult airway, first-attempt awake tracheal intubation success rate was higher with the C-MAC D-Blade compared with Airtraq laryngoscopy. No difference was found between the two videolaryngoscopes in overall tracheal intubation success rate.

Effects of avoidance versus use of neuromuscular blocking agents for facilitation of tracheal intubation in children and infants: a protocol for a systematic review, meta-analysis and trial sequential analysis.

BACKGROUND: The European Society of Anesthesiology and Intensive Care recommends the use of neuromuscular blocking agents (NMBA) in adults, to facilitate tracheal intubation and reduce its associated complications. Children who undergo tracheal intubation may suffer some of the same complications, however, no consensus exists regarding the use of NMBA for tracheal intubation in the pediatric population. We will explore the existing evidence assessing the effects of avoidance versus the use of NMBA for the facilitation of tracheal intubation in children and infants. METHODS: This protocol follows the preferred reporting items for systematic reviews and meta-analyses protocols recommendations. We will include all randomized controlled clinical trials assessing the effects of avoidance versus the use of NMBA for facilitation of tracheal intubation (oral or nasal) using direct laryngoscopy or video laryngoscopy in pediatric participants (<18 years). Our primary outcome is incidence of difficult tracheal intubation. Secondary outcomes include incidence of serious adverse events, failed intubation, events of upper airway discomfort or injury, and difficult laryngoscopy. We will conduct a thorough database search to identify relevant trials, including CENTRAL, MEDLINE, EMBASE, BIOSIS, Web of Science, CINAHL, and trial registries. Two review authors will independently handle the screening of literature and data extraction. Each trial will be evaluated for major sources of bias with the "classic risk of bias tool" used in the Cochrane Collaboration tool from 2011. We will use Review manager (RevMan) or R with the meta package to perform the meta-analysis. We will perform a trial sequential analysis on the meta-analysis of our primary outcome, providing an estimate of statistical reliability. Two review authors will independently assess the quality of the body of evidence using the grading of recommendations assessment, development, and evaluation (GRADE) approach. We will use GRADEpro software to conduct the GRADE assessments and to create "Summary of the findings" tables.

Failed tracheal intubation in primary health care.

Tracheal intubation in primary health care is a necessary skill and usually one that is necessary for appropriate emergency management of unstable patients. Primary care practitioners may not have an anaesthetist or critical care doctor available to help them in these emergencies and must manage these patients themselves. Often tracheal intubation may fail because of multiple possible factors and a different course of action may be needed to minimise the potential for harm to the patient. The primary care professional or family physician will have to manage this failed intubation. Primary health care facilities providing obstetric services must have guidelines and appropriate equipment for management of airway problems. This article will explore reasons for the failure of tracheal intubation and how this can be managed.

A case report of retrograde intubation as rescue procedure in unanticipated difficult airway: an old technique still relevant in low resource settings.

In cases with an unanticipated difficult airway, retrograde intubation can be used as an alternative procedure for airway management when a fiber optic bronchoscope is unavailable. We here report a case of successful management of an unanticipated difficult airway following a failed intubation in a 34-year-old 54 kg male patient with carcinoma lateral border of tongue using retrograde intubation guided technique. Maintaining oxygenation and minimizing airway trauma should be the priority following a failed intubation. Decisions seeking alternative techniques following failed intubation are easy, if valid and applicable techniques (as per anesthesiologist's skills and available resources) are discussed before induction of anesthesia.

Management of difficult and failed intubation in the general surgical population: a historical cohort study in a tertiary care centre.

PURPOSE: The objective of this study was to describe the incidence, management, and complications of difficult and failed endotracheal intubation in a general surgical population. METHODS: This historical cohort study included all cases of difficult endotracheal intubation in general surgical patients at Mount Sinai Hospital (Toronto, ON, Canada) from 1 January 2011 to 31 December 2017. Patient charts and electronic records were reviewed to collect data on airway management and complications. Endotracheal intubation was graded as "difficult" if more than two attempts with direct laryngoscopy or if additional equipment for second or subsequent attempts was required, and "failed" if it could not be achieved despite the attempts. The primary outcome was the incidence of difficult and failed intubation. The secondary outcomes were complications, difficult airway parameters, mask ventilation, number of intubation attempts, and rescue devices including the eventually successful method. RESULTS: We identified 111 cases of difficult intubation (0.26%) and 14 cases of failed intubation (0.03%) in 42,805 surgical cases requiring endotracheal intubation over the seven-year period. The incidence was highest in 2012 (0.36%) and lowest in 2017 (0.13%). Difficulty was anticipated in 84 (76%) patients. The median (range) number of intubation attempts was 2 (2-5). Videolaryngoscopy was the eventually successful method in those with unsuccessful first attempt direct laryngoscopy (n = 91) and videolaryngoscopy (n = 17) in 71% and 77% cases, respectively. Intubation failed in 14 patients, three of whom required a surgical airway because the lungs could not be ventilated. Poor visualization of the glottis (93%) and airway bleeding (36%) were the leading causes of failed intubation. Desaturation was seen in 8%, airway bleeding in 7%, and airway edema in 6% of cases of difficult intubation. CONCLUSION: The incidences of difficult and failed intubations in our study were 2.6 and 0.3 per 1,000 surgeries requiring laryngoscopies, respectively, with a decrease over time. Videolaryngoscopy showed a high success rate as a rescue device.

RéSUMé: OBJECTIF: L'objectif de cette étude était de décrire l'incidence, la prise en charge et les complications d'une intubation endotrachéale difficile et d'un échec d'intubation dans une population chirurgicale générale. MéTHODE: Cette étude de cohorte historique a inclus tous les cas d'intubation endotrachéale difficile chez des patients de chirurgie générale à l'Hôpital Mount Sinai (Toronto, ON, Canada) du 1er janvier 2011 au 31 décembre 2017. Les dossiers papier et électroniques des patients ont été passés en revue afin de recueillir des données sur la prise en charge des voies aériennes et les complications. L'intubation endotrachéale a été classée comme « difficile ¼ si plus de deux tentatives avec laryngoscopie directe ou si du matériel supplémentaire pour la deuxième tentative ou les tentatives ultérieures était nécessaire, et « échec ¼ si elle n'avait pas pu être réalisée malgré les tentatives. Le critère d'évaluation principal était l'incidence d'intubation difficile et d'échec. Les critères d'évaluation secondaires comportaient les complications, les critères de voies aériennes difficiles, la ventilation au masque, le nombre de tentatives d'intubation et les dispositifs de sauvetage, y compris la méthode permettant finalement un succès d'intubation. RéSULTATS: Nous avons identifié 111 cas d'intubation difficile (0,26 %) et 14 cas d'échec d'intubation (0,03 %) parmi les 42 805 cas chirurgicaux nécessitant une intubation endotrachéale au cours de la période de sept ans. L'incidence était la plus élevée en 2012 (0,36 %) et la plus basse en 2017 (0,13 %). Des difficultés avaient été anticipées chez 84 (76 %) patients. Le nombre médian (intervalle) de tentatives d'intubation était de 2 (2 à 5). La vidéolaryngoscopie a été la méthode permettant le succès final de l'intubation chez les patients pour lesquels la première tentative avait échoué avec la laryngoscopie directe (n = 91) ou la vidéolaryngoscopie (n = 17), soit dans 71 % et 77 % des cas, respectivement. L'intubation a échoué chez 14 patients, dont trois ont nécessité un accès chirurgical aux voies aériennes car les poumons ne pouvaient pas être ventilés. Une mauvaise visualisation de la glotte (93 %) et des saignements des voies aériennes (36 %) étaient les principales causes d'échec de l'intubation. Une désaturation a été observée dans 8 % des cas d'intubation difficile, alors que des saignements des voies aériennes ont été observés dans 7 % et un œdème des voies aériennes dans 6 % des cas. CONCLUSION: Dans notre étude, les incidences d'intubations difficiles et d'échec étaient de 2,6 et 0,3 pour 1000 chirurgies nécessitant des laryngoscopies, respectivement, avec une diminution au fil du temps. La vidéolaryngoscopie a montré un taux de réussite élevé en tant que dispositif de sauvetage.

Unanticipated Difficult Airway During Elective Surgery: A Case Report and Review of Literature.

Difficult airway during anesthesia is responsible for several cases of morbidity and mortality worldwide, especially when it is unanticipated. Patients with either history of or with predictive factors of a difficult airway show better outcomes since all preventative measures will ensure patient safety. Approximately 30% of all deaths attributed to anesthesia are related to unsuccessful intubation. In this article, we discuss a patient who had a tracheostomy following an unanticipated difficult airway with undiagnosed subglottic stenosis and also reviewed the current literature on the difficult airway.

Randomized controlled trial comparing an open surgical technique and a Seldinger technique for cricothyrotomy performed on a simulated airway.

OBJECTIVES: Emergency cricothyrotomy is a lifesaving procedure performed when intubation fails and oxygenation cannot occur. There are multiple techniques and kits to perform this procedure. However, current evidence does not provide a definitive answer as to which method is superior. Two techniques in common use are a surgical technique and a percutaneous Seldinger-based cricothyrotomy kit. The objective was to determine which of these two methods was quickest to perform and to determine which was most preferred by participants. METHODS: A prospective randomized controlled crossover trial was conducted involving emergency physicians and trainees. Each participant performed both cricothyrotomy techniques in succession on an airway model, with the technique performed first being randomized for each participant. The primary outcome was time to first insufflation of the artificial lung. A survey was completed by participants asking their comfort with each technique on a 5-point scale from 1 (not at all comfortable) to 5 (very comfortable) and which technique they preferred. RESULTS: Twenty-one emergency physicians and nine emergency medicine trainees were recruited. The surgical technique was performed the fastest, with a mean (±SD) time of 51.6 (±16.3) s versus 66.6 (±14.9) s for the Seldinger technique, with a statistically significant difference of 15.0 s (95% confidence interval = 8.5 to 21.5, p < 0.001). The surgical technique was rated the most comfortable to perform, with a median rating of 5 (interquartile range [IQR] = 4-5) versus 4 (IQR = 3-5) for the Seldinger technique. The surgical technique was most preferred by participants (80% vs 20%). CONCLUSION: The surgical technique was the fastest to perform and was rated the most comfortable to perform and the most preferred technique.

Subglottic stenosis imitating the carina - a case report of airway mimicry.

We present a case of awake tracheal intubation with flexible bronchoscopy which resulted in incorrect tracheal tube placement. The presence of a stenotic subglottic lesion with an appearance similar to the carina led to the tube being positioned with only the tip within the trachea whilst the cuff was located between the vocal cords. A capnography trace was identified before induction of anaesthesia; however, visual confirmation of the carina was undertaken in a rushed manner due to the patient becoming agitated. Once the incorrect tracheal tube placement was identified, the decision was made to wake the patient. Thereafter, a more experienced operator successfully performed awake tracheal intubation with flexible bronchoscopy using a smaller tracheal tube, which easily passed through the subglottic stenosis. This report emphasises the importance of performing the 'two-point check' every time awake tracheal intubation is undertaken: to confirm correct tube placement, both a capnography trace and view of the tracheal lumen including the carina and main bronchi is required. This must be properly performed before induction of anaesthesia; safety should not be compromised by a stressful environment or time pressure.

Combined use of a videolaryngoscope and a flexible bronchoscope for awake tracheal intubation when front-of-neck airway is not an option.

We report a case of successful tracheal intubation with the combined use of a videolaryngoscope and flexible bronchoscope in a patient with difficult airway when both techniques had individually failed. A 35-year-old man presented with airway obstruction due to massive neck swelling causing hypoxia, stridor and respiratory distress. He had a history of oral cancer which had been resected with bilateral neck dissection and free flap reconstruction 2 months previously. Due to extensive anterior neck swelling, we judged that front-of-neck airway would not be a suitable approach. After unsuccessful attempts at awake tracheal intubation with videolaryngoscopy and flexible bronchoscopy separately, we combined both techniques with a successful outcome. By using a combined technique to address the specific problems presented by this case, a life-threatening emergency was resolved. This case highlights why it is useful for anaesthetists to be familiar with multiple techniques to awake tracheal intubation, both individually and in combination.

Difficult and failed intubation in the first 4000 incidents reported on webAIRS.

A review of the first 4000 reports to the webAIRS anaesthesia incident reporting database was performed to analyse cases reported as difficult or failed intubation. Patient, task, caregiver and system factors were evaluated. Among the 4000 reports, there were 170 incidents of difficult or failed intubation. Difficult or failed intubation incidents were most common in the 40-59 years age group. More than half of cases were not predicted. A total of 40% involved patients with a body mass index >30 kg/m2 and 41% involved emergency cases. A third of the reports described multiple intubation attempts. Of the reports, 18% mentioned equipment problems including endotracheal tube cuff rupture, laryngoscope light failure, dysfunctional capnography and delays with availability of additional equipment to assist with intubation. Immediate outcomes included 40 cases of oxygen desaturation below 85%; of these cases, four required cardiopulmonary resuscitation. The majority of the incidents resulted in no harm or minor harm (45%). However, 12% suffered moderate harm, 3.5% severe harm and there were three deaths (although only one related to the airway incident). Despite advances and significant developments in airway management strategies, difficult and failed intubation still occurs. Although not all incidents are predictable, nor are all preventable, the information provided by this analysis might assist with future planning, preparation and management of difficult intubation.

Comprehensive evaluation of manikin-based airway training with second generation supraglottic airway devices.

BACKGROUND: Supraglottic airway devices (SADs) are an essential second line tool during difficult airway management after failed tracheal intubation. Particularly for such challenging situations the handling of an SAD requires sufficient training. We hypothesized that the feasibility of manikin-based airway management with second generation SADs depends on the type of manikin. METHODS: Two airway manikins (TruCorp AirSim® and Laerdal Resusci Anne® Airway Trainer™) were evaluated by 80 experienced anesthesia providers using 5 different second generation SADs (LMA® Supreme™ [LMA], Ambu® AuraGain™, i-gel®, KOO™-SGA and LTS-D™). The primary outcome of the study was feasibility of ventilation measured by assessment of the manikins' lung distention. As secondary outcome measures, oropharyngeal leakage pressure (OLP), ease of gastric tube insertion the insertion time, position and subjective assessments were evaluated. RESULTS: Ventilation was feasible with all combinations of SAD and manikin. By contrast, an OLP exceeding 10 cm H2O could be reached with most of the SADs in the TruCorp but with the LTS-D only in the Laerdal manikin. Gastric tube insertion was successful in above 90% in the Laerdal vs 87% in the TruCorp manikin (P<0.009). Insertion times differed significantly between manikins. The SAD positions were better in the Laerdal manikin for LMA, Ambu, i-gel and LTS-D. Participant's assessments were superior in the Laerdal manikin for LMA, Ambu, i-gel and KOO-SGA. CONCLUSIONS: Ventilation is possible with all combinations. However, manikins are variable in their ability to adequately represent additional functions of second generation SADs. In order to achieve the best performance during training, the airway manikin should be chosen depending on the SAD in question.

Advantages of the New Tao Mask for Bag Mask Ventilation: a randomized crossover trial.

BACKGROUND AND AIMS: Manual bag mask ventilation is a life saving skill. An investigation was made to compare two different facemasks used in bag mask ventilation, the standard and the novel Tao face mask, and evaluate the ability of novices to achieve adequate tidal volume. METHODS: The study design was a crossover trial, which randomized forty medical students with no previous airway experience to learn bag mask ventilation with the standard mask and the Tao face mask. Primary outcome measures were mean and median tidal volume per mask, and secondary measures were hand area, age, gender, and order of mask usage. RESULTS: Medical students who used the Tao mask first achieved significantly more tidal volume than those who used the standard mask first (p = 0.002). However, when comparing face masks that were used second, the tidal volume did not differ significantly between the two masks (p = 1.000). Greater tidal volume was achieved on the second attempt relative to the first attempt with each mask. There was significantly more tidal volume achieved with greater hand size with the standard mask, whether it was used first or second (p < 0.001 and p = 0.012 respectively). Greater hand size was associated with greater tidal volume in the Tao mask also, but only when used first (p < 0.001). When first attempting bag mask ventilation, inexperienced students achieved greater tidal volume with the Tao Mask. The results also suggest that hand size matters less when using the Tao Mask. CONCLUSION: When first attempting bag mask ventilation inexperienced students achieved greater tidal volume with the Tao Mask. The results also suggest that hand size matters less when using the Tao mask.

The Airway App: exploring the role of smartphone technology to capture emergency front-of-neck airway experiences internationally.

In this exploratory study we describe the utility of smartphone technology for anonymous retrospective observational data collection of emergency front-of-neck airway management. The medical community continues to debate the optimal technique for emergency front-of-neck airway management. Although individual clinicians infrequently perform this procedure, hundreds are performed annually worldwide. Ubiquitous smartphone technology and internet connectivity have created the opportunity to collect these data. We created the 'Airway App', a smartphone application to capture the experiences of healthcare providers involved in emergency front-of-neck airway procedures. In the first 18-month period, 104 emergency front-of-neck airway management reports were received; 99 (95%) were internally valid and unique from 21 countries. Eighty-one (82%) were performed by non-surgeons and 63 (64%) were 'cannot intubate, cannot oxygenate' emergencies. Overall first-attempt success varied by technique; 45 scalpel-bougie cricothyroidotomy (37 first-attempt success), 25 surgical cricothyroidotomy (15 first-attempt success), eight cannula cricothyroidotomy (five first-attempt success), six wire-guided cricothyroidotomy (three first-attempt success) and 15 tracheostomy reports (11 first-attempt success). The most commonly reported positive human factors were good communication, good teamwork and/or skilled personnel. The most commonly reported negative human factors were fixation on multiple tracheal intubation attempts, delay in initiating emergency front-of-neck airway and/or the failure to plan for failure. Due to the anonymous nature of reporting, reports are open to recollection bias and spurious reporting. We conclude collection of data using a smartphone application is feasible and has the potential to expand our knowledge of emergency front-of-neck airway management.

Effect of palpable vs. impalpable cricothyroid membranes in a simulated emergency front-of-neck access scenario.

The Difficult Airway Society 2015 guidelines recommend and describe in detail a surgical cricothyroidotomy technique for the can't intubate, can't oxygenate (CICO) scenario, but this can be technically challenging for anaesthetists with no surgical training. Following a structured training session, 104 anaesthetists took part individually in a simulated can't intubate, can't oxygenate event using simulation and airway models to evaluate how well they could perform these front-of-neck access techniques. Main outcomes measures were: ability to correctly perform the technical steps; procedural time; and success rate. Outcomes were compared between palpable and impalpable cricothyroid membrane scenarios. Anaesthetists' technical abilities were good, as assessed by a video analysis checklist score. Mean (SD) procedural time was 44 (16) s and 65 (17) s for the palpable and impalpable cricothyroid membrane models, respectively (p ≤ 0.001). First-pass tracheal tube placement was obtained in 103 out of the 104 palpable cricothyroidotomies and in 101 out of the 104 impalpable cricothyroidotomies (p = 0.31). We conclude that anaesthetists can be trained to perform surgical front-of-neck access to an acceptable level of competence and speed when assessed using a simulator.

Safety and efficacy of rescue flexible bronchoscopic intubation using the Bentson floppy-tip guidewire via a supraglottic airway in critically ill children.

Difficulty in tracheal intubation in paediatric intensive care patients is associated with increased morbidity and mortality. Delays to intubation and interruption to oxygenation and ventilation are poorly tolerated. We developed a safe and atraumatic tracheal intubation technique. A floppy-tipped guidewire and airway exchange catheter were placed to a pre-determined length under bronchoscopic guidance while oxygenation and ventilation was maintained via a supraglottic airway device (SAD). We performed a retrospective review of this technique on patients who were either known to have or who had an unexpected difficultly in intubation. We describe the safety and experience of this in a broad range of critically ill children. Thirteen patients, median (IQR [range]) (9.0 (5.0-10.0 [4.0-12.0]) kg and 15.4 (12.1-23.2 [3.3-49.7]) months) underwent emergency tracheal intubation using this technique, after unsuccessful attempts at intubation using standard laryngoscopy blades. All intubations were successful at the first attempt using this technique and no airway trauma or significant clinical deteriorations were recorded.

The height of the cricothyroid membrane on computed tomography scans in trauma patients.

Emergency cricothyrotomy is a common feature in all difficult airway algorithms. It is the final step following a 'can't intubate, can't oxygenate' scenario. It is rarely performed and has a significant failure rate. There is variation in the reported size of the cricothyroid membrane, especially across population groups. Procedural failure may result from attempting to pass a device with too large an external diameter through the cricothyroid membrane. We aimed to determine the maximum height of the cricothyroid membrane in a UK trauma population. Electronic callipers were used to measure the maximum height of the cricothyroid membrane on 482 reformatted trauma computed tomography scans, 377 (78.2%) of which were in male patients. The mean (SD) height of the cricothyroid membrane, as independently measured by two radiologists, was 7.89 (2.21) mm and 7.88 (2.22) mm in male patients, and 6.00 (1.76) mm and 5.92 (1.71) mm in female patients. The presence of concurrent tracheal intubation or cervical spine immobilisation was found not to have a significant effect on cricothyroid membrane height. The cricothyroid membrane height in the study population was much smaller than that previously reported. Practitioners encountering patients who may require an emergency surgical airway should be aware of these data. Rescue airway equipment with variety of external diameters should be immediately available.

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.