Cough in Children and Adults: Diagnosis, Assessment and Management (CICADA). Summary of an updated position statement on chronic cough in Australia

INTRODUCTION

Cough is the most common symptom leading to medical consultation. Chronic cough results in significant health care costs, impairs quality of life, and may indicate the presence of a serious underlying condition. Here, we present a summary of an updated position statement on cough management in the clinical consultation.

MAIN RECOMMENDATIONS

Assessment of children and adults requires a focused history of chronic cough to identify any red flag cough pointers that may indicate an underlying disease. Further assessment with examination should include a chest x-ray and spirometry (when age > 6 years). Separate paediatric and adult diagnostic management algorithms should be followed. Management of the underlying condition(s) should follow specific disease guidelines, as well as address adverse environmental exposures and patient/carer concerns. First Nations adults and children should be considered a high risk group. The full statement from the Thoracic Society of Australia and New Zealand and Lung Foundation Australia for managing chronic cough is available at https://lungfoundation.com.au/resources/cicada-full-position-statement.

CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT

Algorithms for assessment and diagnosis of adult and paediatric chronic cough are recommended. High quality evidence supports the use of child-specific chronic cough management algorithms to improve clinical outcomes, but none exist in adults. Red flags that indicate serious underlying conditions requiring investigation or referral should be identified. Early and effective treatment of chronic wet/productive cough in children is critical. Culturally specific strategies for facilitating the management of chronic cough in First Nations populations should be adopted. If the chronic cough does not resolve or is unexplained, the patient should be referred to a respiratory specialist or cough clinic.

Instrument adaptation and preliminary validation study of the Laryngeal Hypersensitivity Questionnaire used for assessment of laryngeal symptoms in patients with artificial airways

BACKGROUND

The Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ) was developed to measure abnormal laryngeal sensation and was originally validated in a patient sample from otolaryngologic and respiratory outpatient clinics. Modification is needed for patients who are mechanically ventilated via an endotracheal tube or a tracheostomy tube.

OBJECTIVES

We sought to adapt and preliminarily validate a modified version of the LHQ appropriate for nurses and other clinicians to administer in acute hospital settings called the LHQ-Acute (LHQ-A).

METHODS

Internal consistency and construct validity analyses using secondary data from patients at a tertiary teaching hospital who presented with symptoms of laryngeal irritability/hypersensitivity between September 2012 and October 2013 were performed.

RESULTS

A total of 131 patients, most complaining of coughing and dysphonia, with a median age of 58 (interquartile range: 48, 66) years and 29 healthy participants with a median age of 62 (interquartile range: 50, 66) years were analysed. The original LHQ was reduced from 14 questions with responses on a 7-point scale to the LHQ-A containing 13 questions with responses on a 4-point scale. Correlations between items of the LHQ and LHQ-A were similar, and internal consistency was excellent and highly comparable, with Cronbach's alpha = 0.906 and 0.902, respectively.

CONCLUSIONS

The LHQ-A, which has been adapted for nurses and other clinicians to administer to a critically ill patient population, demonstrated comparable reliability and validity to the original LHQ. Validation of the LHQ-A in independent patient populations from acute settings is necessary to better understand norms and changes during recovery from acute illness.

Interaction effect of chronic cough and ageing on increased risk of exacerbation in patients with asthma: a prospective cohort study in a real-world setting

Background

Older adults with asthma have the greatest burden and worst outcomes, and there is increasing evidence that chronic cough (CC) is associated with asthma severity and poor prognosis. However, the clinical characteristics of older adult patients with both asthma and CC remain largely unknown.

Methods

Participants with stable asthma underwent two cough assessments within 3 months to define the presence of CC. Patients were divided into four groups based on CC and age (cut-off ≥60 years). Multidimensional assessment was performed at baseline, followed by a 12-month follow-up to investigate asthma exacerbations. Logistic regression models were used to explore the interaction effect of CC and age on asthma control and exacerbations.

Results

In total, 310 adult patients were prospectively recruited and divided into four groups: older CC group (n=46), older non-CC group (n=20), younger CC group (n=112) and younger non-CC group (n=132). Compared with the younger non-CC group, the older CC group had worse asthma control and quality of life and increased airflow obstruction. The older CC group showed an increase in moderate-to-severe exacerbations during the 12-month follow-up. There was a significant interaction effect of CC and ageing on the increased moderate-to-severe exacerbations (adjusted risk ratio 2.36, 95% CI 1.47-3.30).

Conclusion

Older asthma patients with CC have worse clinical outcomes, including worse asthma control and quality of life, increased airway obstruction and more frequent moderate-to-severe exacerbations, which can be partly explained by the interaction between CC and ageing.

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.

Impact of Landscape Fire Smoke Exposure on Patients With Asthma With or Without Laryngeal Hypersensitivity

BACKGROUND

Individuals with asthma experienced severe and prolonged symptoms after the Australian 2019 to 2020 landscape fire. Many of these symptoms, such as throat irritation, occur in the upper airway. This suggests that laryngeal hypersensitivity contributes to persistent symptoms after smoke exposure.

OBJECTIVE

This study examined the relationship between laryngeal hypersensitivity and symptoms, asthma control, and health impacts on individuals exposed to landscape fire smoke.

METHOD

The study was a cross-sectional survey of 240 participants in asthma registries who were exposed to smoke during the 2019 to 2020 Australian fire. The survey, completed between March and May 2020, included questions about symptoms, asthma control, and health care use, as well as the Laryngeal Hypersensitivity Questionnaire. Daily concentration levels of particulate matter less than or equal to 2.5 μm in diameter were measured over the 152-day study period.

RESULTS

The 49 participants with laryngeal hypersensitivity (20%) had significantly more asthma symptoms (96% vs 79%; P = .003), cough (78% vs 22%; P < .001), and throat irritation (71% vs 38%; P < .001) during the fire period compared with those without laryngeal hypersensitivity. Participants with laryngeal hypersensitivity had greater health care use (P ≤ .02), more time off work (P = .004), and a reduced capacity to participate in usual activities (P < .001) during the fire period, as well as poorer asthma control during the follow-up (P = .001).

CONCLUSIONS

Laryngeal hypersensitivity is associated with persistent symptoms, reports of lower asthma control, and increased health care use in adults with asthma who were exposed to landscape fire smoke. Management of laryngeal hypersensitivity before, during, or immediately after landscape fire smoke exposure might reduce the symptom burden and health impact.

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.

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.

The impact of the 2019/2020 Australian landscape fires on infant feeding and contaminants in breast milk in women with asthma

BACKGROUND

The 2019/2020 Australian landscape fires (bushfires) resulted in prolonged extreme air pollution; little is known about the effects on breastfeeding women and their infants. This study aimed to examine the impact of prolonged landscape fires on infant feeding methods and assess the concentration of polycyclic aromatic hydrocarbons (PAHs) and elements in breast milk samples.

METHODS

From May - December 2020, women with asthma, who were feeding their infants during the fires, were recruited from an existing cohort. Data on infant feeding and maternal concern during the fires were retrospectively collected. Breast milk samples were collected from a sample of women during the fire period and compared with samples collected outside of the fire period for levels of 16 PAHs (gas chromatography coupled with mass spectrometry), and 20 elements (inductively coupled plasma-mass spectrometry).

RESULTS

One-hundred-and-two women who were feeding infants completed the survey, and 77 provided 92 breast milk samples. Two women reported concern about the impact of fire events on their infant feeding method, while four reported the events influenced their decision. PAHs were detected in 34% of samples collected during, versus no samples collected outside, the fire period (cross-sectional analysis); specifically, fluoranthene (median concentration 0.015 mg/kg) and pyrene (median concentration 0.008 mg/kg) were detected. Women whose samples contained fluoranthene and pyrene were exposed to higher levels of fire-related fine particulate matter and more fire days, versus women whose samples had no detectable fluoranthene and pyrene. Calcium, potassium, magnesium, sodium, sulphur, and copper were detected in all samples. No samples contained chromium, lead, nickel, barium, or aluminium. No statistically significant difference was observed in the concentration of elements between samples collected during the fire period versus outside the fire period.

CONCLUSIONS

Few women had concerns about the impact of fire events on infant feeding. Detection of fluoranthene and pyrene in breast milk samples was more likely during the 2019/2020 Australian fire period; however, levels detected were much lower than levels expected to be related to adverse health outcomes.

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.

Myofunctional device use in oral care and swallowing: a protocol for a feasibility study in an aged care population

Background

Poor oral health is a known predictor of aspiration pneumonia in vulnerable populations such as the elderly and chronically ill and has been linked to systemic disease, morbidity, and mortality. Reduced oral health not only places individuals at a greater risk of aspiration pneumonia but may result in pain or poorer dentition which can impact on mastication and swallowing. Consequences of this may include reduced oral intake, malnutrition, poorer health outcomes, and reduced quality of life. Few evidence-based protocols exist to manage oral care in aged care populations, and maintenance of good oral hygiene is difficult for nursing and care staff to facilitate. However, a recent literature review found that improvements in oral hygiene, oral behaviors, and swallowing, along with breathing and speech have been found to be associated with the use of myofunctional devices due to positive changes in orofacial functions such as lip seal, mastication, swallowing, and nasal breathing patterns. The primary aim of this study is to assess the feasibility of using a myofunctional device to improve oral care and swallowing function in an aged care population.

Methods/design

This project is a feasibility study that involves a 5-week intervention for oral hygiene and dysphagia for residents >65 years old in an aged care setting. Feasibility will be determined by the acceptability of the intervention, study recruitment and retention, and adherence to the intervention. Feasibility testing will also include an evaluation of clinical outcome measures, and sensitivity to detect changes in oral health and swallowing in an aged care population.

Discussion

The results of this trial will provide important information regarding the feasibility of utilizing a myofunctional device to improve oral care and dysphagia in elderly patients in an aged care facility. This knowledge will further guide and inform design of a larger trial or future research.

Trial registration

This trial was registered August 10, 2021, with the Australian New Zealand Clinical Trials Registry and allocated the ACTRN: ACTRN12621001359820.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-01148-3.

Chronic cough in asthma is associated with increased airway inflammation, more comorbidities, and worse clinical outcomes

Background: Cough is often the most prominent and intractable symptom reported by patients with asthma, but few studies have explored the characteristics of patients with asthma and with chronic cough (CC) in a real-world setting. Methods: In a prospective cohort study, patients ages ≥ 18 years with stable asthma were consecutively recruited at the West China Hospital, Sichuan University. The patients were classified as having asthma with CC (the CC group) or asthma with non-CC (the non-CC group) after 3 months of optimized asthma therapy according to standard guidelines. Multidimensional assessment was performed at baseline, followed by a 12-month follow-up to assess asthma exacerbations. Results: Of 323 patients with asthma, 127 patients were assigned to the CC group and 196 patients were assigned to the non-CC group. The participants with CC were older and had more airflow obstruction; worse asthma control and quality of life; increased airway inflammation; upper respiratory tract infection as a trigger; and more comorbidities, such as psychological dysfunction, rhinitis, chronic obstructive pulmonary disease, and bronchiectasis. They reported greater work productivity loss and daily activity impairment, and increased moderate-to-severe exacerbations. Conclusion: The participants with asthma and with CC had a significant disease burden, with increased exacerbations, health-care utilization, and impaired work productivity and daily activity. These observations indicated potential clinical implications in patients with asthma and with CC, and call for more attention to this aspect of asthma.

The Impact of Functional Laryngoscopy on the Diagnosis of Laryngeal Hypersensitivity Syndromes

BACKGROUND

Chronic cough and vocal cord dysfunction are manifestations of laryngeal hypersensitivity syndrome.

OBJECTIVE

The aim of the study was to determine the clinical utility of functional transnasal laryngoscopy in patients with laryngeal hypersensitivity syndromes.

METHODS

This study was a prospective observational cross-sectional study design of 71 participants with laryngeal hypersensitivity syndrome referred for functional transnasal laryngoscopy. Participants had a clinical assessment with a speech pathologist after which a provisional diagnosis of chronic cough, suspected vocal cord dysfunction, suspected muscle tension dysphonia, or a combination was made. A laryngoscopy with provocation was performed and the diagnosis revised after which the provisional and revised diagnoses were compared.

RESULTS

The diagnosis changed in 67% of participants after laryngoscopy. Vocal cord dysfunction was diagnosed in an additional 17 cases when not expected clinically but discounted when suspected clinically in 12 participants. Muscle tension dysphonia was diagnosed in an additional 31 cases when not suspected clinically and not confirmed when suspected in 2.

CONCLUSION

This study demonstrated that conditions such as muscle tension dysphonia and vocal cord dysfunction cannot be diagnosed based on symptoms alone. In addition to diagnostic accuracy, functional laryngoscopy enhances treatment planning and provides immediate feedback regarding laryngeal movement during respiration and phonation.

Feasibility and clinical utility of ambulatory cough monitoring in an outpatient clinical setting: a real-world retrospective evaluation

RESEARCH QUESTION

Objective quantification of cough is rarely utilised outside of research settings and the role of cough frequency monitoring in clinical practice has not been established. This study examined the clinical utility of cough frequency monitoring in an outpatient clinical setting.

METHODS

The study involved a retrospective review of cough monitor data. Participants included 174 patients referred for treatment of cough and upper airway symptoms (103 chronic cough; 50 inducible laryngeal obstruction; 21 severe asthma) and 15 controls. Measures, taken prior to treatment, included 24-h ambulatory cough frequency using the Leicester Cough Monitor, the Leicester Cough Questionnaire and Laryngeal Hypersensitivity Questionnaire. Post-treatment data were available for 50 participants. Feasibility and clinical utility were also reported.

RESULTS

Analysis time per recording was up to 10 min. 75% of participants could use the monitors correctly, and most (93%) recordings were interpretable. The geometric mean cough frequency in patients was 10.1±2.9 (mean±sd) compared to 2.4±2.0 for healthy controls (p=0.003). There was no significant difference in cough frequency between clinical groups (p=0.080). Cough frequency decreased significantly following treatment (p<0.001). There was a moderate correlation between cough frequency and both cough quality of life and laryngeal hypersensitivity. Cough frequency monitoring was responsive to therapy and able to discriminate differences in cough frequency between diseases.

CONCLUSION

While ambulatory cough frequency monitoring remains a research tool, it provides useful clinical data that can assist in patient management. Logistical issues may preclude use in some clinical settings, and additional time needs to be allocated to the process.

Lymphoedema after head and neck cancer treatment: an overview for clinical practice

Lymphoedema is a disorder of the lymphatic system that presents as an atypical swelling and accumulation of protein-rich fluid within the interstitial spaces. Head and neck lymphoedema (HNL) is highly prevalent in patients who have been treated for head and neck cancer (HNC) and may manifest externally on the face and neck; internally within the oral cavity, pharynx or larynx; or as a combination of both. HNL is known to contribute to a wide range of physical, functional and psychological issues, and presents several unique challenges in terms of its management. This review article provides an overview of HNL for clinicians and aims to improve awareness of this condition and the impact it has on patients.

Laryngeal Dysfunction in Severe Asthma: A Cross-Sectional Observational Study

BACKGROUND

Laryngeal disorders can contribute to disease burden in severe asthma yet the nature of laryngeal disorders in severe asthma is poorly understood.

OBJECTIVE

The aim of this study was to examine laryngeal function in patients with severe asthma.

METHOD

A cross-sectional observational study involving 97 participants compared laryngeal function in patients with severe asthma (n = 53) with patients with laryngeal disorders of vocal cord dysfunction/inducible laryngeal obstruction (n = 16) and muscle tension dysphonia (n = 14), and with healthy controls (n = 13). A pre-post pilot study of speech pathology intervention for laryngeal symptoms was then provided to 11 participants with severe asthma and laryngeal dysfunction.

RESULTS

Laryngeal dysfunction was common in severe asthma. The majority of participants with severe asthma (87%) had laryngeal dysfunction, which affected respiration, phonation, or both. Three distinct patterns of laryngeal dysfunction in severe asthma were identified: (1) phonatory laryngeal dysfunction, (2) respiratory laryngeal dysfunction, and (3) combined laryngeal dysfunction. Laryngeal hypersensitivity and impaired voice measures were common in severe asthma. Patient-reported outcome measures improved after therapy, and laryngeal dysfunction improved in 7 (64%) participants.

CONCLUSION

Laryngeal dysfunction affects respiration and phonation in severe asthma. It requires identification and treatment to minimize its impact on asthma symptoms.

Association between external and internal lymphedema and chronic dysphagia following head and neck cancer treatment

BACKGROUND

To examine the relationship between chronic external and internal head and neck lymphedema (HNL) and swallowing function in patients following head and neck cancer (HNC) treatment.

METHODS

Seventy-nine participants, 1-3 years post treatment were assessed for external HNL using the MD Anderson Cancer Centre Lymphedema Rating Scale, and internal HNL using Patterson's Radiotherapy Edema Rating Scale. Swallowing was assessed via instrumental, clinical and patient-reported outcome measures.

RESULTS

HNL presented as internal only (68%), combined external/internal (29%), and external only (1%). Laryngeal penetration/aspiration was confirmed in 20%. Stepwise multivariable regression models, that accounted for primary site, revealed that a higher severity of external HNL and internal HNL was associated with more severe penetration/aspiration (P < .004 and P = .006, respectively), diet modification (P < .001 both), and poorer patient-reported outcomes (P = .037 and P = .014, respectively).

CONCLUSION

Increased swallowing issues can be expected in patients presenting with more severe external HNL and/or internal HNL following HNC treatment.

Comparing the prevalence, location, and severity of head and neck lymphedema after postoperative radiotherapy for oral cavity cancers and definitive chemoradiotherapy for oropharyngeal, laryngeal, and hypopharyngeal cancers

BACKGROUND

This study aimed to examine the prevalence, location, and severity of chronic internal, external, and combined head and neck lymphedema (HNL) in patients with head and neck (HNC) who were treated with definitive chemoradiotherapy (CRT) or postoperative radiotherapy (PORT).

METHODS

Sixty-two participants between 1 and 3 years post-treatment were recruited. Internal HNL was rated with Patterson's Scale. External HNL was graded with the MD Anderson Cancer Center Lymphedema Rating Scale.

RESULTS

Ninety-eight percent of participants presented with some form of chronic HNL. Sixty-one percent had internal HNL only, 35% had combined HNL, and 2% had external HNL only. Participants treated with PORT were more likely to experience combined HNL (69% vs 24%, P = .001), whereas those treated with CRT were more likely to have internal HNL only (74% vs 25%, P = .001).

CONCLUSIONS

Chronic HNL is highly prevalent following multimodal treatment, and differences in HNL presentations exist between treatment modalities.

An Update on Speech Pathology Management of Chronic Refractory Cough

Chronic cough is a common, debilitating condition that can persist for years with little relief from medical treatment. Speech pathology treatment is an effective treatment option for patients with chronic cough. This review outlines current speech pathology assessment and treatment for chronic cough and describes the evidence supporting the intervention. The rationale for speech pathology intervention is described with reference to speech pathology training and expertise that are relevant for this condition. Despite the efficacy and advantages of speech pathology intervention, there is limited guidance in the literature on when patients should be referred for treatment. Patients suitable for speech pathology intervention are those whose cough has persisted despite medical management. Speech pathology intervention may be particularly beneficial for patients with coexisting laryngeal disorders such as muscle tension dysphonia or inducible laryngeal obstruction. Limited information is available regarding current speech pathology training, practice, and service delivery for chronic cough internationally. Timely referral for speech pathology intervention could reduce the disease burden for individuals with chronic cough and decrease the economic burden of this complex condition.

Patient perceptions of living with head and neck lymphoedema and the impacts to swallowing, voice and speech function

Head and neck lymphoedema (HNL) is common following head and neck cancer (HNC) treatment, and may contribute to numerous physical, functional and psychological symptoms. However, its impact on swallowing, voice and speech is less well understood. The aim of this study was to use interpretive description to explore patient perceptions relating to the impact of HNL on swallowing, voice and speech. Twelve participants, >3 months post HNC treatment and experiencing some form of HNL, participated in individual, semi-structured interviews. Transcribed interviews underwent thematic analysis using an inductive approach, with subsequent member checking. Most participants felt their HNL impacted their swallowing and some had impacts on speech; although the impact on voice was less clear. Four themes emerged, including three themes relating to HNL and its impact on swallowing and speech: "it feels tight;" "it changes throughout the day;" "it requires daily self-monitoring and management;" and a fourth general theme "it affects me in other ways." Participants perceived direct impacts from HNL to swallowing and speech. They often experienced daily symptom fluctuations that required additional strategies during times of increased difficulty. Findings highlight the need to improve patient education regarding the functional impacts of HNL and the importance of self-management.

An update and systematic review on drug therapies for the treatment of refractory chronic cough

INTRODUCTION

Chronic Cough (CC) is common and often associated with significant comorbidity and decreased quality of life. In up to 50% of cases, the cough is refractory despite extensive investigation and treatment trials. It is likely that the key abnormality in refractory CC is dysfunctional, hypersensitive sensory nerves, similar to conditions such as laryngeal hypersensitivity and neuropathic pain.

AREAS COVERED

The aim of this systematic review is to assess drug therapies for refractory CC. The authors review the current management of CC and provide discussion of the similarities between neuropathic pain and refractory CC. They review repurposed and new pharmacological treatments. Several meta-analyses were performed to compare the efficacy of treatments where possible.

EXPERT OPINION

Repurposed pain medications such as gabapentin and pregabalin reduce the frequency of cough and improve quality of life. Along with speech pathology, they are important and alternate treatments for refractory CC. However, more treatments are needed and the P2X3 ion channel receptor antagonists show the most promise. With a better understanding of neuronal activation and sensitisation and their signal processing in the brain, improved animal models of cough, and the use of validated cough measurement tools, more effective treatments will develop.

The Effect of a Vocal Loading Test on Cough and Phonation in Patients With Chronic Cough

OBJECTIVE/HYPOTHESIS

Talking is a significant trigger for cough in patients with chronic cough; however, the stimulus required to trigger cough has not been quantified. The aim of this study was to examine the effect of a vocal loading task on phonation and cough behavior in patients with chronic cough and identify change following therapy.

STUDY DESIGN

This is a prospective observational study.

METHODS

This study involved 33 patients with chronic cough. Participants were assessed with the lingWAVES Vocal Loading Test protocol before and after intervention for chronic cough.

RESULTS

At baseline, almost 40% of patients had impaired vocal function and were unable to complete the vocal loading test. This improved following therapy, with 94% of patients being able to complete the test at follow-up. There was difficulty maintaining phonation, with 60% of the task unvoiced at baseline. This improved following therapy. The vocal loading test triggered coughing in 58% of patients; however, this improved following intervention. Acoustic measures during the vocal loading test did not change following therapy.

CONCLUSION

Phonation is an important trigger for cough. Patients with chronic cough demonstrated impaired performance on tests of vocal loading. Most parameters improved following therapy.

Somatic cough syndrome or psychogenic cough-what is the difference?

The term psychogenic cough has been used to describe cough without obvious medical etiology, which is refractory to medical management and considered to have a psychiatric or psychological basis. However there are limitations in the research into psychogenic cough with limited empirical data on how to define the condition or differentially diagnose it from other forms of chronic cough. The term somatic cough syndrome was introduced by the American College of Chest physicians in 2015 during their revision of the 2006 guideline on psychogenic cough. Psychomorbidity can be present in chronic cough arising from a variety of etiologies and can impact on symptom perception and clinical management of the condition. Psychological symptoms can also improve after effective treatment of the chronic cough. The recently published American College of Chest Physicians cough guidelines recommended replacing the term psychogenic cough with the term somatic cough syndrome in order to be consistent with the Diagnostic Statistical Manual of Mental Disorders, 5^th edition (DSM-5) where the term psychogenic is no longer used. This paper outlines the current evidence regarding psychogenic cough, proposes a model for conceptualising psychological issues in chronic cough and discusses strategies for clinical management of psychological issues in patients with chronic cough.

REVIEW SERIES: Chronic cough: Behaviour modification therapies for chronic cough

Chronic cough (CC) can be refractory to medical treatment and newer strategies are required for these patients. Behaviour modification therapies are a potential approach for management of cough that does not respond to medical management. Behaviour modification therapy for CC involves an individually tailored programme teaching individuals to increase control over cough symptoms and includes education, specific strategies to suppress the cough, vocal hygiene training and psychoeducational counselling. Several case series have described speech pathology treatment for CC and a recent randomized control trial has demonstrated a significant improvement in symptoms. Possible mechanisms for this improvement include reduced cough reflex sensitivity, increased voluntary control of the cough and reduced stimulation of cough receptors. Respiratory retraining used by physiotherapists may also have potential for use in CC. The validity of psychological therapeutic approaches to CC rests on concepts of CC as a disorder with a psychogenic component, and the ability of cognitive therapies to modify the cough pathway. This work outlines current literature into behavioural management of CC and suggests new directions for practice and research in adults with this condition. Chronic Respiratory Disease 2007; 4: 89—97

Pregabalin and Speech Pathology Combination Therapy for Refractory Chronic Cough: A Randomized Controlled Trial

BACKGROUND

Chronic refractory cough (CRC) is a difficult problem to treat. Speech pathology treatment (SPT) improves symptoms but resolution is incomplete. Centrally acting neuromodulators also improve cough symptoms, but not cough reflex sensitivity, and the effect is short-lived. We hypothesized that combined SPT and centrally acting neuromodulators would have a superior outcome than SPT alone. Our goal was to determine whether combined pregabalin and SPT is more effective than SPT alone.

METHODS

Randomized placebo controlled trial. Forty patients with CRC were randomly assigned to receive either combined SPT and pregabalin 300 mg daily or combined SPT and placebo. Outcome measures were collected at baseline, end of treatment, and 4 weeks after the end of treatment. Primary outcome measures were cough frequency using the Leicester Cough Monitor, cough severity using a visual analog scale (coughVAS), and cough-related quality of life (QOL) using the Leicester Cough Questionnaire (LCQ).

RESULTS

Cough severity, cough frequency, and cough QOL improved in both groups. The degree of improvement in LCQ and coughVAS was greater with combined SPT and pregabalin than SPT alone; the mean difference in LCQ was 3.5, 95%CI of difference 1.1 to 5.8; the mean difference in coughVAS was 25.1, 95% CI of difference 10.6 to 39.6. There was no significant difference in improvement in cough frequency between groups. There was no deterioration in symptoms once pregabalin was withdrawn. Median capsaicin cough sensitivity improved from 15.7 to 47.5 μM with combined SPT and pregabalin and from 3.92 to 15.7 μM with SPT alone.

CONCLUSIONS

Combined SPT and pregabalin reduces symptoms and improves QOL compared with SPT alone in patients with CRC.

Treatment of Unexplained Chronic Cough: CHEST Guideline and Expert Panel Report

BACKGROUND

Unexplained chronic cough (UCC) causes significant impairments in quality of life. Effective assessment and treatment approaches are needed for UCC.

METHODS

This systematic review of randomized controlled trials (RCTs) asked: What is the efficacy of treatment compared with usual care for cough severity, cough frequency, and cough-related quality of life in patients with UCC? Studies of adults and adolescents aged > 12 years with a chronic cough of > 8 weeks' duration that was unexplained after systematic investigation and treatment were included and assessed for relevance and quality. Based on the systematic review, guideline suggestions were developed and voted on by using the American College of Chest Physicians organization methodology.

RESULTS

Eleven RCTs and five systematic reviews were included. The 11 RCTs reported data on 570 participants with chronic cough who received a variety of interventions. Study quality was high in 10 RCTs. The studies used an assortment of descriptors and assessments to identify UCC. Although gabapentin and morphine exhibited positive effects on cough-related quality of life, only gabapentin was supported as a treatment recommendation. Studies of inhaled corticosteroids (ICS) were affected by intervention fidelity bias; when this factor was addressed, ICS were found to be ineffective for UCC. Esomeprazole was ineffective for UCC without features of gastroesophageal acid reflux. Studies addressing nonacid gastroesophageal reflux disease were not identified. A multimodality speech pathology intervention improved cough severity.

CONCLUSIONS

The evidence supporting the diagnosis and management of UCC is limited. UCC requires further study to establish agreed terminology and the optimal methods of investigation using established criteria for intervention fidelity. Speech pathology-based cough suppression is suggested as a treatment option for UCC. This guideline presents suggestions for diagnosis and treatment based on the best available evidence and identifies gaps in our knowledge as well as areas for future research.

Management of chronic refractory cough

Chronic refractory cough (CRC) is defined as a cough that persists despite guideline based treatment. It is seen in 20-46% of patients presenting to specialist cough clinics and it has a substantial impact on quality of life and healthcare utilization. Several terms have been used to describe this condition, including the recently introduced term cough hypersensitivity syndrome. Key symptoms include a dry irritated cough localized around the laryngeal region. Symptoms are not restricted to cough and can include globus, dyspnea, and dysphonia. Chronic refractory cough has factors in common with laryngeal hypersensitivity syndromes and chronic pain syndromes, and these similarities help to shed light on the pathophysiology of the condition. Its pathophysiology is complex and includes cough reflex sensitivity, central sensitization, peripheral sensitization, and paradoxical vocal fold movement. Chronic refractory cough often occurs after a viral infection. The diagnosis is made once the main diseases that cause chronic cough have been excluded (or treated) and cough remains refractory to medical treatment. Several treatments have been developed over the past decade. These include speech pathology interventions using techniques adapted from the treatment of hyperfunctional voice disorders, as well as the use of centrally acting neuromodulators such as gabapentin and pregabalin. Potential new treatments in development also show promise.

Assessment of Intervention Fidelity and Recommendations for Researchers Conducting Studies on the Diagnosis and Treatment of Chronic Cough in the Adult: CHEST Guideline and Expert Panel Report

BACKGROUND

Successful management of chronic cough has varied in the primary research studies in the reported literature. One of the potential reasons relates to a lack of intervention fidelity to the core elements of the diagnostic and/or therapeutic interventions that were meant to be used by the investigators.

METHODS

We conducted a systematic review to summarize the evidence supporting intervention fidelity as an important methodologic consideration in assessing the effectiveness of clinical practice guidelines used for the diagnosis and management of chronic cough. We developed and used a tool to assess for five areas of intervention fidelity. Medline (PubMed), Scopus, and the Cochrane Database of Systematic Reviews were searched from January 1998 to May 2014. Guideline recommendations and suggestions for those conducting research using guidelines or protocols to diagnose and manage chronic cough in the adult were developed and voted upon using CHEST Organization methodology.

RESULTS

A total of 23 studies (17 uncontrolled prospective observational, two randomized controlled, and four retrospective observational) met our inclusion criteria. These articles included 3,636 patients. Data could not be pooled for meta-analysis because of heterogeneity. Findings related to the five areas of intervention fidelity included three areas primarily related to the provider and two primarily related to the patients. In the area of study design, 11 of 23 studies appeared to be underpinned by a single guideline/protocol; for training of providers, two of 23 studies reported training, and zero of 23 reported the use of an intervention manual; and for the area of delivery of treatment, when assessing the treatment of gastroesophageal reflux disease, three of 23 studies appeared consistent with the most recent guideline/protocol referenced by the authors. For receipt of treatment, zero of 23 studies mentioned measuring concordance of patient-interventionist understanding of the treatment recommended, and zero of 23 mentioned measuring enactment of treatment, with three of 23 measuring side effects and two of 23 measuring adherence. The overall average intervention fidelity score for all 23 studies was poor (20.74 out of 48).

CONCLUSIONS

Only low-quality evidence supports that intervention fidelity strategies were used when conducting primary research in diagnosing and managing chronic cough in adults. This supports the contention that some of the variability in the reporting of patients with unexplained or unresolved chronic cough may be due to lack of intervention fidelity. By following the recommendations and suggestions in this article, researchers will likely be better able to incorporate strategies to address intervention fidelity, thereby strengthening the validity and generalizability of their results that provide the basis for the development of trustworthy guidelines.

Somatic Cough Syndrome (Previously Referred to as Psychogenic Cough) and Tic Cough (Previously Referred to as Habit Cough) in Adults and Children: CHEST Guideline and Expert Panel Report

BACKGROUND

We conducted a systematic review on the management of psychogenic cough, habit cough, and tic cough to update the recommendations and suggestions of the 2006 guideline on this topic.

METHODS

We followed the American College of Chest Physicians (CHEST) methodologic guidelines and the Grading of Recommendations, Assessment, Development, and Evaluation framework. The Expert Cough Panel based their recommendations on data from the systematic review, patients' values and preferences, and the clinical context. Final grading was reached by consensus according to Delphi methodology.

RESULTS

The results of the systematic review revealed only low-quality evidence to support how to define or diagnose psychogenic or habit cough with no validated diagnostic criteria. With respect to treatment, low-quality evidence allowed the committee to only suggest therapy for children believed to have psychogenic cough. Such therapy might consist of nonpharmacologic trials of hypnosis or suggestion therapy, or combinations of reassurance, counseling, and referral to a psychologist, psychotherapy, and appropriate psychotropic medications. Based on multiple resources and contemporary psychologic, psychiatric, and neurologic criteria (Diagnostic and Statistical Manual of Mental Disorders, 5th edition and tic disorder guidelines), the committee suggests that the terms psychogenic and habit cough are out of date and inaccurate.

CONCLUSIONS

Compared with the 2006 CHEST Cough Guidelines, the major change in suggestions is that the terms psychogenic and habit cough be abandoned in favor of somatic cough syndrome and tic cough, respectively, even though the evidence to do so at this time is of low quality.

Gabapentin in chronic cough

BACKGROUND

Chronic cough is regarded as a challenging clinical problem due to its frequency and often limited therapeutic options. Chronic cough that remains refractory to usual medical treatment causes significant quality of life impairment.

METHODS

Recent developments in the treatment of cough include the use of speech pathology and pharmacotherapy with gabapentin. Relevant randomised control trials, reviews and case reports were identified through a PubMed and SCOPUS search of English-language literature referring to these concepts over the last eight years.

RESULTS

The effectiveness of neuromodulating medications such as gabapentin and pregabalin in the treatment of cough has been supported primarily through case series, case reports, prospective reviews and a double blind randomised controlled trial. Gabapentin results in a reduction in cough frequency and cough severity. It improves cough related quality of life. The effect is greatest in patients with features of central reflex sensitisation such as laryngeal paraesthesia, hypertussia and allotussia. These symptoms can be measured using the Newcastle Laryngeal Hypersensitivity Questionnaire. Side effects of gabapentin include somnolence and dizziness.

CONCLUSION

Recent additions in the treatment of chronic cough have been significant as they consider cough to have a unifying diagnosis of cough hypersensitivity with or without the presence of a neuropathic basis. Effective treatments for refractory chronic cough that target these areas include behavioural treatment such as speech pathology and pharmaceutical treatment with neuromodulating medications such as gabapentin.

Management and diagnosis of psychogenic cough, habit cough, and tic cough: a systematic review

BACKGROUND

Several pharmacologic and nonpharmacologic therapeutic options have been used to treat cough that is not associated with a pulmonary or extrapulmonary etiology.

METHODS

We conducted a systematic review to summarize the evidence supporting different cough management options in adults and children with psychogenic, tic, and habit cough. Medline, EMBASE, the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus were searched from the earliest inception of each database to September 2013. Content experts were contacted, and we searched bibliographies of included studies to identify additional references.

RESULTS

A total of 18 uncontrolled studies were identified, enrolling 223 patients (46% male subjects, 96% children and adolescents). Psychogenic cough was the most common descriptive term used (90% of the studies). Most of the patients (95%) had no cough during sleep; barking or honking quality of cough was described in only eight studies. Hypnosis (three studies), suggestion therapy (four studies), and counseling and reassurance (seven studies) were the most commonly used interventions. Hypnosis was effective in resolving cough in 78% of the patients and improving it in another 5%. Suggestion therapy resolved cough successfully in 96% of the patients. The greatest majority of improvements noted with these forms of therapy occurred in the pediatric age group. The quality of evidence is low due to the lack of control groups, the retrospective nature of all the studies, heterogeneity of definitions and diagnostic criteria, and the high likelihood of reporting bias.

CONCLUSIONS

Only low-quality evidence exists to support a particular strategy to define and treat psychogenic, habit, and tic cough. Patient values, preferences, and availability of potential therapies should guide treatment choice.

Laryngeal sensory dysfunction in laryngeal hypersensitivity syndrome

BACKGROUND AND OBJECTIVE

Diseases associated with laryngeal dysfunction include chronic refractory cough (CRC), paradoxical vocal fold movement (PVFM), muscle tension dysphonia (MTD) and globus pharyngeus. We hypothesized the presence of a common sensory laryngeal dysfunction, the 'laryngeal hypersensitivity' syndrome, in these conditions. The aim of the study was to compare symptoms and sensory function in patients with CRC, PVFM, MTD and globus.

METHODS

The 103 participants included healthy controls (n = 13) and four case groups: CRC (n = 33), PVFM (n = 28), globus pharyngeus (n = 11) and MTD (n = 18). Participants completed self-report questionnaires: Symptom Frequency and Severity Scale, Voice Handicap Index and the Laryngeal Paraesthesia Questionnaire; and quantitative sensory testing: capsaicin cough reflex sensitivity, hypertonic saline challenge, the timed swallow test, acoustic voice testing, cough frequency monitor and a voice stress test.

RESULTS

All case groups reported a high-symptom burden in comparison to controls. The case groups showed a similar pattern of symptoms, with impairment in each of the cough, respiration, vocal and upper airway symptom domains. Objective testing revealed significant sensory impairment in the case groups compared to controls and also showed an overlap in sensory dysfunction between the four case groups. Furthermore, there was cross-sensory stimulation of symptoms whereby stimulation of a particular response resulted in symptoms in another domain.

CONCLUSIONS

These discrete clinical laryngeal syndromes display considerable overlap in their clinical features and a common sensory dysfunction, supporting the 'laryngeal hypersensitivity' hypothesis. Reconceptualizing functional laryngeal disorders as a form of laryngeal hypersensitivity syndrome provides an alternative approach to management of these perplexing conditions.

Development and validation of the Newcastle laryngeal hypersensitivity questionnaire

Background

Laryngeal hypersensitivity may be an important component of the common disorders of laryngeal motor dysfunction including chronic refractory cough, pdoxical vocal fold movement (vocal cord dysfunction), muscle tension dysphonia, and globus pharyngeus. Patients with these conditions frequently report sensory disturbances, and an emerging concept of the ‘irritable larynx’ suggests common features of a sensory neuropathic dysfunction as a part of these disorders. The aim of this study was to develop a Laryngeal Hypersensitivity Questionnaire for patients with laryngeal dysfunction syndromes in order to measure the laryngeal sensory disturbance occurring in these conditions.

Methods

The 97 participants included 82 patients referred to speech pathology for behavioural management of laryngeal dysfunction and 15 healthy controls. The participants completed a 21 item self administered questionnaire regarding symptoms of abnormal laryngeal sensation. Factor analysis was conducted to examine correlations between items. Discriminant analysis and responsiveness to change were evaluated.

Results

The final questionnaire comprised 14 items across three domains: obstruction, pain/thermal, and irritation. The questionnaire demonstrated significant discriminant validity with a mean difference between the patients with laryngeal disorders and healthy controls of 5.5. The clinical groups with laryngeal hypersensitivity had similar abnormal scores. Furthermore the Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ) showed improvement following behavioural speech pathology intervention with a mean reduction in LHQ score of 2.3.

Conclusion

The Newcastle Laryngeal Hypersensitivity Questionnaire is a simple, non-invasive tool to measure laryngeal pesthesia in patients with laryngeal conditions such as chronic cough, pdoxical vocal fold movement (vocal cord dysfunction), muscle tension dysphonia, and globus pharyngeus. It can successfully differentiate patients from healthy controls and measure change following intervention. It is a promising tool for use in clinical research and practice.

Auditory-perceptual voice characteristics in pre-operative patients undergoing thyroid or parathyroid surgery

OBJECTIVES

To systematically evaluate auditory perceptual voice characteristics in people with thyroid disease prior to undergoing thyroid surgery.

PATIENTS AND METHODS

This study examined the auditory perceptual voice characteristics of 96 individuals with thyroid disease. Participants were categorised by type of thyroid disease (i.e. multinodular goitre, thyroid cancer, thyroid nodule, toxicity or parathyroidism) and by status of compression (i.e. compression versus no compression). Auditory perceptual voice ratings were made on samples of connected speech by using the Perceptual Voice Profile.

RESULTS

A high prevalence of participants had deviant auditory perceptual voice features; however, the majority of these abnormalities were slight to mild in severity and only 8% of participants had a clinically significant auditory perceptual abnormality. There was no significant difference in features between diagnostic categories, and only high pitch was rated as more significantly deviant in patients without compression versus those with compression.

CONCLUSIONS

This study supports the need for auditory-perceptual ratings to be included as part of pre-operative multidimensional assessment of voice in patients with thyroid disease.

How to set up a severe asthma service

Severe asthma affects 5-20% of the asthma population but is discordantly responsible for the major burden of illness and impairment to quality of life. Patients with severe asthma continue to experience ongoing symptoms despite maximal therapy. A severe asthma service provides a systematic approach to the management of the disease and aids in confirming the correct diagnosis, managing comorbid conditions that may mimic or aggravate asthma, and provides the environment to optimize treatment and asthma self-management skills and education. A severe asthma service is also the ideal environment for trialling add-on therapies and hence can improve patient outcomes and clinical practice. Within such a service there are many opportunities for training and research. In this article we describe the purpose of a severe asthma clinic, the necessary components of a service including staffing and facilities and the processes for trialling additional therapies used in the management of severe asthma.

Clinical and physiological features of postinfectious chronic cough associated with H1N1 infection

BACKGROUND

Post infectious chronic cough is a disabling illness. In 2009 an influenza pandemic occurred due to a novel strain of H1N1 influenza. Prolonged symptoms such as chronic cough remaining after the infection has cleared have not been examined. This study sought to investigate the prevalence, characteristics and mechanism of chronic cough following laboratory-confirmed H1N1 2009 influenza.

METHODS

Out of 836 eligible patients who had been tested by PCR assay for H1N1, 136 responders participated. Nineteen underwent detailed clinical investigation of cough, and airway function using symptom questionnaires, hypertonic saline challenge, and cough monitoring.

RESULTS

Post H1N1 chronic cough was reported by 43%, and chronic cough after non-H1N1 infection was present in 36% of participants. In the participants who progressed to testing objectively measured cough frequency was 3 times greater; there was a 9-fold increase in cough reflex sensitivity and greater quality of life impairment in the participants with postinfectious chronic cough following H1N1 infection than for the participants with no cough following H1N1 infection and for the healthy controls.

CONCLUSIONS

This study reports the first evaluation of chronic cough following H1N1 infection. Patients that develop chronic cough after H1N1 infection display increased cough reflex sensitivity up to 220 days after confirmed infection. There is an absence of associated risk factors and less impairment in quality of life compared to those patients normally seen in a specialist cough clinic. The associated mechanism was found to be cough reflex hypersensitivity.

TRIAL REGISTRATION

This clinical trial has been registered with the Australian New Zealand Clinical Trials Register, ACTRN12610000540011.

Urge to cough and its application to the behavioural treatment of cough

The Urge-To-Cough has recently been recognised as a significant factor in understanding the pathophysiology of cough. The principles in the urge to cough model are relevant to the behavioural management of laryngeal conditions including chronic non-specific cough, cough due to paradoxical vocal fold movement, aspiration and reflux. This paper analyses the pathophysiology and behavioural management of these conditions according to the urge to cough model (Tab. 3, Ref. 28).

Chronic refractory cough as a sensory neuropathy: evidence from a reinterpretation of cough triggers

OBJECTIVES/HYPOTHESIS

The aims of this study were to examine cough triggers in individuals with chronic cough (CC), identify sensory symptoms consistent with central reflex sensitization (paresthesia and allotussia), and interpret this information in relation to sensory laryngeal neuropathy.

STUDY DESIGN

Prospective observational study.

METHODS

Patients (n=53) with CC that was refractory to medical management based on the anatomic diagnostic protocol completed questionnaires regarding cough triggers, anxiety and depression, and factors contributing to laryngeal irritation such as vocal hygiene and laryngopharyngeal reflux.

RESULTS

An abnormal sensation in the laryngeal area (laryngeal paresthesia) was present in 94% of people with refractory CC. Nontussive stimuli including phonation were frequent triggers for cough (allotussia), occurring in 71% of participants. Although tussive stimuli were significantly more potent than nontussive stimuli (P=0.005), the relative clinical importance was not statistically different (P=0.072). Most participants with refractory cough had poor vocal hygiene.

CONCLUSION

The sensory symptom changes that accompany CC suggest central reflex sensitization and include laryngeal paresthesia and allotussia. The results are consistent with cough as a sensory neuropathic disorder.

Cough reflex sensitivity improves with speech language pathology management of refractory chronic cough

Rationale

Speech language pathology is an effective management intervention for chronic cough that persists despite medical treatment. The mechanism behind the improvement has not been determined but may include active cough suppression, reduced cough sensitivity or increased cough threshold from reduced laryngeal irritation. Objective measures such as cough reflex sensitivity and cough frequency could be used to determine whether the treatment response was due to reduced underlying cough sensitivity or to more deliberate control exerted by individual patients. The number of treatments required to effect a response was also assessed.

Objective

The aim of this study was to investigate subjective and objective measures of cough before, during and after speech language pathology treatment for refractory chronic cough and the mechanism underlying the improvement.

Methods

Adults with chronic cough (n = 17) were assessed before, during and after speech language pathology intervention for refractory chronic cough. The primary outcome measures were capsaicin cough reflex sensitivity, automated cough frequency detection and cough-related quality of life.

Results

Following treatment there was a significant improvement in cough related quality of life (Median (IQR) at baseline: 13.5 (6.3) vs. post treatment: 16.9 (4.9), p = 0.002), objective cough frequency (Mean ± SD at baseline: 72.5 ± 55.8 vs. post treatment: 25 ± 27.9 coughs/hr, p = 0.009), and cough reflex sensitivity (Mean ± SD log C5 at baseline: 0.88 ± 0.48 vs. post treatment: 1.65 ± 0.88, p < 0.0001).

Conclusions

This is the first study to show that speech language pathology management is an effective intervention for refractory chronic cough and that the mechanism behind the improvement is due to reduced laryngeal irritation which results in decreased cough sensitivity, decreased urge to cough and an increased cough threshold. Speech language pathology may be a useful and sustained treatment for refractory chronic cough.

Trial Registration

Australian New Zealand Clinical Trials Register, ACTRN12608000284369.

CICADA: Cough in Children and Adults: Diagnosis and Assessment. Australian cough guidelines summary statement

Cough is a common and distressing symptom that results in significant health care costs from medical consultations and medication use. Cough is a reflex activity with elements of voluntary control that forms part of the somatosensory system involving visceral sensation, a reflex motor response and associated behavioural responses. At the initial assessment for chronic cough, the clinician should elicit any alarm symptoms that might indicate a serious underlying disease and identify whether there is a specific disease present that is associated with chronic cough. If the examination, chest x-ray and spirometry are normal, the most common diagnoses in ADULTS are asthma, rhinitis or gastro-oesophageal reflux disease (GORD). The most common diagnoses in CHILDREN are asthma and protracted bronchitis. Management of chronic cough involves addressing the common issues of environmental exposures and patient or parental concerns, then instituting specific therapy. In ADULTS, conditions that are associated with removable causes or respond well to specific treatment include protracted bacterial bronchitis, angiotensin-converting enzyme inhibitor use, asthma, GORD, obstructive sleep apnoea and eosinophilic bronchitis. In CHILDREN, diagnoses that are associated with removable causes or respond well to treatment are exposure to environmental tobacco smoke, protracted bronchitis, asthma, motor tic, habit and psychogenic cough. In ADULTS, refractory cough that persists after therapy is managed by empirical inhaled corticosteroid therapy and speech pathology techniques.

Chronic cough and laryngeal dysfunction improve with specific treatment of cough and paradoxical vocal fold movement

Rationale

Chronic persistent cough can be associated with laryngeal dysfunction that leads to symptoms such as dysphonia, sensory hyperresponsiveness to capsaicin, and motor dysfunction with paradoxical vocal fold movement and variable extrathoracic airflow obstruction (reduced inspiratory airflow). Successful therapy of chronic persistent cough improves symptoms and sensory hyperresponsiveness. The effects of treatment for chronic cough on laryngeal dysfunction are not known.

Objective

The aim of this study was to investigate effects of therapy for chronic cough and paradoxical vocal fold movement.

Methods

Adults with chronic cough (n = 24) were assessed before and after treatment for chronic persistent cough by measuring quality of life, extrathoracic airway hyperresponsiveness to hypertonic saline provocation, capsaicin cough reflex hypersensitivity and fibreoptic laryngoscopy to observe paradoxical vocal fold movement. Subjects with chronic cough were classified into those with (n = 14) or without (n = 10) paradoxical vocal fold movement based on direct observation at laryngoscopy.

Results

Following treatment there was a significant improvement in cough related quality of life and cough reflex sensitivity in both groups. Subjects with chronic cough and paradoxical vocal fold movement also had additional improvements in extrathoracic airway hyperresponsiveness and paradoxical vocal fold movement. The degree of improvement in cough reflex sensitivity correlated with the improvement in extrathoracic airway hyperresponsiveness.

Conclusion

Laryngeal dysfunction is common in chronic persistent cough, where it is manifest as paradoxical vocal fold movement and extrathoracic airway hyperresponsiveness. Successful treatment for chronic persistent cough leads to improvements in these features of laryngeal dysfunction.

Speech pathology for chronic cough: a new approach

Chronic cough may persist despite systematic evaluation and medical treatment of known associated diseases such as asthma, rhinitis, and gastro-esophageal reflux. These patients have refractory chronic cough and many exhibit laryngeal hypersensitivity that is manifest at both a sensory and motor level. Examples of this are heightened sensitivity of the cough reflex to capsaicin, and laryngeal motor dysfunction with hoarse vocal quality and paradoxical vocal cord movement. Chronic cough that persists despite medical treatment may respond to speech pathology intervention. A multidimensional speech pathology treatment programme was designed based upon methods used to treat hyperfunctional voice disorders and paradoxical vocal fold movement. This included education, vocal hygiene training, cough suppression strategies and psychoeducational counseling. When tested in a single-blind, randomized, placebo-controlled trial involving 87 patients, participants in the treatment group demonstrated a significant reduction in cough, breathing, voice and upper airway symptoms following intervention, as well as improvements in auditory perceptual ratings of voice quality (breathy, rough, strain and glottal fry) and significant improvement in voice acoustic parameters (maximum phonation time, jitter and harmonic-to-noise ratio). Speech pathology intervention can be an effective way to treat refractory chronic cough.

Acoustic and Electroglottographic Voice Characteristics in Chronic Cough and Paradoxical Vocal Fold Movement

<i>Objective:</i> Chronic cough (CC) and paradoxical vocal fold movement (PVFM) may be associated with voice problems. Objective acoustic and electroglottographic (EGG) measures have the capacity to delineate these vocal characteristics. This study investigated acoustic and EGG voice features of CC and PVFM. <i>Patients and Methods:</i> Acoustic and EGG findings were compared among 5 groups of participants. The first 3 groups, CC (n = 56), PVFM (n = 8) and combined CC-PVFM (n = 55), included individuals with cough and respiratory symptoms that persisted despite medical treatment. Groups 4 and 5 included individuals with muscle tension dysphonia (n = 25) and healthy controls (n = 27). <i>Results:</i> Participants with CC/PVFM recorded reduced phonation times (p < 0.001), greater jitter (p < 0.001), reduced harmonic to noise ratio (p = 0.001), reduced phonation range (p = 0.007) and shorter closed phase of vocal fold vibration (p = 0.006) in comparison to healthy controls. Females with CC had reduced fundamental frequency in connected speech (p = 0.009). There was consistent overlap between the participants with CC and those with PVFM. Duration of closed phase and fundamental frequency were lower in the participants with CC and PVFM than in those with muscle tension dysphonia. <i>Conclusion:</i> These results confirm abnormalities in acoustic and EGG voice features in CC and PVFM.

The role of sensory dysfunction in the development of voice disorders, chronic cough and paradoxical vocal fold movement

Sensory function may be important in the pathogenesis of Chronic Cough (CC) and Paradoxical Vocal Fold Movement (PVFM). This paper aims to explore sensory issues related to the pathogenesis, classification, assessment and management of these conditions. Sensory disruption of the vagus nerve can occur through neural plasticity whereby a change occurs in the way a central neuron reacts to an incoming stimulus. Such disruption can be demonstrated through assessment of cough reflex sensitivity and extrathoracic airway hyperresponsiveness both of which may be increased in CC and PVFM. In addition, sensory function may be determined by measuring the laryngeal adductor reflex, however this phenomenon is yet to be explored in CC and PVFM. The similarity in sensory dysfunction between CC and PVFM provides support for a link between the two conditions. There are also similarities in underlying medical conditions and symptom profiles between CC/PVFM and voice disorders such as muscle tension dysphonia. Although coughing and throat clearing may be contributing factors in the development and maintenance of voice disorders, they may occur in response to extrathoracic airway hyperresponsiveness. Dysphonia can occur in CC/PVFM and may improve following behavioural treatment of CC.

Perceptual Voice Characteristics in Chronic Cough and Paradoxical Vocal Fold Movement

Voice problems have been reported in chronic cough (CC) and paradoxical vocal fold movement (PVFM), however, there is a lack of a systematic description of voice characteristics in these conditions. This study examined the perceptual voice characteristics of 56 individuals with CC, 8 with PVFM and 55 with both CC and PVFM, compared to 25 people with muscle tension dysphonia (MTD) and 27 healthy controls. There was a high prevalence of abnormal voice quality in the CC and PVFM groups compared with healthy controls. More than one third of participants with CC and PVFM demonstrated strained, rough and/or breathy voices to a moderate or severe degree. The perceptual features in CC and PVFM were similar to those in MTD with greater severity evident in MTD. Possible mechanisms for abnormalities in voice quality include the presence of muscle tension and the frequency of coughing. These results have implications for the identification and management of voice disorders in CC and PVFM and suggest that clinicians should be alert to the incidence of voice abnormalities in these populations.

A comparison of two approaches to the treatment of chronic cough: perceptual, acoustic, and electroglottographic outcomes

Voice problems have been reported to occur in association with chronic cough (CC) and can interfere with quality of life. Voice symptoms can improve following behavioral intervention for CC that persists despite medical management; however, formal measures of voice changes have not been reported. The aim of this study was to measure the changes in perceptual, acoustic, and electroglottographic voice characteristics after a SPEech Pathology Intervention Program for CHronic Cough (SPEICH-C) compared to a Healthy Lifestyle Education intervention program (HLE control). Eighty-two participants with CC that was refractory to medical management were randomly allocated to receive either the SPEICH-C or an HLE control. Participants in the SPEICH-C group demonstrated a significant reduction in perceptual ratings of breathy, rough, strain, and glottal fry qualities (P<0.001) in comparison to the HLE control group. There was a significant improvement between pre- and postintervention maximum phonation time, jitter, and harmonic-to-noise ratio values in the SPEICH-C group; however, the magnitude of change was not significantly different between groups. There was no significant change in fundamental frequency, standard deviation of fundamental frequency, phonation range, or closed phase of vocal fold vibration after intervention for either group. These results demonstrated that SPEICH-C can improve perceptual aspects of voice quality suggesting that dysphonia may be a fundamental characteristic of CC.

A review of voice and upper airway function in chronic cough and paradoxical vocal cord movement

PURPOSE OF THE REVIEW

Chronic cough and paradoxical vocal fold movement (PVFM) are perplexing conditions. This paper reviews the recent literature in relation to the nature of PVFM and chronic cough and the management of symptoms associated with these disorders.

RECENT FINDINGS

There are similarities in the voice and upper airway symptoms in chronic cough and PVFM. Clinically significant voice symptoms are present in approximately 40% of individuals with chronic cough and PVFM and are similar to those occurring in voice disorders such as muscle tension dysphonia. Chronic cough can be associated with PVFM in a large proportion of cases. Extrathoracic airway hyperresponsiveness is a common underlying mechanism in PVFM and chronic cough. Speech pathology intervention can be effective in controlling symptoms in chronic cough, which suggests that the anatomic diagnostic protocol could be expanded to incorporate this intervention. Chronic cough that fails to respond to medical management should be conceptualized as either due to PVFM or idiopathic. PVFM and chronic cough are not necessarily the result of underlying psychopathology.

SUMMARY

Chronic cough and PVFM manifest in a range of clinically significant voice and upper airway symptoms. The anatomic diagnostic protocol used in the management of chronic cough could be expanded to include PVFM as a potential cause of cough, and speech pathology intervention as treatment for chronic cough.