Use of Laryngeal Ultrasound to Observe Laryngeal Movements During Noninvasive Ventilation in Healthy Volunteers.

BACKGROUND: Transnasal fiberoptic laryngoscopy (TFL) has revealed that laryngeal obstruction can hamper assisted ventilation. TFL may be considered invasive, and laryngeal ultrasound (US) could be a noninvasive alternative. The objective of this study was to investigate the feasibility of using laryngeal US to study laryngeal movements in healthy adult volunteers undergoing noninvasive ventilation (NIV) and to compare the observations with those of simultaneous TFL. METHODS: In this cross-sectional study, 30 participants (19 females, age 22-65 y) underwent simultaneous video-recorded TFL and laryngeal US, breathing with and without NIV. Laryngeal US was repeated for anterior and both lateral approaches; the last 5 breaths from each assessment were analyzed. The participants rated discomfort using a numeric rating scale (NRS) from 0 (no discomfort)-10 (worst). Two blinded raters separately described and scored the TFL and laryngeal US recordings, and the findings were subsequently compared. The last 10 laryngeal US recordings were tested for interrater reliability. RESULTS: All participants were successfully assessed using the anterior and both lateral laryngeal US approaches during NIV. Both techniques were well tolerated; 5/30 scored 0 on NRS for TFL and 22/30 for laryngeal US. The visualization rate for all recorded breaths was 99.1% for TFL compared to 81.7% for laryngeal US; overall concordance rate was 84.6%. The discordance rate for the TFL versus laryngeal US observations was 11.1% for vocal fold movements and 11.7% for aryepiglottic fold movements. Interrater reliability showed substantial agreement (0.71). CONCLUSIONS: Laryngeal US emerged as a feasible method to describe laryngeal movements during NIV, providing high-quality observations and high concordance with TFL.

Upper Airway and Translaryngeal Resistance During Mechanical Insufflation-Exsufflation.

BACKGROUND: Mechanical insufflation-exsufflation (MI-E) uses positive and negative pressures to assist weak cough and to help clear airway secretions. Laryngeal visualization during MI-E has revealed that inappropriate upper airway responses can impede its efficacy. However, the dynamics of pressure transmission in the upper airways during MI-E are unclear, as are the relationships among anatomic structure, pressure, and airflow. RESEARCH QUESTION: Can airflow resistance through the upper airway and the larynx feasibly be calculated during MI-E, and if so, how are the pressures transmitted to the trachea? STUDY DESIGN AND METHODS: Cross-sectional study of 10 healthy adults with and without active cough to whom MI-E was provided, using pressure settings +20/-40 cm H2O and ± 40 cm H2O. Airflow and pressure at the level of the facemask were measured using a pneumotachograph, whereas pressure transducers (positioned via transnasal fiber-optic laryngoscopy) recorded pressures above the larynx and within the trachea. Upper airway resistance (Ruaw) and translaryngeal resistance (Rtl) were calculated (in centimeters of water per liter per second) and were compared with direct observations via laryngoscopy. RESULTS: Positive pressures reached the trachea effectively, whereas negative tracheal pressures during exsufflation were approximately half of the intended settings. Insufflation pressure increased slightly when passing through the larynx. Participant effort influenced tracheal pressures and the resistances, with findings consistent with laryngoscopic observations. During MI-E, resistance seems to be dynamic, with Ruaw exceeding Rtl. Inappropriate laryngeal closure increased Rtl during both positive and negative pressures. INTERPRETATION: Ruaw and Rtl can be calculated feasibly during MI-E. The findings indicate different transmission dynamics for positive and negative pressures and that resistances are influenced by participant effort. The findings support using lower insufflation pressures and higher negative pressures in clinical practice.

A speech therapy treatment protocol for exercise induced laryngeal obstruction.

Background: Exercise induced laryngeal obstruction (EILO) is a common cause of exertional breathing problems in young individuals, relevant to 5%-7% of young people. It is 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 that require different therapeutic approaches. Currently applied treatment approaches do not rest on randomized controlled trials (RCTs), and thus evidence-based guidelines cannot be established. This protocol describes the speech therapy treatment approach which is applied to EILO patients in a large prospective RCT called HelpILO. Methods and analysis: Consenting patients consecutively diagnosed with EILO at Haukeland University Hospital are randomized into four treatment arms. Speech therapy is represented in two of these, provided in a structured manner based on general speech therapy principles and abdominal breathing, combined with experience obtained with these patients at our hospital during the last decades. The main outcome measure of HelpILO is changes of laryngoscopically visualized laryngeal adduction, rated at peak exercise before vs. after interventions, using a validated scoring system. Ethics and dissemination: Despite widespread use of speech therapy in patients with EILO, this approach is insufficiently tested in RCTs, and the study is therefore considered ethically appropriate. The study will provide knowledge listed as a priority in a recent statement issued by major respiratory and laryngological societies and requested by clinicians and researchers engaged in this area. The results will be presented at relevant conferences, patient fora, and media platforms, and published in relevant peer reviewed international journals.

Laryngeal response to high-intensity exercise in healthy athletes.

Introduction: Exercise-induced laryngeal obstruction (EILO) is a common cause of exertional breathing problems. The current diagnostic approach rests on evaluation of laryngeal obstruction visualised by laryngoscopy performed continuously throughout a maximal exercise test (continuous laryngoscopy exercise (CLE) test) in patients who present with compatible symptoms. Laryngeal responses to high-intensity exercise in endurance athletes are not well described, potentially leading to inaccurate reference values and increasing the risk of misdiagnosing EILO. Aim: To investigate laryngeal responses to high-intensity exercise in a healthy population of endurance athletes with no self-reported perception of respiratory problems. Methods: A cross-sectional study was conducted at Haukeland University Hospital, Bergen, Norway, inviting amateur and professional athletes with no self-reported breathing problems who performed endurance training minimum four sessions weekly. Thirty-six eligible athletes completed a questionnaire detailing exercise habits and past and current respiratory symptoms. They performed a standardised CLE test from which cardiopulmonary exercise data and corresponding laryngeal responses were recorded. The CLE tests were evaluated in retrospect by two independent raters according to preset criteria providing a CLE score. The CLE score rates the severity of laryngeal obstruction during moderate and maximum exercise on the glottic and supraglottic regions on a scale ranging from 0 (no obstruction) to 3 (maximum obstruction). Results: Twenty-nine (81%) athletes (15 females) aged 15-35 years completed a CLE test. Ten participants (33%) had a supraglottic CLE subscore of 2 or 3. Among these, two also had a glottic CLE subscore of 2 or 3. Notably, none had isolated glottic obstruction. Conclusion: In healthy well-trained endurance athletes with no prior perception of respiratory symptoms, the laryngeal response to high-intensity exercise was diverse. Supraglottic laryngeal obstruction was observed in one-third of the athletes. The findings underline that a diagnosis of EILO should rest on observed laryngeal obstruction supported by compatible symptoms.

Expiratory airflow limitation in adults born extremely preterm: A systematic review and meta-analysis.

Extreme preterm (EP) birth, denoting delivery before the onset of the third trimester, interrupts intrauterine development and causes significant early-life pulmonary trauma, thereby posing a lifelong risk to respiratory health. We conducted a systematic review and meta-analysis to investigate adult lung function following EP birth (gestational age <28 weeks); comparing forced expiratory volume in first second (FEV1), forced vital capacity (FVC), and FEV1/FVC to reference values. Subgroup differences were explored based on timing of birth relative to surfactant use (1991) and bronchopulmonary dysplasia (BPD) status. Systematic searches were performed in Medline, EMBASE, Web of Science and Cochrane Central. Quality assessments were carried out using a modified Newcastle-Ottawa Scale for cohort studies. Sixteen studies encompassing 1036 EP-born adults were included, with 14 studies (n = 787) reporting data as %predicted, and 11 (n = 879) as z-score (not mutually exclusive). Overall mean [95 % confidence interval (CI)] %FEV1 was 85.30 (82.51; 88.09), %FVC was 94.33 (91.74; 96.91), and FEV1/FVC was 79.54 (77.71 to 81.38), all three with high heterogeneity. Overall mean (95 %CI) zFEV1 was -1.05 (-1.21; -0.90) and zFVC was. -0.45 (-0.59; -0.31), both with moderate heterogeneity. Subgroup analyses revealed no difference in FEV1 before versus after widespread use of surfactant, but more impairments after neonatal BPD. This meta-analysis revealed significant airflow limitation in EP-born adults, mostly explained by those with neonatal BPD. FEV1 was more reduced than FVC, and FEV1/FVC was at the lower limit of normal. Although at a group level, most adult EP-born individuals do not meet COPD criteria, these findings are concerning.

When Art Meets Medicine: Use of Flexible Laryngoscopy in Development of Singers' Voices-A Scoping Review.

AIM: To describe what is known from scientific literature on the use of laryngoscopy to enhance singing pedagogy and foster improvements in vocal development. DESIGN: The scoping review methodological framework by Arksey and O'Malley was used. REVIEW METHODS: A systematic search was conducted and peer-reviewed scientific papers were screened through the Rayyan software. Data were extracted and synthesized thematically as narrative text. DATA SOURCES: Searches were carried out on January 2023 in the Web of Science, MEDLINE, PsychINFO, ERIC, Scopus, Google Scholar, Embase and Academic Search Elite databases using relevant keywords to capture evidence, limited to peer-reviewed scientific papers in Nordic or English language. RESULTS: A total of 1413 studies were screened and assessed for eligibility. Two studies met the inclusion criteria reporting results on the use of laryngoscope in development of singers' voices. Different designs were applied and the charted data characteristics varied. Two populations were explored; one cohort of trained professional female musical theater singers and one cohort of students (both sexes) recruited from a music school. Results from examinations with laryngoscopy regarding vowel quality, register quality, anterior-posterior compression scores, and maximum phonation time are presented. None of the retrieved studies aimed to apply laryngoscopy to enhance singing pedagogy. CONCLUSION: Use of laryngoscopy to enable the singer to directly see their song instrument in order to foster improvements in vocal development, have been subject to little exploration. Only two studies were retrieved in our systematic search, none aimed to study potential pedagogical aspects of applying laryngoscopy. These findings support further investigation of the users', especially singers' and voice teachers' perspective, to guide and inform best practice for use of laryngoscopy as a pedagogical tool in a song development context.

Prevalence and impact of exercise-induced laryngeal obstruction in asthma: a study protocol for a cross-sectional and longitudinal study.

INTRODUCTION: Exercise-induced laryngeal obstruction (EILO) and exercise-induced asthma can cause troublesome respiratory symptoms that can be difficult to distinguish between. Further, there is now a growing appreciation that the two conditions may coexist, complicating the interpretation of symptoms. The primary aim of this study is to investigate the prevalence of EILO in patients with asthma. Secondary aims include evaluation of EILO treatment effects and investigation of comorbid conditions other than EILO in patients with asthma. METHODS AND ANALYSIS: The study will be conducted at Haukeland University Hospital and Voss Hospital in Western Norway, and enrol 80-120 patients with asthma and a control group of 40 patients without asthma. Recruitment started in November 2020, and data sampling will continue until March 2024. Laryngeal function will be assessed at baseline and at a 1-year follow-up, using continuous laryngoscopy during high-intensity exercise (CLE). Immediately after the EILO diagnosis is verified, patients will be treated with standardised breathing advice guided by visual biofeedback from the laryngoscope video screen. The primary outcome will be the prevalence of EILO in patients with asthma and control participants. Secondary outcomes include changes in CLE scores, asthma-related quality of life, asthma control and number of the asthma exacerbations, as assessed between baseline and the 1-year follow-up. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Regional Committee for Medical and Health Research Ethics, Western Norway, (ID number 97615). All participants will provide signed informed consent before enrolment. The results will be presented in international journals and conferences. TRIAL REGISTRATION NUMBER: NCT04593394.

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

BACKGROUND: 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. OBJECTIVES: We sought to establish consensus-based diagnostic criteria and methods for VCD/ILO. METHODS: 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. RESULTS: 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. CONCLUSIONS: This Delphi study reached consensus on multiple aspects of VCD/ILO diagnosis and can inform clinical practice and facilitate research.

Use of inhaled ipratropium bromide to improve exercise-induced laryngeal obstruction cannot be recommended.

Introduction: Exercise-induced laryngeal obstruction (EILO) is a common cause of exertional breathing problems in young adults. Current management generally consists of breathing advice, speech therapy, inspiratory muscle training or supraglottoplasty in highly motivated subjects with supraglottic collapse. Inhaled ipratropium bromide (IB) is a muscarinic receptor antagonist used to treat asthma that is suggested in a few reports to improve EILO symptoms. The aim of the present study was to investigate effects of inhaled IB in EILO diagnosed by continuous laryngoscopy exercise (CLE) test and classified by CLE scores. Methods: A randomised crossover trial was conducted at Haukeland University Hospital, Bergen, Norway, enrolling participants diagnosed with EILO defined by characteristic symptoms and CLE score ≥3 (range 0-12). Two consecutive CLE tests were performed within 2 weeks, one test with and one test without prior administration of inhaled IB in a randomised order. Main outcomes were the CLE score, dyspnoea measured using a modified BORG scale (range 0-10) and cardiopulmonary exercise data provided by the CLE test. Results: 20 participants (14 females) aged 12-25 years participated, and all ran to exhaustion on both tests. Mean CLE score, BORG score and peak oxygen consumption were similar in tests performed with and without IB; mean differences (95% confidence interval) were 0.08 (-0.28-0.43), 0.35 (-0.29-0.99) and -0.4 (-1.9-1.1) mL·kg-1·min-1, respectively. Conclusion: Inhaled IB did not improve CLE score, dyspnoea or exercise capacity in subjects with EILO. The study does not support the use of inhaled IB to treat EILO.

Is it feasible to perform a continuous laryngoscopy exercise test with a cold air inhalate? A case report.

The continuous laryngoscopy exercise (CLE) test can be combined with breathing cold air. Combining the CLE test and cold air does not cause excessive discomfort. The indicated laryngeal responses with cold air support the need for more research. https://bit.ly/3AChJ7V.

Exercise Training in Duchenne Muscular Dystrophy: A Systematic Review and Meta-Analysis.

OBJECTIVE:  To evaluate the effects and safety of exercise training, and to determine the most effective exercise intervention for people with Duchenne muscular dystrophy. Exercise training was compared with no training, placebo or alternative exercise training. Primary outcomes were functioning and health-related quality of life. Secondary outcomes were muscular strength, endurance and lung function.  Data sources: A systematic literature search was conducted in Medline, EMBASE, CINAHL, Cochrane Central, PEDro and Scopus.  Study selection and data extraction: Screening, data extraction, risk of bias and quality assessment were carried out. Risk of bias was assessed using the Cochrane Collaborations risk of bias tools. The certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. DATA SYNTHESIS: Twelve studies with 282 participants were included. A narrative synthesis showed limited or no improvements in functioning compared with controls. Health-related quality of life was assessed in only 1 study. A meta-analysis showed a significant difference in muscular strength and endurance in favour of exercise training compared with no training and placebo. However, the certainty of evidence was very low. CONCLUSION: Exercise training may be beneficial in Duchenne muscular dystrophy, but the evidence remains uncertain. Further research is needed on exercise training to promote functioning and health-related quality of life in Duchenne muscular dystrophy.

Adjustments of non-invasive ventilation and mechanically assisted cough by combining ultrasound imaging of the larynx with transnasal fibre-optic laryngoscopy: a protocol for an experimental study.

INTRODUCTION: Application of non-invasive positive airway pressure may provoke laryngeal responses that obstruct the airways, especially in patients with disturbed laryngeal control. To control and adjust for this, transnasal fibre-optic laryngoscopy (TFL) is used to visualise laryngeal movements during therapeutic interventions. Being an invasive procedure, this may be unpleasant for patients. The aim of this study is to evaluate if ultrasound (US) imaging of the larynx may be used as an alternative less invasive diagnostic tool for evaluating the upper airway responses to non-invasive ventilation (NIV) and mechanical insufflation-exsufflation (MI-E). METHODS AND ANALYSIS: This protocol presents an experimental cross-sectional study of a novel method to study laryngeal responses in adult healthy volunteers (n=30). The participants will be assessed with simultaneous TFL and laryngeal US imaging (anterior and lateral approaches) during NIV and MI-E therapy. Additionally, airflow and pressure signals will be registered during the procedures. The primary outcome is whether laryngeal US is a feasible method to study laryngeal responses and, if so, to compare the laryngeal responses visualised with TFL and US. The participants' perception of the examinations will be recorded. Secondary outcomes include airflow curve shapes and calculated ventilation volumes during the interventions. ETHICS AND DISSEMINATION: The study has been approved by The Regional Committee for Medical Research Ethics in Norway, and registered in ClinicalTrials.gov. Results will be disseminated through peer-reviewed journals, presentation of scientific abstracts at international medical conventions and oral presentations in relevant medical conventions. TRIAL REGISTRATION NUMBER: NCT04586855.

Tracking of lung function from 10 to 35 years after being born extremely preterm or with extremely low birth weight.

BACKGROUND: Lifelong pulmonary consequences of being born extremely preterm or with extremely low birth weight remain unknown. We aimed to describe lung function trajectories from 10 to 35 years of age for individuals born extremely preterm, and address potential cohort effects over a period that encompassed major changes in perinatal care. METHODS: We performed repeated spirometry in three population-based cohorts born at gestational age ≤28 weeks or with birth weight ≤1000 g during 1982-85, 1991-92 and 1999-2000, referred to as extremely preterm-born, and in term-born controls matched for age and gender. Examinations were performed at 10, 18, 25 and 35 years. Longitudinal data were analysed using mixed models regression, with the extremely preterm-born stratified by bronchopulmonary dysplasia (BPD). RESULTS: We recruited 148/174 (85%) eligible extremely preterm-born and 138 term-born. Compared with term-born, the extremely preterm-born had lower z-scores for forced expiratory volume in 1 s (FEV1) at most assessments, the main exceptions were in the groups without BPD in the two youngest cohorts. FEV1 trajectories were largely parallel for the extremely preterm- and term-born, also during the period 25-35 years that includes the onset of the age-related decline in lung function. Extremely preterm-born had lower peak lung function than term-born, but z-FEV1 values improved for each consecutive decade of birth (p=0.009). More extremely preterm-than term-born fulfilled the spirometry criteria for chronic obstructive pulmonary disease, 44/148 (30%) vs 7/138 (5%), p<0.001. CONCLUSIONS: Lung function after extremely preterm birth tracked in parallel, but significantly below the trajectories of term-born from 10 to 35 years, including the incipient age-related decline from 25 to 35 years. The deficits versus term-born decreased with each decade of birth from 1980 to 2000.

From bedside to bench - In vivo and in vitro evaluation of mechanically assisted cough treatment in a patient with bulbar Amyotrophic Lateral Sclerosis.

When the ability to cough is impaired, secretion clearance may be assisted and augmented by Mechanical Insufflation-Exsufflation (MI-E) treatment. In patients with Amyotrophic Lateral Sclerosis, the efficacy of MI-E may be hampered by counterproductive upper airway responses. Careful adjustment of MI-E settings can be beneficial. During the disease progression, a 41-year-old woman with bulbar Amyotrophic Lateral Sclerosis experienced that treatment with MI-E was exhausting and inefficient. Despite adjustments of settings, all treatment led to retching. A change of MI-E device led to more effective treatment. A bench test revealed variations in flow and pressure waveforms in the two devices. When MI-E treatment fails, differences in equipment delivery need to be considered in addition to the adjustment of MI-E settings.

Reliability of translaryngeal airway resistance measurements during maximal exercise.

Objective: Exercise-induced laryngeal obstruction is an important cause of exertional dyspnoea. The diagnosis rests on visual judgement of relative changes of the laryngeal inlet during continuous laryngoscopy exercise (CLE) tests, but we lack objective measures that reflect functional consequences. We aimed to investigate repeatability and normal values of translaryngeal airway resistance measured at maximal intensity exercise. Methods: 31 healthy nonsmokers without exercise-related breathing problems were recruited. Participants performed two CLE tests with verified positioning of two pressure sensors, one at the tip of the epiglottis (supraglottic) and one by the fifth tracheal ring (subglottic). Airway pressure and flow data were continuously collected breath-by-breath and used to calculate translaryngeal resistance at peak exercise. Laryngeal obstruction was assessed according to a standardised CLE score system. Results: Data from 26 participants (16 females) with two successful tests and equal CLE scores on both test sessions were included in the translaryngeal resistance repeatability analyses. The coefficient of repeatability (CR) was 0.62 cmH2O·L-1·s-1, corresponding to a CR% of 21%. Mean±sd translaryngeal airway resistance (cmH2O·L-1·s-1) in participants with no laryngeal obstruction (n=15) was 2.88±0.50 in females and 2.18±0.50 in males. Higher CLE scores correlated with higher translaryngeal resistance in females (r=0.81, p<0.001). Conclusions: This study establishes translaryngeal airway resistance obtained during exercise as a reliable parameter in respiratory medicine, opening the door for more informed treatment decisions and future research on the role of the larynx in health and disease.

Conundrums in the breathless athlete; exercise-induced laryngeal obstruction or asthma?

PURPOSE: Exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) are the two disorders commonly considered when athletes complain of exertional dyspnea. They are highly different but often confused. We aimed to address this diagnostic challenge and its consequences in elite athletes. METHODS: We included all athletes competing at national or international level, referred to our institution for workup for EILO during 2013-2016. We diagnosed EILO from video-recorded laryngoscopy performed during maximal cardiopulmonary treadmill exercise (CLE test). Symptoms and previous diagnostic evaluations were obtained from referral letters and chart reviews. RESULTS: Exercise-induced laryngeal obstruction was diagnosed in 73/101 referred athletes, of whom 70/73 had moderate/severe supraglottic obstruction and 3/73 had primarily glottic obstruction with only minor supraglottic involvement. Of the 73 athletes with EILO, we were able to identify objective tests for asthma in 55 participants, of whom 22 had findings supporting asthma. However, 58/73 had used asthma therapy at some time previously, with current use in 28. Only three reported that asthma medication had improved their exercise-related breathing problems, two of whom with tests confirming asthma. Treatment for EILO improved breathing problems in all but four. CONCLUSIONS: Objective testing verified EILO in most of the referred athletes. EILO coexisting with asthma was common, and large proportions had used asthma medication; however, few reported effect on exercise-related breathing problems. Unexplained persistent exertional dyspnea must not lead to indiscriminate escalation of asthma treatment, but instead incite investigation for EILO, either as a co-morbidity or as a differential diagnosis.

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.