Feasibility of continuous bronchoscopy during exercise in the assessment of large airway movement in healthy subjects.

Excessive dynamic airway collapse (EDAC) is a recognized cause of exertional dyspnea arising due to invagination of the trachea and/or main bronchi. EDAC is typically assessed by evaluating large airway movement with forced expiratory maneuvers. This differs from the respiratory response to exercise hyperpnea. We aimed to evaluate large airway movement during physical activity, with continuous bronchoscopy during exercise (CBE), in healthy subjects and compare findings with resting bronchoscopic maneuvers and imaging techniques. Twenty-eight individuals were recruited to complete two visits including treadmill-based CBE, to voluntary exhaustion, and cine magnetic resonance imaging (MRI) with forced expiratory maneuvers at rest. Twenty-five subjects [aged 29 (26-33) yr, 52% female] completed the study (n = 2 withdrew before bronchoscopy, and one was unable to tolerate insertion of bronchoscope). The majority (76%) achieved a peak heart rate of >90% predicted during CBE. The procedure was prematurely terminated in five subjects (n = 3; elevated blood pressure and n = 2; minor oxygen desaturation). The CBE assessment enabled adequate tracheal visualization in all cases. Excessive dynamic airway collapse (tracheal collapse ≥50%) was identified in 16 subjects (64%) on MRI, and in six (24%) individuals during resting bronchoscopy, but in no cases with CBE. No serious adverse events were reported, but minor adverse events were evident. The CBE procedure permits visualization of large airway movement during physical activity. In healthy subjects, there was no evidence of EDAC during strenuous exercise, despite evidence during forced maneuvers on imaging, thus challenging conventional approaches to diagnosis.NEW & NOTEWORTHY This study demonstrates that large airway movement can be visualized with bronchoscopy undertaken during vigorous exercise. This approach does not require sedation and permits characterization of the behavior of the large airways and the tendency toward collapse during upright, ambulatory exercise. In healthy individuals, the response pattern of the large airways during exercise appears to differ markedly from the pattern of airway closure witnessed during forced expiratory maneuvers, assessed via imaging.

Artificial Intelligence for Assessment of Endotracheal Tube Position on Chest Radiographs: Validation in Patients From Two Institutions.

BACKGROUND. Timely and accurate interpretation of chest radiographs obtained to evaluate endotracheal tube (ETT) position is important for facilitating prompt adjustment if needed. OBJECTIVE. The purpose of our study was to evaluate the performance of a deep learning (DL)-based artificial intelligence (AI) system for detecting ETT presence and position on chest radiographs in three patient samples from two different institutions. METHODS. This retrospective study included 539 chest radiographs obtained immediately after ETT insertion from January 1 to March 31, 2020, in 505 patients (293 men, 212 women; mean age, 63 years) from institution A (sample A); 637 chest radiographs obtained from January 1 to January 3, 2020, in 302 patients (157 men, 145 women; mean age, 66 years) in the ICU (with or without an ETT) from institution A (sample B); and 546 chest radiographs obtained from January 1 to January 20, 2020, in 83 patients (54 men, 29 women; mean age, 70 years) in the ICU (with or without an ETT) from institution B (sample C). A commercial DL-based AI system was used to identify ETT presence and measure ETT tip-to-carina distance (TCD). The reference standard for proper ETT position was TCD between greater than 3 cm and less than 7 cm, determined by human readers. Critical ETT position was separately defined as ETT tip below the carina or TCD of 1 cm or less. ROC analysis was performed. RESULTS. AI had sensitivity and specificity for identification of ETT presence of 100.0% and 98.7% (sample B) and 99.2% and 94.5% (sample C). AI had sensitivity and specificity for identification of improper ETT position of 72.5% and 92.0% (sample A), 78.9% and 100.0% (sample B), and 83.7% and 99.1% (sample C). At a threshold y-axis TCD of 2 cm or less, AI had sensitivity and specificity for critical ETT position of 100.0% and 96.7% (sample A), 100.0% and 100.0% (sample B), and 100.0% and 99.2% (sample C). CONCLUSION. AI identified improperly positioned ETTs on chest radiographs obtained after ETT insertion as well as on chest radiographs obtained of patients in the ICU at two institutions. CLINICAL IMPACT. Automated AI identification of improper ETT position on chest radiographs may allow earlier repositioning and thereby reduce complications.

Effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults: a retrospective cephalometric assessment.

Background: This study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment. Methods: This retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson's correlation test (alpha = 0.05). Results: A significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P < 0.001), which was correlated with the magnitude of retraction of upper and lower incisors (r = 0.6 - 0.8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0.001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0.001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r = 0.4 - 0.6). Conclusion: According to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions.

Role of ultrasonography in upper airway assessment: A comparison with computerized tomography measurements.

INTRODUCTION: This study aimed to compare ultrasonography (US) measurements of the upper airway to computerized tomography (CT) measurements. Our study's primary outcome is to research the accuracy of US measurements in the evaluation of upper airway diameters when CT is taken as the gold standard; the secondary outcome is to determine the time required to obtain US measurements. METHODS: This prospective study included patients ≥18 years old that had undergone thoracic or neck CT due to current clinical necessity. The US measurement for each patient was performed by two researchers with different levels of experience, both of whom were blinded to each other and the CT measurements. Measurements were obtained from the vocal cords and subglottic region. The duration of the US performance was also recorded. RESULTS: The US and CT measurements were obtained from 94 patients. Concordance between US and CT measurements was found in the Bland-Altman analysis, with a mean -0.05 mm difference for vocal cord diameter and -1.2 mm for subglottic diameter. The intra-class correlation coefficients (ICC) between the CT and US measurements were 0.993, and 0.609 for vocal cord and subglottic diameter measurements, respectively. The ICC between US performers was 0.992 for vocal cord diameter and 0.959 for subglottic diameter. The US's mean time for vocal cord diameter measurement was 38 ± 23 s, and the mean time for subglottic diameter measurement was 49 ± 30 s. CONCLUSION: The concordance between US and CT measurements is high and the measurements of different practitioners with different experience levels are compatible with each other.

Ultrasound assessment of endotracheal tube depth in neonates: a prospective feasibility study.

OBJECTIVE: To examine the reliability of a novel ultrasound (US) method for assessment of endotracheal tube (ETT) position in neonates. DESIGN: Prospective, observational, single-centre, feasibility study. SETTING: Level III neonatal intensive care unit. PATIENTS: Term and preterm neonates requiring endotracheal intubation. INTERVENTION: US measurement of the ETT tip to right pulmonary artery (RPA) distance was used to determine ETT position according to one-fourth to three-fourths estimated tracheal length for weight. US demonstration of pleural sliding and diaphragmatic movement was also assessed. Chest radiography (CXR) was performed following each intubation. MAIN OUTCOME MEASURES: Agreement between US assessment of ETT tip position and CXR served as the gold standard. Sensitivity, specificity, positive and negative predictive values for each US method and correlation between ETT tip to RPA distance on US, and ETT tip to carina distance on CXR were assessed. RESULTS: Forty-two US studies were performed on 33 intubated neonates. US evaluation of ETT-RPA distance identified 100% of ETTs positioned correctly: 77% deep and 80% high, demonstrating strong agreement with CXR (kappa=0.822). Sensitivity was 78%, specificity 100%, positive predictive value 100% and negative predictive value 86%. US ETT-RPA distance strongly correlated with CXR ETT-carina distance (r=0.826). No significant agreement was found between CXR and US assessment of pleural sliding and diaphragmatic movement. No adverse events were encountered during US scans. CONCLUSION: US evaluation of ETT-RPA distance demonstrated excellent accuracy for determining ETT position in neonates compared with CXR. More research is needed to support its feasibility in clinical settings.

Socioeconomic Influence on Speech Rehabilitation After Total Laryngectomy.

OBJECTIVE: Speech rehabilitation following a total laryngectomy significantly impacts the quality of life. Indwelling prosthetic voice restoration provides optimal outcomes; however, the long-term maintenance of these devices carries considerable financial costs, which are not universally covered by insurance. This investigation aimed to analyze associations between socioeconomic factors and outcomes in postlaryngectomy speech rehabilitation. STUDY DESIGN: Retrospective cohort analysis. SETTING: Academic tertiary-care center from May 2014 to September 2021. METHODS: In patients undergoing total laryngectomy, the incidence of tracheoesophageal puncture with indwelling vocal prostheses (TEP-VP) placement within the first postoperative year was compared among household income, demographic factors, and disease characteristics. Functional and maintenance outcomes served as secondary endpoints. RESULTS: Seventy-seven patients were included. Forty-five (58%) underwent indwelling TEP-VP (41 primaries). Eighty-nine percent of patients with annual incomes greater than $50k underwent TEP-VP compared to only 35% with incomes less than $50k/year. TEP-VP was performed in 85% of patients with commercial insurance, 70% with Medicare, 42% with Medicaid, and 0% with no insurance. On multivariate analysis, annual household incomes greater than $50k were predicted for TEP-VP placement (odds ratio: 12.7 [2.45-65.8], p = .002). The utilization of postoperative speech therapy and functional communication outcomes were similar among socioeconomic groups. Twelve patients were unable to afford supplies within the first year, with differences noted among insurance (p = .015) and income status (p = .003). CONCLUSION: Disparities in vocal and speech rehabilitation following laryngectomy may disproportionally affect underserved patients.

[Difficult Airway Management (DAM) Algorithms - A narrative synopsis and site assessment]. / Algorithmen zum Atemwegsmanagement.

Centuries ago an "algorithm" was originally inaugurated to depicture a pathway to solve mathematical problems using a decision tree. Nowadays this tool is also well established in clinical medicine. Ever since management errors in difficult airway handling and subsequent litigations remain high referring to ASA closed claims database. However, even since 2010, the ESA postulates every institution dealing with airway management should have a DAM algorithm (ESA Declaration of Helsinki on Patient Safety in Anaesthesiology). In 2018 a systematic review of 38 international DAM algorithms was published; most of them show a four-step flow chart: failed tracheal intubation, insufficient bag-mask ventilation and supraglottic airway, leads to establish an emergency sugical airway. In conclusion authors state that a universal, globally valid, DAM algorithm is lacking. German language guideline development is governed by the AWMF, which labels guidelines with the highest evidence levels and methodological strength "S3". The ASA published a revised DAM practice guideline in 2022, which was developed by 13 international members and was endorsed by international anesthesiological societies. - Though it is based on a systematic literature search and evaluation, final recommendations (without grading) were generated by a survey among experts in the field: Pre-procedural evaluation of the airway is essential; meanwhile more data are available especially regarding ultrasound examination of the upper airway and in 2022 a promising nomogram was developed for the prediction of difficult laryngoscopy. Pre-procedural planning of expected DAM: it should be decided beforehand, if awake intubation is feasible for the patient. Preoxygenation of every elective patient (3 mins with PEEP 5 cmH2O, aim: 95% pulse oxymetry) and continuous nasal high-flow oxygen delivery during airway management. In case of unexpectedly difficult/emergency airway, ASA recommends: call for help, use cognitive aid (algorithm), consider restoration of spontaneous breathing, adjust bag-mask ventilation, monitor time passing; if "cannot intubate, cannot oxygenate" situation occurs (etCO2 < 10 mmHg, < 80% pulse oxymetry) establish surgical airway; if failed consider ECMO therapy, if feasible and available. ASA restricts intubation attempts to 3+ based on experience and decision of the clinician, however evidence shows, that attempts should not exceed 2 attempts to avoid serious complications, e.g. hyoxemia and even cardiopulmonary resuscitation (CPR). Additionally, we recommend a cockpit strategy for airway management using crisis resource elements as used in aviation (situation awareness, sterile communication, read-back/hear-back and canned decisions) and a supervisor/team leader as already established in CPR. Last, but not least, continuous airway management training increases algorithm adherence.

Plugging membranes after fetoscopy in congenital diaphragmatic hernia: early cost-effectiveness analysis.

OBJECTIVES: Fetal endoscopic tracheal occlusion (FETO) improves neonatal survival of fetuses with congenital diaphragmatic hernia (CDH). However, FETO also increases the risk of preterm prelabor rupture of membranes (PPROM) and preterm delivery (PTD), as fetal membrane defects after fetoscopy do not heal. To solve this issue, an advanced sealing plug for closing the membrane defect is being developed. Using early-stage health economic modeling, we aimed to estimate the potential value of this innovative plug in terms of costs and effects, and to determine the properties required for it to become cost-effective. METHODS: Early-stage health economic modeling was applied to the case of performing FETO in women with a singleton pregnancy whose fetus is diagnosed prenatally with CDH. We simulated a cohort of patients using a state-transition model over a 45-year time horizon. In our best-case-scenario analysis, we compared the current-care strategy with the perfect-plug strategy, which reduces the risk of PPROM and PTD by 100%, to determine the maximum quality-adjusted life years (QALYs) gained and costs saved. Using threshold analysis, we determined the minimum percentage reduction in the risk of PPROM and PTD required for the plug to be considered cost-effective. The impact of model parameters on outcome was investigated using a sensitivity analysis. RESULTS: Our model indicated that a perfect-plug strategy would yield on average an additional 1.94 QALYs at a cost decrease of €2554 per patient. These values were influenced strongly by the percentage of cases with early PTD (27-34 weeks). Threshold analysis showed that, for €500 per plug, the plug strategy needs a minimum percentage reduction of 1.83% in the risk of PPROM and PTD (i.e. reduction in the risk from 47.50% to 46.63% for PPROM and from 71.50% to 70.19% for PTD) to be cost-effective. CONCLUSIONS: Our model-based approach showed clear potential of the plug strategy when applied in the context of FETO for CDH fetuses, as only a minor reduction in the risk of PPROM and PTD is needed for the plug to be cost-effective. Its value is expected to be even higher when used in conditions associated with a higher rate of early PTD. Continued investment in research and development of the plug strategy appears to provide value for money. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Computational assessment of upper airway muscular activity in obstructive sleep apnea - In vitro validation.

Neuromuscular control of the upper airway contributes to obstructive sleep apnea (OSA). An accurate, non-invasive method to assess neuromuscular function is needed to improve surgical treatment outcomes. Currently, surgical approaches for OSA are based on airway anatomy and are often not curative. When the airway surface moves, the power transferred between air in the airway lumen and the structures of the upper airway may be a measure of airway neuromuscular activity. The aim of this study was to validate power transfer as a measure of externally applied forces, representing neuromuscular activity, through cine computed tomography (CT) imaging and computational fluid dynamics (CFD) analysis in a 3D-printed airway model. A hollow elastic airway model was manufactured. An insufflation/exsufflation device generated airflow within the model lumen. The model was contained in an airtight chamber that could be positively or negatively pressurized to represent muscular forces. These forces were systematically applied to dilate and collapse the model. Cine CT imaging captured airway wall movement during respiratory cycles with and without externally applied forces. Power transfer was calculated from the product of wall movement and internal aerodynamic pressure forces using CFD simulations. Cross-correlation peaks between power transfer and changes in externally applied pressure during exhalation and inhalation were -0.79 and 0.95, respectively. Power transfer calculated via cine CT imaging and CFD was an accurate surrogate measure of externally applied forces representing airway muscular activity. In the future, power transfer may be used in clinical practice to phenotype patients with OSA and select personalized therapies.

Computational fluid dynamics assessment of congenital tracheal stenosis.

PURPOSE: The severity of congenital tracheal stenosis (CTS) is commonly evaluated based on the degree of stenosis. However, it does not always reflect the clinical respiratory status. We applied computational fluid dynamics (CFD) to the assessment of CTS. The aim of this study was to evaluate its validity. METHODS: CFD models were constructed on 15 patients (12 preoperative models and 15 postoperative models) with CTS before and after surgery, using the computed tomographic data. Energy flux, needed to drive airflow, measured by CFD and the minimum cross-sectional area of the trachea (MCAT) were quantified and evaluated retrospectively. RESULTS: The energy flux correlated positively with the clinical respiratory status before and after surgery (rs = 0.611, p = 0.035 and rs = 0.591, p = 0.020, respectively). Although MCAT correlated negatively with the clinical respiratory status before surgery (rs = -0.578, p = 0.044), there was not significant correlation between the two after surgery (p = 0.572). CONCLUSIONS: The energy flux measured by CFD assessment reflects the respiratory status in CTS before and after surgery. CFD can be an additional objective and quantitative evaluation tool for CTS.

The Burden of Trachea, Bronchus, and Lung Cancer Attributable to Occupational Exposure From 1990 to 2019.

Objectives: Occupational exposure to carcinogens is associated with trachea, bronchus, and lung (TBL) cancer. The objective of this study was to provide global and regional estimates of the burden of TBL cancer associated with occupational carcinogens (OCs) between 1990 and 2019. Methods: Age-standardized mortality rates (ASMR) and age-standardized disability-adjusted life years (DALYs) rates (ASDR) of TBL cancer related to exposure to OCs at the global and regional levels were extracted for 1990-2019 from the Global Burden of Disease 2019. Joinpoint regression was used to analyze trends in the ASMR and ASDR of TBL cancer burden related to OCs, and the annual percent change and the average annual percent change (AAPC) were recorded. Results: The mortality from TBL cancer related to exposure to OCs increased globally. The ASMR and ASDR decreased in both sexes and in men between 1990 and 2019. The AAPC of ASMR and ASDR decreased in men between 1990 and 2019, but increased in women. Asbestos accounted for the highest death number and beryllium accounted for the lowest; diesel engine exhaust caused the largest percentage change in death number (145.3%), in ASDR (14.9%), and in all ages DALY rates (57.6%). Asbestos accounted for the largest death number in high social development index (SDI) countries, whereas low-middle SDI countries had the largest percent change (321.4%). Asbestos was associated with decreased ASDR in high SDI countries and increased ASDR in low-middle SDI countries, and similar changes were observed for other OCs. Conclusions: The overall mortality and DALYs of TBL cancer burden related to OCs showed a decreasing trend between 1990 and 2019, whereas death number increased. Asbestos accounted for the highest death number. TBL cancer burden related to OCs decreased to different degrees in high, low, low-middle, and middle SDI countries, which showed variable levels of TBL cancer burden related to exposure to OCs (except asbestos).

Multiparametric CT-based assessment of pretracheal anatomical relationships for safe tracheotomy: A long-forgotten issue revisited.

OBJECTIVES: To assess the anatomical relationships and variations in the pretracheal space and to guide tracheotomy procedures in a safe manner with image-based evidence. MATERIALS AND METHODS: A retrospective study was conducted on unirradiated patients requiring elective tracheotomies. Preoperative contrast-enhanced CT (CECT)/CT venography (CTV) was applied for an anatomical evaluation of the pretracheal region. Vascular morphologies were compared for three vessels: the anterior jugular vein (AJV), the innominate artery (IA) and the inferior thyroid vascular plexus (ITVP). The relationships between the thyroid isthmus and the 2nd-4th tracheal rings were also analyzed. RESULTS: A total of 120 patients were identified, most of whom (n = 110, 91.7%) had head and neck squamous cell carcinomas. Patients with recognizable AJVs (n = 118) were divided into 3 groups: single-branch (n = 11, 9.2%), double-branch (n = 105, 87.5%), and multibranch (n = 2, 1.7%). In addition, IAs were categorized as low-bifurcation (n = 51, 42.5%), high-bifurcation (n = 40, 33.3%), platform (n = 27, 22.5%) and variant types (n = 2, 1.7%). Within the platform types, high-lying IAs (n = 15, 8.3%) might have interfered with the standard tracheal incisions due to possible IA-tracheal overlay. This interference was also related to the height of intraoperative tracheal incisions (rn = 0.364, P = 0.001). Within ITVPs, independent-trunk types were found in 71 cases (59.2%), while common-trunk types were found in 45 (37.5%). In addition, a low thyroid isthmus (suprasternal-isthmus distance <3 cm) was found in 83 cases (69.2%). CONCLUSIONS: CT image-based evidence can prepare junior practitioners with important pretracheal anatomical information, thereby facilitating safer tracheotomy procedures. Our results shed light on vascular relationships for emergent tracheotomy.

Radiographic vertical tracheal diameter assessment at different levels along the trachea as an alternative method for the evaluation of the tracheal diameter in non-brachycephalic small breed dogs.

BACKGROUND: Tracheal narrowing due to congenital tracheal hypoplasia, acquired tracheal stenosis and tracheal collapse can lead to life-threatening respiratory distress. Tracheal hypoplasia has been identified in brachycephalic dog breeds, predominantly English Bulldogs, by measuring the tracheal diameter compared to the diameter of the thoracic inlet and creating a ratio. However, reference ranges for tracheal diameter have not been established for non-brachycephalic small breed dogs. It would be advantageous to have established tracheal diameters for non-brachycephalic small breed dogs, as these are the dogs most at risk of tracheal collapse. The main objective, of this study was to radiographically evaluate vertical tracheal diameter (VTD) at three standardized locations along the trachea of non-brachycephalic small breed dogs, in an attempt to further establish a screening diagnostic protocol for canine tracheal hypoplasia. Medical records and thoracic radiographs of non-brachycephalic small breed dogs without respiratory disease were reviewed. Right lateral radiographs were reviewed. The absolute and average VTDs at three locations (location A: caudal cervical VTD; location B thoracic inlet VTD; location C: intrathoracic VTD) were standardized by manubrium length (ML), as well as by the previously utilized thoracic inlet distance (Ti-D) and proximal 3rd rib width (PR3-W) to calculate manubrium-tracheal index (M-TI), thoracic inlet-tracheal index (Ti-TI), and proximal R3-tracheal score (PR3-TS), respectively. Correlations between averaged tracheal diameter and each of the ML, Ti-D, and PR3-W, and between M-TI and each of Ti-TI and PR3-TS were calculated. RESULTS: Eighty-one healthy dogs met the criteria for inclusion. Significant differences (P < 0.0001) were identified among the mean values of the absolute and standardized VTDs at levels A, B, and C. The smallest tracheal diameter was identified at the level of the thoracic inlet (Level B). The average VTD correlated better with ML (rs = 0.82, P < 0.0001) compared to Ti-D and PR3-W. A relatively strong correlation (rs = 0.77, P < 0.0001) was identified between the averaged manubrium tracheal index (M-TI) and thoracic inlet tracheal index (Ti-TI). CONCLUSION: M-TI is an appropriate alternative to Ti-TI and PR3-TS to radiographically evaluate VTD in dogs. M-TI < 0.43, < 0.34, or < 0.38 at level A, B, or C, respectively, may indicate tracheal hypoplasia in non-brachycephalic small breed dogs. Screening of canine VTD could be achieved using M-TI.

Step-by-step development and evaluation of a 3D printed home-made low-cost pediatric tracheobronchial tree for foreign body aspiration extractions.

OBJECTIVES: The management of foreign body aspirations (FBA) is dreaded by pediatric physicians due to the high risk of respiratory distress and a potential fatal outcome, favored by a lack of experience of young specialists. Furthermore, there has been an increasing requirement for low-cost simulation. The aim was to describe the step-by-step manufacturing process and to validate a low-cost, easily home-made training model of pediatric tracheo-bronchial tree (pTBT) for simulation-based training in order to teach young physicians to practice foreign body (FBA) extractions. METHODS: A simulator was designed in order to reproduce the physical and esthetic properties of a pTBT. The production cost of a single simulator was estimated. The simulator was then tested by experienced physicians using a rigid bronchoscope. A manufacturing manual of the simulator is hereby presented. A group of 7 experienced pediatric otolaryngologists performed a FBA extraction in the conditions of installation of an operating room. RESULTS: The result of the survey showed a high fidelity of the simulator in mimicking the biological esthetics and physical properties of a pTBT during a FBA extraction (mean 4.3 ± 0.8). The total cost of the custom-made simulator is about 20.5 € ($23.4) for the production of the first simulator. CONCLUSIONS: A highly realistic and easily reproducible pediatric tracheo-bronchial tree simulator is presented and can therefore be used during simulation-based training.

Experimental Assessment of Cuff Pressures on the Walls of a Trachea-Like Model Using Force Sensing Resistors: Insights for Patient Management in Intensive Care Unit Settings.

The COVID-19 outbreak has increased the incidence of tracheal lesions in patients who underwent invasive mechanical ventilation. We measured the pressure exerted by the cuff on the walls of a test bench mimicking the laryngotracheal tract. The test bench was designed to acquire the pressure exerted by endotracheal tube cuffs inflated inside an artificial model of a human trachea. The experimental protocol consisted of measuring pressure values before and after applying a maneuver on two types of endotracheal tubes placed in two mock-ups resembling two different sized tracheal tracts. Increasing pressure values were used to inflate the cuff and the pressures were recorded in two different body positions. The recorded pressure increased proportionally to the input pressure. Moreover, the pressure values measured when using the non-armored (NA) tube were usually higher than those recorded when using the armored (A) tube. A periodic check of the cuff pressure upon changing the body position and/or when performing maneuvers on the tube appears to be necessary to prevent a pressure increase on the tracheal wall. In addition, in our model, the cuff of the A tube gave a more stable output pressure on the tracheal wall than that of the NA tube.

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.

Using Deep Learning Segmentation for Endotracheal Tube Position Assessment.

PURPOSE: The purpose of this study was to determine the efficacy of using deep learning segmentation for endotracheal tube (ETT) position on frontal chest x-rays (CXRs). MATERIALS AND METHODS: This was a retrospective trial involving 936 deidentified frontal CXRs divided into sets for training (676), validation (50), and 2 for testing (210). This included an "internal test" set of 100 CXRs from the same institution, and an "external test" set of 110 CXRs from a different institution. Each image was labeled by 2 radiologists with the ETT-carina distance. On the training images, 1 radiologist manually segmented the ETT tip and inferior wall of the carina. A U-NET architecture was constructed to label each pixel of the CXR as belonging to either the ETT, carina, or neither. This labeling allowed the distance between the ETT and carina to be compared with the average of 2 radiologists. The interclass correlation coefficients, mean, and SDs of the absolute differences between the U-NET and radiologists were calculated. RESULTS: The mean absolute differences between the U-NET and average of radiologist measurements were 0.60±0.61 and 0.48±0.47 cm on the internal and external datasets, respectively. The interclass correlation coefficients were 0.87 (0.82, 0.91) and 0.92 (0.88, 0.94) on the internal and external datasets, respectively. CONCLUSION: The U-NET model had excellent reliability and performance similar to radiologists in assessing ETT-carina distance.

Congenital Aortic Vascular Ring: In-Utero Sonographic Assessment of Tracheal Patency and Postnatal Outcome.

OBJECTIVE: Congenital aortic vascular ring may present after birth with variable degrees of respiratory distress due to tracheal compression. The aim of this study was to prospectively evaluate in utero tracheal patency in correlation with postnatal outcome. METHODS: During an eight-year period, fetuses with aortic arch abnormality encircling the trachea and forming a complete ring were recruited for the study. Tracheal patency was classified as: no compression, partial compression, or complete compression. Postnatal MRI/CTangio studies were performed and outcome data was retrospectively analyzed from the medical records. RESULTS: Among the 46 fetuses recruited to the study, 38 had right aortic arch (RAA), and 8 presented with double aortic arch (DAA). In the RAA group 35 (92.1 %) of the fetuses presented no compression and 34 (97.1 %) of them were asymptomatic in the long-term follow-up. Three fetuses (7.9 %) in this group presented in utero compression: one was terminated at 16 weeks of gestation due to associated ominous findings, and the other two had mild respiratory symptoms around 12 months of age and underwent surgery with a good outcome. In the DAA group, all fetuses presented in utero with tracheal compression. Seven showed partial and one complete compression. Among the seven with partial compression, six were symptomatic and underwent surgery. The case with severe airway occlusion had emergency tube insertion in the delivery room and underwent surgery at 7 days but died from severe respiratory complications. CONCLUSION: This is the first study to evaluate in utero tracheal patency in cases with vascular ring. It allows better prenatal and postnatal workup and follow-up including potentially life-threatening respiratory failure.