Understanding the Impact of Chronic Cough on the Quality of Life in the General Population

WAO - ARIA consensus on chronic cough: Executive summary

Acute cough is a highly prevalent symptom in clinical practice. Chronic cough is a complex disease with significant impact on quality of life. The mechanistic pathways of chronic cough in cough-comorbid clinical phenotypes are elusive. Mounting evidence suggests presence of a hypersensitive cough reflex and implication of transient receptor potential channels and P2X receptors in cough neuronal pathways. Previously, the World Allergy Organization (WAO)/Allergic Rhinitis and its Impact on Asthma (ARIA) Joint Committee on Chronic Cough published updated experimental and clinical data on chronic cough, in addition to a multidisciplinary care pathway approach to its management. The goal of this manuscript is to provide clinicians with a succinct summary of chronic cough pathophysiology, clinical phenotypes, and management strategies in both primary and cough specialty care. This executive summary is a primer for clinicians on chronic cough. Increasing awareness on the topic among primary care physicians will improve the outcome of management of patients with chronic cough.

Abnormal breathing pattern features in chronic refractory cough

Background

Chronic refractory cough (CRC) is a challenging condition that responds to speech pathology intervention. Clinical observation suggests abnormal breathing patterns occur in CRC and may be indirectly addressed as part of behavioural treatment, yet breathing pattern changes in CRC are poorly understood. The aims of this study were to 1) describe breathing patterns in patients with CRC, 2) compare breathing pattern features between patients with CRC and inducible laryngeal obstruction (ILO), and 3) estimate the effect of breathing pattern features on clinical measures of laryngeal sensory and motor dysfunction.

Methods

This retrospective cross-sectional observational study included 634 patients with CRC or ILO. A file audit of speech pathology assessment data was undertaken. Analysis of self-reported laryngeal symptoms (via questionnaires) and clinical assessment of voice and breathing of those with CRC and ILO was conducted.

Results

Most participants with CRC (73%) demonstrated at least one abnormal breathing pattern feature. The most common feature was thoracic breathing (69%) followed by oral breathing (33%). The type and prevalence of abnormal breathing patterns were similar between CRC and ILO. Abnormal breathing patterns were associated with reduced maximum phonation time (MPT); however, there was no association between these features and Newcastle Laryngeal Hypersensitivity Questionnaire scores.

Conclusions

Abnormal breathing features are common in patients with CRC and are not significantly different from those occurring in ILO. There is some association between abnormal breathing features and MPT, suggesting impairment of laryngeal motor function. Conversely, there is no association between abnormal breathing features and laryngeal hypersensitivity.

Neuromodulators in Acute and Chronic Cough in Children: An Update from the Literature

Cough is one of the most common reasons leading to pediatric consultations, negatively impacting the quality of life of patients and caregivers. It is defined as a sudden and forceful expulsion of air from the lungs through the mouth, typically triggered by irritation or the stimulation of sensory nerves in the respiratory tract. This reflex is controlled by a neural pathway that includes sensory receptors, afferent nerves, the brainstem's cough center, efferent nerves, and the muscles involved in coughing. Based on its duration, cough in children may be classified as acute, lasting less than four weeks, and chronic, persisting for more than four weeks. Neuromodulators have shown promise in reducing the frequency and severity of cough by modulating the neural pathways involved in the cough reflex, although they require careful monitoring and patient selection to optimize the outcomes. This review aims to examine the rationale for using neuromodulators in the management of cough in children.

Chronic Refractory Cough: Long-Term Outcomes Following Cough Suppression Therapy

OBJECTIVE

This study aimed to determine the long-term outcomes of patients with chronic refractory cough (CRC) following treatment for cough suppression therapy (CST). Currently, there is a lack of objective data regarding the long-term outcome of behavioral treatment for CRC.

METHODS

From the charts of 106 adult patients diagnosed with CRC, 24 patients were identified as having long-term data at least 3 months post-CST in the form of otolaryngologic examination, Voice Handicap Index-10 (VHI-10), and Cough Severity Index (CSI) scores. Patients underwent otolaryngologic evaluation and completed the VHI-10 and CSI assessments during pretreatment, posttreatment, and long-term follow-up visits. Patients were also divided into two groups based on their number of comorbidities.

RESULTS

Twenty of the 24 patients had significant reduction in cough severity after completing CST (P < 0.001). A significant difference was also found in CSI scores from pretherapy to the long-term follow-up visits (P = 0.001). No significant difference was found in CSI scores from posttherapy to long-term follow-up visits (P = 0.93). No significant difference was found in VHI-10 scores over time (P = 0.83). No correlation was found between changes in cough and voice severity and number of comorbidities at the tested level.

CONCLUSIONS

Findings of no significant change in CRC over the long term compared to posttherapy measures suggest that patients were able to maintain improvement in cough over the long term despite various comorbidities. The current results suggest that CST represents a satisfactory approach to treating CRC and provides patients with an ongoing tool to maintain reduced cough severity. No significant correlations between number of comorbidities and mean CSI or VHI-10 scores were found over the long term.

Cough Assessment and Management in Pulmonary Rehabilitation- A Canadian Survey

Pulmonary rehabilitation is a cornerstone intervention for controlling respiratory symptoms in people with chronic respiratory diseases. Chronic cough affects up to 90% of people with chronic respiratory diseases, however, it is currently unknown whether chronic cough is assessed and/or managed in pulmonary rehabilitation. This study aimed to determine if and how chronic cough is assessed and managed in pulmonary rehabilitation. This was a cross-sectional study. Pulmonary rehabilitation programs in Canada were identified via online websites. A representative from each program was invited to complete an online survey including the following topics: program demographics, assessment and management practices, and barriers and facilitators. Of 133 programs contacted, 31 returned a completed survey (23% response rate). Approximately half (52%) of respondents reported enrolling patients with chronic cough. Of those, 45% reported assessing and 62% reported intervening in chronic cough. Inadequate knowledge of assessment and management techniques was commonly identified to be a barrier and increased education was suggested as a possible facilitator. Based on pulmonary rehabilitation programs that responded to our survey, chronic cough is a prevalent symptom; however, it is scarcely assessed and managed. A need for structured education and the use of standardised strategies were reported as facilitators to the assessment and management of chronic cough in pulmonary rehabilitation.

Efficacy, Safety and Economic Evaluation of Wolbigachul-Tang for Chronic Cough Due to Upper Airway Cough Syndrome (UACS): A Study Protocol for Randomized, Double-Blind, Active-Comparator Controlled, Parallel, Exploratory Clinical Trial

Upper airway cough syndrome (UACS) is a common cause of chronic cough characterized by upper airway symptoms, including nasal discharge and throat discomfort. Empirical treatments for UASC-induced chronic cough, such as first-generation antihistamines, have been used; however, the long-term use of these medicines has adverse effects. Therefore, we evaluate the efficacy, safety, and economic feasibility of Wolbigachul-tang (WBGCT), an herbal medication for UASC-induced chronic cough. This is a randomized, double-blind, active-comparator-controlled, parallel, and exploratory clinical trial. Thirty patients with UASC-induced chronic cough will be recruited and randomly allocated to the WBGCT and control groups in a 1:1 allocation ratio. The investigational medicine will be administered three times per day for 2 weeks (3 g of WBGCT at a time). The primary outcome measure is the cough symptom score measured at screening, before starting the trial, and after 2 and 4 weeks. Secondary outcome measures include the cough visual analog scale, nasal discharge score, questionnaire of clinical symptoms of cough and sputum, Leicester cough questionnaire-Korean version, integrative medicine outcome scale, integrative medicine patient satisfaction scale, and 5-level EuroQol 5-dimensional questionnaire, which will be assessed before starting the trial and after 2 and 4 weeks. This study aims to investigate the efficacy, safety, and economic feasibility of WBGCT in the treatment of chronic cough. Therefore, the results of this trial provide evidence for the application of WBGCT in the treatment of UACS-induced chronic cough.

State of the Art for Refractory Cough: Multidisciplinary Approach

Chronic cough is a common problem that can be refractory to medical treatment. Nonpharmaceutical management of chronic cough has an important role in well selected patients. This review article outlines the history of chronic cough management, current approaches to speech pathology management of the condition and new modalities of nonpharmaceutical treatment. There is a need for further research into nonpharmaceutical options with well described randomised control trials.

Characterization of a chronic cough in cerebellar ataxia, neuropathy, vestibular areflexia syndrome

Objectives

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a common cause of late-onset ataxia that often presents with chronic cough. This study is the first to characterize the CANVAS cough both objectively and subjectively.

Methods

A cross-sectional study of 13 patients was conducted. Medical records and available esophagram, modified barium swallow study, esophageal manometry, and video laryngostroboscopy data were reviewed. Leicester cough questionnaire (LCQ) and Eating Assessment Tool-10 were administered to evaluate quality of life (QoL) impairments and dysphagia symptoms, respectively. CANVAS history questionnaire was developed to characterize the clinical course.

Results

92% of patients endorsed chronic cough that preceded gait instability by a median of 16 years. Cough was dry (67%), disturbed sleep (75%), triggered by various factors, including talking, eating, and dry/spicy foods, did not respond to standard reflux therapy, and inconsistently responded to neuromodulators and superior laryngeal nerve injections. Despite perceived cough severity worsening or remaining constant in most patients, no correlation was found between cough duration and total LCQ scores. Patients reported significantly more negative social QoL impacts compared to physical QoL impacts. Ataxia duration and years of cough before ataxia symptoms were directly and inversely correlated with total LCQ scores, respectively. Imaging data revealed esophageal dysmotility (71%), vestibular penetration (57%), vestibular aspiration (14%), supraglottic compression (63%), vocal fold lesions/atrophy (50%), and arytenoid erythema (38%).

Conclusion

Chronic cough is a hallmark presenting symptom in CANVAS with predominantly psychosocial QoL effects and unrecognized laryngeal alterations. In cases of idiopathic, refractory chronic cough, genetic testing for CANVAS should be considered, especially in association with sensory, cerebellar, and/or vestibular involvement.

Level of evidence

VI.

GERD-related chronic cough: Possible mechanism, diagnosis and treatment

GERD, or gastroesophageal reflux disease, is a prevalent medical condition that affects millions of individuals throughout the world. Chronic cough is often caused by GERD, and chronic cough caused by GER is defined as GERD-related chronic cough (GERC). It is still unclear what the underlying molecular mechanism behind GERC is. Reflux theory, reflex theory, airway allergies, and the novel mechanism of esophageal motility disorders are all assumed to be linked to GERC. Multichannel intraluminal impedance combined with pH monitoring remains the gold standard for the diagnosis of GERC, but is not well tolerated by patients due to its invasive nature. Recent discoveries of new impedance markers and new techniques (mucosal impedance testing, salivary pepsin, real-time MRI and narrow band imaging) show promises in the diagnosis of GERD, but the role in GERC needs further investigation. Advances in pharmacological treatment include potassium-competitive acid blockers and neuromodulators (such as Baclofen and Gabapentin), prokinetics and herbal medicines, as well as non-pharmacological treatments (such as lifestyle changes and respiratory exercises). More options have been provided for the treatment of GERC other than acid suppression therapy and anti-reflux surgery. In this review, we attempt to review recent advances in GERC mechanism, diagnosis, and subsequent treatment options, so as to provide guidance for management of GERC.