Managing cough as a defense mechanism and as a symptom. A consensus panel report of the American College of Chest Physicians

Reclassification of items in the Leicester Cough Questionnaire: Correlation analysis

BACKGROUND

The Leicester Cough Questionnaire (LCQ) is a validated tool for assessing cough that has three domains (physical, psychological, and social), with eight, seven, and four items, respectively. However, the assigned domain may not accurately reflect the characteristics of an item. This study aimed to reclassify the items in the Korean version of the LCQ (K-LCQ) to improve the coherence in each domain.

METHODS

Data of patients with chronic cough from 16 centers who completed the K-LCQ were retrospectively analyzed. Spearman's rank correlation analysis was used to assess the correlations between items and their domains. Principal component analysis was performed to recategorize the K-LCQ items.

RESULTS

The correlation analysis of the data from 255 patients demonstrated that certain items such as tiredness, embarrassment, and interference with daily work or overall life enjoyment showed strong or very strong correlations with all three domains. Cough bout frequency showed the weakest correlation with the physical domain, despite being included in that domain, and had stronger correlations with the psychological and social domain. The principal component analysis led to the reclassification of six items: one from the physical to psychological, two from the social to psychological, and three from the psychological to social domain. The within-domain correlation coherence was higher in the new classification than in the original. Validation using an independent cohort of 203 patients yielded similar results.

CONCLUSIONS

The new classification of the K-LCQ items showed improved within-domain correlation coherence.

Multidisciplinary team discussion based on etiological treatment improves refractory chronic cough outcomes

BACKGROUND

Refractory chronic cough (RCC) causes significant impairments in the life quality of patients. Further research into the identification of etiologies and development of the treatment schedules for RCC is needed.

PATIENTS AND METHODS

We established an multidisciplinary team (MDT) clinic, by integrating respiratory medicine, otorhinolaryngology, and gastroenterology departments, to investigate cough etiologies and the effectiveness of treatment. The therapeutic effect was assessed quantitatively using the Cough Visual Analog Scales (VAS), Leicester Cough Questionnaire (LCQ), and Reflux Symptoms Index (RSI) scores.

RESULTS

In total, 213 patients attending the MDT outpatient clinic were examined, and 115 patients with RCC were included for analysis. The RCC diagnosis rate among the outpatient was 88.7%. Common causes of RCC included gastroesophageal reflux cough (63.5%), upper airway cough syndrome (UACS) (43.5%), and cough variant asthma (CVA) (14.8%). After an average treatment period of 2.17 ± 1.06 weeks (wk), 73.9% of the patients had partial cough remission, and 6.1% had complete cough remission. The cough VAS score before and after treatment was 6.11 ± 2.02 vs. 3.66 ± 2.22 (P < 0.05), respectively; LCQ total score before and after treatment was 10.24 ± 3.11 vs. 13.16 ± 3.59 (P < 0.05), respectively; and RSI score before and after treatment was 15.82 ± 7.01 vs. 10.71 ± 6.64 (P < 0.05), respectively.

CONCLUSION

The etiologies of most patients with RCC could be identified in the MDT clinic, and the cough-related symptoms of a significant number of patients with RCC improved in a short period.

Development of the Rapid Cough Questionnaire: Key item identification

BACKGROUND

The Leicester Cough Questionnaire (LCQ) is a reliable tool for measuring the multidimensional impact of cough on patients' quality of life; however, its scoring algorithm is lengthy and complex for routine clinical use.

OBJECTIVE

The study aimed to develop a simplified version of the LCQ, the Rapid Cough Questionnaire (RCQ), as a substitue in clinical practice and validate the RCQ using an independent cohort.

METHODS

To select items for the RCQ score, a correlation network was used to determine the items from each domain that were strongly correlated with the total LCQ score. The final items for the RCQ were selected on the basis of the centrality of the node degree, betweenness, and closeness in the correlation network.

RESULTS

The RCQ score was derived from 3 items: tiredness (LCQ3) in the physical domain, the feeling of being fed up (LCQ13) in the psychological domain, and annoyance with partner/family/friends (LCQ19) in the social domain. The correlation between the LCQ and RCQ was high, with a coefficient of 0.93 (P < .001). The mean score of the RCQ was 11.2 ± 3.2, with scores ranging from 5.15 to 19.55. The minimal clinically important difference in the RCQ score was calculated to be 1.6 using a distribution-based method. The concurrent validity of the LCQ and the RCQ with cough numeric rating scale was similar. In the validation cohort, the correlation between the LCQ and RCQ scores was consistent regardless of sex and etiology.

CONCLUSION

The RCQ score, which is concise, reliable, and valid, can be a valuable tool for patient assessment, particularly in clinical practice.

An Accelerometer-Based Wearable Patch for Robust Respiratory Rate and Wheeze Detection Using Deep Learning

Wheezing is a critical indicator of various respiratory conditions, including asthma and chronic obstructive pulmonary disease (COPD). Current diagnosis relies on subjective lung auscultation by physicians. Enabling this capability via a low-profile, objective wearable device for remote patient monitoring (RPM) could offer pre-emptive, accurate respiratory data to patients. With this goal as our aim, we used a low-profile accelerometer-based wearable system that utilizes deep learning to objectively detect wheezing along with respiration rate using a single sensor. The miniature patch consists of a sensitive wideband MEMS accelerometer and low-noise CMOS interface electronics on a small board, which was then placed on nine conventional lung auscultation sites on the patient's chest walls to capture the pulmonary-induced vibrations (PIVs). A deep learning model was developed and compared with a deterministic time-frequency method to objectively detect wheezing in the PIV signals using data captured from 52 diverse patients with respiratory diseases. The wearable accelerometer patch, paired with the deep learning model, demonstrated high fidelity in capturing and detecting respiratory wheezes and patterns across diverse and pertinent settings. It achieved accuracy, sensitivity, and specificity of 95%, 96%, and 93%, respectively, with an AUC of 0.99 on the test set-outperforming the deterministic time-frequency approach. Furthermore, the accelerometer patch outperforms the digital stethoscopes in sound analysis while offering immunity to ambient sounds, which not only enhances data quality and performance for computational wheeze detection by a significant margin but also provides a robust sensor solution that can quantify respiration patterns simultaneously.

Association of novel adult cough subclasses with clinical characteristics and lung function across six decades of life in a prospective, community-based cohort in Australia: an analysis of the Tasmanian Longitudinal Health Study (TAHS)

BACKGROUND

Cough is a common yet heterogeneous condition. Little is known about the characteristics and course of cough in general populations. We aimed to investigate cough subclasses, their characteristics from childhood across six decades of life, and potential treatable traits in a community-based cohort.

METHODS

For our analysis of the Tasmanian Longitudinal Health Study (TAHS), a prospective, community-based cohort study that began on Feb 23, 1968, and has so far followed up participants in Tasmania, Australia, at intervals of 10 years from a mean age of 7 years to a mean age of 53 years, we used data collected as part of the TAHS to distinguish cough subclasses among current coughers at age 53 years. For this analysis, participants who answered Yes to at least one cough-related question via self-report questionnaire were defined as current coughers and included in a latent class analysis of cough symptoms; participants who answered No to all nine cough-related questions were defined as non-coughers and excluded from this analysis. Two groups of longitudinal features were assessed from age 7 years to age 53 years: previously established longitudinal trajectories of FEV1, forced vital capacity [FVC], FEV1/FVC ratio, asthma, and allergies-identified via group-based trajectory analysis or latent class analysis-and symptoms at different timepoints, including asthma, current productive cough, ever chronic productive cough, current smoking, and second-hand smoking.

FINDINGS

Of 8583 participants included at baseline in the TAHS, 6128 (71·4%) were traced and invited to participate in a follow-up between Sept 3, 2012, and Nov 8, 2016; 3609 (58·9%) of these 6128 returned the cough questionnaire. The mean age of participants in this analysis was 53 years (SD 1·0). 2213 (61·3%) of 3609 participants were defined as current coughers and 1396 (38·7%) were categorised as non-coughers and excluded from the latent class analysis. 1148 (51·9%) of 2213 participants in this analysis were female and 1065 (48·1%) were male. Six distinct cough subclasses were identified: 206 (9·3%) of 2213 participants had minimal cough, 1189 (53·7%) had cough with colds only, 305 (13·8%) had cough with allergies, 213 (9·6%) had intermittent productive cough, 147 (6·6%) had chronic dry cough, and 153 (6·9%) had chronic productive cough. Compared with people with minimal cough, and in contrast to other cough subclasses, people in the chronic productive cough and intermittent productive cough subclasses had worse lung function trajectories (FEV1 persistent low trajectory 2·9%, 6·4%, and 16·1%; p=0·0011, p<0·0001; FEV1/FVC early low-rapid decline trajectory 2·9%, 12·1%, and 13·0%; p=0·012, p=0·0007) and a higher prevalence of cough (age 53 years 0·0%, 32·4% [26·1-38·7], and 50·3% [42·5-58·2]) and asthma (age 53 years 6·3% [3·7-10·6], 26·9% [21·3-33·3], and 41·7% [24·1-49·7]) from age 7 years to age 53 years.

INTERPRETATION

We identified potential treatable traits for six cough subclasses (eg, asthma, allergies, and active and passive smoking for productive cough). The required management of productive cough in primary care (eg, routine spirometry) might differ from that of dry cough if our findings are supported by other studies. Future population-based studies could apply our framework to address the heterogeneity and complexity of cough in the community.

FUNDING

The National Health and Medical Research Council of Australia, The University of Melbourne, Clifford Craig Medical Research Trust of Tasmania, Victorian Asthma Foundation, Queensland Asthma Foundation, Tasmanian Asthma Foundation, The Royal Hobart Hospital Research Foundation, the Helen MacPherson Smith Trust, GlaxoSmithKline, and the China Scholarship Council.

Sex-related disparities in cough-associated symptoms across different age groups

BACKGROUND

Sex-related disparities in the prevalence of chronic cough have been consistently reported globally, with varying male-to-female ratios.

OBJECTIVES

This study aimed to evaluate sex-related differences by comparing correlations between cough-related symptoms in males and females of different age groups.

DESIGN

Adult patients with chronic cough who completed the Leicester Cough Questionnaire (LCQ) were recruited from 16 respiratory centers.

METHODS

Correlation networks were constructed based on Spearman's correlation coefficients in males and females of various age groups. The distinct relationships of cough-related symptoms between subgroups were validated by an independent cohort.

RESULTS

A total of 255 patients were enrolled in this study (male-to-female ratio, 1:1.71). The following LCQ items were highly correlated: embarrassment and interference with daily work, anxiety, and interference with overall life enjoyment/feeling of being fed up, interference with daily work and overall life enjoyment, interference with overall life enjoyment and feeling of being fed up, and feeling of being fed up and annoyance to partner/family/friends. The patterns of these correlations between LCQ items varied in males and females of different ages. The strongest interrelationship was observed in male patients aged >50 years old, which was similar to those in the validation cohort.

CONCLUSION

The correlation patterns between cough-related symptoms vary significantly according to age and sex. Understanding the mechanisms underlying the development of cough-related symptoms may facilitate sex- and age-specific strategies for chronic cough.

Cough Hypersensitivity Syndrome: Why Its Use Is Inappropriate in Children

In children and adults, chronic cough is a common symptom presenting to health professionals worldwide. It is internationally accepted that children with chronic cough should be managed with pediatric specific management guidelines. The newly proposed clinical entity of 'cough hypersensitivity syndrome' has gained significant attention in adult literature. Given the significant differences between childhood and adult chronic cough, including in respiratory physiology and anatomy, and cough sensitivity, we address the suitability of the use of cough hypersensitivity syndrome in children. We explore these differences between childhood and adult chronic cough, explain what cough hypersensitivity is and highlight why the term cough hypersensitivity syndrome should not be used in children.

[Guidelines for the management of chronic cough in adults]

Patients with chronic cough experience major alteration in their quality of life. Given its numerous etiologies and treatments, this disease is a complex entity. To help clinicians involved in patient management of patients, guidelines have been issued by a group of French experts. They address definitions of chronic cough and initial management of patients with this pathology. We present herein the second-line tests that might be considered in patients whose coughing has persisted, notwithstanding initial management. The experts have also put forward a definition of unexplained or refractory chronic cough (URCC), the objective being to more precisely identify those patients whose cough persists despite optimal management. Lastly, these guidelines indicate the pharmacological and non-pharmacological interventions of use in URCC. Amitriptyline, pregabalin, gabapentin or morphine combined with speech and/or physical therapy are mainstays in treatment strategies. Other treatment options, such as P2X3 antagonists, are being developed and have generated high hopes among physicians and patients alike.

Yardstick for managing cough, part 1: In adults and adolescent patients older than 14 years of age

Nationwide statistics in the United States and Australia reveal that cough of undifferentiated duration is the most common complaint for which patients of all ages seek medical care in the ambulatory setting. Management of chronic cough is one of the most common reasons for new patient visits to pulmonologists. Because symptomatic cough is such a common problem and so much has been learned about how to diagnose and treat cough of all durations but especially chronic cough, this 2-part yardstick has been written to review in a practical way the latest evidence-based guidelines most of which have been developed from recent high quality systematic reviews on how best to manage cough of all durations in adults, adolescents, and children. In this manuscript, part 1 of the 2-part series, we provide evidence-based, and expert opinion recommendations on the management of chronic cough in adult and adolescent patients (>14 years of age).

Canadian Health Care Professionals' Familiarity with Chronic Cough Guidelines and Experiences with Diagnosis and Management: A Cross-Sectional Survey

INTRODUCTION

Educational programs on chronic cough may improve patient care, but little is known about how Canadian physicians manage this common debilitating condition. We aimed to investigate Canadian physicians' perceptions, attitudes, and knowledge of chronic cough.

METHODS

We administered a 10-min anonymous, online, cross-sectional survey to 3321 Canadian physicians in the Leger Opinion Panel who managed adult patients with chronic cough and had been in practice for > 2 years.

RESULTS

Between July 30 and September 22, 2021, 179 physicians (101 general practitioners [GPs] and 78 specialists [25 allergists, 28 respirologists, and 25 ear/nose/throat specialists]) completed the survey (response rate: 5.4%). In a month, GPs saw a mean of 27 patients with chronic cough, whereas specialists saw 46. About one-third of physicians appropriately identified a duration of > 8 weeks as the definition for chronic cough. Many physicians reported not using international chronic cough management guidelines. Patient referrals and care pathways varied considerably, and patients frequently experienced lost to follow-up. While physicians endorsed nasal and inhaled corticosteroids as common treatments for chronic cough, they rarely used other guideline-recommended treatments. Both GPs and specialists expressed high interest in education on chronic cough.

CONCLUSION

This survey of Canadian physicians demonstrates low uptake of recent advances in chronic cough diagnosis, disease categorization, and pharmacologic management. Canadian physicians also report unfamiliarity with guideline-recommended therapies, including centrally acting neuromodulators for refractory or unexplained chronic cough. This data highlights the need for educational programs and collaborative care models on chronic cough in primary and specialist care.

Efficacy of laparoscopic fundoplication in patients with chronic cough and gastro-oesophageal reflux

BACKGROUND

The outcome of anti-reflux surgery in patients with suspected gastro-oesophageal reflux-induced cough is frequently uncertain. The aims of this study were to assess the efficacy of laparoscopic fundoplication for controlling cough in patients with chronic cough without asthma, who have pathologic gastro-oesophageal reflux, and to identify predictors of response.

METHODS

From a prospective database of 1598 patients who have undergone laparoscopic fundoplication, 66 (4%) with proven gastro-oesophageal reflux disease (GORD) and chronic cough without asthma were studied. All patients underwent gastroscopy and 24-h pH monitoring before operation. Heartburn and regurgitation were assessed using a modified DeMeester score. Severity of cough before and after surgery was self-assessed by the patient using a visual analog scale at a minimum of 12 months post-operatively (median 43 mo; range: 14-104 mo). Patients were considered to have responded to fundoplication if they had no cough or the cough had improved by 50% or more after operation.

RESULTS

Cough and heartburn/regurgitation were relieved in 61% (40/66) and 90% (44/49) of the patients, respectively. The presence of typical GORD symptoms or oesophagitis, and pH study variables did not predict the response of the cough to fundoplication.

CONCLUSION

Refinement in the aetiological diagnosis of chronic cough due to GORD is necessary for improved outcome. Patients diagnosed with GORD-related chronic cough need to be counseled regarding their expectations from anti-reflux surgery.

A case of atopic cough with aphonia showed a prominent response to a histamine H1 receptor antagonist

A 33-year-old woman admitted to our hospital for further examination of severe non-productive cough lasting for about two months. Her symptom did not ameliorate by treatments including long acting β2 agonists. She had a medical history of drug allergy to non-steroidal anti-inflammatory drugs. At the initial visit, she could not speak at all and communicated with us in writing. Chest auscultation revealed no wheezes, rhonchi and other crackles. Laboratory findings showed a mild eosinophilia with normal total and specific serum immunoglobulin E. The results of an electrocardiogram, a chest X-ray and a chest CT were unremarkable. A fractional exhaled nitric oxide value was within normal limit. Based on these observations, a diagnosis of atopic cough (AC) was suspected, and we started treatment with a histamine H1 receptor antagonist (H1-RA). She had become able to speak again in association with complete disappearance of cough by eight-weeks after treatment initiation, and her symptoms did not recur even after cessation of treatment. By the confirmation of remarkable clinical improvement in response to a H1-RA, a diagnosis of AC was made. To the best of our knowledge, this is the first report of an AC patient who presented severe cough with aphonia. J. Med. Invest. 70 : 281-284, February, 2023.

Upper airway cough syndrome may be the main cause of chronic cough in Japan: a cohort study

BACKGROUND

Upper airway cough syndrome (UACS) is generally considered a common cause of chronic cough but remains poorly recognised in Japan.

OBJECTIVE

This study aimed to assess whether UACS was a common cause of chronic cough in Japan, as is true in other countries. Interview and examination items were evaluated for their potential use in UACS diagnosis.

METHODS

All patients with chronic cough were preliminarily diagnosed with bronchial asthma, UACS, gastroesophageal reflux disease, or postinfectious prolonged cough, based on interviews and examinations. Treatment centred on nasal steroids was administered to the UACS group and standard treatment to the other groups. The observation period lasted 4 weeks. The subjective cough score at first diagnosis was set at 10, and the final diagnosis was made based on the treatment administered at the time the cough score had decreased to ≤2. The associations between the presence or absence of UACS and interview and examination items were statistically evaluated.

RESULTS

Among 230 patients with chronic cough, 146 were diagnosed with UACS-only. Multivariate logistic regression revealed that the assessment items 'awareness of mucus accumulating in the back of the throat', 'presence of abnormal echography findings', 'absence of associated coughing when exercising' and 'presence of coughing persisting after onset' were significantly correlated with the presence or absence of UACS (p < 0.05).

CONCLUSIONS

UACS may be the most common cause of chronic cough in Japan and may be effectively treated with nasal corticosteroids. Diagnosing UACS might be possible by selecting appropriate interview and examination items.

Audio-based cough counting using independent subspace analysis

In this paper, an algorithm designed to detect characteristic cough events in audio recordings is presented, significantly reducing the time required for manual counting. Using time-frequency representations and independent subspace analysis (ISA), sound events that exhibit characteristics of coughs are automatically detected, producing a summary of the events detected without the need for a pre-trained model. Using a dataset created from publicly available audio recordings, this algorithm has been tested on a variety of synthesized audio scenarios representative of those likely to be encountered by subjects undergoing an ambulatory cough recording, achieving a true positive rate of 76% with an average of 2.85 false positives per minute.

Multifaceted Beneficial Effects of Erdosteine: More than a Mucolytic Agent

Erdosteine is a drug approved for the treatment of acute and chronic pulmonary diseases, originally developed as a mucolytic agent. It belongs to the thiol-based family of drugs that are known to also possess potentially important antioxidant and anti-inflammatory properties, and exhibit antibacterial activity against a variety of medically important bacterial species. Erdosteine is a prodrug that is metabolized to the ring-opening compound metabolite M1 (MET 1), which has mucolytic properties. Experimental studies have documented that erdosteine prevents or reduces lung tissue damage induced by oxidative stress and, in particular, that Met 1 also regulates reactive oxygen species production. The RESTORE study, which has been the only trial that investigated the effects of a thiol-based drug in chronic obstructive pulmonary disease (COPD) frequent exacerbators, documented that erdosteine significantly reduces the risk of acute exacerbations of COPD (AECOPDs), shortens their course, and also decreases the risk of hospitalization from COPD. The preventive action of erdosteine on AECOPDs was not affected by the presence or absence of inhaled corticosteroids (ICSs) or blood eosinophil count. These findings clearly contrast with the Global Initiative for Chronic Obstructive Lung Disease strategy’s approach to use erdosteine only in those COPD patients not treated simultaneously with an ICS. Furthermore, they support the possibility of using erdosteine in a step-down approach that in COPD is characterized by the withdrawal of the ICS.

Differential features of chronic cough according to etiology and the simple decision tree for predicting causes

Finding etiology of chronic cough is an essential part of treatment. Although guidelines include many laboratory tests for diagnosis, these are not possible in many primary care centers. We aimed to identify the characteristics and the differences associated with its cause to develop a clinical prediction model. Adult subjects with chronic cough who completed both Korean version of the Leicester Cough Questionnaire (K-LCQ) and COugh Assessment Test (COAT) were enrolled. Clinical characteristics of each etiology were compared using features included in questionnaires. Decision tree models were built to classify the causes. A total of 246 subjects were included for analysis. Subjects with asthma including cough variant asthma (CVA) suffered from more severe cough in physical and psychological domains. Subjects with eosinophilic bronchitis (EB) presented less severe cough in physical domain. Those with gastro-esophageal reflux disease (GERD) displayed less severe cough in all 3 domains. In logistic regression, voice hoarseness was an independent feature of upper airway cough syndrome (UACS), whereas female sex, tiredness, and hypersensitivity to irritants were predictors of asthma/CVA; less hoarseness was a significant feature of EB, and feeling fed-up and hoarseness were less common characteristics of GERD. The decision tree was built to classify the causes and the accuracy was relatively high for both K-LCQ and COAT, except for UACS. Voice hoarseness, degree of tiredness, hypersensitivity to irritants and feeling fed-up are important features in determining the etiologies. The decision tree may further assists classifying the causes of chronic cough.

Pulmonary function testing in COPD: looking beyond the curtain of FEV1

Chronic obstructive pulmonary disease (COPD) management remains challenging due to the high heterogeneity of clinical symptoms and the complex pathophysiological basis of the disease. Airflow limitation, diagnosed by spirometry, remains the cornerstone of the diagnosis. However, the calculation of the forced expiratory volume in the first second (FEV1) alone, has limitations in uncovering the underlying complexity of the disease. Incorporating additional pulmonary function tests (PFTs) in the everyday clinical evaluation of COPD patients, like resting volume, capacity and airway resistance measurements, diffusion capacity measurements, forced oscillation technique, field and cardiopulmonary exercise testing and muscle strength evaluation, may prove essential in tailoring medical management to meet the needs of such a heterogeneous patient population. We aimed to provide a comprehensive overview of the available PFTs, which can be incorporated into the primary care physician's practice to enhance the efficiency of COPD management.

Safety and efficacy of gefapixant, a novel drug for the treatment of chronic cough: A systematic review and meta-analysis of randomized controlled trials

AIM

We conducted this systematic review and meta-analysis to investigate the efficacy and safety of gefapixant, a novel P2X3 receptor antagonist, in patients with chronic cough.

METHODS

We searched four databases for randomized controlled trials (RCTs). We assessed the cough frequency, severity, total Leicester cough questionnaire (LCQ) score, and adverse events. We analyzed the data using Open Meta-Analyst and Review Manager Software.

RESULTS

We included four unique studies (comprising five stand-alone RCTs) with 439 patients. Compared to placebo, gefapixant had positive anti-tussive effects by improving awake cough frequency (mean difference [MD] = -5.27, 95% confidence interval [CI] [-6.12, -4.42], P < 0.00001), night cough frequency (MD = -3.71, 95% CI [-6.57, -0.85], P = 0. 01), 24 h cough frequency (MD = -4.18, 95% CI [-5.01, -3.36], P < 0.00001), cough severity using the Visual Analog Scale (MD = -13.36, 95% CI [-17.80, -8.92], P < 0.00001), cough severity diary (MD = -0.88, 95% CI [-1.25, -0.51], P < 0.00001), and total LCQ score (MD = 2.00, 95% CI [1.15, 2.86], P = 0. 00001). Meta-regression analyses showed a positive correlation between the gefapixant dose and the incidence of any adverse event (relative risk [RR] = 0.239, 95% CI [0.093, 1.839], P = 0.001) and incidence of adverse event related to treatment (RR = 0.520, 95% CI [0.117, 0.922], P = 0.011).

CONCLUSIONS

In patient with chronic cough, gefapixant exhibits favorable anti-tussive outcomes by improving the cough frequency, severity, and quality of life. While gefapixant is largely tolerable, its side effects (notably taste alteration) are dose dependent.

Characteristic appearance of the oropharynx in patients with postnasal drip (PND)-induced cough

INTRODUCTION

Post-nasal drip (PND)-induced cough is a common cause of chronic cough. However, there is little known about the characteristic physical findings of this condition.

OBJECTIVES

We investigated views of the pharyngeal wall in patients with PND-induced cough using a handy endoscopic images.

METHODS

The subjects were 135 consecutive patients referred to our hospital with a sensation of something "dripping down the throat" as one of their symptoms. Physical findings for the oropharynx were examined using Wi-Fi endoscope camera. The difference in probability of symptoms in patients with acute cough and those with subacute/chronic cough was assessed using a Bayesian Fisher exact test on a 2 × 2 table.

RESULTS

Among the patients, 105 (78%) complained of cough, 78 (58%) of acute cough, 20 (15%) of subacute cough, and 7 (5%) of chronic cough; and 71 (53%) had coexisting asthma. Using Bayesian inference, a sore or scratchy throat and fever were more common in patients with acute cough than in those with subacute/chronic cough. In endoscopic images of the oropharynx, a reddish curtain sign on the posterior pharyngeal wall behind the palatopharyngeal arch was found in 121 patients (90%).

CONCLUSION

Patients with acute PND-induced cough have a component of acute upper respiratory infection, because of high probability of a sore or scratchy throat and fever as symptom. A reddish curtain sign may be a useful finding for identifying PND-induced cough in these cases.

Non-Contact Measurements of Electrocardiogram and Cough-Associated Electromyogram from the Neck Using In-Pillow Common Cloth Electrodes: A Proof-of-Concept Study

Asthma and chronic obstructive pulmonary disease are associated with nocturnal cough and changes in heart rate. In this work, the authors propose a proof-of-concept non-contact system for performing capacitive electrocardiogram (cECG) and cough-associated capacitive electromyogram (cEMG) measurements using cloth electrodes under a pillowcase. Two electrodes were located along with the approximate vector of lead II ECG and were used for both cECG and cEMG measurements. A signature voltage follower was introduced after each electrode to detect biopotentials with amplitudes of approximately 100 µV. A bootstrapping technique and nonlinear electrical component were combined and implemented in the voltage follower to attain a high input impedance and rapid static discharge. The measurement system was evaluated in a laboratory experiment for seven adult males and one female (average age: 22.5 ± 1.3 yr). The accuracy of R-wave detection for 2-min resting periods was 100% in six subjects, with an overall average of 87.5% ± 30.0%. Clearly visible cEMGs were obtained for each cough motion for all subjects, synchronized with reference EMGs from submental muscle. Although there remains room for improvement in practical use, the proposed system is promising for unobtrusive detection of heart rate and cough over a prolonged period of time.

Upper Airway Cough Syndrome in Pathogenesis of Chronic Cough

Cough is one of the most important defensive reflexes. However, extensive non- productive cough is a harmful mechanism leading to the damage of human airways. Cough is initiated by activation of vagal afferents in the airways. The site of their convergence is particularly the nucleus of the solitary tract (nTS). The second-order neurons terminate in the pons, medulla and spinal cord and there is also the cortical and subcortical control of coughing.Upper airway cough syndrome (UACS) - previously postnasal drip syndrome - is one of the most common causes of chronic cough together with asthma and gastroesophageal reflux. The main mechanisms leading to cough in patients with nasal and sinus diseases are postnasal drip, direct irritation of nasal mucosa, inflammation in the lower airways, upper airway inflammation and the cough reflex sensitization. The cough demonstrated by UACS patients is probably due to hypersensitivity of the upper airways sensory nerve or lower airways sensory nerve, or a combination of both. Further studies are needed to clarify this mechanism.

Inflammatory Subtypes in Classic Asthma and Cough Variant Asthma

Background

Measurement of sputum is used to define airway inflammatory phenotypes. Cough variant asthma (CVA) is considered to be the initial stage of classic asthma (CA). The aim of this study was to describe the association between the different subtypes of CVA and CA.

Methods

A total of 459 patients with CVA and CA were screened for the study. All included patients performed spirometry, underwent a bronchial challenge with methacholine and induced sputum according to the guidelines.

Results

A higher frequency of female patients were found with CVA and the eosinophilic airway inflammation of CVA than in CA and the noneosinophilic airway inflammation of CA (p=0.004 and p=0.024, respectively). Bronchial hyper-responsiveness (BHR) was lower in eosinophilic CVA and CA (p=0.006), while no difference was found in noneosinophilic CVA and CA. Association between the percentage of sputum eosinophils and the FEV₁ level fell below 20% of the baseline value (PD₂₀) in CVA and CA (r= −0.1245, p=0.0357 and r= −0.2148, p=0.0014, respectively).

Conclusion

Eosinophilia may be associated with more severe disease, yet there was no difference in spirometry between the eosinophilic and noneosinophilic groups, and the BHR difference was not dramatic.

Small Airways Dysfunction and Bronchial Hyper-Responsiveness in Cough Variant Asthma

Background

Cough variant asthma (CVA) is one kind of atypical asthma. The study was to compare spirometric parameters of small airways and the degree of bronchial hyper-responsiveness (BHR) between CVA and classic asthma (CA), and examine the relationship between BHR and small airways to determine the accuracy of these markers as indicators of CVA.

Methods

A total of 825 asthmatic patients were screened for the study, and 614 were included. All patients performed spirometry and underwent a bronchial challenge with methacholine.

Results

The number of small airways dysfunctions in the CVA group was less than those of the CA group with MMEF% predicted (70% vs 80.91%, P=0.002) and FEF_50% predicted (62.71% vs 73.5%, P=0.004). The degree of small airways dysfunction was less in the CVA group compared with the CA group (P<0.001). Significant positive correlations were observed between the FEV₁ level below 20% of the baseline value (PD₂₀) and MMEF% predicted (r=0.282, P<0.001), FEF_50% predicted (r=0.2522, P<0.001), and FEF_75% predicted (r=0.2504, P<0.001) in patients with CVA. The area under curve (AUC) of MMEF, FEF₅₀, and FEF₇₅ (% predicted) was 0.615, 0.621, and 0.606, respectively. In addition, 0.17 mcg of PD₂₀ was the best diagnostic value for CVA, with an AUC of 0.582 (P=0.001).

Conclusion

Small airway dysfunction is milder in CVA. The value of BHR combined with small airways in CVA prediction, which was significant, but not enough to be clinically useful.

Somatic cough syndrome: a report of two cases and review of literature

Background

Somatic cough syndrome is a somatization disorder that usually presents in children and which is often diagnosed late after an extensive search for organic causes. The condition was redefined by the DSM-5 criteria and grouped with the other conditions under the umbrella of somatoform disorders. Nonetheless, clinical presentation is heterogeneous, and etiology is still not clearly defined. Several management approaches have been proposed, but treatment remains essentially nonpharmacological.

Case presentation

We report two cases of somatic cough syndrome that were diagnosed after 4 years and 3 months respectively, and document the successful treatment of both cases using behavioral therapy.

Discussion

Behavioral therapy is the most reportedly successful nonpharmacological treatment in somatic cough syndrome, and it was successful with both our cases. The condition poses a significant burden over the function and quality of life in patients and their caregivers. The heterogeneous nature of this syndrome necessitates a high index of suspicion on part of both the physician and the psychiatrist in order to secure a timely diagnosis and mitigate the impact of this condition.

Chronic cough and uncontrolled asthma: Ending a three year clinical course with successful foreign body removal

Acute foreign body aspiration can cause severe damage to the respiratory system, leading to laceration and even death due to asphyxia. However, a foreign body that has been aspirated could go unnoticed acutely and lead to persistent shortness of breath symptoms. Most of the patients will be able to recall the acute aspiration event, but others do not. On the latter, a more meticulous approach will lead to the diagnosis and subsequent effective management. We hereby present the case of a 52-year-old male with history of partly controlled severe asthma and chronic persistent cough with bloody sputum. Upon evaluation, he was found with a right-sided pneumonia and pertinent history remarkable for several episodes of bronchitis in the past 3 years. There circumstances and subsequent images led to the successful finding and removal of a chronic foreign body aspirated 3 years prior to evaluation. A procedure led to almost complete resolution of symptoms of cough and asthma.

Chronic cough in Vocal Cord Dysfunction: Description of a clinical entity

BACKGROUND AND AIM

Vocal Cord Dysfunction (VCD) and chronic cough (CC) are challenging conditions which lead to significant quality of life impairment. The underlying mechanisms are poorly understood, but laryngeal dysfunction may be common to both conditions. The aim of this study was to determine the characteristics of cough in VCD and whether patients with cough have coexisting VCD.

METHOD

Participants included 51 patients with VCD and a comparison group of 39 patients with chronic cough that was refractory to medical treatment. Participants underwent a comprehensive assessment including questionnaires, laryngoscopy, cough frequency monitoring and voice testing.

RESULTS

Patients with VCD had significant cough morbidity with an increased cough frequency of 17.3 coughs/hour and reduced cough quality of life with mean Leicester Cough Questionnaire Score of 12.8. Breathing pattern abnormalities were also common in VCD and there was a strong correlation between the number of breathing pattern abnormalities and cough frequency (r = -0.827, p = 0.002). Cough measures were not significantly different between patients with VCD and those with CC. Moderate-severe PVFM was present in 69% of patients with CC. Abnormal vocal fold closure during phonation was also present in patients with chronic cough and was similar between the VCD (n = 40, 78.4%) and cough (n = 25, 64.1%) groups, p = 0.240.

CONCLUSION

Cough is an important symptom in VCD. Patients presenting with chronic cough may have underlying VCD as a cause of their cough. Since cough and VCD symptoms co-occur clinicians need to consider cough when are treating VCD and VCD when treating chronic cough.

Clinical outcomes of gastroesophageal reflux disease-related chronic cough following antireflux fundoplication

BACKGROUND

Despite the effectiveness of antireflux fundoplication for typical gastroesophageal reflux disease, outcomes regarding surgical therapy for patients with gastroesophageal reflux disease-related chronic cough are currently unclear. The purpose of this study was to evaluate whether antireflux surgery for patients with chronic cough is effective, and to assess the correlation between indexes, such as symptom index and symptom association probability, and response to surgery.

METHODS

We performed a retrospective review of a prospectively collected database from a 3-site institution from 2013 to 2017. Of 1149 patients who underwent antireflux surgery, 41 presented with chronic cough as a main symptom related to gastroesophageal reflux disease. Preoperatively, patients underwent a symptom assessment, esophagogastroduodenoscopy, esophageal 24-h pH monitoring, and manometry. Patients were followed up at 6 weeks and 12 months post-surgery.

RESULTS

Thirty-three (80.5%) patients underwent Nissen fundoplication, while 8 (19.5%) underwent Toupet fundoplication. Isolated chronic cough was present in 8 (19.5%) patients, and median (range) DeMeester score was 28.9 (0.3-96.7). After 12-month follow-up, chronic cough was absent in 28 (68.3%) patients (P = .02). Typical reflux symptoms responded well to surgery, but response was not optimal. Postoperative dysphagia and atypical reflux symptoms were slightly worse on long-term follow-up; however, differences were not significant (P ≥ .2). When examining how the different symptom indexes correlated with complete, partial, or no response in patients with gastroesophageal reflux disease-related cough, there was no notable agreement on predicted response to surgery.

CONCLUSIONS

Antireflux surgery, although less predictable, is effective for the treatment of gastroesophageal reflux disease-related chronic cough.

The clinical usefulness of a new hand-held device for fractional exhaled nitric oxide measurement, NIOX VERO®, for diagnosing the etiology of cough

Cough is one of the most common symptoms seen in clinical practice, however the differential diagnosis is often difficult. The utility of fractional exhaled nitric oxide (FeNO) measurement in the differential diagnosis of the etiology of cough has been reported. NIOX VERO® (NOV) is a new hand-held device that will replace NIOX MINO®, but its diagnostic utility has not been fully elucidated in clinical practice. In this study, the performance of NOV for FeNO measurements was determined. We retrospectively analyzed 243 consecutive patients complaining cough. Among 243 patients, final diagnosis was cough variant asthma (CVA) in 74 (30.5%), bronchial asthma (BA) in 48 (19.8%), post-infectious cough (PIC) in 52 (21.4%), atopic chough (AC) in 24 (9.9%), gastroesophageal reflux disease (GERD) in 10 (4.1%), and Others in 35 (14.4%). FeNO values were significantly higher in CVA and BA as compared to PIC, AC, GERD, and Others. In the multivariate analysis, only FeNO value was identified as independent factors to discriminate CVA and non-CVA other than BA. These findings indicated that FeNO measured by using NOV could be used as a diagnostic marker of intractable cough, especially for the differential diagnosis of CVA from non-CVA. J. Med. Invest. 67 : 265-270, August, 2020.

Speech and language therapy for management of chronic cough

BACKGROUND

Cough both protects and clears the airway. Cough has three phases: breathing in (inspiration), closure of the glottis, and a forced expiratory effort. Chronic cough has a negative, far-reaching impact on quality of life. Few effective medical treatments for individuals with unexplained (idiopathic/refractory) chronic cough (UCC) are known. For this group, current guidelines advocate the use of gabapentin. Speech and language therapy (SLT) has been considered as a non-pharmacological option for managing UCC without the risks and side effects associated with pharmacological agents, and this review considers the evidence from randomised controlled trials (RCTs) evaluating the effectiveness of SLT in this context.

OBJECTIVES

To evaluate the effectiveness of speech and language therapy for treatment of people with unexplained (idiopathic/refractory) chronic cough.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, trials registries, and reference lists of included studies. Our most recent search was 8 February 2019.

SELECTION CRITERIA

We included RCTs in which participants had a diagnosis of UCC having undergone a full diagnostic workup to exclude an underlying cause, as per published guidelines or local protocols, and where the intervention included speech and language therapy techniques for UCC.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of 94 records. Two clinical trials, represented in 10 study reports, met our predefined inclusion criteria. Two review authors independently assessed risk of bias for each study and extracted outcome data. We analysed dichotomous data as odds ratios (ORs), and continuous data as mean differences (MDs) or geometric mean differences. We used standard methods recommended by Cochrane. Our primary outcomes were health-related quality of life (HRQoL) and serious adverse events (SAEs).

MAIN RESULTS

We found two studies involving 162 adults that met our inclusion criteria. Neither of the two studies included children. The duration of treatment and length of sessions varied between studies from four sessions delivered weekly, to four sessions over two months. Similarly, length of sessions varied slightly from one 60-minute session and three 45-minute sessions to four 30-minute sessions. The control interventions were healthy lifestyle advice in both studies.One study contributed HRQoL data, using the Leicester Cough Questionnaire (LCQ), and we judged the quality of the evidence to be low using the GRADE approach. Data were reported as between-group difference from baseline to four weeks (MD 1.53, 95% confidence interval (CI) 0.21 to 2.85; participants = 71), revealing a statistically significant benefit for people receiving a physiotherapy and speech and language therapy intervention (PSALTI) versus control. However, the difference between PSALTI and control was not observed between week four and three months. The same study provided information on SAEs, and there were no SAEs in either the PSALTI or control arms. Using the GRADE approach we judged the quality of evidence for this outcome to be low.Data were also available for our prespecified secondary outcomes. In each case data were provided by only one study, therefore there were no opportunities for aggregation; we judged the quality of this evidence to be low for each outcome. A significant difference favouring therapy was demonstrated for: objective cough counts (ratio for mean coughs per hour on treatment was 59% (95% CI 37% to 95%) relative to control; participants = 71); symptom score (MD 9.80, 95% CI 4.50 to 15.10; participants = 87); and clinical improvement as defined by trialists (OR 48.13, 95% CI 13.53 to 171.25; participants = 87). There was no significant difference between therapy and control regarding subjective measures of cough (MD on visual analogue scale of cough severity: -9.72, 95% CI -20.80 to 1.36; participants = 71) and cough reflex sensitivity (capsaicin concentration to induce five coughs: 1.11 (95% CI 0.80 to 1.54; participants = 49) times higher on treatment than on control). One study reported data on adverse events, and there were no adverse events reported in either the therapy or control arms of the study.

AUTHORS' CONCLUSIONS

The paucity of data in this review highlights the need for more controlled trial data examining the efficacy of SLT interventions in the management of UCC. Although a large number of studies were found in the initial search as per protocol, we could include only two studies in the review. In addition, this review highlights that endpoints vary between published studies.The improvements in HRQoL (LCQ) and reduction in 24-hour cough frequency seen with the PSALTI intervention were statistically significant but short-lived, with the between-group difference lasting up to four weeks only. Further studies are required to replicate these findings and to investigate the effects of SLT interventions over time. It is clear that SLT interventions vary between studies. Further research is needed to understand which aspects of SLT interventions are most effective in reducing cough (both objective cough frequency and subjective measures of cough) and improving HRQoL. We consider these endpoints to be clinically important. It is also important for future studies to report information on adverse events.Because of the paucity of data, we can draw no robust conclusions regarding the efficacy of SLT interventions for improving outcomes in unexplained chronic cough. Our review identifies the need for further high-quality research, with comparable endpoints to inform robust conclusions.

Frequent Sips of the Water for the Management of Gastroesophageal Reflux Induced Refractory Cough: A Case Report and Review of the Literature

BACKGROUND

Chronic cough is often associated with gastroesophageal reflux disease (GERD). The role of gastroenterologist in the management of the chronic cough is to identify and manage GERD. Ineffective esophageal motility is often associated with GERD induced cough. Chronic cough is often refractory to medical and surgical management despite adequate acid control. Unresponsiveness warrants a thorough pulmonary evaluation. The pathophysiology of refractory cough in these patients is poorly understood, and hence management is often challenging.

CASE PRESENTATION

A 75-year-old woman from Ghana was evaluated for GERD associated chronic cough. A 48-hour ambulatory pH study revealed acid exposure of 4.9% and high-resolution manometry showed decreased lower esophageal sphincter pressure, an inadequate response to medical and surgical management of GERD. Postfundoplication ambulatory pH testing demonstrated well-controlled acid reflux but her cough still persisted. Repeat manometry showed an ineffective motility disorder (IEM). Taking frequent sips of water eventually resolved her chronic cough.

CONCLUSION

Frequent sips of water can be used in the management of the gastroesophageal reflux and ineffective motility induced cough. It results in increased esophageal clearance of acid, nonacid reflux, and ingested pharyngeal secretions, thus breaking the cycle of cough generated increased intra-abdominal pressure with reflux and more cough.

[From acute cough to chronic cough in adults: Overview on a common reason for consultation]

Cough is divided into two categories: acute cough lasting less than 3 weeks, and chronic cough lasting more than 8 weeks. Acute cough is usually triggered by a viral infection of the upper airways. Evidence of treatment effectiveness is low and management of acute cough is complex in clinical practice. Chronic cough is a common reason for consultation in medicine. The most frequent causes are upper airway diseases, gastroesophageal reflux disease, asthma, eosinophilic bronchitis, and drugs. Before investigation, smoking cessation and drug withdrawal must be achieved for 4 to 6 weeks. Once this step is completed, simple investigations have to be performed in order to find common causes of chronic cough (questioning, physical examination, spirometry, chest X-ray). If no causes have been identified or cough remains despite optimal treatment, exhaustive exploration has to be performed to rule out rare causes. A chronic cough hypersensitivity syndrome is suggested if any causes have been found despite exhaustive assessment or if cough remains with optimal treatments. This syndrome is characterized by an increase in the sensitivity of cough peripheral receptors and is not sensitive to usual therapies. The therapeutic options are limited but innovative treatments such as P2X3 receptor antagonists are in development.

Antitussive therapy: A role for levodropropizine

Cough is a protective reflex that serves to clear the airways of excessive secretions and foreign matter and which sometimes becomes excessive, and troublesome to patients. Cough is one of the most common reasons why individuals seek medical attention. A range of drugs have been developed in the past with antitussive activity and different mechanisms of action, but there are still very few safe and effective treatments available. The poor tolerability of most available antitussives is closely related to their action on the central nervous system (CNS). An international group of experts specialized in cough met to discuss the need to identify an effective antitussive treatment with a good tolerability profile. The aim of this expert review is to increase the knowledge about the cough mechanism and the activity of levodropropizine, a peripherally acting antitussive drug.

Development and validation of the COugh Assessment Test (COAT)

BACKGROUND AND OBJECTIVE

A cough-specific quality-of-life questionnaire is recommended to assess the impact of cough; however, a simple instrument to quantify cough is required for everyday clinical practice. This study was aimed to develop a short patient-completed questionnaire (COugh Assessment Test, COAT).

METHODS

The COAT was developed and validated by comparison with the Korean version of Leicester Cough Questionnaire (K-LCQ) and cough numeric rating scale (NRS, 0-10, 11-point scale) for chronic cough patients.

RESULTS

Item selection identified five items regarding cough frequency, daily activity, sleep disturbance, fatigue and cough hypersensitivity (0-4 scaling of items, 0-20 score range) through reliability test cohort (n = 78). Test-retest reliability was strong (intra-class correlation coefficient = 0.88). The final COAT was compared with K-LCQ and cough NRS in a validation cohort (n = 323). In Rasch analysis, COAT fitted well to a unidimensional model. Pearson correlations of COAT versus K-LCQ (i) before treatment, (ii) after treatment; COAT versus cough NRS (iii) before treatment, (iv) after treatment; (v) delta-COAT versus delta-cough NRS, (vi) delta-COAT versus delta-K-LCQ were (i) -0.71, (ii) -0.81, (iii) 0.69, (iv) 0.82, (v) -0.66 and (vi) 0.72, respectively.

CONCLUSION

The COAT is a useful, simple questionnaire for assessing and monitoring cough.

Altering cough reflex sensitivity with aerosolized capsaicin paired with behavioral cough suppression: a proof-of-concept study

Background

The purpose of this prospective, quasi-experimental, single cohort proof-of-concept study was to determine feasibility and proof-of-concept of programmatically decreasing cough sensitivity through use of cough suppression strategies following inhalation of aerosolized capsaicin, in gradually increasing doses, across repeated treatment sessions.

Methods

Five healthy adults, ages 20-32 years of age, enrolled and completed the study. The study commenced in three phases. Phase I consisted of baseline cough sensitivity testing using pharmaceutical-grade aerosolized capsaicin, delivered via a Koko DigiDoser with nebulizer. The single-inhale, dose-response method was used. Doses that elicited two coughs (C2) and five coughs (C5) were recorded. Testing ceased when participants met the C5 threshold or when they had been given the maximum dose of 1,000 µmol/L. Phase II consisted of 5-6 treatment sessions, during which participants were exposed to increasing doses of aerosolized capsaicin while implementing behavioral cough suppression strategies. In phase III, cough sensitivity was re-tested at 1 and 3 weeks post-treatment. Participants were given explicit instructions to not try to suppress their cough. Participants who did not reach the C2 or C5 threshold at 1,000 µmol/L were assigned a score of 1,250 µmol/L.

Results

Each participant demonstrated a gradual increase in maximum capsaicin dose suppressed during each treatment session, with each successfully suppressing at 1,000 µmol/L by the final treatment session. C2 was greater than baseline in 4 of the 5 participants at 1 week post-treatment, and in 3 of the 5, at 3 weeks post-treatment. C5 was greater in all 5 participants at both post-treatment time points. In fact, 4 of the 5 participants did not reach the C5 threshold during either post-treatment testing sessions. Wilcoxon's Signed Rank Test, using the logC2 and logC5 values, revealed a significant difference relative to baseline in logC5 at 1 week (z=-2.02, P=0.04) and 3 weeks (z=-2.03, P=0.04) post-treatment. The difference in logC2 neared significance at 1 week post-treatment (z=-1.77, P=0.077), but was insignificant at 3 weeks post-treatment (z=-1.46, P=0.144).

Conclusions

This study demonstrates the potential of treating patients with refractory chronic cough (RCC), due to cough hypersensitivity, with a progressive desensitization approach paired with behavioral cough suppression. Additional research is needed using a randomized, placebo-controlled trial with patients with RCC.

A Mobile Cough Strength Evaluation Device Using Cough Sounds

Although cough peak flow (CPF) is an important measurement for evaluating the risk of cough dysfunction, some patients cannot use conventional measurement instruments, such as spirometers, because of the configurational burden of the instruments. Therefore, we previously developed a cough strength estimation method using cough sounds based on a simple acoustic and aerodynamic model. However, the previous model did not consider age or have a user interface for practical application. This study clarifies the cough strength prediction accuracy using an improved model in young and elderly participants. Additionally, a user interface for mobile devices was developed to record cough sounds and estimate cough strength using the proposed method. We then performed experiments on 33 young participants (21.3 ± 0.4 years) and 25 elderly participants (80.4 ± 6.1 years) to test the effect of age on the CPF estimation accuracy. The percentage error between the measured and estimated CPFs was approximately 6.19%. In addition, among the elderly participants, the current model improved the estimation accuracy of the previous model by a percentage error of approximately 6.5% (p < 0.001). Furthermore, Bland-Altman analysis demonstrated no systematic error between the measured and estimated CPFs. These results suggest that the developed device can be applied for daily CPF measurements in clinical practice.

Trigger Reduction Prior to Systemic Drugs for Neurogenic Chronic Cough

OBJECTIVE/HYPOTHESIS

Neurogenic chronic cough typically presents as a postviral chronic cough, often with paroxysms of coughing preceded by a tickle sensation with multiple triggers and often recalcitrant to multiple treatments for reflux disease, sinus disease, and asthma. Current treatment uses neuromodulating agents with moderate success. Post nasal drainage and laryngopharyngeal reflux can be triggers in the setting of laryngopharyngeal hypersensitivity. Treatment will focus on trigger reduction using nasal toilet and a dietary regimen for laryngopharyngeal reflux.

STUDY DESIGN

Systematic review of retrospective cohort studies METHODS: One-year retrospective review of new patients with cough (R05.0) excluding asthma, proton pump inhibitor response, and sinus or pulmonary disease. Cough severity index (CSI) and reflux symptom index (RSI) were evaluated initially and 6 weeks after trigger-reduction treatment using nasal saline irrigation, nasal steroids, nasal antihistamines, and a plant-based diet with alkaline water.

RESULTS

Of 119 patients, 29 met the criteria. Using the six-point reduction (improvement) in RSI as an accepted response, 20 of 29 patients (68.9%, P = .0014) experienced a clinical response. Using reduction in RSI and CSI as a continuous variable to assess response, patients experienced a 10 (95% confidence interval [CI]: 6.75-13.2) and 10.9 (95% CI: 7.4-14.3) mean point reduction, respectively. The mean percent reduction in RSI following 6 weeks of treatment was 54.7% (95% CI: 41.5-68.0; P = .0001). These patients experienced a 59.8% (95% CI: 43.4-76.2; P = .0001) reduction in CSI.

CONCLUSIONS

A trigger-reduction approach using nasal toilet and a plant-based diet in patients with neurogenic chronic cough prior to the initiation of systemic neuromodulating medications should be considered.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:198-202, 2019.

Assessing referral and practice patterns of patients with chronic cough referred for behavioral cough suppression therapy

The purpose of this exploratory research was to describe current referral and practice patterns for behavioral cough suppression therapy (BCST) throughout the United States, and to assess the need for improving the efficiency of BCST referral patterns. In study I, 126 speech-language pathologists, who treat patients with refractory chronic cough (RCC) in the United States, completed a survey about referral patterns, cough duration, and patient frustration level. In study II, 36 adults with RCC referred for BCST completed a four-part survey about cough symptoms and treatment. The survey included the Leicester Cough Questionnaire (LCQ) before and after BCST. Study I revealed significant patient frustration about the treatment process and the wait-time for BCST. Participants in study II reported average cough duration of over 2 years before BCST. Twenty-seven of 31 participants in study II improved by at least 1.3 on the LCQ, indicating a clinically significant improvement in 87% of patients. This study suggests that the current management model for CC may be unduly time-consuming, and expensive for patients with CC who are successfully treated with BCST. Practitioners are encouraged to consider BCST earlier in the treatment process.

Antibiotics for prolonged wet cough in children

BACKGROUND

Cough is a frequent symptom presenting to doctors. The most common cause of childhood chronic (greater than fours weeks' duration) wet cough is protracted bacterial bronchitis (PBB) in some settings, although other more serious causes can also present this way. Timely and effective management of chronic wet or productive cough improves quality of life and clinical outcomes. Current international guidelines suggest a course of antibiotics is the first treatment of choice in the absence of signs or symptoms specific to an alternative diagnosis. This review sought to clarify the current evidence to support this recommendation.

OBJECTIVES

To determine the efficacy of antibiotics in treating children with prolonged wet cough (excluding children with bronchiectasis or other known underlying respiratory illness) and to assess risk of harm due to adverse events.

SEARCH METHODS

We undertook an updated search (from 2008 onwards) using the Cochrane Airways Group Specialised Register, Cochrane Register of Controlled Trials (CENTRAL), MEDLINE, Embase, trials registries, review articles and reference lists of relevant articles. The latest searches were performed in September 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing antibiotics with a placebo or a control group in children with chronic wet cough. We excluded cluster and cross-over trials.

DATA COLLECTION AND ANALYSIS

We used standard methods as recommended by Cochrane. We reviewed results of searches against predetermined criteria for inclusion. Two independent review authors selected, extracted and assessed the data for inclusion. We contacted authors of eligible studies for further information as needed. We analysed data as 'intention to treat.'

MAIN RESULTS

We identified three studies as eligible for inclusion in the review. Two were in the previous review and one new study was included. We considered the older studies to be at high or unclear risk of bias whereas we judged the newly included study at low risk of bias. The studies varied in treatment duration (from 7 to 14 days) and the antibiotic used (two studies used amoxicillin/clavulanate acid and one used erythromycin).We included 190 children (171 completed), mean ages ranged from 21 months to six years, in the meta-analyses. Analysis of all three trials (190 children) found that treatment with antibiotics reduced the proportion of children not cured at follow-up (primary outcome measure) (odds ratio (OR) 0.15, 95% confidence interval (CI) 0.07 to 0.31, using intention-to -treat analysis), which translated to a number needed to treat for an additional beneficial outcome (NNTB) of 3 (95% CI 2 to 4). We identified no significant heterogeneity (for both fixed-effect and random-effects model the I² statistic was 0%). Two older trials assessed progression of illness, defined by requirement for further antibiotics (125 children), which was significantly lower in the antibiotic group (OR 0.10, 95% CI 0.03 to 0.34; NNTB 4, 95% CI 3 to 5). All three trials (190 children) reported adverse events, which were not significantly increased in the antibiotic group compared to the control group (OR 1.88, 95% CI 0.62 to 5.69). We assessed the quality of evidence GRADE rating as moderate for all outcome measures, except adverse events which we assessed as low quality.

AUTHORS' CONCLUSIONS

Evidence suggests antibiotics are efficacious for the treatment of children with chronic wet cough (greater than four weeks) with an NNTB of three. However, antibiotics have adverse effects and this review reported only uncertainty as to the risk of increased adverse effects when they were used in this setting. The inclusion of a more robust study strengthened the previous Cochrane review and its results.