Vocal Cord Dysfunction in Patients Hospitalized with Symptoms of Acute Asthma Exacerbation

Living With Asthma and Vocal Cord Dysfunction/Inducible Laryngeal Obstruction: "I Just Can't Get Air In"

BACKGROUND

Asthma and vocal cord dysfunction (VCD), also known as inducible laryngeal obstruction (ILO), may coexist, resulting in worse outcomes for patients. The experience of people with VCD/ILO and coexisting asthma is unknown.

OBJECTIVE

We sought to determine whether coexistent VCD/ILO and asthma have deleterious impacts on quality of life.

METHODS

We undertook a descriptive qualitative study using one-to-one semistructured interviews with 30 purposively recruited adult participants with a prior confirmed doctor asthma diagnosis and laryngoscopy-confirmed VCD/ILO. A thematic and content analysis was conducted to explore the data.

RESULTS

Participants were mostly female (63%), mean ± SD age 63 ± 12 years. Four themes were identified: trapped voice, altered life, knowledge about VCD/ILO, and looking for solutions. Participants reported their voice being trapped in their throat or the voice being suddenly cut off when talking or singing. Self-reported VCD/ILO symptoms including throat tightness and breathlessness were highlighted by participants. The second theme described how patients struggle to communicate or tended to shorten conversations. Insufficient knowledge and existing confusion regarding whether asthma was causing the breathlessness was described in the third theme. Looking for solutions depicted participants' diagnostic journey and how they sought an explanation for the symptoms.

CONCLUSIONS

People with asthma and coexisting VCD/ILO experience a substantial burden affecting the quality of life. These data describe the impact on patients with coexisting conditions and should be used to increase clinician awareness of the experience of VCD/ILO from patients' perspectives to support a personalized approach to care.

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.

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.)

Vocal cord dysfunction/inducible laryngeal obstruction: novel diagnostics and therapeutics

INTRODUCTION

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is an important medical condition but understanding of the condition is imperfect. It occurs in healthy people but often co-exists with asthma. Models of VCD/ILO pathophysiology highlight predisposing factors rather than specific mechanisms and disease expression varies between people, which is seldom appreciated. Diagnosis is often delayed, and the treatment is not evidence based.

AREAS COVERED

A unified pathophysiological model and disease phenotypes have been proposed. Diagnosis is conventionally made by laryngoscopy during inspiration with vocal cord narrowing >50% Recently, dynamic CT larynx was shown to have high specificity (>80%) with potential as a noninvasive, swift, and quantifiable diagnostic modality. Treatment entails laryngeal retraining with speech pathology intervention and experimental therapies such as botulinum toxin injection. Multidisciplinary team (MDT) clinics are a novel innovation with demonstrated benefits including accurate diagnosis, selection of appropriate treatment, and reductions in oral corticosteroid exposure.

EXPERT OPINION

Delayed diagnosis of VCD/ILO is pervasive, often leading to detrimental treatments. Phenotypes require validation and CT larynx can reduce the necessity for laryngoscopy, thereby fast-tracking diagnosis. MDT clinics can optimize management. Randomized controlled trials are essential to validate speech pathology intervention and other treatment modalities and to establish international standards of care.

Diagnosis of vocal cord dysfunction / inducible laryngeal obstruction-A Delphi study protocol

INTRODUCTION

Currently there is no consistent and widely accepted approach to the diagnosis of vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO). Harmonised diagnostic methods are vital to enable optimal diagnosis, advance management and enable research. We aim to obtain consensus on how expert clinicians recognise and diagnose VCD/ILO.

METHODS AND ANALYSIS

Two-round modified Delphi, with workshop validation.

ETHICS AND DISSEMINATION

Institutional Board Review was obtained from the Monash Health Human Research Ethics Committee. The dissemination plan is for presentation and publication.

REGISTRATION DETAILS

Registered at Australia and New Zealand Clinical Trials Registry ACTRN12621001520820p.

Diagnostic and Therapeutic Outcomes Following Systematic Assessment of Patients with Concurrent Suspected Vocal Cord Dysfunction and Asthma

BACKGROUND

Vocal cord dysfunction (VCD) is present in 25% to 50% of patients with asthma. When both diagnoses are suspected, accurate diagnosis and targeted management represent a clinical challenge.

OBJECTIVE

To evaluate diagnostic and therapeutic outcomes following systematic assessment for patients with concurrent suspected VCD and asthma.

METHODS

Patients underwent systematic evaluation by clinical assessment and validated questionnaires, followed by multidisciplinary management. VCD was confirmed by visualization of paradoxical vocal fold motion at baseline or following provocation. Asthma was confirmed by demonstrating variable airflow obstruction. Asthma medications were deescalated in those with low clinical probability of asthma and no variable airflow obstruction. Response to 2 or more sessions of speech pathology was assessed by subjective report and standardized questionnaires.

RESULTS

Among 212 consecutive patients, 62 (29%) patients had both VCD and asthma, 54 (26%) had VCD alone, 51 (24%) had asthma alone, and 45 (21%) had neither. Clinician assessment and the Laryngeal Hypersensitivity Questionnaire both predicted laryngoscopy-confirmed VCD. Deescalation or discontinuation of asthma therapy was possible in 37 of 59 (63%) patients without variable airflow obstruction, and was most successful (odds ratio, 5.5) in the presence of laryngoscopy-confirmed VCD (25 of 31, or 81%) Patients with VCD responded subjectively to 2 or more sessions of speech pathology, but laryngeal questionnaire scores did not improve.

CONCLUSIONS

Expert clinician assessment and the Laryngeal Hypersensitivity Questionnaire predict the presence of laryngoscopy-confirmed VCD. Systematic assessment for both VCD and asthma facilitates deescalation or discontinuation of unnecessary asthma medications. Subjective symptom improvement following speech pathology was not paralleled by laryngeal questionnaire scores in this cohort.

Prevalence and impact of comorbid laryngeal dysfunction in asthma: A systematic review and meta-analysis

BACKGROUND

Laryngeal or vocal cord dysfunction has long been regarded as a mimic of asthma; however, recent evidence indicates that it may be a significant comorbid condition in patients with asthma.

OBJECTIVE

We aimed to systematically estimate the prevalence of comorbid laryngeal dysfunction (LD) in adults with asthma and characterize its clinical impact on asthma.

METHODS

Electronic databases were searched for relevant studies published until June 2019. Studies were included if LD was objectively defined by direct visualization of laryngeal movement. Outcomes included the prevalence of LD and its association with clinical asthma indicators, such as severity, control, and quality of life. Random effects meta-analyses were performed to calculate the estimates.

RESULTS

A total of 21 studies involving 1637 patients were identified. Overall, the pooled prevalence of LD in adults with asthma was 25% (95% CI = 15%-37%; I² = 96%). Prevalence estimates differed according to the diagnostic test utilized, with the lowest overall prevalence (4% [95% CI = 0%-10%; I² = 90%]) seen when LD was diagnosed by resting laryngoscopy without external stimuli; however, it was much higher when diagnosed by laryngoscopy studies utilizing an external trigger, such as exercise (38% [95% CI = 24%-53%; I² = 90%]) or in studies using a computed tomography-based diagnostic protocol (36% [95% CI = 24%-49%; I² = 78%]). Only 7 studies reported the associations between LD and clinical asthma indicators; inconsistencies between studies limited meaningful conclusions.

CONCLUSION

LD may be a common comorbidity in asthma, affecting about 25% of adult patients. Further prospective studies are needed to better characterize its clinical impact and the benefits of detecting and managing LD in patients with asthma.