Pitfalls in Respiratory Tract Cytopathology.

BACKGROUND: Cytopathology is integral to the investigation and diagnosis of respiratory disease, and, in the last decade or so, transbronchial needle aspiration by endobronchial ultrasound has made possible diagnosis and staging of malignant thoracic tumours at a single procedure. In addition, interventional teams increasingly include cytopathologists and cytotechnologists who, by providing rapid onsite evaluation, ensure efficient sampling of intrathoracic targets with the ultimate goal of accurate diagnosis as well as sufficient material for comprehensive predictive testing. Nonetheless, "traditional" cytological investigations such as bronchial washings, brushings, and lavages are still carried out for investigation of both suspected neoplastic and non-neoplastic conditions, and all these procedures still produce specimens in which florid benign cells mimic malignancy, while truly neoplastic cells lurk quietly in the background. Furthermore, even when neoplasia is not suspected, issues in preparation and interpretation may render a final assessment inaccurate and, therefore, clinically unhelpful or misleading. In this overview, we have tried to adopt a format partly modelled on the passage of a specimen from clinical acquisition to laboratory endpoint, thus taking in potential pitfalls in communication, clinical interaction, transport, and clinic-based preparation, as well as in morphology, immunocytochemistry, and suitability for predictive testing. It is not exhaustive but highlights areas that may frequently be encountered or are part of our personal experience. SUMMARY: The account highlights potential pitfalls in respiratory cytopathology at key stages of the process from acquisition to reporting and presents these in both flow diagram and tabular form. We hope this is useful for the increasingly collaborative roles of cytotechnologist and cytopathologist and their wider involvement in the clinical investigative teams. KEY MESSAGES: Correct clinical and radiological information is crucially important and promotes the correct acquisition and processing of cytopathological specimens. Cross-discipline collaborative working ensures the most efficient use of the specimen such that diagnoses and predictive tests are performed on optimal material, reducing the potential for misinterpretation. Nonetheless, even with optimal material, morphological mimics and atypical antigen expression may mislead and render accurate diagnosis challenging.

Effect of Electronic Cigarette Liquid pH on Retention of 11C-Nicotine in a Respiratory Tract Model.

INTRODUCTION: Based on our preliminary 11C-nicotine positron emission tomography (PET) imaging studies in humans, we speculated that greater deposition of nicotine in the respiratory tract from electronic cigarettes compared to combustible cigarettes could result from the alkaline pH of typical aerosol-producing electronic cigarette liquids (e-liquids). To address this hypothesis, we assessed the effect of e-liquid pH on the retention of nicotine in vitro using 11C-nicotine, PET, and a human respiratory tract model of nicotine deposition. AIMS AND METHODS: A single 2-second 35-mL puff was delivered to a human respiratory tract cast from a 2.8-Ohm cartomizer at 4.1 volts. Immediately after the puff, a 2-second 700-mL air wash-in volume was administered. E-liquids (glycerol and propylene glycol 50/50 vol/vol) containing 24 mg/mL nicotine were mixed with 11C-nicotine. Deposition (retention) of nicotine was assessed using a GE Discovery MI DR PET/CT scanner. Eight e-liquids with different pH values (range 5.3-9.6) were investigated. All experiments were performed at room temperature and at a relative humidity of 70%-80%. RESULTS: Retention of nicotine in the respiratory tract cast was pH dependent and the pH-sensitive component of the retention was well described by a sigmoid curve. In total, 50% of the maximal pH-dependent effect was observed at pH 8.0, which is close to the pKa2 of nicotine. CONCLUSIONS: The retention of nicotine in the respiratory tract conducting airways is dependent on the e-liquid pH. Lowering the e-liquid pH reduces retention of nicotine. Nonetheless, reduction of the pH below 7 has little effect, consistent with the pKa2 of protonated nicotine. IMPLICATIONS: Similar to combustible cigarettes, the retention of nicotine in the human respiratory tract from consumption of electronic cigarettes may have some health consequences and affect nicotine dependence. Here we demonstrated that the retention of nicotine in the respiratory tract is dependent on the e-liquid pH, and lowering pH reduces retention of nicotine in conducting airways of the respiratory tract. Therefore, e-cigarettes with low pH values would result in reduced respiratory tract nicotine exposure and faster delivery of nicotine to the central nervous system (CNS). The latter can be associated with e-cigarette abuse liability and the effectiveness of e-cigarettes as substitutes for combustible cigarettes.

Respiratory Tract Deposition of E-Cigarette Particles.

Total and regional deposition of inhaled electronic cigarette (E-cig) particles in the respiratory tract (RT) depends on both physical properties of the inhaled particles and biological factors of users, for example, breathing pattern or puff profile, airway anatomy, and regional ventilation. Accurate particle sizing of E-cig aerosols is essential for predicting particle deposition in the RT. Studies using a variety of sizing methods have shown mass median aerodynamic diameters ranging from 0.2 to 1.2 um and secondary count diameters in the ultrafine range (<0.1 µm). Incorporating these particle sizes into a multiple-path particle dosimetry (MPPD) model shows 10% to 45% total lung deposition by mass and 30% to 80% for ultrafine particles depending on the breathing patterns. These predictions are consistent with experimental measures of deposition fraction of submicron and ultrafine particles. While box-mod-type E-cig devices allow for full "direct-lung" inhalations of aerosol, the more recent pod-based, and disposable E-cigs (e.g., JUUL, Puff Bar, Stig) deliver the aerosol as a "mouth-to-lung" puff, or bolus, that is inhaled early in the breath followed to various degrees by further inhalation of ambient air. Measurement of realistic ventilation patterns associated with these various devices may further improve deposition predictions. Finally, while in vivo measures of RT deposition present a challenge, a recent methodology to radiolabel E-cig particles may allow for such measurements by gamma scintigraphy. Supported by NIH/NHLBI R01HL139369. © 2022 American Physiological Society. Compr Physiol 12: 1-10, year.

Multi-disciplinary management of patients with benign airway strictures: A review.

Histologically benign airway strictures are frequently misdiagnosed as asthma or COPD and may present with severe symptoms including respiratory failure. A clear understanding of pathophysiology and existing classification systems is needed to determine the appropriate treatment options and predict clinical course. Clinically significant airway strictures can involve the upper and central airways extending from the subglottis to the lobar airways. Optimal evaluation includes a proper history and physical examination, neck and chest computed tomography, pulmonary function testing, endoscopy and serology. Available treatments include medical therapy, endoscopic procedures and open surgery which are based on the stricture's extent, location, etiology, morphology, severity of airway narrowing and patient's functional status. The acuity of the process, patient's co-morbidities and operability at the time of evaluation determine the need for open surgical or endoscopic interventions. The optimal management of patients with benign airway strictures requires the availability, expertise and collaboration of otolaryngologists, thoracic surgeons and interventional pulmonologists. Multidisciplinary airway teams can facilitate accurate diagnosis, guide management and avoid unnecessary procedures that could potentially worsen the extent of the disease or clinical course. Implementation of a complex airway program including multidisciplinary clinics and conferences ensures that such collaboration leads to timely, patient-centered and evidence-based interventions. In this article we outline algorithms of care and illustrate therapeutic techniques based on published evidence.

Clinical Prediction Models for Suspected Pediatric Foreign Body Aspiration: A Systematic Review and Meta-analysis.

Importance: Although various clinical prediction models (CPMs) have been described for diagnosing pediatric foreign body aspiration (FBA), to our knowledge, there is still no consensus regarding indications for bronchoscopy, the criterion standard for identifying airway foreign bodies. Objective: To evaluate currently available CPMs for diagnosing FBA in children. Data Sources: Performed in Ovid MEDLINE, Ovid Embase, PubMed, Web of Science, and CINAHL database with citation searching of retrieved studies. Study Selection: Prediction model derivation and validation studies for diagnosing FBA in children were included. Exclusion criteria included adult studies; studies that included variables that were not available in routine clinical practice and outcomes for FBA were not separate or extractable. Data Extraction and Synthesis: We followed the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modeling Studies and the Prediction Model Risk of Bias Assessment Tool framework. Data were pooled using a random-effects model. Main Outcomes and Measures: The primary outcome was the diagnosis of FBA as confirmed by bronchoscopy. Characteristics of CPMs and individual predictors were evaluated. The final model presentation with available measures of performance was provided by narrative synthesis. A meta-analysis of individual predictor variables and prediction models was performed. Results: After screening 4233 articles, 7 studies (0.2%; 1577 patients) were included in the final analysis. There were 6 model derivation studies and 1 validation study. Air trapping (odds ratio [OR], 8.3; 95% CI, 4.4-15.5), unilateral reduced air entry (OR, 4.8; 95% CI, 3.5-6.5), witnessed choking (OR, 3.1; 95% CI, 1.0-9.6), wheezing (OR, 2.5; 95% CI, 1.2-5.2), and suspicious findings suggestive of FBA on radiography (OR, 18.5; 95% CI, 5.0-67.7) were the most commonly used predictor variables. Model performance varied, with discrimination scores (C statistic) ranging from 0.74 to 0.88. The pooled weighted C statistic score of all models was 0.86 (95% CI, 0.80-0.92). All studies were deemed to be at high risk of bias, with overfitting of models and lack of validation as the most pertinent concerns. Conclusions and Relevance: This systematic review and meta-analysis suggests that existing CPMs for FBA in children are at a high risk of bias and have not been adequately validated. No current models can be recommended to guide clinical decision-making. Future CPM studies that adhere to recognized standards for development and validation are required.

Airway Sensory Nerve Density Is Increased in Chronic Cough.

Rationale: Chronic cough is characterized by frequent urges to cough and a heightened sensitivity to inhaled irritants. Airway sensory nerves trigger cough. We hypothesized that sensory nerve density is increased in chronic cough, which may contribute to excessive and persistent coughing.Objectives: To measure airway nerve density (axonal length) and complexity (nerve branching, neuropeptide expression) in humans with and without chronic cough.Methods: Bronchoscopic human airway biopsies were immunolabeled for nerves and the sensory neuropeptide substance P. Eosinophil peroxidase was also quantified given previous reports showing associations between eosinophils and nerve density. Three-dimensional image z-stacks of epithelium and subepithelium were generated using confocal microscopy, and from these z-stacks, total nerve length, the number of nerve branch points, substance P expression, and eosinophil peroxidase were quantified within each airway compartment.Measurements and Main Results: Nerve length and the number of branch points were significantly increased in epithelium, but not subepithelium, in chronic cough compared with healthy airways. Substance P expression was scarce and was similar in chronic cough and healthy airways. Nerve length and branching were not associated with eosinophil peroxidase nor with demographics such as age and sex in either group.Conclusions: Airway epithelial sensory nerve density is increased in chronic cough, suggesting sensory neuroplasticity contributes to cough hypersensitivity.

The Role of Indirect Laryngoscopy, Clinical and Ultrasonographic Assessment in Prediction of Difficult Airway.

OBJECTIVES: Pre-operative airway evaluation is essential to decrease the proportion of possible mortality and morbidity due to difficult airway (DA). The study aimed to evaluate the accuracy of pre-operative ultrasonographic airway assessment (UAA) and indirect laryngoscopy (IL) in predicting DA. STUDY DESIGN: Prospective obsevational study. METHODS: Preoperative clinical examination (body mass index [BMI], mallampati classification [MP], thyromental distance, sternomental distance, neck circumference), UAA (epiglottis-skin distance [ESD], hyoid bone-skin distance [HSD], the thickness of tongue root [ToTR], anterior commissure-skin distance [ACSD]) and IL with the rigid 70-degree laryngoscope were performed to predict DA (Cormack-Lehane grade 3 and 4). The sensitivity, specificity, positive predictive value (PP), and negative predictive values of the parameters were assessed. RESULTS: Twenty-two of 140 (15.7%) patients were diagnosed with DA. The cut-off points of ESD, HSD, ToTR, ACSD, and BMI were 2.09 cm, 0.835 cm, 4.05 cm, 0.545 cm, and 27.10, respectively. AUC values were 0.874, 0.885, 0.871, 0.658, and 0.751 in the same order. AUC values for IL and MP were 0.773 and 0.925, respectively. MP and HSD had the best sensitivity (91%), IL grading had the best specificity (100%), and PP (100%) value among all measurements. The best-balanced sensitivity (91%), specificity (97%), and PP (88%) values were obtained by combining the IL with MP and ESD or with MP and HSD. CONCLUSIONS: Ultrasonographic measurements and IL were found significantly correlated to predict DA. Combined parameters, the IL with MP and ESD or with MP and HSD, are the best parameters in predicting the DA. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E555-E560, 2021.

Yield of preoperative findings in pediatric airway foreign bodies - A meta-analysis.

IMPORTANCE: Foreign body (FB) aspiration into the airway is a significant cause of pediatric morbidity and mortality, yet the clinical presentation is diverse and dynamic. There are conflicting recommendations which pre-procedural findings support performing a bronchoscopy, the gold standard for diagnosis and removal of FBs, however a procedure that entails general anesthesia and possible risks. OBJECTIVE: Decision whether to proceed to a bronchoscopy may be challenging. Our goal was to enhance decision-making by analyzing the diagnostic values of the different pre-procedural findings in this setting. DATA SOURCES: A comprehensive search was performed in PUBMED, EMBASE and Cochrane Review databases to find studies from the last 19 years that reported pre-procedural history, physical examination and radiological findings in patients who had bronchoscopies. STUDY SELECTION: Studies were included of pediatric populations if they contained bronchoscopy results (positive and negative for foreign body) with a breakdown according to pre-intervention findings. DATA EXTRACTION AND SYNTHESIS: Titles and abstracts retrieved from our search were screened. Thereafter, full-texts were carefully reviewed and selected for inclusion if the aforementioned criteria were met. PRISMA guidelines for systematic review and meta-analyses were followed. MAIN OUTCOME(S) AND MEASURE(S): Cumulative weighted prevalence, sensitivity, specificity, positive and negative predictive values of each pre-procedural finding were calculated, as well as for the "classic triad" (history of an acute event, wheezing, and unilateral decreased breath sounds). Calculation for other combinations of findings, or optimally, constructing a weighted score based on all the findings for each specific patient were not possible to perform, as the specific data breakdown is rarely reported. RESULTS: Fifteen studies met inclusion criteria, totaling 5606 patients who underwent bronchoscopies. All studies but one were single center based and all except one were retrospective. No single finding has both positive and negative predictive values over 50%. The "classic triad" has 90% specificity, however only 35% sensitivity. CONCLUSIONS: The data is very heterogeneous with regard to pre-procedural findings and how best to guide treatment according to them. This meta-analysis provides cumulative weighted metrics for each finding, to optimize decision-making for the individual patient. Future reporting of data should be enhanced, so that combinations of findings for a specific patient can be used to optimize management. LEVEL OF EVIDENCE: 4.

Lung function evaluation through computerized tomography and 3D reconstruction of airways: a body mass index pilot study / Evaluación de la función pulmonar mediante tomografía computarizada y reconstrucción 3D de las vías respiratorias: estudio piloto del índice de masa corporal

SUMMARY: Obesity is a worldwide epidemic that has become a risk factor for the development of respiratory problems, meaning it is necessary to generate models that assess lung function in obese patients for proper treatment. The objective of this study was to evaluate a model for analyzing respiratory function according to body composition, by analyzing the structure and function of the airways by computed tomography (CT). Lung function and body fat percentage (BF%) were measured in three male subjects (25 ± 6 years), with different body mass index (BMI; normal, overweight, obese). A third-dimensional (3D) reconstruction of the airways was performed using CT. Trachea, right and left main bronchi and anterior segmental bronchus of the right and left lung were measured. Three measurement points were established for each structure, and the average value of these three points was used for the analysis. An increase in the thickness of the airways wall of the left and right main bronchi and right segmental bronchus was observed as BMI and BF% increased. The same was observed for the percentage of airway wall area (%AWA) and airway resistance in the main and segmental bronchi. The proposed 3D reconstruction model and the three-point analysis simplified image assessment and allowed to observe the problems caused by obesity in lung function.

RESUMEN: La obesidad es una epidemia mundial, la que se ha transformado en un factor de riesgo en el desarrollo problemas respiratorios. Al respecto, generar modelos de evaluación de la función pulmonar en pacientes obesos es relevante para su adecuado tratamiento. El objetivo de este trabajo fue evaluar un modelo de la estructura y función de las vías aéreas (VA) con tomografía computarizada (TC) que permita analizar su compor- tamiento de acuerdo a la composición corporal. A tres sujetos de sexo masculino (25±6 años), de distinto índice de masa corporal (IMC; normal, sobrepeso, obeso), se les midió función pulmonar y porcentaje de grasa corporal (% GC). A través de TC se realizó una reconstrucción en tercera dimensión (3D) de las VA. Se realizaron mediciones de las VA de la tráquea, bronquios principales derecho e izquierdo y bronquio segmentario anterior del pulmón derecho e izquierdo. Para cada estructura se establecieron tres puntos de medición, el valor utilizado para los análisis fue el promedio de estos tres puntos. En los tres participantes se observó un aumento del grosor de la pared de las vías aéreas de los bronquios principal derecho e izquierdo y bronquio segmentario derecho a medida que aumenta el IMC y el % GC. Por otra parte, el porcentaje de área de la pared de las vías aéreas (% APVA) se comportó de la misma manera para ambos bronquios principales y segmentarios. La resistencia de las vías aéreas (RVA), tanto general como específica, aumentó en paralelo con el % APVA en los bronquios principales y segmentarios. A través de un modelo de reconstrucción 3D de la estructura de la VA por TC, evaluando tres puntos, se pudo observar los problemas que trae la obesidad a la función pulmonar simplificando el análisis de imagen.

Air Breathing in an Exceptionally Preserved 340-Million-Year-Old Sea Scorpion.

Arachnids are the second most successful terrestrial animal group after insects [1] and were one of the first arthropod clades to successfully invade land [2]. Fossil evidence for this transition is limited, with the majority of arachnid clades first appearing in the terrestrial fossil record. Furthermore, molecular clock dating has suggested a Cambrian-Ordovician terrestrialization event for arachnids [3], some 60 Ma before their first fossils in the Silurian, although these estimates assume that arachnids evolved from a fully aquatic ancestor. Eurypterids, the sister clade to terrestrial arachnids [4-6], are known to have undergone major macroecological shifts in transitioning from marine to freshwater environments during the Devonian [7, 8]. Discoveries of apparently subaerial eurypterid trackways [9, 10] have led to the suggestion that eurypterids were even able to venture on land and possibly breathe air [11]. However, modern horseshoe crabs undertake amphibious excursions onto land to reproduce [12], rendering trace fossil evidence alone inconclusive. Here, we present details of the respiratory organs of Adelophthalmus pyrrhae sp. nov. from the Carboniferous of Montagne Noire, France [13], revealed through micro computed tomography (µ-CT) imaging. Pillar-like trabeculae on the dorsal surface of each gill lamella indicate eurypterids were capable of subaerial breathing, suggesting that book gills are the direct precursors to book lungs while vascular ancillary respiratory structures known as Kiemenplatten represent novel air-breathing structures. The discovery of air-breathing structures in eurypterids indicates that characters permitting terrestrialization accrued in the arachnid stem lineage and suggests the Cambrian-Ordovician ancestor of arachnids would also have been semi-terrestrial.

Will Airway Gene Therapy for Cystic Fibrosis Improve Lung Function? New Imaging Technologies Can Help Us Find Out.

The promise of genetic therapies has turned into reality in recent years, with new first-line treatments for fatal diseases now available to patients. The development and testing of genetic therapies for respiratory diseases such as cystic fibrosis (CF) has also progressed. The addition of gene editing to the genetic agent toolbox, and its early success in other organ systems, suggests we will see rapid expansion of gene correction options for CF in the future. Although substantial progress has been made in creating techniques and genetic agents that can be highly effective for CF correction in vitro, physiologically relevant functional in vivo changes have been largely prevented by poor delivery efficiency within the lungs. Somewhat hidden from view, however, is the absence of reliable, accurate, detailed, and noninvasive outcome measures that can detect subtle disease and treatment effects in the lungs of humans or animal models. The ability to measure the fundamental function of the lung-ventilation, the effective transport of air throughout the lung-has been constrained by the available measurement technologies. Without sensitive measurement methods, it is difficult to quantify the effectiveness of genetic therapies for CF. The mainstays of lung health assessment are spirometry, which cannot provide adequate disease localization and is not sensitive enough to detect small early changes in disease; and computed tomography, which provides structural rather than functional information. Magnetic resonance imaging using hyperpolarized gases is increasingly useful for lung ventilation assessment, and it removes the radiation risk that accompanies X-ray methods. A new lung imaging technique, X-ray velocimetry, can now offer highly detailed regional lung ventilation information well suited to the diagnosis, treatment, and monitoring needs of CF lung disease, particularly after the application of genetic therapies. In this review, we discuss the options now available for imaging-based lung function measurement in the generation and use of genetic and other therapies for treating CF lung disease.

18F-FDG PET/MRI of Rhinosporidiosis of the Upper Airways.

A 41-year-old man from South Asia presented with a several months' history of unilateral nasal obstruction and bleeding. At nasal endoscopy, two strawberry-like, friable, polypoid masses in the upper airways were detected. The patient's clinical trait was compatible with an infectious disease. F-FDG PET/MRI was performed to evaluate the disease extension. Two lesions occupying the nasal cavity and the nasopharynx, slightly hyperintense in T2-weighted sequences, with intense radiopharmaceutical uptake were evidenced. Endoscopic resection was performed with histopathologic diagnosis of rhinosporidiosis, a chronic granulomatous disease caused by Rhinosporidium seeberi. Although rare, rhinosporidiosis should be considered in the differential diagnoses of sinonasal hypermetabolic lesions.

Secondary spontaneous pneumothorax and bullous lung disease in cannabis and tobacco smokers: A case-control study.

BACKGROUND: The notion that smoking cannabis may damage the respiratory tract has been introduced in recent years but there is still a paucity of studies on this subject. The aim of this study was to investigate the relationship between cannabis smoking, pneumothorax and bullous lung disease in a population of operated patients. METHODS AND FINDINGS: We performed a retrospective study on patients operated on for spontaneous pneumothorax. Patients were divided into three groups according to their smoking habit: cannabis smokers, only-tobacco smokers and nonsmokers. Cannabis lifetime exposure was expressed in dose-years (1d/y = 1 gram of cannabis/week for one year). Clinical, radiological and perioperative variables were collected. The variables were analyzed to find associations with smoking habit. The impact of the amount of cannabis consumption was also investigated by ROC curves analysis. Of 112 patients, 39 smoked cannabis, 23 smoked only tobacco and 50 were nonsmokers. Median cannabis consumption was 28 dose/years, median tobacco consumption was 6 pack/years. Cannabis smokers presented with more severe chronic respiratory symptoms and bullous lung disease and with a higher incidence of tension pneumothorax than both tobacco smokers and nonsmokers. Cannabis smokers also developed a larger pneumothorax, experienced prolonged postoperative stay and demonstrated a higher incidence of pneumothorax recurrence after the operation than nonsmokers did. The risk of occurrence of chronic respiratory symptoms and bullous lung disease in cannabis smokers was dose-related. CONCLUSIONS: Cannabis smoking seems to increase the risk of suffering from respiratory complaints and can have detrimental effects on lung parenchyma, in a dose-dependent manner. Cannabis smoking also negatively affected the outcome of patients operated for spontaneous pneumothorax. A history of cannabis abuse should always be taken in patients with pneumothorax. There may be need for a specific treatment for pneumothorax in cannabis smokers.

3-D airway analysis related to facial morphology / Análisis 3-D de la vía aerea relacionado con la morfología facial

The aim of this investigation was to define the volume and area of the airway in subjects with Class II and Class III skeletal deformity. A cross-sectional study was designed including subjects with facial deformity defined by Steiner's analysis in subjects with indication of orthognathic surgery who presented diagnosis by cone beam computerised tomography. We determined the measurements of maximum area, minimum area and volume of the airway. The data were compared using Spearman's test, with statistical significance defined as p<0.05. 115 subjects were included: 61.7 % Class II and 38.3 % Class III, mean age 27.8 years (± 11.6). A significant difference was observed in the area and volume measurements in the groups studied, with significantly smaller measurements found in Class II (p=0.034). The minimum area was 10.4 mm2 smaller in Class II patients than in Class III, while the general volume of the airway was 4.1 mm3 smaller in Class II than in Class III. We may conclude that Class II subjects present a smaller airway volume than Class III subjects.

El objetivo de esta investigación de definir el volumen y área de vía aérea en sujetos con deformidad esqueletal clase II y III. Se diseñó un estudio de corte transversal incluyendo sujetos con deformidad facial definida según análisis de Stainer en sujetos con indicación de cirugía ortognática que presentaran una tomografía computadorizada de haz cónico como elemento diagnóstico; en este examen se determinaron medidas de área mayor, menor de vía aérea y volumen presente; los datos fueron comparados utilizando pruebas estadísticas con el test de spearman considerando el valor de p<0,05 para definir significancia estadística. 115 sujetos fueron incluidos, siendo 61,7 % de tipo clase II y 38,3 % de sujetos clase III, con una edad promedio de 27,8 años (± 11,6). Se observó una diferencia significativa en mediciones de area y volumen en los grupos estudiados, siendo el grupo de clase II significativamente menor (p=0,034). El área de menor tamaño fue 10,4 mm2 en pacientes clase II que en pacientes clase III, mientras que el volumen general de la vía área fue 4,1 menor en los clase II que en los clase III. Es posible concluir que los sujetos de clase II presentan menor volumen de vía área que los sujetos clase III.

Modelling Particle Transport and Deposition in the Human Healthy and Stented Tracheobronchial Airways.

The main goal of this study is the quantification of the particle transport and deposition within the human airways during light, normal and exercise breathing conditions using the computational fluid dynamics. In particular we presented a comparison between healthy and stented airways. The considered tracheobronchial model is based on the Weibel symmetric model in which we have inserted the Dumon prosthesis at different locations and on the CT-based geometries of a healthy and a stented airway. The results indicate an important redistribution of the particle deposition locations. Local overdoses can be found in the proximal regions of the prostheses, independently of the breathing conditions, of the particle size and of the considered geometry. The presented work is aimed to contribute to the understanding of the particle deposition in the human lung and to improve drug-aerosol therapies. For patients that underwent airways reconstructive surgery, it can give detailed information about the deposition efficiency and it may help targeting specific airways regions.

Comparison of Direct and Video Laryngoscopes during Different Airway Scenarios Performed by Experienced Paramedics: A Randomized Cross-Over Manikin Study.

Introduction. Airway management plays an essential role in anaesthesia practice, during both elective and urgent surgery procedures and emergency medicine. AIM: The aim of the study was to compare Macintosh laryngoscope (MAC), McGrath, and TruView PCD in 5 separate airway management scenarios. METHODS: This prospective cross-over simulation study involved 93 paramedics. All paramedics performed intubation using direct laryngoscope (MAC), McGrath, and TruView PCD video laryngoscopes. The study was performed in 5 different scenarios: (A) normal airway, (B) tongue oedema, (C) pharyngeal obstruction, (D) cervical collar stabilization with tongue oedema, and (E) cervical collar stabilization with pharyngeal obstruction. RESULTS: In scenario A, the success rate was 99% with MAC, 100% with McGrath, and 94% with PCD. Intubation time was 17 s (IQR: 16-21) for MAC, 18 s (IQR: 16-21) for McGrath, and 27 s (IQR: 23-34) for PCD. In scenario B, the success rate was 61% with MAC, 97% with McGrath, and 97% with PCD (p < 0.001). Intubation time was 44 s (IQR: 24-46) for MAC, 22 s (IQR: 20-27) for McGrath, and 39 s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (p < 0.001). Intubation time was 44 s (IQR: 24-46) for MAC, 22 s (IQR: 20-27) for McGrath, and 39 s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (p < 0.001). Intubation time was 44 s (IQR: 24-46) for MAC, 22 s (IQR: 20-27) for McGrath, and 39 s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (p < 0.001). Intubation time was 44 s (IQR: 24-46) for MAC, 22 s (IQR: 20-27) for McGrath, and 39 s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (. CONCLUSIONS: The McGrath video laryngoscope proved better than Truview PCD and direct intubation with Macintosh laryngoscope in terms of success rate, duration of first intubation attempt, number of intubation attempts, Cormack-Lehane grade, percentage of glottis opening (POGO score), number of optimization manoeuvres, severity of dental compression, and ease of use.