Exercise-Associated Dyspnea and Stridor: Thinking Beyond Asthma

Prevalence and characterisation of exercise-induced laryngeal obstruction in patients with exercise-induced dyspnoea

OBJECTIVE

The prevalence of exercise-induced laryngeal obstruction is largely unknown. This study aimed to evaluate the prevalence of this condition in a selected study population of patients with exercise-induced dyspnoea.

METHOD

A retrospective analysis was conducted of demographic data, co-morbidities, medication, symptoms, performance level of sporting activities, continuous laryngoscopy exercise test results and subsequent treatment.

RESULTS

Data from 184 patients were analysed. The overall prevalence of exercise-induced laryngeal obstruction in the study population was 40 per cent, and the highest prevalence was among females aged under 18 years (61 per cent). However, a high prevalence among males aged under 18 years (50 per cent) and among adults regardless of gender (34 per cent) was also found.

CONCLUSION

The prevalence of exercise-induced laryngeal obstruction is clinically relevant regardless of age and gender. Clinicians are encouraged to consider exercise-induced laryngeal obstruction as a possible diagnosis in patients suffering from exercise-induced respiratory symptoms. No single characteristic that can distinguish exercise-induced laryngeal obstruction from other similar conditions was identified.

Computational fluid dynamics of upper airway aerodynamics for exercise-induced laryngeal obstruction: A feasibility study

Objective

Use of computational fluid dynamic (CFD) simulations to measure the changes in upper airway geometry and aerodynamics during (a) an episode of Exercise-Induced Laryngeal Obstruction (EILO) and (b) speech therapy exercises commonly employed for patients with EILO.

Methods

Magnetic resonance imaging stills of the upper airway including the nasal and oral cavities from an adult female were used to re-construct three-dimensional geometries of the upper airway. The CFD simulations were used to compute the maximum volume flow rate (l/s), pressure (Pa), airflow velocity (m/s) and area of cross-section opening in eight planes along the vocal tract, separately for inhalation and exhalation.

Results

Numerical predictions from three-dimensional geometrical modeling of the upper airway suggest that the technique of nose breathing for inhalation and pursed lip breathing for exhalation show most promising pressure conditions and cross-sectional diameters for rescue breathing exercises. Also, if EILO is due to the constriction at the vocal fold level, then a quick sniff may also be a proper rescue inhalation exercise. EILO affects both the inspiratory and the expiratory phases of breathing.

Conclusions

A prior knowledge of the supraglottal aerodynamics and the corresponding upper airway geometry from CFD analysis has the potential to assist the clinician in choosing the most effective rescue breathing technique for optimal functional outcome of speech therapy intervention in patients with EILO and in understanding the pathophysiology of EILO on a case-by-case basis with future studies.

Level of Evidence

4.

Less Social Deprivation Is Associated With Better Health-Related Quality of Life in Asthma and Is Mediated by Less Anxiety and Better Sleep Quality

BACKGROUND

Previous studies on health-related quality of life (HRQoL) in asthma have mainly focused on clinical and environmental determinants. Little is known about the role of social determinants on HRQoL in asthma.

OBJECTIVES

We aimed to investigate the association between social deprivation and HRQoL in asthma.

METHODS

A total of 691 adult asthmatics from Canada, India, New Zealand, and the United Kingdom were administered a digital questionnaire containing demographic information and questions about social and psychological attributes, sleep disturbances, and alcohol abuse. HRQoL was measured using the Short Form of the Chronic Respiratory Questionnaire (SF-CRQ). We analyzed the direct and indirect relationships between social deprivation and HRQoL using structural equation models with social deprivation as a latent variable. We tested for mediation via anxiety, depression, sleep disturbances, and alcohol abuse.

RESULTS

We found that less social deprivation (latent variable) was directly associated with better SF-CRQ domain scores such as dyspnea (regression coefficient β: 0.33; 95% confidence interval [CI]: 0.07 to 0.58), fatigue (β: 0.39; 95% CI: 0.14 to 0.64), and emotional function (β: 0.37; 95% CI: 0.11 to 0.62), but with the worse mastery score (β: -0.29; 95% CI: -0.55 to -0.03); however, those associations varied across participating countries. We also observed that among all individual social deprivation indicators, education, companionship, emotional support, instrumental support, and social isolation were directly associated with HRQoL, and the relationship between social deprivation and HRQoL was mediated through anxiety and sleep disturbances.

CONCLUSIONS

Our results demonstrated that less social deprivation was directly, and indirectly through less anxiety and better sleep quality, associated with better HRQoL in asthma.

Exercise-induced laryngeal obstruction (EILO) in athletes: a narrative review by a subgroup of the IOC Consensus on 'acute respiratory illness in the athlete'

Exercise-induced laryngeal obstruction (EILO) is caused by paradoxical inspiratory adduction of laryngeal structures during exercise. EILO is an important cause of upper airway dysfunction in young individuals and athletes, can impair exercise performance and mimic lower airway dysfunction, such as asthma and/or exercise-induced bronchoconstriction. Over the past two decades, there has been considerable progress in the recognition and assessment of EILO in sports medicine. EILO is a highly prevalent cause of unexplained dyspnoea and wheeze in athletes. The preferred diagnostic approach is continuous visualisation of the larynx (via laryngoscopy) during high-intensity exercise. Recent data suggest that EILO consists of different subtypes, possibly caused via different mechanisms. Several therapeutic interventions for EILO are now in widespread use, but to date, no randomised clinical trials have been performed to assess their efficacy or inform robust management strategies. The aim of this review is to provide a state-of-the-art overview of EILO and guidance for clinicians evaluating and treating suspected cases of EILO in athletes. Specifically, this review examines the pathophysiology of EILO, outlines a diagnostic approach and presents current therapeutic algorithms. The key unmet needs and future priorities for research in this area are also covered.

Evaluating Children and Adolescents with Suspected Exercise Induced Asthma: Real Life Data

OBJECTIVE

Exercise-induced bronchoconstriction (EIB) occurs frequently in children and adolescents and may be a sign of insufficient asthma control. EIB is often evaluated by respiratory symptoms, spirometry, eNO measurement and methacholine testing (MCT) instead of time consuming exercise test. Aim of this study was to analyse the amount of patients for which an exercise challenge in a cold chamber (ECC) was needed for a clear EIB diagnosis, to characterize EIB phenotypes and the incidence of exercise induced laryngeal obstruction (EILO) in a large cohort of patients with EIB.

METHODS

A retrospective analysis was performed in 595 children and adolescents (mean age 12.1 years) with suspected EIB from January 2014 to December 2018. Complete data sets of skin prick test, spirometry, eNO and MCT were available from 336 patients.

RESULTS

An ECC to confirm the EIB diagnosis was performed in 125 (37.2%) of patients. Three EIB phenotypes were detected: group 1: EIB without allergic sensitization (n=159); group 2: EIB with other than house dust mite (HDM) sensitization (n=87) and group 3: EIB with HDM sensitization (n=90). MCT and eNO showed significant differences between the subgroups: An eNO>46 ppb and/or a MCT<0.1 mg was found in 23.9% vs. 50.6% vs. 57.8% in group 1-3, respectively. Significantly more patients suffered from EILO in group 1 compared to group 2 and 3 (n=13 vs. n=1).

CONCLUSION

EIB without sensitization is as often as EIB with sensitization. In patients without sensitization, EILO has to be considered as a possible cause of symptoms during exercise.

Exercise-induced Laryngeal Obstruction: Protocol for a Randomized Controlled Treatment Trial

BACKGROUND

Exercise-induced laryngeal obstruction (EILO) is a common cause of exertional breathing problems in young individuals, caused by paradoxical inspiratory adduction of laryngeal structures, and diagnosed by continuous visualization of the larynx during high-intensity exercise. Empirical data suggest that EILO consists of different subtypes, possibly requiring different therapeutic approaches. Currently applied treatments do not rest on randomized controlled trials, and international guidelines based on good evidence can therefore not be established. This study aims to provide evidence-based information on treatment schemes commonly applied in patients with EILO.

METHODS AND ANALYSIS

Consenting patients consecutively diagnosed with EILO at Haukeland University Hospital will be randomized into four non-invasive treatment arms, based on promising reports from non-randomized studies: (A) standardized information and breathing advice only (IBA), (B) IBA plus inspiratory muscle training, (C) IBA plus speech therapy, and (D) IBA plus inspiratory muscle training and speech therapy. Differential effects in predefined EILO subtypes will be addressed. Patients failing the non-invasive approach and otherwise qualifying for surgical treatment by current department policy will be considered for randomization into (E) standard or (F) minimally invasive laser supraglottoplasty or (G) no surgery. Power calculations are based on the main outcomes, laryngeal adduction during peak exercise, rated by a validated scoring system before and after the interventions.

ETHICS AND DISSEMINATION

The study will assess approaches to EILO treatments that despite widespread use, are insufficiently tested in structured, verifiable, randomized, controlled studies, and is therefore considered ethically sound. The study will provide knowledge listed as a priority in a recent statement issued by the European Respiratory Society, requested by clinicians and researchers engaged in this area, and relevant to 5-7% of young people. Dissemination will occur in peer-reviewed journals, at relevant media platforms and conferences, and by engaging with patient organizations and the healthcare bureaucracy.

Clinical responses following inspiratory muscle training in exercise-induced laryngeal obstruction

Purpose

Exercise-induced laryngeal obstruction (EILO) is relatively common in young people. Treatment rests on poor evidence; however, inspiratory muscle training (IMT) has been proposed a promising strategy. We aimed to assess laryngeal outcomes shortly after IMT, and to compare self-reported symptoms with a control group 4–6 years later.

Methods

Two groups were retrospectively identified from the EILO-register at Haukeland University Hospital, Norway; one group had received only information and breathing advice (IBA), and another additionally IMT (IBA + IMT). At diagnosis, all participants performed continuous laryngoscopy during exercise (CLE), with findings split by glottic and supraglottic scores, and completed a questionnaire mapping exercise-related symptoms. After 2–4 weeks, the IBA + IMT-group was re-evaluated with CLE-test. After 4–6 years, both groups were re-assessed with a questionnaire.

Results

We identified 116 eligible patients from the EILO-register. Response rates after 4–6 years were 23/58 (40%) and 32/58 (55%) in the IBA and IBA + IMT-group, respectively. At diagnosis, both groups rated symptoms similarly, but laryngeal scores were higher in the IBA + IMT-group (P = 0.003). After 2–4 weeks, 23/32 in the IBA + IMT-group reported symptom improvements, associated with a decrease of mainly glottic scores (1.7–0.3; P < 0.001), contrasting unchanged scores in the 9/32 without symptom improvements. After 4–6 years, exercise-related symptoms and activity levels had decreased to similar levels in both groups, with no added benefit from IMT; however, full symptom resolution was reported by only 8/55 participants.

Conclusion

Self-reported EILO symptoms had improved after 4–6 years, irrespective of initial treatment. Full symptom resolution was rare, suggesting individual follow-up should be offered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00405-021-07214-5.

[Vocal cord dysfunction in athletes: Interest of rehabilitation to effort]

INTRODUCTION

Vocal Cord Dysfunction (VCD) is a syndrome characterized by paradoxical adduction of the vocal folds during breathing. Its non-specific clinical manifestations frequently lead to misdiagnosis and delay in its treatment. The treatment of VCD is not pharmacological but rehabilitative and remains poorly appreciated.

OBSERVATION

In this clinical case we describe a 16-year-old female judoka who presented with effort intolerance associated with occasional dyspnea, which had suddenly worsened over the preceding few months so that in now produced sudden respiratory difficulty, mainly during intense and sudden efforts. After a period where her symptoms were confused with asthma, she was diagnosed with exercise-induced VCD. Her treatment was aimed to: (a) rehabilitate respiratory mechanics in order to eliminate abdominal-thoracic asynchrony, (b) rehabilitate naso-nasal breathing, (c) train her to control abdominal-diaphragmatic breathing at rest and then during effort, (d) train her to use ventilatory control as soon as prodromal symptoms appear in order to prevent the development of stridor or complete closure of the vocal folds (at rest and then progressively during exercise).

CONCLUSION

Following the implementation of these rehabilitation strategies to correct her ventilatory and dyskinetic issues, the patient no longer develops respiratory discomfort during exercise, including during judo competitions.

Reliability of maximum oxygen uptake in cardiopulmonary exercise testing with continuous laryngoscopy

Aims

A cardiopulmonary exercise test (CPET) is the gold standard to evaluate symptom-limiting exercise intolerance, while continuous laryngoscopy performed during exercise (CLE) is required to diagnose exercise-induced laryngeal obstruction. Combining CPET with CLE would save time and resources; however, the CPET data may be distorted by the extra equipment. We therefore aimed to study whether CPET with CLE influences peak oxygen uptake (V′_O2peak) and other gas exchange parameters when compared to a regular CPET.

Methods

Forty healthy athletes without exercise-related breathing problems, 15–35 years of age, performed CPET to peak exercise with and without an added CLE set-up, in randomised order 2–4 days apart, applying an identical computerised treadmill protocol.

Results

At peak exercise, the mean difference (95% confidence interval) between CPET with and without extra CLE set-up for V′_O2peak, respiratory exchange ratio (RER), minute ventilation (V′_E) and heart rate (HR) was 0.2 (−0.4 to 0.8) mL·kg⁻¹·min⁻¹, 0.01(−0.007 to 0.027) units, 2.6 (−1.3 to 6.5) L·min⁻¹ and 1.4 (−0.8 to 3.5) beats·min⁻¹, respectively. Agreement (95% limits of agreement) for V′_O2peak, RER and V′_E was 0.2 (±3.7) mL·kg⁻¹·min⁻¹, 0.01 (±0.10) units and 2.6 (±24.0) L·min⁻¹, respectively. No systematic or proportional bias was found except for the completed distance, which was 49 m (95% CI 16 to 82 m) longer during CPET.

Conclusion

Parameters of gas exchange, including V′_O2peak and RER, obtained from a maximal CPET performed with the extra CLE set-up can be used interchangeably with data obtained from standard CPET, thus preventing unnecessary additional testing.

Cardiopulmonary exercise testing (CPET) with concurrent continuous laryngoscopy provides reliable measures for maximal oxygen consumption and other CPET datahttps://bit.ly/36wVJhb

The Need for Testing-The Exercise Challenge Test to Disentangle Causes of Childhood Exertional Dyspnea

Exertional dyspnea is a common symptom in childhood which can induce avoidance of physical activity, aggravating the original symptom. Common causes of exertional dyspnea are exercise induced bronchoconstriction (EIB), dysfunctional breathing, physical deconditioning and the sensation of dyspnea when reaching the physiological limit. These causes frequently coexist, trigger one another and have overlapping symptoms, which can impede diagnoses and treatment. In the majority of children with exertional dyspnea, EIB is not the cause of symptoms, and in asthmatic children it is often not the only cause. An exercise challenge test (ECT) is a highly specific tool to diagnose EIB and asthma in children. Sensitivity can be increased by simulating real-life environmental circumstances where symptoms occur, such as environmental factors and exercise modality. An ECT reflects daily life symptoms and impairment, and can in an enjoyable way disentangle common causes of exertional dyspnea.

The interest of rehabilitation of respiratory disorders in athletes: Myth or reality?

BACKGROUND

Healthy trained athletes generally have an "overbuilt" respiratory system in order to face the huge ventilation and gas-exchange demand imposed by strenuous exercise. Athletes frequently complain of respiratory symptoms regardless of whether they have a diagnosed respiratory disease, therefore evoking a kind of respiratory limitation during exercise. Some respiratory pathologies athletes present are closely linked to exercise and include asthma, exercise-induced bronchoconstriction (EIB) or exercise-induced laryngeal obstruction. Management of asthma and EIB are mainly based on pharmacological treatments. However, many athletes still complain of respiratory symptoms despite optimal pharmacological treatments, which highlights the need for non-pharmacological approaches including breathing retraining, inspiratory muscle training and/or laryngeal exercise performed under the guidance of a physiotherapist in this specific population.

OBJECTIVES

With this literature overview, we aimed to report evidence supporting the interest of rehabilitation for athletes with respiratory disorders and discuss whether inspiratory muscle training programs can improve performance in healthy athletes.

METHODS

We searched MEDLINE and Cochrane databases for trials, reviews and meta-analyses assessing respiratory rehabilitation and muscle training programs in athletes by using the MesH terms "athletes", "asthma", "dyspnea", "rehabilitation" and "education" published from January 2010 to March 2020. The selection of articles was based on the author's expertise to elaborate this review of the literature.

RESULTS

Major findings suggest that breathing retraining may help asthmatic athletes better control their respiratory symptoms and that inspiratory muscle training may improve respiratory symptoms of exercise-induced laryngeal obstruction in athletes. Improvement of performance by respiratory muscle training still remains controversial.

CONCLUSIONS

Respiratory rehabilitation could be of interest in the specific population of athletes but should be further evaluated to improve the level of evidence of such strategies.

The feasibility of eucapnic voluntary hyperpnoea for the diagnosis of exercise-induced bronchoconstriction in a community pulmonary practice

OBJECTIVE

Exercise-induced bronchoconstriction (EIB) is a common condition and is typically treated empirically based on symptoms alone. However, symptoms of EIB are typically nonspecific. Objective testing with eucapnic voluntary hyperpnea (EVH) is a sensitive and specific method to diagnose EIB and may suggest alternative etiologies such as exercise-induced laryngeal obstruction (EILO). To this point, EVH has been primarily utilized in large academic centers and in elite athletes. We intend to discuss the feasibility and clinical application of utilizing EVH to diagnose EIB in a community-based pulmonary practice.

METHODS

Retrospective analysis of 62 patients who completed EVH at The Oregon Clinic Pulmonary Clinic. Patients with inspiratory flow volume loop flattening or clinical symptoms were assessed by otolaryngology for evidence of EILO.

RESULTS

61 of 62 patients were included in the final analysis. 52 of 61 patients (85%) achieved an interpretable test with a maximum voluntary ventilation (MVV) >60%. There was no difference in baseline spirometry or patient characteristics between those who were able to reach an MVV >60% and those who did not. 14 (23%) patients were diagnosed with EIB, 18 (30%) with EILO, and 4 (7%) were diagnosed with both EIB and EILO. Only 1 patient had a non-diagnostic evaluation with MVV <60% and negative for EIB and EILO.

CONCLUSIONS

EVH is a feasible diagnostic modality to evaluate for EIB in a community pulmonary practice and may suggest alternative conditions such as EILO. Accurate diagnosis is paramount to prescribing proper therapy, decreasing inappropriate medication use, and relieving exercise-induced symptoms.

High prevalence of exercise-induced stridor during Parkrun: a cross-sectional field-based evaluation

BACKGROUND AND OBJECTIVE

The differential diagnosis for exercise-associated breathlessness is broad, however, when a young athletic individual presents with respiratory symptoms, they are most often prescribed inhaler therapy for presumed exercise-induced asthma (EIA). The purpose of this study was therefore to use a novel sound-based approach to assessment to evaluate the prevalence of exertional respiratory symptoms and characterise abnormal breathing sounds in a large cohort of recreationally active individuals.

METHODS

Cross-sectional field-based evaluation of individuals completing Parkrun. PHASE 1: Prerace, clinical assessment and baseline spirometry were conducted. At peak exercise and immediately postrace, breathing was monitored continuously using a smartphone. Recordings were analysed retrospectively and coded for signs of the predominant respiratory noise. PHASE 2: A subpopulation that reported symptoms with at least one audible sign of respiratory dysfunction was randomly selected and invited to attend the laboratory on a separate occasion to undergo objective clinical workup to confirm or refute EIA.

RESULTS

Forty-eight participants (22.6%) had at least one audible sign of respiratory dysfunction; inspiratory stridor (9.9%), expiratory wheeze (3.3%), combined stridor+wheeze (3.3%), cough (6.1%). Over one-third of the cohort (38.2%) were classified as symptomatic. Ten individuals attended a follow-up appointment, however, only one had objective evidence of EIA.

CONCLUSIONS

The most common audible sign, detected in approximately 1 in 10 individuals, was inspiratory stridor, a characteristic feature of upper airway closure occurring during exercise. Further work is now required to further validate the precision and feasibility of this diagnostic approach in cohorts reporting exertional breathing difficulty.

Is the healthy respiratory system built just right, overbuilt, or underbuilt to meet the demands imposed by exercise?

In the healthy, untrained young adult, a case is made for a respiratory system (airways, pulmonary vasculature, lung parenchyma, respiratory muscles, and neural ventilatory control system) that is near ideally designed to ensure a highly efficient, homeostatic response to exercise of varying intensities and durations. Our aim was then to consider circumstances in which the intra/extrathoracic airways, pulmonary vasculature, respiratory muscles, and/or blood-gas distribution are underbuilt or inadequately regulated relative to the demands imposed by the cardiovascular system. In these instances, the respiratory system presents a significant limitation to O₂ transport and contributes to the occurrence of locomotor muscle fatigue, inhibition of central locomotor output, and exercise performance. Most prominent in these examples of an "underbuilt" respiratory system are highly trained endurance athletes, with additional influences of sex, aging, hypoxic environments, and the highly inbred equine. We summarize by evaluating the relative influences of these respiratory system limitations on exercise performance and their impact on pathophysiology and provide recommendations for future investigation.