Innovative (and Safe) Techniques With Supraglottic Airways.

ABSTRACT: Supraglottic airways have been utilized as an alternative to facemask ventilation and endotracheal intubation and thus have been essential to airway management since their introduction in the late 1980s. This chapter describes basic considerations in their use and an update on current clinical practice, with an emphasis on safe management. The devices have evolved to meet today's clinical airway challenges, and they provide benefits for patients and practitioners.

Development and Evaluation of the Advanced Joint Airway Management System for Educational Utility in Endotracheal Intubation, as Assessed by Expert Paramedic Instructors.

INTRODUCTION: Between 2011 and 2014, The Combat Casualty Training Consortium research study sought to evaluate all aspects of combat casualty care, including mortality, with a special focus on the incidence and causes of potentially preventable deaths among U.S. combat fatalities. This study identified a major training gap in critical airway management. To address this gap, the Advanced Joint Airway Management System (AJAMS) was designed and assessed for physical fidelity and educational utility in a population of paramedic instructors. MATERIALS AND METHODS: Paramedic instructors served as participants in this prospective observational pilot study (n = 12). Participants interacted with three airway management trainers: The AJAMS trainer, the Laerdal Airway Management Trainer, and the TruCorp AirSim Advance Bronchi X Trainer. Participants then completed an evaluation of the trainer using a purpose-built data collection instrument that queried the trainer's realism and educational utility. Within-group differences were analyzed via a 1-way repeated measures ANOVA, with a Bonferroni post hoc analysis. Rank data were analyzed via non-parametric Freidman's test, and Wilcoxon signed-rank test post hoc analysis, corrected using the Bonferroni correction. RESULTS: The AJAMS trainer conveys significantly more physical fidelity (visual: P < .001, ηp2 = 0.977; tactile: P < .001, ηp2 = 0.983; and behavioral: P = .001, ηp2 = 0.971) and overall educational utility (χ2(2) = 15.273, P < .001) than the two commercially available skill trainers. CONCLUSIONS: These data suggest that physical fidelity is an important attribute in the design of simulators for health care, as perceived by expert instructors. These data illustrate that the AJAMS-integrated simulator demonstrates unparalleled physical fidelity, relative to commercially available airway management skill trainers.

Endotracheal Intubation Performance in Novices: Comparing the Training Effect Resulting From Two Airway Management Training Simulators.

INTRODUCTION: Between 2011 and 2014, the Combat Casualty Training Consortium research study sought to evaluate all aspects of combat casualty care, including mortality, with a special focus on the incidence and causes of potentially preventable deaths among American combat fatalities. This study identified a major training gap in critical airway management. Because of the high rate of morbidity and mortality associated with poor or incorrect airway management, an effort to address this training gap was necessary. MATERIALS AND METHODS: This experiment compared the training using the Advanced Joint Airway Management System, a novel high-fidelity airway simulator, relative to one of the most utilized simulators for endotracheal intubation (ETI) via a parallel group randomized control trial design. Before training, participants (n = 19) attempted an ETI on a cadaver using direct laryngoscopy. Performance during the attempt was recorded and scored by trained blinded raters. Participants were then randomly allocated to either novel or conventional training. Post-training, participants completed a second ETI under the same parameters. Analysis was completed via 2 × 2 mixed analysis of variance for (1) ETI Score, (2) Errors, (3) Critical Failures, and (4) Duration, across both the pre- and post-training tests and between the two groups. RESULTS: A priori power analysis required a total sample size of 84 participants in this experimental design. Consequently, this study is under-powered to reach statistical significance. Scores for all trainees did improve with training, yet analyses did not reveal a difference in overall ETI score between the novel and conventional training group, at baseline or at the post-training test (P = .249). CONCLUSION: The Advanced Joint Airway Management System simulator presents a training effect that is comparable to the conventional training model. However, given this study's small sample size, these results must be considered preliminary and further research is merited to draw firm conclusions about its impact on trainee performance. Future studies engaging larger cohorts of trainees and exploring the other capabilities of the Advanced Joint Airway Management System (cricothyroidotomy, needle chess decompression) are needed to further examine the educational potential of this novel airway management training system.

A new video laryngoscope combined with flexible laryngeal mask insertion: A prospective randomized study.

BACKGROUND: The video laryngoscope (VLS) has been proven to be an effective insertion device for airway management. However, no laryngoscope has been specifically designed for the placement of the laryngeal mask airway (LMA). We improved the current VLS and developed a novel VLS method. This study aimed to evaluate the clinical efficacy of an improved VLS for inserting a flexible laryngeal mask airway (F-LMA) compared with the standard blind method. METHODS: One hundred and fifty-seven patients who underwent F-LMA insertion under general anesthesia were randomly assigned to either the standard blind insertion technique (group B) or VLS -assisted insertion (group VL). First attempt success rates were recorded. Secondary outcomes included oropharyngeal leakage pressure (OLP), fiberoptic view, insertion time, position adjustment, reinsertion rate, and postoperative airway morbidity. RESULTS: The first-attempt success rate was higher in group VL than that in group B (99% vs. 86%; p = 0.002). The OLP was significantly higher in the VLS-guided technique (26.4 ± 5.1 vs 23.8 ± 4.4 cmH2O, p = 0.002). The fiberoptic view was significantly better in the group VL (p < 0.001) and required less readjustment and reinsertion to establish an effective airway (p < 0.001). The insertion time was shorter in the group B than that in group VL (33.9 vs 41.3 s, p < 0.001). Hemodynamic stress responses and postoperative airway complications did not differ between the two groups. CONCLUSIONS: The new VLS-guided insertion technology has a high success rate, achieves greater OLP, and provides an ideal anatomical position with minimal adjustment, without increasing the risk of hemodynamic stress or adverse events. TRIAL REGISTRATION: Chinese Clinical Trial Registry (registration number: ChiCTR2300075866; https://www.chictr.org.cn).

Tracheal tube introducer-associated airway trauma: a systematic review.

BACKGROUND: Tracheal tube introducers are recommended in airway management guidelines and are used increasingly as videolaryngoscopy becomes more widespread. This systematic review aimed to summarise the published literature concerning tracheal tube introducer-associated airway trauma. METHODS: PubMed, EMBASE and CINAHL databases were searched using pre-determined criteria. Two authors independently assessed search results and performed data extraction and risk of bias assessments. RESULTS: We included 16 randomised controlled trials and five observational studies involving 10,797 patients. There was heterogeneity in patient characteristics, airway manipulation, and airway trauma definition and measurement. One study investigated hyperangulated videolaryngoscopy. The standard stylet was the most commonly reported introducer, followed by bougie and stylets with additional features such as video or lighted tip. Airway trauma resulted in low harm and most frequently involved injuries to the upper airway, followed by laryngeal and tracheobronchial injuries. Eighteen studies were comparative and reported a reduction in airway trauma incidence when an introducer was used, with the exception of the standard stylet. Median (IQR [range]) pooled incidence of airway trauma associated with standard stylets was 13.1% (4.2-31.4 [0.5-79.2])% and with bougies was 5.4% (0.4-49.9 [0.0-68.0])%. The risk of bias of included studies was variable and many randomised trials were found to be at high risk due to non-robust measurement of the outcome. CONCLUSIONS: Stylets might be associated with an increased risk of airway trauma compared with other devices or when no stylet was used, though the quality of evidence is modest. However, other introducers appear to be safe and reduce the risk of airway trauma.

The role of supraglottic airway devices for caesarean section under general anaesthesia. A scoping literature review with a proposed algorithm for the appropriate use of supraglottic airway devices for caesarean sections.

This review aims to assess the published evidence on airway management with a supraglottic airway device (SGA) for general anaesthesia in patients requiring a caesarean section. Physiological changes during pregnancy can make airway management in parturients challenging. At the same time, pregnant patients are at risk of pulmonary aspiration due to hormonal and mechanical alterations. The standard airway management for parturients undergoing caesarean section is rapid sequence induction followed by tracheal intubation. Evidence exists that using second-generation SGA devices is well tolerated and effective in selected patients. In this review, we provide an overview of the existing evidence and provide an algorithm to make an evidence-based clinical decision on the use of SGA devices. An online literature search was performed in Medline, Embase, PubMed, Emcare, Cochrane Library and CINAHL. The search terms used were 'supraglottic airway', 'supraglottic airway device', 'supraglottic airway management', 'supraglottic tube', 'i-gel', laryngeal mask', 'laryngeal mask airway', 'LMA', 'SGA', 'Proseal', 'Supreme', 'obstetric surgery', 'obstetric operation', 'general anaesthesia', 'caesarean' or 'caesarean section', 'abdominal delivery'. Full-text articles in English, Dutch and French were included. Case reports and studies in which the surgery was not a caesarean section were excluded. The initial search yielded 815 results. Following screening, deduplication and removal of publications that were unrelated to the topic or did not fit the inclusion criteria, 13 manuscripts were included in our analysis. A total of 7722 patients were described in the articles included. In the majority of manuscripts, second-generation SGA devices were used. There were seven cases of failed insertion and a need for conversion to tracheal intubation; first-generation SGA devices were used in these cases. There were no cases of pulmonary aspiration, and only one case of gastric regurgitation was described. Growing evidence suggests that the use of second-generation SGA devices might be well tolerated as the primary method for securing the airway for caesarean sections requiring general anaesthesia, in selected patients with a low risk for aspiration and difficult intubation.

Effect of different lung recruitment strategies and airway device on oscillatory mechanics in children under general anaesthesia.

BACKGROUND: Atelectasis has been reported in 68 to 100% of children undergoing general anaesthesia, a phenomenon that persists into the recovery period. Children receiving recruitment manoeuvres have less atelectasis and fewer episodes of oxygen desaturation during emergence. The optimal type of recruitment manoeuvre is unclear and may be influenced by the airway device chosen. OBJECTIVE: We aimed to investigate the different effects on lung mechanics as assessed by the forced oscillation technique (FOT) utilising different recruitment strategies: repeated inflations vs. one sustained inflation and different airway devices, a supraglottic airway device vs. a cuffed tracheal tube. DESIGN: Pragmatic enrolment with randomisation to the recruitment strategy. SETTING: We conducted this single-centre trial between February 2020 and March 2022. PARTICIPANTS: Seventy healthy patients (53 boys) aged between 2 and 16 years undergoing general anaesthesia were included. INTERVENTIONS: Forced oscillations (5 Hz) were superimposed on the ventilator waveform using a customised system connected to the anaesthesia machine. Pressure and flow were measured at the inlet of the airway device and used to compute respiratory system resistance and reactance. Measurements were taken before and after recruitment, and again at the end of surgery. MAIN OUTCOME MEASURES: The primary endpoint measured is the change in respiratory reactance. RESULTS: Statistical analysis (linear model with recruitment strategy and airway device as factors) did not show any significant difference in resistance and reactance between before and after recruitment. Baseline reactance was the strongest predictor for a change in reactance after recruitment: prerecruitment Xrs decreased by mean (standard error) of 0.25 (0.068) cmH 2 O s l -1 per  1 cmH 2 O -1  s l -1 increase in baseline Xrs ( P  < 0.001). After correcting for baseline reactance, the change in reactance after recruitment was significantly lower for sustained inflation compared with repeated inflation by mean (standard error) 0.25 (0.101) cmH 2 O ( P  = 0.0166). CONCLUSION: Although there was no significant difference between airway devices, this study demonstrated more effective recruitment via repeated inflations than sustained inflation in anaesthetised children. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12619001434189.

Hyperangulated vs. Macintosh videolaryngoscopy in adults with anticipated difficult airway management: a randomised controlled trial.

BACKGROUND: It is not certain whether the blade geometry of videolaryngoscopes, either a hyperangulated or Macintosh shape, affects glottic view, success rate and/or tracheal intubation time in patients with expected difficult airways. We hypothesised that using a hyperangulated videolaryngoscope blade would visualise a higher percentage of glottic opening compared with a Macintosh videolaryngoscope blade in patients with expected difficult airways. METHODS: We conducted an open-label, patient-blinded, randomised controlled trial in adult patients scheduled to undergo elective ear, nose and throat or oral and maxillofacial surgery, who were anticipated to have a difficult airway. All airway operators were consultant anaesthetists. Patients were allocated randomly to tracheal intubation with either hyperangulated (C-MAC D-BLADE™) or Macintosh videolaryngoscope blades (C-MAC™). The primary outcome was the percentage of glottic opening. First attempt success was designated a key secondary outcome. RESULTS: We assessed 2540 adults scheduled for elective head and neck surgery for eligibility and included 182 patients with expected difficult airways undergoing orotracheal intubation. The percentage of glottic opening visualised, expressed as median (IQR [range]), was 89 (69-99 [0-100])% with hyperangulated videolaryngoscope blades and 54 (9-90 [0-100])% with Macintosh videolaryngoscope blades (p < 0.001). First-line hyperangulated videolaryngoscopy failed in one patient and Macintosh videolaryngoscopy in 12 patients (13%, p = 0.002). First attempt success rate was 97% with hyperangulated videolaryngoscope blades and 67% with Macintosh videolaryngoscope blades (p < 0.001). CONCLUSIONS: Glottic view and first attempt success rate were superior with hyperangulated videolaryngoscope blades compared with Macintosh videolaryngoscope blades when used by experienced anaesthetists in patients with difficult airways.

A Simpler Method for Choosing Adult i-gel Size: An Evaluation of Real-World Prehospital Data.

OBJECTIVE: The i-gel supraglottic airway device (Intersurgical, Berkshire, UK) is commonly used in the United States and worldwide for prehospital airway management. Previous research has suggested that a sex-based method of size selection (4.0 for female patients and 5.0 for male patients) is superior to a weight-based method in patients undergoing elective anesthesia. Our objective was to compare a sex-based i-gel size selection strategy with a weight-based strategy using real-world prehospital data. METHODS: The ESO Data Collaborative 2018 to 2022 dataset was used. All initial i-gel insertion attempts in patients > 18 years of age were evaluated for inclusion. Insertion attempts were excluded if age, sex, weight, success, or device size was not documented. Logistic regression was used to compare the rate of insertion failure on the first attempt for the group placed in alignment with the weight-based but not sex-based method with the group placed in alignment with the sex-based but not weight-based method. RESULTS: After the application of the exclusion criteria, 39,867 initial i-gel insertion attempts were included. The overall rate of failure was 6.5% (2,585/39,867). The rate of unsuccessful i-gel placement was similar when i-gel devices were placed in alignment with a sex-based size selection method in comparison to i-gel placement in alignment with a weight-based selection strategy (6.0% vs. 6.4%). Logistic regression analysis did not reveal a significant difference between groups (odds ratio: 1.08; 95% confidence interval: 0.95-1.23). CONCLUSION: The use of a sex-based method of i-gel size selection may be equivalent with respect to the rate of unsuccessful i-gel placement on the first attempt in comparison to a weight-based method.

Comparison of video laryngoscope, video stylet, and flexible videoscope for transoral endotracheal intubation in patients with difficult airways: a randomized, parallel-group study.

BACKGROUND: The 2022 ASA guidelines recommend the video laryngoscope, video stylet, and flexible videoscope as airway management tools. This study aims to compare the efficacy of three airway devices in intubating patients with difficult airways. METHODS: A total of 177 patients were selected and randomized into the following three groups: the video laryngoscope group (Group VL, n = 59), video stylet group (Group VS, n = 59), and flexible videoscope group (Group FV, n = 59). The success rate of the first-pass intubation, time of tracheal intubation, level of glottic exposure, and occurrence of intubation-related adverse events were recorded and analyzed. RESULTS: All patients were successfully intubated with three devices. The first-pass intubation success rate was significantly higher in Groups VS and FV than in Group VL (96.61% vs. 93.22% vs. 83.05%, P < 0.01), but it was similar in the first-pass intubation success rate between Groups VS and FV(P > 0.05). The number of patients categorized as Wilson-Cormack-Lehane grade I-II was fewer in Group VL than in Groups VS and FV (77.97% vs. 98.30% vs. 100%, P = 0.0281). The time to tracheal intubation was significantly longer in Group FV(95.20 ± 4.01) than in Groups VL(44.56 ± 4.42) and VS(26.88 ± 4.51) (P < 0.01). No significant differences were found among the three groups in terms of adverse intubation reactions (P > 0.05). CONCLUSIONS: In patients with difficult airways requiring intubation, use of the video stylet has the advantage of a relatively shorter intubation time, and the flexible videoscope and video stylet yield a higher first-pass intubation success rate and clearer glottic exposure than the use of the video laryngoscope. TRIAL REGISTRATION: Chinese Clinical Trial Registry. No: ChiCTR2200061560, June 29, 2022.

Use of a gum elastic bougie in a cat with severe upper airway stenosis.

Background: Gum elastic bougie (GEB) is an airway management device for patients who are difficult to intubate and its use has been reported in human medicine. However, to our knowledge, no reports in veterinary medicine have described oxygenation using GEB. We describe a case in which GEB was used to maintain oxygenation in a cat with severe upper airway stenosis. Case Description: A 10-year-old neutered male domestic shorthair cat was diagnosed with a laryngeal tumor with severe upper airway stenosis. During anesthesia induction, the normal laryngeal structure could not be confirmed; orotracheal intubation was difficult, resulting in a "cannot intubate, cannot oxygenate" status. The GEB was inserted, making it possible to oxygenate the cat until a permanent tracheostoma could be created, but hypoventilation was noted. Conclusion: Although GEB are not useful for proper ventilation, they can be useful for temporary oxygenation in veterinary medicine when airway management is difficult.

COMBINED USE OF VIDEOLARYNGOSCOPE AND BONFILS INTUBATION ENDOSCOPE AS RESCUE OPTION FOR DIFFICULT AIRWAY MANAGEMENT: A CASE REPORT.

Difficult airway management poses a great challenge for clinicians, especially if it is unanticipated. Numerous guidelines and a wide array of devices constitute the anesthesiologist's armamentarium for managing the airway. When the use of individual devices fails, the use of combination techniques is advised. We present a case of difficult intubation in a 50-year-old male patient scheduled for aortic valve replacement. He had no prior history of difficult airway management, and no abnormalities were detected on preoperative airway assessment. Body mass index was 29 kg/m2. After the separate use of direct laryngoscopy, videolaryngoscopy and a BONFILS intubation endoscope (BIE) had failed, we resorted to a combination technique, combining videolaryngoscopy and BIE. While the videolaryngoscope provided the space needed for BIE and visual guidance through copious secretions, the BIE served as a stylet for endotracheal tube guidance, leading to successful intubation. Since the technique requires costly equipment, experience in handling it and at least two operators, it is more appropriate as a rescue measure than an elective procedure. Given the potentially disastrous outcomes of failed intubation, mastering advanced airway management techniques remains of vital importance, and the combination technique is one of them.

Comparison of Vie Scope® and Macintosh laryngoscopes for intubation during resuscitation by paramedics wearing personal protective equipment.

BACKGROUND: Endotracheal intubation (ETI) is still the gold standard of airway management, but in cases of sudden cardiac arrest in patients with suspected SARS-CoV-2 infection, ETI is associated with risks for both the patient and the medical personnel. We hypothesized that the Vie Scope® is more useful for endotracheal intubation of suspected or confirmed COVID-19 cardiac arrest patients than the conventional laryngoscope with Macintosh blade when operators are wearing personal protective equipment (PPE). METHODS: Study was designed as a prospective, multicenter, randomized clinical trial performed by Emergency Medical Services in Poland. Patients with suspected or confirmed COVID-19 diagnosis who needed cardiopulmonary resuscitation in prehospital setting were included. Patients under 18 years old or with criteria predictive of impossible intubation under direct laryngoscopy, were excluded. Patients were randomly allocated 1:1 to Vie Scope® versus direct laryngoscopy with a Macintosh blade. Study groups were compared on success of intubation attempts, time to intubation, glottis visualization and number of optimization maneuvers. RESULTS: We enrolled 90 out-of-hospital cardiac arrest (OHCA) patients, aged 43-92 years. Compared to the VieScope® laryngoscope, use of the Macintosh laryngoscope required longer times for tracheal intubation with an estimated mean difference of -48 s (95%CI confidence interval [CI], -60.23, -35.77; p < 0.001). Moreover VieScope® improved first attempt success rate, 93.3% vs. 51.1% respectively (odds ratio [OR] = 13.39; 95%CI: 3.62, 49.58; p < 0.001). CONCLUSIONS: The use of the Vie Scope® laryngoscope in OHCA patients improved the first attempt success rate, and reduced intubation time compared to Macintosh laryngoscope in paramedics wearing PPE for against aerosol generating procedures. TRIAL REGISTRATION: ClinicalTrials registration number NCT04365608.

Formation of an Airway Lead Network: an essential patient safety initiative.

We outline the history, implementation and clinical impact of the formation of an Airway Lead Network. Although recommendations to improve patient safety in airway management are published and revised regularly, uniform implementation of such guidelines are applied sporadically throughout the hospital and prehospital settings. The primary roles of an Airway Lead are to ensure supply, quality and storage of airway equipment, promote the use of current practice guidelines as well as the organisation of training and audits. Locally, the Airway Lead may chair a multi-disciplinary airway committee within their organisation; an Airway Lead Network enables Airway Leads to share common problems and solutions to promote optimal airway management on a national level. Support from governing bodies is an essential part of this structure.

An assessment of introducers used for airway management.

Different introducers are available to assist with tracheal intubation. Subtle differences in the design of introducers can have a marked effect on safety and performance. The Difficult Airway Society's Airway Device Evaluation Project Team proposal states that devices should only be purchased for which there is at least a case-control study on patients assessing airway devices. However, resources are not currently available to carry out a case-control study on all introducers available on the market. This study comprised a laboratory and manikin-based investigation to identify introducers that could be suitable for clinical investigation. We included six different introducers in laboratory-based assessments (design characteristics) and manikin-based assessments involving the participation of 30 anaesthetists. Each anaesthetist attempted placement in the manikin's trachea with each of the six introducers in a random order. Outcomes included first-time insertion success rate; insertion success rate; number of attempts; time to placement; and distance placed. Each anaesthetist also completed a questionnaire. First-time insertion success rate depended significantly on the introducer used (p = 0.0016) and varied from 47% (Armstrong and P3) to 77% (Intersurgical and Frova). Median time to placement (including oesophageal placement) varied from 10 s (Eschmann and Frova) to 20 s (P3) (p = 0.0025). Median time to successful placement in the trachea varied from 9 s (Frova) to 22 s (Armstrong) (p = 0.037). We found that the Armstrong and P3 devices were not as acceptable as other introducers and, without significant improvements to their design and characteristics, the use of these devices in studies on patients is questionable. The study protocol is suitable for differentiating between different introducers and could be used as a basis for assessing other types of devices.