Most important airway articles 2018 and 2019 as determined by the respective journal editors and presented at the World Airway Management Meeting 2019

Difficult Airway Society guidelines for awake tracheal intubation (ATI) in Adults (1)

Abstract:

Awake tracheal intubation has a high success rate and a favourable safety profile but is underused in cases of anticipated difficult airway management. These guidelines are a comprehensive document to support decision making, preparation and practical performance of awake tracheal intubation. We performed a systematic review of the literature seeking all of the available evidence for each element of awake tracheal intubation in order to make recommendations. In the absence of high‐quality evidence, expert consensus and a Delphi study were used to formulate recommendations. We highlight key areas of awake tracheal intubation in which specific recommendations were made, which included: indications; procedural setup; checklists; oxygenation; airway topicalisation; sedation; verification of tracheal tube position; complications; management of unsuccessful awake tracheal intubation; post‐tracheal intubation management; consent; and training. We recognise that there are a range of techniques and regimens that may be effective and one such example technique is included. Breaking down the key practical elements of awake tracheal intubation into sedation, topicalisation, oxygenation and performance might help practitioners to plan, perform and address complications. These guidelines aim to support clinical practice and help lower the threshold for performing awake tracheal intubation when indicated.

The DIFFMASK score for prediction difficult facemask ventilation: a cohort study of 46,804 patients (2)

Abstract:

Facemask ventilation is an essential part of airway management. Correctly predicting difficulties in facemask ventilation may reduce the risk of morbidity and mortality among patients at risk. We aimed to develop and evaluate a weighted risk score for predicting difficult facemask ventilation during anaesthesia. We analysed a cohort of 46,804 adult patients who were assessed pre‐operatively airway for 13 predictors of difficult airway management and subsequently underwent facemask ventilation during general anaesthesia. We developed the Difficult Facemask (DIFFMASK) score in two consecutive steps: first, a multivariate regression analysis was performed; and second, the regression coefficients of the adjusted regression model were converted into a clinically applicable weighted point score. The predictive accuracy of the DIFFMASK score was evaluated by assessment of receiver operating characteristic curves. The prevalence of difficult facemask ventilation was 1.06% (95%CI 0.97–1.16). Following conversion of regression coefficients into 0, 1, 2 or 3 points, the cumulated DIFFMASK score ranged from 0 to 18 points and the area under the receiver operating characteristic curve was 0.82. The Youden index indicated a sum score ≥ 5 as an optimal cut‐off value for prediction of difficult facemask ventilation giving a sensitivity of 85% and specificity of 59%. The DIFFMASK score indicated that a score of 6–10 points represents a population of patients who may require heightened attention when facemask ventilation is planned, compared with those patients who are obviously at a high‐ or low risk of difficulties. The DIFFMASK score may be useful in a clinical context but external, prospective validation is needed.

Airway management research: a systematic review (3)

Abstract:

Recent controversy regarding the ethics of conducting airway research in patients led to disagreements concerning the value and frequency of manikin‐based investigation. However, no formal examination of the methodology of airway research has been undertaken. We, therefore, performed a systematic bibliometric review of airway management research to describe the conduct, quantify the subjects (patient vs. manikin vs. other), assess the reported outcomes and map global trends. We retrieved 1505 relevant studies published between 2006 and 2017, together recruiting 359,648 subjects, of which 341,233 were patients, the remaining being volunteers or subjects managing manikins, human cadavers, animals or bench models. There were 701 randomised controlled clinical trials (46.6%), 83 non‐randomised experimental clinical trials (5.5%), 298 observational studies (19.8%) and 423 non‐patient studies (28.1%). A total of 1082 studies (71.9%) were patient studies and 322 were manikin studies (21.4%). The total annual number of airway management studies increased over time, as did the annual number of patient studies, but there was no significant increase in the annual number of manikin studies over time. Of the patient studies, subject baseline characteristics were most likely to be ASA status 1–2 (n = 531, 49.1%), populations were most often elective surgical patients (n = 918, 84.8%) and the most common interventions studied were tracheal intubation (n = 820, 54.4%) or supraglottic airway device insertion (n = 257, 17.1%). There was a total of 77 different primary outcomes used in the included studies, the most commonly reported being success rate and procedure time. By understanding how and what has been previously studied these data can be used to form the basis for future priority setting exercises, core outcome set development, and could inform strategy on the future directions of airway management research.

Videolaryngsocopy vs fibreoptic bronchoscopy for awake tracheal intubation: a systematic review and meta-analysis (4)

Abstract:

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.

Strategies for the prevention of airway complications – a narrative review (5)

Abstract:

Despite being infrequent, complications of airway management remain an important contributor to morbidity and mortality during anaesthesia and care of the critically ill. Developments in the last three decades have made anaesthesia safer, and this has been mirrored in the equipment and techniques available for airway management. Modern technology including novel oxygenation modalities, widespread availability of capnography, second‐generation supraglottic airway devices and videolaryngoscopy provide the tools to make airway management safer still. However, technology will only take safety so far, and non‐technical aspects of airway management are critically important for communication and decision making during airway crises, acknowledging a ‘cannot intubate, cannot oxygenate’ situation and transitioning to emergency front of neck airway. Randomised controlled trials provide little useful information about safety in this setting, and data from registries and databases are likely to be of more value. This narrative review focuses on recent evidence in this area.

Performance of emergency surgical front of neck airway access by head and neck surgeons, general surgeons, or anaesthetists: an in situ simulation study (6)

Abstract:

Background
The ‘cannot intubate cannot oxygenate’ (CICO) emergency requires urgent front of neck airway (FONA) access to prevent death. In cases reported to the 4th National Audit Project, the most successful FONA was a surgical technique, almost all of which were performed by surgeons. Subsequently, UK guidelines adopted surgical cricothyroidotomy as the preferred emergency surgical FONA technique. Despite regular skills-based training, anaesthetists may still be unwilling to perform an emergency surgical FONA. Consultant anaesthetists, head and neck surgeons, and general surgeons were compared in a high-fidelity simulated emergency. We hypothesised that head and neck surgeons would successfully execute emergency surgical FONA faster than anaesthetists and general surgeons.

Methods
We recruited 15 consultants from each specialty (total of 45) at a single tertiary care hospital in the UK. All agreed to participate in an in situ high-fidelity simulation of an ‘anaesthetic emergency’. Participants were not told in advance that this would be a CICO scenario.

Results
There were no significant differences in total time to successful ventilation between anaesthetists, head and neck surgeons and general surgeons (median 86 vs 98 vs 126 s, respectively, P=0.078). Anaesthetists completed the emergency surgical FONA procedure significantly faster than general surgeons (median 50 vs 86 s, P=0.018). Despite this strong performance, qualitative data suggested some anaesthetists still believed ‘surgeons’ best placed to perform emergency surgical FONA in a genuine CICO situation.

Conclusion
Anaesthetists 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.

Guidelines for the management of tracheal intubation in critically ill adults (7)

Abstract:

These guidelines describe a comprehensive strategy to optimize oxygenation, airway management, and tracheal intubation in critically ill patients, in all hospital locations. They are a direct response to the 4th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society, which highlighted deficient management of these extremely vulnerable patients leading to major complications and avoidable deaths. They are founded on robust evidence where available, supplemented by expert consensus opinion where it is not. These guidelines recognize that improved outcomes of emergency airway management require closer attention to human factors, rather than simply introduction of new devices or improved technical proficiency. They stress the role of the airway team, a shared mental model, planning, and communication throughout airway management. The primacy of oxygenation including pre- and peroxygenation is emphasized. A modified rapid sequence approach is recommended. Optimal management is presented in an algorithm that combines Plans B and C, incorporating elements of the Vortex approach. To avoid delays and task fixation, the importance of limiting procedural attempts, promptly recognizing failure, and transitioning to the next algorithm step are emphasized. The guidelines recommend early use of a videolaryngoscope, with a screen visible to all, and second generation supraglottic airways for airway rescue. Recommendations for emergency front of neck airway are for a scalpel–bougie–tube technique while acknowledging the value of other techniques performed by trained experts. As most critical care airway catastrophes occur after intubation, from dislodged or blocked tubes, essential methods to avoid these complications are also emphasized.

Point-of-care ultrasound (POCUS) of the upper airway (8)

Abstract:

Airway management is a critical skill in the practice of several medical specialities including anesthesia, emergency medicine, and critical care. Over the years mounting evidence has showed an increasing role of ultrasound (US) in airway management. The objective of this narrative review is to provide an overview of the indications for point-of-care ultrasound (POCUS) of the upper airway. The use of US to guide and assist clinical airway management has potential benefits for both provider and patient. Ultrasound can be utilized to determine airway size and predict the appropriate diameter of single-lumen endotracheal tubes (ETTs), double-lumen ETTs, and tracheostomy tubes. Ultrasonography can differentiate tracheal, esophageal, and endobronchial intubation. Ultrasonography of the neck can accurately localize the cricothyroid membrane for emergency airway access and similarly identify tracheal rings for US-guided tracheostomy. In addition, US can identify vocal cord dysfunction and pathology before induction of anesthesia. A rapidly growing body of evidence showing ultrasonography used in conjunction with hands-on management of the airway may benefit patient care. Increasing awareness and use of POCUS for many indications have resulted in technologic advancements and increased accessibility and portability. Upper airway POCUS has the potential to become the first-line non-invasive adjunct assessment tool in airway management.

Reintubation in the ICU following cardiac surgery: is it more difficult than first time intubation in the operating room? (9)

Abstract:

Background
After cardiac surgery, a patient's trachea is usually extubated; however, 2 to 13% of cardiac surgery patients require reintubation in the ICU.

Objective
The objective of this study was to compare the initial intubation in the cardiac operating room with reintubation (if required) in the ICU following cardiac surgery.

Design
A prospective, observational study.

Setting
Department of Anesthesiology and Intensive Care Medicine, Clinical Hospital of Santiago, Spain.

Patients
With approval of the local ethics committee, over a 44-month period, we prospectively enrolled all cardiac surgical patients who were intubated in the operating room using direct laryngoscopy, and who required reintubation later in the ICU.

Main outcome measures
The primary endpoint was to compare first-time success rates for intubation in the operating room and ICU. Secondary endpoints were to compare the technical difficulties of intubation (modified Cormack-Lehane glottic view, operator-reported difficulty of intubation, need for support devices for direct laryngoscopy) and the incidence of complications.

Results
A total of 122 cardiac surgical patients required reintubation in the ICU. Reintubation was associated with a lower first-time success rate than in the operating room (88.5 vs. 97.6%, P = 0.0048). Reintubation in the ICU was associated with a higher incidence of Cormack-Lehane grades IIb, III or IV views (34.5 vs. 10.7%, P < 0.0001), a higher incidence of moderate or difficult intubation (17.2 vs. 6.5%, P = 0.0001) and a greater need for additional support during direct laryngoscopy (20.5 vs. 10.7%, P = 0.005). Complications were more common during reintubations in the ICU (39.3 vs. 5.7%, P < 0.0001).

Conclusion
Compared with intubations in the operating room, reintubation of cardiac surgical patients in the ICU was associated with more technical difficulties and a higher incidence of complications.

A Retrospective Analysis of Neuromuscular Blocking Drug Use and Ventilation Technique on Complications in the Pediatric Difficult Intubation Registry Using Propensity Score Matching (10)

Abstract:

Background
Ventilation is critical in airway management, and failure can be fatal. The optimal ventilation approach for endotracheal intubation in children with difficult airways remains controversial. The Pediatric Difficult Intubation (PeDI) Registry is an international multicenter registry that collects intubation data in difficult to intubate children. The registry captures the initial (at induction) and final ventilation technique (at intubation), the use of neuromuscular blocking drugs (NMBDs), airway reactivity during intubation, and complications. We analyzed data in the PeDI Registry to determine the frequency of use of various ventilation techniques and associated complications. Because spontaneously breathing patients ventilate throughout intubation, we hypothesized that spontaneous ventilation would be associated with fewer complications than other approaches.

Methods
We queried the PeDI Registry for cases entered between September 2012 and February 2016, from 16 children's hospitals. We categorized the attending anesthesiologist's ventilation plan into 3 groups: spontaneous ventilation, controlled ventilation after administering an NMBD, and controlled ventilation without administering an NMBD. Generalized Estimating Equation (GEE) model, with a binomial family distribution and logit link, was used to determine the association between ventilation technique and the risk of complications, as well as to account for within-site clustering. Propensity score matching was further applied to balance pretreatment characteristics of ventilation groups.

Results
Of 1289 anticipated difficult intubations, 507 (39%) were managed with spontaneous ventilation, 453 (35%) controlled ventilation with an NMBD, and 329 (26%) controlled ventilation without an NMBD. Complications occurred in 242 (18.8%; 95% confidence interval [CI], 16.6%-20.9%) patients. Of these, 218 (16.9%) were nonsevere, and 24 (1.9%) were severe. The spontaneous ventilation group had 114 (22.5%, standardized residual [Std.Res] = 4.29) nonsevere complications, which was higher than the controlled ventilation with an NMBD 60 (13.3%, Std.Res = -2.58), and controlled ventilation without an NMBD 44 (13.4%, Std.Res = -1.98), P < .001. Nearest neighbor matching with caliper width equal to 0.2 of the standard deviation (SD) of the logit of the propensity score also demonstrated that patients with spontaneous ventilation had greater odds of complications compared to controlled ventilation techniques: odds ratio (OR) = 2.07 (95% CI, 1.36-3.15; P = .001).

Conclusion
Spontaneous ventilation is associated with more nonsevere complications, such as hypoxemia and laryngospasm, than controlled ventilation techniques during intubation of children with difficult airways. Inadequate anesthetic depth may contribute to increased complications.

Videolaryngsocopy for Physician-Based, Prehospital Emergency Intubation: A Prospective, Randomized, Multicenter Comparison of Different Blade Types Using A.P. Advance, C-MAC System and King Vision (11)

Abstract:

Videolaryngoscopy is a valuable technique for endotracheal intubation. When used in the perioperative period, different videolaryngoscopes vary both in terms of technical use and intubation success rates. However, in the prehospital environment, the relative performance of different videolaryngoscopic systems is less well studied. METHODS: We conducted this prospective, randomized, multicenter study at 4 German prehospital emergency medicine centers. One hundred sixty-eight adult patients requiring prehospital emergency intubation were treated by an emergency physician and randomized to 1 of 3 portable videolaryngoscopes (A.P. Advance, C-MAC PM, and channeled blade KingVision) with different blade types. The primary outcome variable was overall intubation success and secondary outcomes included first-attempt intubation success, glottis visualization, and difficulty with handling the devices. P values for pairwise comparisons are corrected by the Bonferroni method for 3 tests (P[BF]). All presented P values are adjusted for center. RESULTS: Glottis visualization was comparable with all 3 devices. Overall intubation success for A.P. Advance, C-MAC, and KingVision was 96%, 97%, and 61%, respectively (overall: P < .001, A.P. Advance versus C-MAC: odds ratio [OR], 0.97, 95% confidence interval [CI], 0.13-7.42, P[BF] > 0.99; A.P. Advance versus KingVision: OR, 0.043, 95% CI, 0.0088-0.21, P[BF] < 0.001; C-MAC versus KingVision: OR, 0.043, 95% CI, 0.0088-0.21, P[BF] < 0.001). Intubation success on the first attempt with A.P. Advance, C-MAC, and KingVision was 86%, 85%, and 48%, respectively (overall: P < .001, A.P. Advance versus C-MAC: OR, 0.89, 95% CI, 0.31-2.53, P[BF] > 0.99; A.P. Advance versus KingVision: OR, 0.24, 95% CI, 0.055-0.38, P[BF] = 0.0054; C-MAC versus KingVision: OR, 0.21, 95% CI, 0.043-.34, P[BF] < 0.003). Direct laryngoscopy for successful intubation with the videolaryngoscopic device was necessary with the A.P. Advance in 5 patients, and with the C-MAC in 4 patients. In the KingVision group, 21 patients were intubated with an alternative device. CONCLUSIONS: During prehospital emergency endotracheal intubation performed by emergency physicians, success rates of 3 commercially available videolaryngoscopes A.P. Advance, C-MAC PM, and KingVision varied markedly. We also found that although any of the videolaryngoscopes provided an adequate view, actual intubation was more difficult with the channeled blade KingVision. 

References

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(2) Lundstrøm, L.H., Rosenstock, C.V., Wetterslev, J. and Nørskov, A.K. (2019), The DIFFMASK score for predicting difficult facemask ventilation: a cohort study of 46,804 patients. Anaesthesia, 74: 1267-1276. doi:10.1111/anae.14701

(3) Ahmad, I., Onwochei, D.N., Muldoon, S., Keane, O. and El‐Boghdadly, K. (2019), Airway management research: a systematic review. Anaesthesia, 74: 225-236. doi:10.1111/anae.14471

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(5) Cook, T.M. (2018), Strategies for the prevention of airway complications – a narrative review. Anaesthesia, 73: 93-111. doi:10.1111/anae.14123

(6) Peter Groom, Louise Schofield, Natasha Hettiarachchi, Samuel Pickard, Jeremy Brown, John Sandars, Ben Morton,Performance of emergency surgical front of neck  airway access by head and neck surgeons, general surgeons, or anaesthetists: an in situ simulation study, British Journal of Anaesthesia,Volume 123, Issue 5,2019, Pages 696-703,

(7) A. Higgs, B.A. McGrath, C. Goddard, J. Rangasami, G. Suntharalingam, R. Gale, T.M. Cook, Guidelines for the management of tracheal intubation in critically ill adults, British Journal of Anaesthesia,Volume 120, Issue 2, 2018, Pages 323-352,

(8) You-Ten, K.E., Siddiqui, N., Teoh, W.H. et al. Can J Anesth/J Can Anesth (2018) 65: 473. https://doi-org.ezproxy.anzca.edu.au/10.1007/s12630-018-1064-8

(9) Taboada, Manuel; Rey, Raul; Martinez, Susana; Soto-Jove, Rosa; Miron, Paula; Selas, Salome; Eiras, Maria; Martinez, Adrian; Rial, Maria; Carinena, Agustin; Rodriguez, Irene; Veiras, Sonia; Alvarez, Julian; Baluja, Aurora; Atanassoff, Peter G. Reintuation in the ICU following cardiac surgery: is it more difficult than first-time intubatino in the operating room. EJA (2020) 37 (1) 25 – 0

(10) Annery G. et al. A Retrospective Analysis of Neuromuscular Blocking Drug Use and Ventilation Technique on Complications in the Pediatric Difficult Intubation Registry Using Propensity Score Matching. Anaesthesia & Analgesia (2019) September

(11) Erol Cavus et al. Videolaryngsocopy for Physician-Based, Prehospital Emergency Intubation: A Prospective, Randomized, Multicenter Comparison of Different Blade Types Using A.P. Advance, C-MAC System and King Vision. Anaesthesia & Analgesia (2018), 126 (5): 1565 - 1574