Detection and diagnosis of large airway collapse: a systematic review

Acquired tracheobronchomalacia developed following voice prosthesis implantation

Acquired tracheobronchomalacia (ATBM) is a condition in which the tracheobronchial wall and cartilage progressively lose their rigidity, resulting in dynamic collapse during exhalation. In this report, we present a case of ATBM that developed following voice prosthesis implantation. To the best of our knowledge, this is the first documented case of such a condition in the medical English literature based on a PubMed search. A 63-year-old man was referred to National Kyushu Cancer Center in Japan with complaints of pharyngeal pain and a laryngeal tumor. The tumor was diagnosed as laryngeal cancer, and the patient underwent laryngectomy. Three months after the surgery, we implanted a voice prosthesis through a tracheoesophageal puncture. Two months after implantation, the patient experienced dyspnea. This condition was subsequently diagnosed as ATBM through computed tomography and bronchofiberscope examinations. After the removal of the voice prosthesis, there has been no progression of ATBM for over five years. While ATBM may not be a common occurrence in the practice of head and neck surgeons, it should be considered as a potential complication when patients report dyspnea following voice prosthesis implantation.

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.

The role of radiological imaging in the management of severe and difficult-to-treat asthma

Radiological imaging has proven to be a useful tool in the assessment of asthma, its comorbidities and potential complications. Characteristic chest radiograph and computed tomography scan findings can be seen in asthma and in other conditions that can coexist with or be misdiagnosed as asthma, including chronic rhinosinusitis, inducible laryngeal obstruction, excessive dynamic airway collapse, tracheobronchomalacia, concomitant COPD, bronchiectasis, allergic bronchopulmonary aspergillosis, eosinophilic granulomatosis with polyangiitis, and eosinophilic pneumonia. The identification of the characteristic radiological findings of these conditions is often essential in making the correct diagnosis and provision of appropriate management and treatment. Furthermore, radiological imaging modalities can be used to monitor response to therapy.

Recurrent Respiratory Infections in Children with Down Syndrome: A Review

Down Syndrome (DS) is the most common chromosomal abnormality compatible with life. The life of patients suffering from DS can be strongly impacted by Recurrent Respiratory tract Infections (RRIs), leading to an increased rate of hospitalisation, a higher need for intensive care and fatality. With a literature review, we summarise here the main etiological factors for RRI in this category of patients, particularly focusing on airway malformations such as tracheomalacia, tracheal bronchus and bronchomalacia, comorbidities associated with the syndrome, like congenital heart diseases, dysphagia, gastroesophageal reflux, musculoskeletal involvement and obesity, and immunologic impairments, involving both innate and adaptive immunity. For these patients, a multidisciplinary approach is imperative as well as some preventive strategies, in particular vaccinations in accordance with their national schedule for immunization.

Fleischner Society: Glossary of Terms for Thoracic Imaging

Members of the Fleischner Society have compiled a glossary of terms for thoracic imaging that replaces previous glossaries published in 1984, 1996, and 2008, respectively. The impetus to update the previous version arose from multiple considerations. These include an awareness that new terms and concepts have emerged, others have become obsolete, and the usage of some terms has either changed or become inconsistent to a degree that warranted a new definition. This latest glossary is focused on terms of clinical importance and on those whose meaning may be perceived as vague or ambiguous. As with previous versions, the aim of the present glossary is to establish standardization of terminology for thoracic radiology and, thereby, to facilitate communications between radiologists and clinicians. Moreover, the present glossary aims to contribute to a more stringent use of terminology, increasingly required for structured reporting and accurate searches in large databases. Compared with the previous version, the number of images (chest radiography and CT) in the current version has substantially increased. The authors hope that this will enhance its educational and practical value. All definitions and images are hyperlinked throughout the text. Click on each figure callout to view corresponding image. © RSNA, 2024 Supplemental material is available for this article. See also the editorials by Bhalla and Powell in this issue.

Laryngeal widening and adequate ventilation by expiratory pressure load training improve aerobic capacity in COPD: a randomised controlled trial

RATIONALE

Despite strategies acting on peripheral airway obstruction in chronic obstructive pulmonary disease (COPD), exercise intolerance remains inadequately improved. We hypothesised that laryngeal narrowing is a potential treatment target of expiratory pressure load training (EPT) to improve exercise intolerance in COPD.

METHODS

The effect of 3-month EPT was assessed in 47 patients with COPD divided into Global Initiative for Chronic Obstructive Lung Disease (GOLD) mild-to-moderate (I-II) and severe-to-very severe (III-IV), randomly allocating 1:1 to EPT or control groups. The primary outcome was endurance time in the constant work rate exercise test in GOLD III-IV patients.

RESULTS

Compared with controls, EPT increased: (1) endurance time, with estimated treatment effect: +703 (95% CI: 379 to 1031) s, p=0.0008 (GOLD I-II); +390 (95% CI: 205 to 574) s, p=0.0006 (GOLD III-IV); (2) peak oxygen uptake (p=0.0086 in GOLD I-II; p=0.0004 in GOLD III-IV); (3) glottic dilatation ratio at maximum collapse on laryngoscopy in the submaximal exercise (p=0.0062 in GOLD I-II; p=0.0001 in GOLD III-IV); and (4) the inflection point of expiratory tidal volume relative to minute ventilation during the incremental exercise (p=0.0015 in GOLD I-II; p=0.0075 in GOLD III-IV). Across GOLD grades, the responses of glottic dilatation ratio at maximum collapse and the expiratory tidal volume at the inflection point were selected as more influential variables correlating with the improvement in peak oxygen uptake and endurance time, respectively.

CONCLUSION

These results show that EPT improved aerobic capacity and endurance time with larger laryngeal widening and adequate ventilation despite advanced COPD.

TRIAL REGISTRATION NUMBER

UMIN000041250.

Quantitative CT Scan Imaging of the Airways for Diagnosis and Management of Lung Disease

CT scan imaging provides high-resolution images of the lungs in patients with chronic respiratory diseases. Extensive research over the last several decades has focused on developing novel quantitative CT scan airway measurements that reflect abnormal airway structure. Despite many observational studies demonstrating that associations between CT scan airway measurements and clinically important outcomes such as morbidity, mortality, and lung function decline, few quantitative CT scan measurements are applied in clinical practice. This article provides an overview of the relevant methodologic considerations for implementing quantitative CT scan airway analyses and provides a review of the scientific literature involving quantitative CT scan airway measurements used in clinical or randomized trials and observational studies of humans. We also discuss emerging evidence for the clinical usefulness of quantitative CT scan imaging of the airways and discuss what is required to bridge the gap between research and clinical application. CT scan airway measurements continue to improve our understanding of disease pathophysiologic features, diagnosis, and outcomes. However, a literature review revealed a need for studies evaluating clinical benefit when quantitative CT scan imaging is applied in the clinical setting. Technical standards for quantitative CT scan imaging of the airways and high-quality evidence of clinical benefit from management guided by quantitative CT scan imaging of the airways are required.

Excessive Dynamic Airway Collapse Severity Scoring System: A Call Out for an Overall Severity Determination

BACKGROUND

Severe excessive dynamic airway collapse (EDAC) is defined as airway narrowing due to posterior wall protrusion into the airway lumen, >90%. We aimed to establish an overall severity score to assess severe EDAC and the need for subsequent intervention.

METHODS

A retrospective study of patients who underwent dynamic bronchoscopy for evaluation of expiratory central airway collapse between January 2019 and July 2021. A numerical value was given to each tracheobronchial segmental collapse: 0 points (<70%), 1 point (70% to 79%), 2 points (80% to 89%), and 3 points (>90%) to be added for an overall EDAC severity score per patient. We compared the score among patients who underwent stent trials (severe EDAC) and those who did not. Based on the receiver operating characteristics curve, a cutoff total score to predict severe EDAC was calculated.

RESULTS

One hundred fifty-eight patients were included. Patients were divided into severe (n = 60) and nonsevere (n = 98) EDAC. A cutoff of 9 as the total score had a sensitivity of 94% and a specificity of 74% to predict severe EDAC, based on an area under the curve 0.888 (95% CI: 0.84, 0.93; P < 0.001).

CONCLUSION

Our EDAC Severity Scoring System was able to discern between severe and nonsevere EDAC by an overall score cutoff of 9, with high sensitivity and specificity for predicting severe disease and the need for further intervention, in our institution.

Pneumatic stenting in the surgical candidacy assessment for cough variant expiratory central airway collapse

Expiratory Central Airway Collapse (ECAC) is a multifactorial, underdiagnosed entity that poses unique challenges. Airway stenting is used as a predictor for successful outcomes after central airway stabilization surgery via tracheobronchoplasty (TBP). This approach may pose suboptimal performance in certain ECAC variants. We hypothesize that Continuous Positive Airway Pressure (CPAP), used as a pneumatic stent, could be a non-invasive alternative to evaluate surgical candidacy in cough-predominant ECAC presentations. We report on a 67-year-old female with a history of chronic cough and confirmed ECAC. After optimization of medical therapy without significant relief and unsuccessful stent trial. We opted to perform CPAP trial during exercise, the patient exercised on a treadmill, and CPAP was applied at two levels (9 cmH₂O, 11 cmH₂O). The use of CPAP was associated with resolution of cough and a decrease in exercise-related perceived exertion. Applying CPAP during exercise may be a promising alternative to stent trials to determine patients' candidacy for surgical management of cough-predominant ECAC.

Dynamic chest radiography: a state-of-the-art review

Dynamic chest radiography (DCR) is a real-time sequential high-resolution digital X-ray imaging system of the thorax in motion over the respiratory cycle, utilising pulsed image exposure and a larger field of view than fluoroscopy coupled with a low radiation dose, where post-acquisition image processing by computer algorithm automatically characterises the motion of thoracic structures. We conducted a systematic review of the literature and found 29 relevant publications describing its use in humans including the assessment of diaphragm and chest wall motion, measurement of pulmonary ventilation and perfusion, and the assessment of airway narrowing. Work is ongoing in several other areas including assessment of diaphragmatic paralysis. We assess the findings, methodology and limitations of DCR, and we discuss the current and future roles of this promising medical imaging technology.Critical relevance statement Dynamic chest radiography provides a wealth of clinical information, but further research is required to identify its clinical niche.

Diagnosis and management of allergy and respiratory disorders in sport: An EAACI task force position paper

Allergy and respiratory disorders are common in young athletic individuals. In the context of elite sport, it is essential to secure an accurate diagnosis in order to optimize health and performance. It is also important, however, to consider the potential impact or consequences of these disorders, in recreationally active individuals engaging in structured exercise and/or physical activity to maintain health and well-being across the lifespan. This EAACI Task Force was therefore established, to develop an up-to-date, research-informed position paper, detailing the optimal approach to the diagnosis and management of common exercise-related allergic and respiratory conditions. The recommendations are informed by a multidisciplinary panel of experts including allergists, pulmonologists, physiologists and sports physicians. The report is structured as a concise, practically focussed document, incorporating diagnostic and treatment algorithms, to provide a source of reference to aid clinical decision-making. Throughout, we signpost relevant learning resources to consolidate knowledge and understanding and conclude by highlighting future research priorities and unmet needs.

Tiao-bu-fei-shen formula promotes downregulation of the caveolin 1-p38 mapk signaling pathway in COPD - Associated tracheobronchomalacia cell model

ETHNOPHARMACOLOGICAL RELEVANCE

The Tiao-bu-fei-shen (TBFS) formula, extensively used in Traditional Chinese Medicine (TCM), can enhance therapeutic efficacy and reduce the frequency of acute exacerbations of lung-kidney Qi deficiency in patients with chronic obstructive pulmonary disease (COPD). According to both TCM theory and long-term observation of practice, TBFS has become an effective treatment for COPD-associated tracheobronchomalacia (TBM).

AIM OF THE STUDY

To investigate the mechanism of the TBFS formula in treating COPD-associated TBM based on caveolin 1-p38 MAPK signaling and apoptosis.

MATERIALS AND METHODS

A rat COPD model was prepared by exposure to smoking combined with tracheal lipopolysaccharide injection. The trachea or bronchus chondrocytes from COPD rats were isolated, cultured, and treated with 10 ng/mL IL-1β for 24 h to develop a model of COPD-associated TBM. Normal rats were administered TBFS to prepare drug-containing serum, and CCK8 assays were used to screen the optimal drug-containing serum concentration and SB203580 dose. TBFS drug-containing serum and SB203580 were processed separately for the control, model, drug-containing serum, blocker, and drug-containing serum combined with blocker groups. Flow cytometry and CCK8 assays were used to detect apoptosis and proliferative activity. Toluidine blue staining and immunohistochemistry were used to analyze the chondrocyte proteoglycan and type II collagen content. Western blotting was used to detect the expression of caveolin 1, p-p38 MAPK, TNF-α, IL-1β, MMP-13, Bax, and Bcl-2 proteins. Quantitative PCR was used to detect the expression of caveolin 1, p38 MAPK, IL-1β, MMP-13, Bax, Bcl-2, and miR-140-5p.

RESULTS

The isolation and identification of bronchial chondrocytes from COPD rats revealed that 10 ng/mL IL-1β can produce a stable COPD-associated TBM model. Screened via the CCK8 method, fourth-generation bronchial chondrocytes were determined as the optimal cells, and 5 μM SB203580 and 5% low-dose drug-containing serum were the optimal intervention doses. The experimental chondrocytes of each group were treated separately for 48 h. Toluidine blue staining and immunohistochemical analysis revealed that TBFS drug-containing serum, SB203580, and TBFS drug-containing serum combined with SB203580 can effectively increase the proteoglycan and type II collagen content after chondrocyte degradation. Flow cytometry of cells treated with SB203580 and TBFS drug-containing serum combined with SB203580 revealed significantly reduced cell apoptosis and enhanced cell proliferation activity. Western blot and qPCR analyses revealed that the TBFS drug-containing serum, SB203580, and TBFS drug-containing serum combined with SB203580 effectively inhibit the expression of caveolin 1, p-p38 MAPK, MMP-13, IL-1β, TNF-α, and Bax proteins while promoting Bcl -2 protein expression. Treatment with TBFS drug-containing serum and SB203580 effectively inhibited the expression of MMP-13, p38 MAPK, caveolin 1, and Bax genes, and promoted the expression of Bcl-2 and miR-140-5p genes.

CONCLUSIONS

A concentration of 10 ng/mL of IL-1β can generate a stable COPD-associated TBM cell model. TBFS can improve the proteoglycan and type II collagen content, increase cell activity, and reduce the amount of chondrocyte apoptosis. The role of TBFS may be related to mechanisms of inhibiting the expression of the key signaling molecules caveolin 1 and p-p38 MAPK in the caveolin 1-p38 MAPK signaling pathway, thereby reducing the expression of the downstream effector products MMP-13, IL-1β, and TNF-α, while inhibiting the expression of the apoptotic gene Bax and improving the expression of Bcl-2 and miR-140-5p genes.

International Olympic Committee (IOC) consensus statement on acute respiratory illness in athletes part 2: non-infective acute respiratory illness

Acute respiratory illness (ARill) is common and threatens the health of athletes. ARill in athletes forms a significant component of the work of Sport and Exercise Medicine (SEM) clinicians. The aim of this consensus is to provide the SEM clinician with an overview and practical clinical approach to non-infective ARill in athletes. The International Olympic Committee (IOC) Medical and Scientific Committee appointed an international consensus group to review ARill in athletes. Key areas of ARill in athletes were originally identified and six subgroups of the IOC Consensus group established to review the following aspects: (1) epidemiology/risk factors for ARill, (2) infective ARill, (3) non-infective ARill, (4) acute asthma/exercise-induced bronchoconstriction and related conditions, (5) effects of ARill on exercise/sports performance, medical complications/return-to-sport (RTS) and (6) acute nasal/laryngeal obstruction presenting as ARill. Following several reviews conducted by subgroups, the sections of the consensus documents were allocated to 'core' members for drafting and internal review. An advanced draft of the consensus document was discussed during a meeting of the main consensus core group, and final edits were completed prior to submission of the manuscript. This document (part 2) of this consensus focuses on respiratory conditions causing non-infective ARill in athletes. These include non-inflammatory obstructive nasal, laryngeal, tracheal or bronchial conditions or non-infective inflammatory conditions of the respiratory epithelium that affect the upper and/or lower airways, frequently as a continuum. The following aspects of more common as well as lesser-known non-infective ARill in athletes are reviewed: epidemiology, risk factors, pathology/pathophysiology, clinical presentation and diagnosis, management, prevention, medical considerations and risks of illness during exercise, effects of illness on exercise/sports performance and RTS guidelines.

Physiotherapy for large airway collapse: an ABC approach

Large airway collapse (LAC) describes the phenomenon of excessive, abnormal, inward movement of the large airways (i.e. trachea and/or main bronchi and/or bronchus intermedius) occurring during the expiratory phase of the respiratory cycle. It is an increasingly well-recognised problem and a prevalent comorbidity in other chronic respiratory conditions (e.g. COPD and asthma). LAC is associated with pervasive respiratory features such as a barking cough, exertional dyspnoea and an increased propensity to lower respiratory tract infection. These symptoms are unpleasant, and patients are often limited in their daily life and their function. The pathophysiology of this condition impairs airway clearance and can cause breathlessness and exercise intolerance, due to a loss of airway patency during expiratory flow. Dysfunctional adaptations to breathing and coughing may further amplify symptoms. This article provides, for the first time, clinically focused physiotherapeutic intervention advice based on our understanding of the pathophysiology of LAC, to support conservative management. It uses the available evidence from LAC, transferable evidence from other conditions and knowledge based on clinical experience. It proposes a practical "ABC model" to ensure physiotherapy assessment and treatments are centred around optimising three key clinical areas: Airways, including airway clearance and cough; Breathing, including breathlessness and breathing pattern; and Capacity for exercise, including an assessment of functional exercise ability.