Clinical presentation, assessment, and management of inducible laryngeal obstruction

Long-Term Outcomes of Respiratory Retraining Therapy for Exercise-Induced Laryngeal Obstruction

OBJECTIVE

To assess the long-term outcomes and efficacy of respiratory retraining therapy in patients with exercise-induced laryngeal obstruction (EILO).

METHODS

A retrospective chart review and prospective questionnaire-based survey were conducted on 88 patients who received respiratory retraining therapy for EILO at our institution over the past 5 years RESULTS: Thirty-four patients were included in the final analysis, with a mean age at symptom onset and age at initial evaluation of 13.67 ± 2.96 and 15.12 ± 3.48, respectively. We found a statistically significant difference in the pretreatment and post-treatment Dyspnea indices following respiratory retraining therapy, with a mean difference of 12.03 ± 7.18 (P < 0.001). When asked about the effectiveness of respiratory retraining therapy, the majority of patients (n = 28) reported improvement (13.3% "a little," 13.3% "somewhat better," 53.3% ("a lot better," and 13.3% complete resolution of symptoms. Only two patients (6.7%) responded that their breathing "did not get better." The most effective therapy techniques cited by patients were abdominal breathing (n = 10), ratio breathing (n = 5), and pursed lips or "straw" breathing (n = 5).

CONCLUSIONS

Respiratory retraining therapy represents an effective technique in both the short-term and long-term management of EILO. This therapy remains the first line in the management of EILO due to its ease of administration, non-invasive nature, and durable effect on breathing function.

Protocol for a scoping review to map health outcomes in individuals with inducible laryngeal obstruction

BACKGROUND

Inducible laryngeal obstruction causes narrowing of the laryngeal aperture in response to external triggers. Outcomes are measured in inducible laryngeal obstruction to monitor changes in health status over time.

METHODS

This study is a scoping review based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. The review will be guided by the following research question: 'What health outcomes are measured in studies including people with inducible laryngeal obstruction?' The research question was validated using the Population-Concept-Context framework according to the methodology for Joanna Briggs Institution Scoping Reviews. Relevant peer-reviewed studies and grey literature conducted over the last 40 years will be identified from electronic databases including AMED, CINAHL, Embase, EMCARE, MEDLINE, OVID, PubMed and PsycINFO. The search strings 'inducible laryngeal obstruction', 'ILO', 'vocal cord dysfunction', 'VCD', 'paradoxical vocal fold motion', 'PVFM', 'outcome', 'measure', 'measurement instrument', 'assessment', 'scale', 'questionnaire' will be combined using Boolean logic. An independent reviewer will conduct title screening; two independent reviewers will conduct abstract and full article screening, followed by data extraction by two reviewers. Analyses will be conducted appropriate to the findings.

DISCUSSION

The review will document evidence of health outcomes measured in inducible laryngeal obstruction, identifying measurement characteristics and potential utility. Collating studies may identify gaps in coverage, the need for novel tools, and for standardisation for clinical and research purposes.

WHAT THIS PAPER ADDS

What is already known on the subject Inducible laryngeal obstruction causes narrowing of the laryngeal aperture in response to external triggers. Outcomes are measured in inducible laryngeal obstruction to monitor changes in health status over time. Currently, there are no standardised outcome measures for measuring the effects of interventions in inducible laryngeal obstruction (ILO). What this paper adds to existing knowledge Assessment of health can be measured in a variety of ways. Physiological, radiological and biochemical measurements of impairment are more common historically but there are a lot of outcomes of other factors now including subjective measures of functional status and health-related quality of life, with data collected directly from patients. This study will allow us to scope the literature to see the health outcomes being measured in ILO to attempt to standardise and develop future health outcomes. What are the potential or actual clinical implications of this work? The review will document evidence of health outcomes measured in inducible laryngeal obstruction, identifying measurement characteristics and potential utility. Collating studies may identify gaps in coverage, the need for novel tools and for standardisation for clinical and research purposes.

Vocal cord dysfunction/inducible laryngeal obstruction cannot be diagnosed from symptoms

Vocal cord dysfunction/inducible laryngeal obstruction is highly variable. Standard clinical symptoms and questionnaires cannot predict laryngoscopic diagnosis in a "lung disease" population. https://bit.ly/3QUtsbB.

Recognizing Vocal Cord Dysfunction: Exercising Caution Before Intubation

Vocal cord dysfunction (VCD) is the inappropriate adduction of the vocal cords during inhalation and sometimes, exhalation. Vocal cord dysfunction is often misdiagnosed in the emergency room as asthma exacerbation or laryngeal angioedema, leading to unnecessary and potentially harmful interventions including intubation and mechanical ventilation. Based on this, it is especially important to recognize this condition early to avoid intubation, which can further worsen VCD. This case presents a 74-year-old female with a history of hypertension and colon cancer who presented to the emergency department (ED) with respiratory distress associated with stridor and wheezing. Our literature review sheds light on identifying key clinical features, physical exam findings, diagnostic tests, existing treatment options for this condition, and preventive measures to minimize its occurrence.

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.

Multidisciplinary management of inducible laryngeal obstruction and breathing pattern disorder

We provide an overview of the assessment and management of inducible laryngeal obstruction and breathing pattern disorder. We highlight the multidisciplinary team members involved and their essential roles within a complex breathlessness service. We discuss treatments initiated by physiotherapy and speech and language therapy, the importance of joint working, and discuss the high incidence of comorbidities and the association with other respiratory disorders.

Educational aims

Inducible laryngeal obstruction and breathing pattern disorder are common causes of breathlessness.Inducible laryngeal obstruction is an inappropriate, transient, reversible narrowing of the laryngeal area that causes breathlessness and laryngeal symptoms.Breathing pattern disorder is an alteration in the normal biomechanical patterns of breathing that results in intermittent or chronic symptoms, which may be respiratory and/or non-respiratory.People with inducible laryngeal obstruction or breathing pattern disorder often have other comorbidities that will also need addressing.Multidisciplinary assessment and treatment is essential for comprehensive workup and holistic care.Timely assessment and diagnosis can prevent unnecessary medication use and hospital admissions and facilitate effective management of the condition using reassurance, advice, education, breathing retraining and vocal exercises.

Applying behaviour change theory to speech and language therapy intervention for inducible laryngeal obstruction

BACKGROUND

Speech and language therapists (SLTs) provide interventions for inducible laryngeal obstruction (ILO) despite a current lack of evidence to inform intervention delivery. This study is the first step to develop an evidence-based intervention for ILO, using behaviour change theory and the Behaviour Change Technique Taxonomy version 1 (BCTTv1). Outcomes will inform the early development stage of a complex speech and language therapy intervention for ILO, enabling more precise reporting of ILO intervention studies, as per CONSORT guidelines.

AIMS

(1) To identify whether the BCTTv1 is a useful tool for characterising speech and language therapy interventions for ILO, based on existing literature, current practice and patient interviews. (2) To identify key behaviour change techniques (BCT) used within existing complex speech and language therapy interventions for ILO METHODS AND PROCEDURES: A five-phase study was conducted: (1) a systematic literature search of six electronic databases (Medline, EMBASE, CINAHL (EBSCO), Scopus, Trip, Web of Science) and grey literature between 2008 and 2020; (2) observations of six speech and language therapy intervention sessions; (3) a semi-structured interview with an SLT to validate the observed BCTTs; (4) consensus from four national expert SLTs regarding application of synthesised BCTT data to their own experiences of ILO interventions; and (5) patient engagement to review and comment on findings.

OUTCOMES AND RESULTS

Forty-seven BCTs in total were coded across all three sources. Thirty-two BCTs were identified in clinical observations; 31 in interviews with SLTs and 18 in the literature. Only six BCT were identified in all three sources. Expert SLTs confirmed clinical application and relevance. Patients reported finding the concept of BCT challenging but highlighted the value of psychoeducation to support their understanding of symptoms and in turn to understand the rationale behind speech and language therapy intervention recommendations.

CONCLUSION

This study indicates that the BCTTv1 is a suitable framework to identify and describe intervention components used within speech and language therapy interventions for ILO. A practice-research gap exists, reinforcing that existing literature does not capture the complexity of speech and language therapy intervention for ILO. Further research is needed to develop our understanding of the BCTs that support optimal behaviour change for this patient group.

WHAT THIS PAPER ADDS

What is already known on the subject There is growing recognition for the value of speech and language therapists (SLTs) in delivering complex interventions for patients with inducible laryngeal obstruction (ILO), including evidence to suggest that their intervention can improve quality of life for patients and reduce excessive healthcare use. There are, however, no randomised controlled trials in this field; thus it is unclear what constitutes the most effective intervention. What this study adds This study demonstrates the complexity of speech and language therapy interventions for ILO and highlights the practice-research gap. It identifies a range of behaviour change techniques that are used in existing practice and captures patient views relating to the components identified within this study. What are the clinical implications of this work? Findings highlight the value of providing education about factors that might be driving ILO symptoms and in turn the importance of sharing with patients the rationale for treatment recommendations that necessitate a change in their behaviours. Identified behaviour change techniques can be used when developing and implementing SLT interventions for ILO.

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.

Computed Tomography Imaging of the Larynx for Diagnosis of Vocal Cord Dysfunction

BACKGROUND: Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is characterized by breathlessness and often mimics or accompanies severe asthma. The disorder occurs intermittently, and the diagnosis is established by using laryngoscopy. Dynamic computed tomography (CT) imaging of the larynx at low-radiation doses has the potential to provide an alternative method to make the diagnosis of VCD/ILO. METHODS: We report two case series: in series A, laryngoscopy (diagnostic standard) and CT imaging of the larynx were each performed within 1 hour of each other (n=31), and in series B, the procedures were performed on separate days 4 to 6 weeks apart (n=72). Diagnosis of VCD/ILO by laryngoscopy used conventional criteria, and diagnosis by CT imaging was based on vocal cord narrowing in excess of a validated normal threshold. In each series, we evaluated the accuracy of CT imaging of the larynx to establish a diagnosis of VCD/ILO compared with laryngoscopy. RESULTS: In series A, the sensitivity of CT imaging of the larynx was 53.8%, and specificity was 88.9%; in series B, the sensitivity of CT imaging of the larynx was 76.2%, and specificity was 93.3%. At a disease prevalence of 30% (which was known to be the case in our clinic), the positive predictive value was 67.5% in series A and 83% in series B. Negative predictive values were 81.8% and 90.1% in series A and B, respectively, and false-positive rates were 11.1% and 6.7%. CONCLUSIONS: When the population prevalence was assumed to be 30%, low-dose CT imaging of the larynx detected VCD/ILO with negative predictive values greater than 80% in both series settings and agreed with each other within 9 percentage points. Positive predictive values for laryngeal CT imaging varied substantially between the settings of the two case series. (Supported by Monash Lung and Sleep Institute and Grant APP ID 1198362 and others.)

Distraction Breathing Exercise in Managing Inducible Laryngeal Obstruction in a Female Patient

Inducible laryngeal obstruction (ILO) describes as inappropriate, episodic, reversible laryngeal closure during inspiration, occurring at the glottic and/or supraglottic level, in response to external triggers causing exertional breathing difficulties. We describe a case of a female patient with an underlying major depressive disorder who presented with sudden onset of stridor and tachypnoea, whereby the external trigger was psychogenic in origin. Bedside flexible nasopharyngolaryngoscopy (FNPLS) showed characteristic findings of paradoxical adduction of vocal cords during inspiration. Arterial blood gas analysis, routine blood tests, chest radiography, and computed tomography (CT) scan of brain, neck, and thorax excluded neurological or airway abnormality. Bedside distraction breathing exercise alleviated the stridor and tachypnoea. The patient was managed by supportive psychotherapy, speech therapy, and anti-reflux medication and was discharged well with resolution of her respiratory distress. We would like to highlight that meticulous history along with physical examinations are imperative especially amongst Otorhinolaryngologists as emergent airway management tracheostomy would have been unnecessary and cause more stress and burden to the patient as well as family members.

Multimorbidity in Difficult Asthma: The Need for Personalised and Non-Pharmacological Approaches to Address a Difficult Breathing Syndrome

Three to ten percent of people living with asthma have difficult-to-treat asthma that remains poorly controlled despite maximum levels of guideline-based pharmacotherapy. This may result from a combination of multiple adverse health issues including aggravating comorbidities, inadequate treatment, suboptimal inhaler technique and/or poor adherence that may individually or collectively contribute to poor asthma control. Many of these are potentially "treatable traits" that can be pulmonary, extrapulmonary, behavioural or environmental factors. Whilst evidence-based guidelines lead clinicians in pharmacological treatment of pulmonary and many extrapulmonary traits, multiple comorbidities increase the burden of polypharmacy for the patient with asthma. Many of the treatable traits can be addressed with non-pharmacological approaches. In the current healthcare model, these are delivered by separate and often disjointed specialist services. This leaves the patients feeling lost in a fragmented healthcare system where clinical outcomes remain suboptimal even with the best current practice applied in each discipline. Our review aims to address this challenge calling for a paradigm change to conceptualise difficult-to-treat asthma as a multimorbid condition of a "Difficult Breathing Syndrome" that consequently needs a holistic personalised care attitude by combining pharmacotherapy with the non-pharmacological approaches. Therefore, we propose a roadmap for an evidence-based multi-disciplinary stepped care model to deliver this.

Systematic review of the effectiveness of non-pharmacological interventions used to treat adults with inducible laryngeal obstruction

Introduction

Inducible laryngeal obstruction (ILO) describes transient laryngeal closure during respiration and can cause significant morbidity. Non-pharmacological behavioural therapy is the commonly cited treatment but efficacy is largely unknown.

Aim

To synthesise the current evidence base on the effectiveness of non-pharmacological interventions used to treat adults with ILO.

Methods

Electronic databases (Medline/Embase/CINAHL/PsycINFO/AMED/CENTRAL) were systematically searched, informed by a population, intervention, comparison, outcome framework. Two reviewers independently screened a representative sample, with lead-author completion due to excellent inter-rater reliability. Data was extracted using a predefined piloted form. Methodological quality was appraised (blindly by two reviewers) using the Joanna Briggs Institute Critical Appraisal Tools. A narrative synthesis was performed due to heterogeneity of studies (PROSPERO registration number: CRD42020213187).

Results

Initial searching identified 3359 records. Full-text screening occurred in 92 records and 14 studies, comprising 527 participants, were deemed eligible. All studies were low-level evidence (observational by design, with four case reports), with a high risk of bias; none contained control arms for comparison. Intervention description was inconsistently and poorly described but direction of effect was positive in 76% of outcomes measured. The majority of studies showed a reduction in symptom scores and improved direct laryngeal imaging post intervention; there was an overall reduction, 59.5%, in healthcare utilisation.

Discussion

The literature is in an embryonic state and lacks robust data to truly inform on the effectiveness of non-pharmacological interventions used to treat adults with ILO. However, positive signals in the synthesis performed support non-pharmacological treatment approaches and further development is warranted.

UK consensus statement on the diagnosis of inducible laryngeal obstruction in light of the COVID-19 pandemic

Prior to the COVID‐19 pandemic, laryngoscopy was the mandatory gold standard for the accurate assessment and diagnosis of inducible laryngeal obstruction. However, upper airway endoscopy is considered an aerosol‐generating procedure in professional guidelines, meaning routine procedures are highly challenging and the availability of laryngoscopy is reduced. In response, we have convened a multidisciplinary panel with broad experience in managing this disease and agreed a recommended strategy for presumptive diagnosis in patients who cannot have laryngoscopy performed due to pandemic restrictions. To maintain clinical standards whilst ensuring patient safety, we discuss the importance of triage, information gathering, symptom assessment and early review of response to treatment. The consensus recommendations will also be potentially relevant to other future situations where access to laryngoscopy is restricted, although we emphasize that this investigation remains the gold standard.

Triggers of breathlessness in inducible laryngeal obstruction and asthma

BACKGROUND

Inducible laryngeal obstruction (ILO) is often misdiagnosed as, or may coexist with, asthma. Identifying differences in triggering factors may assist clinicians to differentiate between the two conditions and could give mechanistic insights.

OBJECTIVE

To identify and compare patient-reported triggers in ILO and asthma.

METHODS

This was a two-part study. Initially, we conducted a retrospective case note review of the triggers of ILO from endoscopically confirmed ILO patients to generate a Breathlessness Triggers Survey (BrTS). Triggers were categorized as scents, environmental factors, temperature, emotions, mechanical factors and daily activities. Secondly, ILO and/or asthma patients completed the BrTS prospectively, rating the likelihood of each item triggering their symptoms using a five-point Likert scale (strongly disagree to strongly agree). Chi-square testing was performed to compare responses by cohort.

RESULTS

Data from 202 patients with ILO [73% female, mean (SD) age 53(16) years] were included in the case note review. For the prospective study, 38 patients with ILO only [63% females, age 57(16) years], 39 patients with asthma only [(56% female, age 53(13) years] and 12 patients with both ILO and asthma [83% female, mean age, 57 (14) years)] completed the BrTS. The triggers identified in the case note review were confirmed in the independent sample of patients with ILO and/or asthma and identified several difference in prevalence of the triggers between disease types. Mechanical factors (talking [P < .001], shouting [P = .007] and swallowing [P = .002]) were more common in the ILO cohort compared to patients with asthma. Environmental factors (pollen/flowers [P = .005] and damp air [P = .012]) were more common in asthma. There were no differences between groups in frequency of reporting scents as triggers (except for vinegar, more common in ILO, P = .019), temperature, emotions or daily activities.

CONCLUSION

There were notable differences between patient-reported triggers of ILO and asthma, which may support clinician differential diagnosis.

Struggling to Breathe: Inspiratory Muscle Training in Adolescent Athletes

OBJECTIVE

Dyspnea is a primary characteristic of exercise-induced laryngeal obstruction and prevents individuals from inhaling and exhaling without effort. This single subject research study investigated the effects of inspiratory muscle training (IMT) on exercise-induced symptoms characteristic of exercise-induced laryngeal obstruction in adolescent athletes.

METHODS

Five weeks of IMT was provided to five adolescent athletes, four females and one male, aged 10 to 16. Variables that were measured prior to, during, and after completion of IMT program included maximum phonation time, maximum perceived breathlessness, duration of running, and quality of life regarding dyspnea.

RESULTS

Results showed a reduction in maximum perceived breathlessness as well as a significant increase in maximum phonation time across participants. The majority of participants rated their quality of life regarding dyspnea as significant improved after IMT.

CONCLUSIONS

These findings contribute to the increasing body of literature investigating the use of alternative therapy strategies for treatment of symptoms of exercise-induced laryngeal obstruction in adolescent athletes.

Severe Exercise-Induced Laryngeal Obstruction Treated With Supraglottoplasty

Introduction: Exercise induced laryngeal obstruction (EILO) is relatively common in adolescents, with symptoms often confused with exercise induced asthma. EILO often starts with medial or inward rotation of supraglottic structures of the larynx, whereas glottic adduction appears as a secondary phenomenon in a majority. Therefore, surgical treatment (supraglottoplasty) is used in thoroughly selected and highly motivated patients with pronounced symptoms and severe supraglottic collapse.

Aim: To investigate efficacy and safety of laser supraglottoplasty as treatment for severe supraglottic EILO by retrospective chart reviews.

Methods: The EILO register at Haukeland University Hospital, Bergen, Norway was used to identify patients who had undergone laser supraglottoplasty for severe supraglottic EILO, verified by continuous laryngoscopy exercise (CLE) test, during 2013–2015. Laser incision in both aryepiglottic folds anterior to the cuneiform tubercles and removal of the mucosa around the top was performed in general anesthesia. Outcomes were questionnaire based self-reported symptoms, and laryngeal obstruction scored according to a defined scheme during a CLE-test performed before and after surgery.

Results: Forty-five of 65 eligible patients, mean age 15.9 years, were included. Post-operatively, 38/45 (84%) patients reported less symptoms, whereas CLE-test scores had improved in all, of whom 16/45 (36%) had no signs of obstruction. Most improvements were at the supraglottic level, but 21/45 (47%) also improved at the glottic level. Two of 65 patients had complications; self-limiting vocal fold paresis and scarring/shortening of plica ary-epiglottica.

Conclusion: Supraglottoplasty improves symptoms and decreases laryngeal obstruction in patients with severe supraglottic EILO, and appears safe in highly selected cases.