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.

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.

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.

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.

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.

Intubation using VieScope vs. Video laryngoscopy in full personal protective equipment - a randomized, controlled simulation trial.

BACKGROUND: VieScope is a new type of laryngoscope, with a straight, transparent and illuminated blade, allowing for direct line of sight towards the larynx. In addition, VieScope is disposed of after single patient use, which can avoid cross-contaminations of contagious material. This has gained importance especially when treating patients with highly contagious infectious diseases, such as during the SARS-CoV2 pandemic. In this context, VieScope has not been evaluated yet in a clinical study. MATERIAL AND METHODS: This study compared intubation with VieScope to video-laryngoscopy (GlideScope) in normal and difficult airway in a standardized airway manikin in a randomized controlled simulation trial. Thirty-five medical specialists were asked to perform endotracheal intubation in full personal protective equipment (PPE). Primary endpoint was correct tube position. First-pass rate (i.e., success rate at the first attempt), time until intubation and time until first correct ventilation were registered as secondary endpoints. RESULTS: For correct tracheal tube placement, there was no significant difference between VieScope and GlideScope in normal and difficult airway conditions. VieScope had over 91% fist-pass success rate in normal airway setting. VieScope had a comparable success rate to GlideScope in difficult airway, but had a significantly longer time until intubation and time until ventilation. CONCLUSION: VieScope and GlideScope had high success rates in normal as well as in difficult airway. There was no unrecognized esophageal intubation in either group. Overall time for intubation was longer in the VieScope group, though in an acceptable range given in literature. Results from this simulation study suggest that VieScope may be an acceptable alternative for tracheal intubation in full PPE. TRIAL REGISTRATION: The study was registered at the German Clinical Trials Register www.drks.de (Registration date: 09/11/2020; TrialID: DRKS00023406 ).

All-fiber probes for endoscopic optical coherence tomography of the large airways.

Endoscopic optical coherence tomography of large airways poses unique challenges. A hybrid lens is described that consists of a section of coreless fiber and graded index fiber (GIF), followed by a ball lens section. This design produces low numerical aperture beams better suited for large airway imaging. The performance of this lens is compared against conventional GIF and ball lens designs. Forward- and side-viewing probes were modeled, fabricated, and tested. The impact of a sheath on the beam profile was also investigated. Probes with working distances larger than 10 mm and depth-of-focus exceeding 12 mm are demonstrated with the proposed design.

Airway Management in Surgical Patients With Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder, and the difficult airway is perhaps the anesthesiologists' quintessential concern. OSA and the difficult airway share certain similar anatomical, morphological, and physiological features. Individual studies and systematic reviews of retrospective, case-control, and large database studies have shown a likely association between patients with OSA and the difficult airway; OSA patients have a 3- to 4-fold higher risk of difficult intubation, difficult mask ventilation, or a combination of both. The presence of OSA should initiate proactive perioperative management in anticipation of a difficult airway. Prudent intraoperative management comprises the use of regional anesthesia where possible and considering an awake intubation technique where there is the presence of notable difficult airway predictors and risk of rapid desaturation following induction of general anesthesia. Familiarity with difficult airway algorithms, cautious extubation, and appropriate postoperative monitoring of patients with OSA are necessary to mitigate perioperative risks.

First Pass Success Without Adverse Events Is Reduced Equally with Anatomically Difficult Airways and Physiologically Difficult Airways.

INTRODUCTION: The goal of emergency airway management is first pass success without adverse events (FPS-AE). Anatomically difficult airways are well appreciated to be an obstacle to this goal. However, little is known about the effect of the physiologically difficult airway with regard to FPS-AE. This study evaluates the effects of both anatomically and physiologically difficult airways on FPS-AE in patients undergoing rapid sequence intubation (RSI) in the emergency department (ED). METHODS: We analyzed prospectively recorded intubations in a continuous quality improvement database between July 1, 2014-June 30, 2018. Emergency medicine (EM) or emergency medicine/pediatric (EM-PEDS) residents recorded patient, operator, and procedural characteristics on all consecutive adult RSIs performed using a direct or video laryngoscope. The presence of specific anatomically and physiologically difficult airway characteristics were also documented by the operator. Patients were analyzed in four cohorts: 1) no anatomically or physiologically difficult airway characteristics; 2) one or more anatomically difficult airway characteristics; 3) one or more physiologically difficult airway characteristics; and 4) both anatomically and physiologically difficult airway characteristics. The primary outcome was FPS-AE. We performed a multivariable logistic regression analysis to determine the association between anatomically difficult airways or physiologically difficult airways and FPS-AE. RESULTS: A total of 1513 intubations met inclusion criteria and were analyzed. FPS-AE for patients without any difficult airway characteristics was 92.4%, but reduced to 82.1% (difference = -10.3%, 95% confidence interval (CI), -14.8% to -5.6%) with the presence of one or more anatomically difficult airway characteristics, and 81.7% (difference = -10.7%, 95% CI, -17.3% to -4.0%) with the presence of one or more physiologically difficult airway characteristics. FPS-AE was further reduced to 70.9% (difference = -21.4%, 95% CI, -27.0% to -16.0%) with the presence of both anatomically and physiologically difficult airway characteristics. The adjusted odds ratio (aOR) of FPS-AE was 0.37 [95% CI, 0.21 - 0.66] in patients with anatomically difficult airway characteristics and 0.36 [95% CI, 0.19 - 0.67] for patients with physiologically difficult airway characteristics, compared to patients with no difficult airway characteristics. Patients who had both anatomically and physiologically difficult airway characteristics had a further decreased aOR of FPS-AE of 0.19 [95% CI, 0.11 - 0.33]. CONCLUSION: FPS-AE is reduced to a similar degree in patients with anatomically and physiologically difficult airways. Operators should assess and plan for potential physiologic difficulty as is routinely done for anatomically difficulty airways. Optimization strategies to improve FPS-AE for patients with physiologically difficult airways should be studied in randomized controlled trials.

A prospective observational study comparing two supraglottic airway devices in out-of-hospital cardiac arrest.

BACKGROUND: Airway management in patients with out of hospital cardiac arrest (OHCA) is important and several methods are used. The establishment of a supraglottic airway device (SAD) is a common technique used during OHCA. Two types of SAD are routinely used in Norway; the Kings LTS-D™ and the I-gel®. The aim of this study was to compare the clinical performance of these two devices in terms of difficulty, number of attempts before successful insertion and overall success rate of insertion. METHODS: All adult patients with OHCA, in whom ambulance personnel used a SAD over a one-year period in the ambulance services of Central Norway, were included. After the event, a questionnaire was completed and the personnel responsible for the airway management were interviewed. Primary outcomes were number of attempts until successful insertion, by either same or different ambulance personnel, and the difficulty of insertion graded by easy, medium or hard. Secondary outcomes were reported complications with inserting the SAD's. RESULTS: Two hundred and fifty patients were included, of whom 191 received I-gel and 59 received LTS-D. Overall success rate was significantly higher in I-gel (86%) compared to LTS-D (75%, p = 0.043). The rates of successful placements were higher when using I-gel compared to LTS-D, and there was a significant increased risk that the insertion of the LTS-D was unsuccessful compared to the I-gel (risk ratio 1.8, p = 0.04). I-gel was assessed to be easy to insert in 80% of the patients, as opposed to LTS-D which was easy to insert in 51% of the patients. CONCLUSIONS: Overall success rate was significantly higher and the difficulty in insertion was significantly lower in the I-gel group compared to the LTS-D in patients with OHCA.

Perception of level of knowledge, skills, and safety before and after training to perform videolaryngoscopy with the Intubox barrier system for airway management in patients with COVID-19. / Grado de percepción sobre el conocimiento, las habilidades y la seguridad antes y después de un programa de entrenamiento con videolaringoscopia y mecanismo de protección Intubox® en el manejo de la vía aérea de pacientes con COVID-19.

OBJECTIVES: The main objective was to describe physicians' perception of their knowledge, skill, and safety before and after training to perform videolaryngoscopy while using the Intubox barrier system when managing the airway of a patient with the coronavirus 2019 disease (COVID-19). The secondary objective was to assess the safety afforded by the barrier by means of visually evaluating particle dispersion during intubation. MATERIAL AND METHODS: Single-arm clinical simulation trial. The participants were physicians who received training in both a lowfidelity and a high-fidelity simulation zone. The participants assessed their knowledge, skill, and safety when using the Intubox before and after training using a specially designed and validated questionnaire. Droplet contamination was estimated visually. RESULTS: Twenty-seven physicians with a mean (SD) age of 40 (10.8) years participated; 63% were women. They perceived their knowledge, skill, and safety to be significantly higher after training. Droplet contamination was seen to decrease when airway management maneuvers were done with the barrier in place. CONCLUSION: After simulation training the emergency physicians judged their knowledge, skill, and safety to be greater when they used the barrier during airway management in patients with COVID-19. The combined use of a laryngoscope and the Intubox barrier resulted in less particle dispersion during intubation.

OBJETIVO: El objetivo principal fue describir el grado de percepción sobre el conocimiento, las habilidades y la seguridad antes y después de un programa de entrenamiento con videolaringoscopia y mecanismo de protección Intubox® en el manejo de la vía aérea de pacientes con COVID-19. El objetivo secundario fue evaluar la seguridad de los dispositivos de barrera en la intubación a través de un análisis visual de dispersión de partículas. METODO: Ensayo clínico de un solo brazo basado en simulación. Los participantes fueron médicos que realizaron un programa de formación mediante simulación clínica de baja y alta fidelidad. Se usó un instrumento diseñado y validado específico para evaluar la percepción sobre el conocimiento, las habilidades y la seguridad antes y después del programa. Se realizó un análisis visual de la contaminación por gotas. RESULTADOS: La muestra final estuvo compuesta por 27 médicos, con una edad media de 40 (DE 10,8) años y el 63% mujeres. Se obtuvo un incremento estadísticamente significativo en las dimensiones conocimiento, habilidad y seguridad tras el entrenamiento. Se observó una menor contaminación cuando se realizaron las técnicas de manejo de vía aérea con urna protectora. CONCLUSIONES: Los urgenciólogos incrementaron su percepción sobre los conocimientos, habilidades y seguridad en el manejo de la vía aérea en pacientes con COVID-19 tras un programa de formación con simulación. El uso combinado de laringoscopia y dispositivo de barrera Intubox® causó menor dispersión de partículas durante la intubación.