Pulse oximetry coupled with spirometry in the emergency department helps differentiate an asthma exacerbation from possible vocal cord dysfunction

Vocal Cord Dysfunction: The Spectrum Across the Ages

Vocal cord dysfunction (VCD) is an upper airway disorder characterized by exaggerated and transient glottic constriction causing respiratory and laryngeal symptoms. Although the origin of VCD symptoms is in the upper airway, it is frequently misdiagnosed as asthma resulting in significant morbidity. VCD can coexist with asthma or mimic allergic conditions affecting the upper airway. VCD may be difficult to diagnose, because patients are intermittently symptomatic and VCD awareness in the medical community is underappreciated. Once VCD is diagnosed and treated, most patients report significant improvement in their symptoms as well as a decrease in asthma medication use.

Differentiating vocal cord dysfunction from asthma

Vocal cord dysfunction (VCD)-associated symptoms are not rare in pediatric patients. Dyspnea, wheezing, stridor, chest pain or tightness and throat discomfort are the most commonly encountered symptoms. They may occur either at rest or more commonly during exercise in patients with VCD, as well as in asthmatic subjects. The phase of respiration (inspiration rather than expiration), the location of the wheezing origin, the rapid resolution of symptoms, and the timing occurring in relation to exercise, when VCD is exercise induced, raise the suspicion of VCD in patients who may have been characterized as merely asthmatics and, most importantly, had not responded to the appropriate treatment. The gold standard method for the diagnosis of VCD is fiberoptic laryngoscopy, which may also identify concomitant laryngeal abnormalities other than VCD. However, as VCD is an intermittent phenomenon, the procedure should be performed while the patient is symptomatic. For this reason, challenges that induce VCD symptoms should be performed, such as exercise tests. Recently, for the evaluation of patients with exercise-induced VCD, continuous laryngoscopy during exercise (such as treadmill, bicycle ergometer, swimming) was used. A definite diagnosis of VCD is of importance, especially for those patients who have been erroneously characterized as asthmatics, without adequate response to treatment. In these cases, another therapeutic approach is necessary, which will depend on whether they suffer solely from VCD or from both conditions.

Severe or life-threatening asthma exacerbation: patient heterogeneity identified by cluster analysis

BACKGROUND

Severe or life-threatening asthma exacerbation is one of the worst outcomes of asthma because of the risk of death. To date, few studies have explored the potential heterogeneity of this condition.

OBJECTIVES

To examine the clinical characteristics and heterogeneity of patients with severe or life-threatening asthma exacerbation.

METHODS

This was a multicentre, prospective study of patients with severe or life-threatening asthma exacerbation and pulse oxygen saturation < 90% who were admitted to 17 institutions across Japan. Cluster analysis was performed using variables from patient- and physician-orientated structured questionnaires.

RESULTS

Analysis of data from 175 patients with severe or life-threatening asthma exacerbation revealed five distinct clusters. Cluster 1 (n = 27) was younger-onset asthma with severe symptoms at baseline, including limitation of activities, a higher frequency of treatment with oral corticosteroids and short-acting beta-agonists, and a higher frequency of asthma hospitalizations in the past year. Cluster 2 (n = 35) was predominantly composed of elderly females, with the highest frequency of comorbid, chronic hyperplastic rhinosinusitis/nasal polyposis, and a long disease duration. Cluster 3 (n = 40) was allergic asthma without inhaled corticosteroid use at baseline. Patients in this cluster had a higher frequency of atopy, including allergic rhinitis and furred pet hypersensitivity, and a better prognosis during hospitalization compared with the other clusters. Cluster 4 (n = 34) was characterized by elderly males with concomitant chronic obstructive pulmonary disease (COPD). Although cluster 5 (n = 39) had very mild symptoms at baseline according to the patient questionnaires, 41% had previously been hospitalized for asthma.

CONCLUSIONS & CLINICAL RELEVANCE

This study demonstrated that significant heterogeneity exists among patients with severe or life-threatening asthma exacerbation. Differences were observed in the severity of asthma symptoms and use of inhaled corticosteroids at baseline, and the presence of comorbid COPD. These findings may contribute to a deeper understanding and better management of this patient population.

Vocal cord dysfunction in bronchial asthma. A review article

INTRODUCTION

Vocal cord dysfunction (VCD) is a condition in which the larynx exhibits paradoxical vocal cord adduction during inspiration, resulting in extra-thoracic variable airway obstruction. It has been described as a mimic of asthma, and hence, many patients with VCD are diagnosed as difficult-to-treat asthma and suffer significant morbidity as such.

METHODS

In completing this review we searched the literature using the database from MEDLINE, PubMed, and the Cochrane library using the medical terms "vocal cord/vocal cord dysfunction and asthma".

RESULTS

During the last few decades, many publications have described many conditions that may cause or coexist with VCD. In addition, the association between asthma and VCD was recognized. In this narrative review we provide an overview of the current knowledge about VCD and, in particular its relationship to asthma. We also provide a pragmatic diagnostic algorithm and treatment options based on our collaborative multi-disciplinary management of patients attending a difficult to control asthma clinic.

CONCLUSION

Most VCD patients present with inadequately controlled asthma rather than the typical symptoms described in association with VCD. Careful diagnostic strategy as outlined in this review may be helpful in confirming the diagnosis.

Vocal cord dysfunction and asthma

PURPOSE OF REVIEW

Vocal cord dysfunction can occur independently or can co-exist with asthma. It often mimics asthma in presentation and can be challenging to diagnose, particularly in those with known asthma. Vocal cord dysfunction remains under-recognized, which may result in unnecessary adjustments to asthma medicines and increased patient morbidity. There is a need to review current literature to explore current theories regarding disease presentation, diagnosis, and treatment.

RECENT FINDINGS

The underlying cause of vocal cord dysfunction is likely multifactorial but there has been increased interest in hyper-responsiveness of the larynx. Many intrinsic and extrinsic triggers have been identified which in part may explain asthma-like symptomatology. A variety of techniques have been reported to provoke vocal cord dysfunction during testing which may improve diagnosis. There is a significant gap in the literature regarding specific laryngeal control techniques, duration of therapy, and the effectiveness of laryngeal control as a treatment modality.

SUMMARY

Those with vocal cord dysfunction and asthma report more symptoms on standardized asthma control questionnaires, which can result in increasing amounts of medication if vocal cord dysfunction is not identified and managed appropriately. Clinicians need to maintain a high index of suspicion to identify these patients. Videolaryngostroboscopy remains the diagnostic method of choice. Evidence-based guidelines are needed for the most effective diagnostic techniques. Laryngeal control taught by speech pathologists is the most common treatment. Effectiveness is supported in case reports and clinical experience, but not in larger randomized trials which are needed.

Diagnostic criteria for the classification of vocal cord dysfunction

Vocal cord dysfunction (VCD) is a syndrome characterized by paroxysms of glottic obstruction due to true vocal cord adduction resulting in symptoms such as dyspnea and noisy breathing. Since first described as a distinct clinical entity in 1983, VCD has inadvertently become a collective term for a variety of clinical presentations due to glottic disorders. Despite an increased understanding of laryngeal function over the past 25 years, VCD remains a poorly understood and characterized entity. Disparities in the literature regarding etiology, pathophysiology, and management may be due to the historic approach to this patient population. Additionally, disorders clearly not due to paroxysms of true vocal cord adduction, such as laryngomalacia, vocal cord paresis, and CNS causes, need to be differentiated from VCD. Although a psychologic origin for VCD has been established, gastroesophageal reflux disease (GERD), nonspecific airway irritants, and exercise have also been associated with intermittent laryngeal obstruction with dyspnea and noisy breathing. VCD has been repeatedly misdiagnosed as asthma; however, the relationship between asthma and VCD is elusive. There are numerous case reports on VCD, but there is a paucity of prospective studies. Following an in-depth review of the medical literature, this article examines the available retrospective and prospective evidence to present an approach for evaluation of VCD including: (1) evaluation of factors associated with VCD, (2) differential diagnosis of movement disorders of the upper airway, and (3) clinical, spirometric, and endoscopic criteria for the diagnosis.