Laryngeal Narrowing Research Articles

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

RationaleDespite 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...

Diagnosis of vocal cord dysfunction/inducible laryngeal obstruction: An International Delphi Consensus Study

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is characterized by breathing difficulties in association with excessive supraglottic or glottic laryngeal narrowing. The condition is common and can occur independently; however, it may also be comorbid with other disorders or mimic them. Presentations span multiple specialties and misdiagnosis or delayed diagnosis is commonplace. Group-consensus methods can efficiently generate internationally accepted diagnostic criteria and descriptions to increase clinical recognition, enhance clinical service availability, and catalyze research. We sought to establish consensus-based diagnostic criteria and methods for VCD/ILO. We performed a modified 2-round Delphi study between December 7, 2021, and March 14, 2022. The study was registered at ANZCTR (Australian New Zealand Clinical Trials Registry; ACTRN12621001520820p). In round 1, experts provided open-ended statements that were categorized, deduplicated, and amended for clarity. These were presented to experts for agreement ranking in round 2, with consensus defined as ≥70% agreement. Both rounds were completed by 47 international experts. In round 1, 1102 qualitative responses were received. Of the 200 statements presented to experts across 2 rounds, 130 (65%) reached consensus. Results were discussed at 2 international subject-specific conferences in June 2022. Experts agreed on a diagnostic definition for VCD/ILO and endorsed the concept of VCD/ILO phenotypes and clinical descriptions. The panel agreed that laryngoscopy with provocation is the gold standard for diagnosis and that ≥50% laryngeal closure on inspiration or Maat grade ≥2 define abnormal laryngeal closure indicative of VCD/ILO. This Delphi study reached consensus on multiple aspects of VCD/ILO diagnosis and can inform clinical practice and facilitate research.

Vocal cord dysfunction/inducible laryngeal obstruction-2022 Melbourne Roundtable Report.

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO), is a common condition characterized by breathlessness associated with inappropriate laryngeal narrowing. Important questions remain unresolved, and to improve collaboration and harmonization in the field, we convened an international Roundtable conference on VCD/ILO in Melbourne, Australia. The aims were to delineate a consistent approach to VCD/ILO diagnosis, appraise disease pathogenesis, outline current management and model(s) of care and identify key research questions. This report summarizes discussions, frames key questions and details recommendations. Participants discussed clinical, research and conceptual advances in the context of recent evidence. The condition presents in a heterogenous manner, and diagnosis is often delayed. Definitive diagnosis of VCD/ILO conventionally utilizes laryngoscopy demonstrating inspiratory vocal fold narrowing >50%. Computed tomography of the larynx is a new technology with potential for swift diagnosis that requires validation in clinical pathways. Disease pathogenesis and multimorbidity interactions are complex reflecting a multi-factorial, complex condition, with no single overarching disease mechanism. Currently there is no evidence-based standard of care since randomized trials for treatment are non-existent. Recent multidisciplinary models of care need to be clearly articulated and prospectively investigated. Patient impact and healthcare utilization can be formidable but have largely escaped inquiry and patient perspectives have not been explored. Roundtable participants expressed optimism as collective understanding of this complex condition evolves. The Melbourne VCD/ILO Roundtable 2022 identified clear priorities and future directions for this impactful condition.

Letter from Norway

Letter from Norway

Percutaneous Sclerotherapy of a Large Trans-Spatial Oropharyngeal Venous Malformation Using Multimodality Guidance

A 37-year-old woman with a large, infiltrative face and neck venous malformation (VM) was treated with percutaneous sclerotherapy using combined ultrasound, fluoroscopy, and computed tomography (CT) guidance. No institutional review board approval was required for this case report. Symptoms included pain, swelling, difficulty in swallowing, and facial pressure. On magnetic resonance imaging, the VM involved the right masticator, parotid, and parapharyngeal spaces, causing laryngeal narrowing (Fig 1).

Stressed and Distressed: Potential Underpinnings of Exercise-Related Inspiratory Distress in Adolescent Sport Performers.

This Perspective adds to the understanding of respiratory distress in populations other than adults, which is important and necessary. Adolescent sport performers are exposed to a number of stressors that may affect breathing and laryngeal narrowing, which in turn may have implications for the management of their overall health and well-being.

Effect of inhaled fluticasone propionate on laryngotracheal stenosis after balloon dilation: a randomized controlled trial.

PurposeLaryngotracheal stenosis describes various airflow compromising conditions leading to laryngeal and tracheal narrowing, including subglottic and tracheal stenosis. Direct laryngobronchoscopy is the diagnostic gold standard for laryngotracheal stenosis. This study aimed to explore the effect of inhaled fluticasone propionate as adjuvant medical therapy in patients with laryngotracheal stenosis after balloon dilation. MethodsThis prospective randomized controlled trial was conducted from April 2019 to April 2020. Fourteen adults (≥ 18 years) with laryngotracheal stenosis consented to participate. All patients underwent endoscopic balloon dilation. Seven patients were treated with inhaled fluticasone propionate, and seven acted as controls. Detailed documentation of operative findings and pre- and post-balloon dilation spirometry measurements were recorded. Basic demographic data and operative details, including information about the percentage of laryngotracheal stenosis, distance of laryngotracheal stenosis from the vocal cords, the stenotic segment vertical length, and the largest endotracheal tube used before and after dilation were noted. ResultsSpirometry measurements were obtained on 34 occasions (17 before and 17 after balloon dilation). The two groups were similar in spirometry values after treatment. Both groups had significantly improved on most spirometry values after balloon dilation.ConclusionWe found that using inhaled steroids after balloon dilatation in patients with laryngotracheal stenosis had no benefit over non-user patients in spirometry parameters during the short postoperative follow-up. To confirm this outcome, we recommend a large-scale double-blind study with a longer follow-up period. Supplementary InformationThe online version contains supplementary material available at 10.1007/s00405-021-06622-x.

Characterizing Vocal Tract Dimensions in the Vocal Modes Using Magnetic Resonance Imaging

The aim was to study vocal tract dimensions in four vocal modes - Neutral, Curbing, Overdrive and Edge - from Complete Vocal Technique (CVT) by means of magnetic resonance imaging (MRI). Furthermore, the purpose was to test the feasibility of MRI to assess CVT vocal modes. Four nonclassical singers (two females, two males) trained in CVT were imaged with an MRI scanner while singing sustained vowels at same pitch (Bb4 for females, F4 for males) in all vocal modes. Audio signals were simultaneously recorded through a pipe for quality assurance purposes. Auditory evaluation was performed by three CVT teachers in the scanner control room via headphones, and by one CVT teacher inside the MRI room. Previously developed measurement models modified by the authors were used to measure vocal tract dimensions from sagittal MRI projections. Repeatability test was performed for all measurements. In all subjects, vocal tract dimensions displayed differences between the vocal modes. Edge stood out from other vocal modes by showing most laryngeal narrowing accompanied by shortest vocal tract and highest vertical laryngeal position. For Neutral, least mouth opening and shortest distance between tongue and palate were found. Curbing differed consistently from Edge and somewhat from Overdrive showing higher measured values for vocal fold length. Differences regarding vocal fold length were also detected between Neutral and Edge. As expected, differences in vocal tract dimensions were found between samples sung with different vowels. Vocal tract adjustments play a key role in the production of the vocal modes. The model used to measure vocal tract dimensions succeeded in finding significant differences between the vocal modes, also detecting differences between different vowel productions. The method used to characterize vocal tract dimensions seem promising and would be worthwhile to apply to a larger material.

Predictive value of cuff leak test, laryngeal ultrasound, and fiberoptic laryngoscopy for postextubation stridor after prolonged intubation

Background Endotracheal intubation is frequently complicated by laryngeal edema, which may present as postextubation stridor (PES) or respiratory difficulty or both. Multiple tests were used to predict the PES. The present study aimed at description and evaluation of the predictive values of the cuff leak test (CLT), laryngeal ultrasound (LUS), and indirect flexible fiberoptic laryngoscopy (FOL) to predict PES in ICU patients after prolonged intubation. Patients and methods This prospective study was conducted on 60 intubated patients who were admitted into the surgical intensive care unit. After successful 30-min spontaneous breathing trial and within 6 h before the planned extubation, CLT, LUS, and FOL were performed for all patients. After extubation, the patients were observed and classified into two groups according to the presence of PES within 48 h. Results Two patients were excluded owing to self-extubation, and 58 patient’s data were analyzed. There was no significant difference in CLT volume and the leak fraction between the patients with PES (PES group) and those without PES (non-PES group). However, statistically, air column width with balloon inflated or deflated was significantly lesser in the PES group than the corresponding values in the non-PES group (P=0.04 and 0.009, respectively). Moreover, there was a high significant difference in the air column width difference between both groups (P Conclusion For the noninvasive methods, the CLT has a low predictive value with high possibility of false results, but the data from LUS can be used for approximate evaluation of the laryngeal lumen narrowing; however, the interpretations of the ultrasound data are not conclusive. On the contrary, the FOL is the best accurate diagnostic tool but it is invasive.

Unsuccessful tracheal intubation in a patient with Kniest dysplasia undergoing repeated general anesthesia: a case report

BackgroundKniest dysplasia is a type of chondrodysplasia characterized by severe craniofacial abnormalities including tracheomalacia, midface hypoplasia, and cleft palate.Case presentationWe previously described a 6-year-old girl with Kniest dysplasia, in whom glottic edema rapidly developed after tracheal intubation. At the age of 13 years, a reoperation was scheduled to correct talipes equinovarus but was subsequently canceled due to failure of tracheal intubation and subsequent glottic edema. Airway evaluation by endoscopy and computed tomography 1 month later revealed severe laryngeal narrowing. Therefore, the second anesthesia was maintained with spinal anesthesia combined with sciatic nerve block without tracheal intubation.ConclusionCareful perioperative airway evaluation is required in patients with Kniest dysplasia, and alternative strategies for airway management other than tracheal intubation should be considered.

Characteristic plethysmographic findings in a guinea pig model of COPD

ABSTRACTAim of the Study: Long-term exposure to cigarette smoke generates chronic obstructive pulmonary disease (COPD) in guinea pigs, but a comprehensive evaluation of changes in lung function, as assessed by barometric whole body plethysmography (WBP), is lacking. Materials and Methods: Female guinea pigs were exposed to the smoke of 20 cigarettes/day, 5 days/week, during 10 weeks (COPD group, n = 8), and were compared with unexposed female guinea pigs of the same age (control group, n = 8). WBP was performed in both groups, followed by lung histology. Results: At the end of the exposure period, guinea pigs in the COPD group had higher respiratory frequency, while duty cycle (Ti/Ttot) was unaffected. There was a trend toward minute ventilation (MV) and expiratory flow at the mid-tidal volume (EF50) to be higher in the COPD group. Enhanced pause (Penh) was lower, while time of braking (TB) and time to PEF relative to Te (Rpef) were higher in the COPD group. All guinea pigs exposed to tobacco smoke developed emphysematous lesions in their lungs and gained less body weight than controls. Conclusions: In this COPD model, exposure to cigarette smoke produced changes in WBP characterized by a shallow breathing pattern with decreased Penh and a trend toward increasing EF50 (probably due to decreased elastic recoil), increased TB (suggesting dynamic laryngeal narrowing), and a trend of increasing MV (probably due to a higher metabolic rate). Many of these functional changes resemble those observed in patients with COPD and corroborate the suitability of this guinea pig model for the study of COPD.

Effects of Inspiratory Pressure Rise Time and Hypoxic or Hypercapnic Breathing on Inspiratory Laryngeal Constrictor Muscle Activity During Nasal Pressure Support Ventilation

We previously reported the development of an active inspiratory laryngeal narrowing against ventilator insufflations when inspiratory pressure is increased during nasal pressure support ventilation in lambs. The present study aimed to further understand the factors involved in this inspiratory laryngeal narrowing. More specifically, we tested the hypothesis that a short inspiratory pressure rise time or a low PaCO2 level promotes inspiratory laryngeal narrowing observed in nasal pressure support ventilation. The effect of hypoxia was also assessed. Prospective, randomized, interventional study. Animal research laboratory at the Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada. Thirteen lambs aged 4-5 days. Polysomnographic recordings were performed in chronically instrumented lambs to study states of alertness, glottal muscle electrical activity, tracheal pressure, SpO2, and respiratory movements. Lambs were ventilated with progressively increasing levels of nasal pressure support ventilation (10/4, 15/4, and 20/4 cm H2O), using a broad range of inspiratory rise times from 0.05 to 0.4 s. Thereafter, either CO2 (PaCO2 = baseline value + 10 mm Hg) or N2 (PaO2 = 45-55 mm Hg) was added to the inspiratory line. The percentage of respiratory cycles with phasic inspiratory activity of glottal constrictor muscle was measured and compared between the various experimental conditions. The different inspiratory pressure rise times tested did not alter the phasic inspiratory activity of glottal constrictor muscle during nasal pressure support ventilation. By contrast, this activity was virtually abolished by increasing PaCO2 in all lambs. Finally, no alterations in the phasic inspiratory activity of glottal constrictor muscle during nasal pressure support ventilation were observed during hypoxia. Active inspiratory laryngeal narrowing during nasal pressure support ventilation is not altered by inspiratory rise times ranging from 0.05 to 0.4 s or by moderate hypoxia, whereas a moderate increase in PaCO2 abolishes this activity.

Laryngeal Muscle Activity during Nasal High-Frequency Oscillatory Ventilation in Nonsedated Newborn Lambs

Background: We have previously shown that nasal pressure support ventilation (nPSV) can lead to an active inspiratory laryngeal narrowing in lambs. This, in turn, can limit lung ventilation and divert air into the digestive system, with potentially deleterious consequences. On the other hand, nasal high-frequency oscillatory ventilation (nHFOV) is particularly attractive in newborns, especially since, unlike nPSV, it does not require synchronization with the patient's inspiratory efforts. Objectives: The main aim of the present study was to test the hypothesis that glottal constrictor muscle activity (EMG) does not develop during nHFOV. A secondary objective was to study laryngeal EMG during nHFOV-induced central apneas. Methods: Polysomnographic recordings were performed in 7 nonsedated lambs which were ventilated with increasing levels of nPSV and nHFOV at both 4 and 8 Hz, in random order. States of alertness, diaphragm and glottal muscle EMG, SpO₂, and respiratory movements were continuously recorded. Results: While phasic inspiratory glottal constrictor EMG appeared with increasing nPSV levels in 6 out of 7 lambs, it was never observed with nHFOV. In addition, nHFOV at 4 Hz dramatically inhibited central respiratory drive in 4/7 lambs, with 64-100% of recording time spent in central apnea in 3 lambs. No glottal constrictor EMG was observed during these central apneas. Conclusion: nHFOV does not induce glottal constrictor muscle EMG in nonsedated newborn lambs, in contrast to nPSV. This may be an additional advantage of nHFOV relative to nPSV.

Dynamic laryngeal narrowing during exercise: a mechanism for generating intrinsic PEEP in COPD?

IntroductionPatients with COPD commonly exhibit pursed-lip breathing during exercise, a strategy that, by increasing intrinsic positive end-expiratory pressure, may optimise lung mechanics and exercise tolerance. A similar role for laryngeal...

P67 Laryngeal Narrowing In Chronic Obstructive Pulmonary Disease (copd): A Mechanism For Generating Intrinsic Peep?

Introduction and rationale Patients with COPD often exhibit pursed lip breathing during exercise, a strategy to help overcome a rise in intrinsic PEEP secondary to dynamic hyperinflation. A similar role for laryngeal closure to optimise respiratory mechanics during exertion is postulated. Objectives Assessment of laryngeal narrowing and its role in exercise intolerance and dynamic hyperinflation in COPD. Methods and Measurements: We studied 30 age and sex matched subjects (n = 11 healthy, n = 8 mild to moderate COPD, n = 11 severe COPD). Baseline physiological characteristics and clinical status were assessed prior to an incremental maximal cardiopulmonary exercise test with continuous laryngoscopy. Laryngeal narrowing was calculated at the glottic and supra-glottic aperture at rest and peak exercise. Results Expiratory laryngeal narrowing was pronounced in patients with COPD at rest and peak exercise and related to FEV 1 (r=-0.53, p Conclusion Dynamic laryngeal closure during expiration is prevalent in patients with COPD and is related to disease severity, respiratory duty cycle and exercise capacity.

Laryngeal narrowing during nasal ventilation does not originate from bronchopulmonary C-fibers

We previously showed that nasal pressure support ventilation (nPSV) can lead to active inspiratory laryngeal narrowing, which originates from the stimulation of bronchopulmonary receptors. Among the three major types of bronchopulmonary receptors, which are variably stimulated by lung distension, C-fiber endings are remarkable, given that their stimulation can also trigger laryngeal closure. Taking advantage of our lamb model with blocked C-fibers, we aimed to assess whether bronchopulmonary C-fiber endings are involved in the active inspiratory laryngeal narrowing during nPSV. Nine lambs were surgically instrumented to assess states of alertness, electrical activity of a glottal constrictor (EaTA), respiratory movements and arterial blood gases. Forty-eight hours later, two polysomnographic recordings were performed during nPSV 15/4cmH2O, before and after C-fiber blockade. During nPSV, blockade of C-fibers did not prevent inspiratory EaTA (present for 74±41% of respiratory cycles vs. 64±35%, p=0.9). We conclude that active inspiratory laryngeal narrowing during nPSV does not originate from bronchopulmonary C-fiber endings.

Bronchial obstruction and reversibility in children: inspiratory or expiratory resistance?

To the Editor: Assessing bronchial obstruction and reversibility is of help in diagnosing asthma. The forced oscillation technique (FOT) has gained popularity in children since minimal cooperation is required. Owing to the fact that measurements are performed during tidal breathing, the upper airway may significantly impact on the respiratory resistance ( R rs) [1], [2]. The glottic aperture narrows during tidal expiration [3], contributing to R rs being larger than in inspiration [2], [4], [5]. Acute bronchial obstruction promotes further laryngeal narrowing [6]–[8], which is expected to impact the R rs measured during expiration. It is not known to what extent the mechanism is present in children with stable asthma, or whether the ability of R rs to diagnose bronchial obstruction and reversibility is impeded in expiration. With a single excitation frequency, R rs may be described along the respiratory cycle and computed in expiration ( R rs,e) and inspiration ( R rs,i). The aim of this study was to compare R rs,i and R rs,e, their response to salbutamol and respective ability to separate asthmatics from controls. The hypothesis was that the diagnostic value of R rs,e and its response to bronchodilator inhalation is impeded compared with R rs,i. Patients with asthma were diagnosed in the local paediatric pulmonology clinic (Hopital d’enfants, CHU de Nancy, Nancy, France). All had discontinued their bronchodilator therapy ≥12 h prior to the study. Age-matched healthy children served as controls. Written informed consent was obtained and the study was approved by the Ethics Committee (Comite de Protection des Personnes EST III, CHU de Nancy, …

Migrating Laryngeal Foreign Body

We report the case of a 6-year-old boy who presented with a 2-month history of stridor and respiratory difficulty, preceded 1 month earlier by dry cough. The evaluation before admission revealed glottic narrowing due to diffuse inflammatory changes. On examination, the patient was seen to have biphasic stridor and respiratory distress with diminished breath sounds throughout both lung fields. Laryngoscopy revealed multiple polyps and granulation tissue causing marked laryngeal narrowing. No foreign body was detected in the larynx. Elective tracheostomy was performed before proceeding to bronchoscopy. The latter procedure revealed a foreign body in the left main bronchus. One week after the foreign body extraction, repeat bronchoscopy revealed nearly total disappearance of polyps and granulation tissues. The tracheostomy tube was removed and the patient recovered uneventfully. To our knowledge, this is the first reported case of stridor caused by a migrating laryngeal foreign body. A thorough endobronchial examination should be carried out in patients with unexplained laryngeal polyps and granulation tissue.

Proposal for staging airway hemangiomas

Objective To describe a method of airway infantile hemangioma staging using standardized assessment of airway narrowing, and hemangioma location and volume, as determined with endoscopy and CT angiography. Study design Case series with chart review. Setting Tertiary pediatric hospital, 2003-2008. Subjects and methods Subjects included airway hemangioma patients evaluated at a tertiary pediatric hospital. Data collected were age at first symptoms, diagnostic evaluation, percent airway compromise, and estimated hemangioma volume. Data were analyzed with descriptive and Fisher exact statistics. Results Twelve patients were identified and seven had complete data sets. Mean age at first symptoms was 1.9 months (SD 1.09 months, range 0.5-4 months). Evaluation consisted of nasopharyngoscopy, microlaryngoscopy, CT angiography, and/or MRI. Mean laryngeal airway narrowing was estimated at 63.75 percent (SD 19.0%, range 40%-90%). Total hemangioma volume was less in patients with isolated (focal) endolaryngeal hemangiomas compared with airway hemangiomas associated with extralaryngeal (segmental) hemangiomas. Airway hemangioma stages were stage one (5 of 12; 41.6%), stage two (6 of 12; 50.0%), and stage three (1 of 12; 8.3%). Conclusion This method of airway hemangioma staging may be applicable to treatment planning and used to measure treatment outcomes.

Pathogenesis of laryngeal narrowing in patients with multiple system atrophy

1. We do not fully understand the pathogenesis of nocturnal laryngeal stridor in patients with multiple system atrophy (MSA). Recent studies suggest that inspiratory thyroarytenoid (TA) muscle activation has a role in the development of the stridor. 2. The breathing pattern and firing timing of TA muscle activation were determined in ten MSA patients, anaesthetized with propofol and breathing through the laryngeal mask airway, while the behaviour of the laryngeal aperture was being observed endoscopically. 3. Two distinct breathing patterns, i.e. no inspiratory flow limitation (no-IFL) and IFL, were identified during the measurements. During IFL, significant laryngeal narrowing was observed leading to an increase in laryngeal resistance and end-tidal carbon dioxide concentration. Development of IFL was significantly associated with the presence of phasic inspiratory activation of TA muscle. Application of continuous positive airway pressure suppressed the TA muscle activation. 4. The results indicate that contraction of laryngeal adductors during inspiration narrows the larynx leading to development of inspiratory flow limitation accompanied by stridor in patients with MSA under general anaesthesia.