Mechanic study based on untargeted metabolomics of Pi-pa-run-fei-tang on pepper combined with ammonia induced chronic cough model mice

ETHNOPHARMACOLOGICAL RELEVANCE

Pi-pa-run-fei-tang (PPRFT), a traditional Chinese medicine formula with long-standing history, demonstrated beneficial effect on chronic cough. However, the mechanism underlying efficacy unclear. In current research, we explored the impact and molecular mechanism of chronic cough mouse stimulating with capsaicin combined with ammonia.

AIM OF THE STUDY

To investigate the metabolic modulating effects, and potential mechanisms underlying the therapeutic effect of PPRFT in chronic cough.

MATERIALS AND METHODS

Chronic cough mouse models were created by stimulating mice by capsaicin combined with ammonia. Number of coughs and cough latency within 2 min were recorded. With lung tissue and serum samples collected for histopathology, metabolomics, RT-qPCR, immunohistochemistry, and WB analysis. Lymphocytes were isolated and flow cytometric assays were conducted to evaluate the differentiation between Th17 and Treg cell among CD4+ cells.

RESULTS

Results indicated that PPRFT obviously reduced the number of coughs, prolonged cough latency, reduced inflammatory cell infiltration and lung tissues damage, and decreased the serum level of IL-6, IL-1β, TNF-α, and IL-17 while increasing IL-10 levels. Notably, PPRFT suppressed Th17 cell divergence and promoted Treg cell divergence. Furthermore, serum metabolomic assays showed that 46 metabolites differed significantly between group, with 35 pathways involved. Moreover, mRNA levels of IL-6, NF-κB, IL-17, RORγT, JAK2, STAT3, PI3K and AKT in lung tissues remarkably reduced and mRNA levels of IL-10 and FOXP3 were elevated after PPRFT pretreatment. Additionally, PPRFT treatments decreased the protein levels of IL-6, NF-κB, IL-17, RORγT, p-JAK2, p-STAT3, p-PI3K, and p-AKT and increased the protein levels of IL-10 and FOXP3, but no significantly effects to the levels on JAK2, STAT3, PI3K, and AKT in the lungs.

CONCLUSION

Conclusively, our result suggested the effect with PPRFT on chronic cough may be mediated through IL-6/JAK2/STAT3 and PI3K/AKT/NF-κB pathway, which regulate the differentiation between Th17 and Treg cell. This beneficial effect of PPRFT in capsaicin and ammonia-stimulated chronic cough mice indicates its potential application in treating chronic cough.

Prevalence and causes of chronic cough in Japan

BACKGROUND

Chronic cough is one of the most common symptoms of respiratory diseases and can adversely affect patients' quality of life and interfere with social activities, resulting in a significant social burden. A survey is required to elucidate the frequency and treatment effect of chronic cough. However, clinical studies that cover all of Japan have not yet been conducted.

METHODS

Patients who presented with a cough that lasted longer than 8 weeks and visited the respiratory clinics or hospitals affiliated with the Japan Cough Society during the 2-year study period were registered.

RESULTS

A total of 379 patients were enrolled, and those who did not meet the definition of chronic cough were excluded. A total of 334 patients were analyzed: 201 patients had a single cause, and 113 patients had two or more causes. The main causative diseases were cough variant asthma in 92 patients, sinobronchial syndrome (SBS) in 36 patients, atopic cough in 31 patients, and gastroesophageal reflux (GER)-associated cough in 10 patients. The time required to treat undiagnosed patients and those with SBS was significantly longer and the treatment success rate for GER-associated cough was considerably poor.

CONCLUSIONS

We confirmed that the main causes of chronic cough were cough variant asthma, SBS, atopic cough, and their complications. We also showed that complicated GER-associated cough was more likely to become refractory. This is the first nationwide study in Japan of the causes and treatment effects of chronic cough.

Quality of Life in Adults with Chronic Cough: A Mixed Methods Study Informing the Development of a Quantitative Patient Preference Study

OBJECTIVES

This study aimed to describe quality of life for patients with chronic cough (CC) and identify meaningful attributes that affect patient treatment preferences to inform the design of a quantitative preference study.

METHODS

Eligible patients (≥ 18 years) with a CC (> 8 weeks) participated in qualitative interviews with two defined steps. Step one: concept elicitation and bidding games were used to collect descriptions of patient experiences with CC and identify important CC-related attributes. Step two: attributes were confirmed using concept elicitation and bidding games and prioritized using structured card sort activities. Purposive sampling ensured diversity of patient experiences. Qualitative content analysis was used to analyze participant narratives, and descriptive statistics were used to summarize card sort results. This study follows a fully mixed concurrent dominant status design, with qualitative (dominant) and quantitative components.

RESULTS

A total of 20 participants were interviewed with a mean age of 61.4 years (range 24-79 years). Coughing episodes, described as intense consecutive coughs that made catching breath difficult, were important to most participants (n = 17). Participants emphasized the emotional impact of episodes including feelings of uncertainty, loss of control, self-consciousness, and fear. Severity of CC was most often judged by frequency (n = 11) and intensity (n = 12) of cough. Daily, physical, or social activities were impacted for most participants. Impact on sleep (n = 14) included waking during the night, difficulty falling asleep, and daytime fatigue. Medication-related taste disturbances were an important consideration for what participants were willing to accept in exchange for cough relief.

CONCLUSIONS

This study emphasizes the importance of coughing episodes for adults with CC and provides initial evidence that taste alterations are an important component of patient treatment decisions for CC.

Proximal esophageal impedance baseline increases the yield of impedance-pH and is associated with response to PPIs in chronic cough patients

BACKGROUND

Chronic cough significantly impairs the quality of life. Although various studies focused on MNBI as assessed in the distal esophagus, scarce data are available on the clinical value of proximal measurements.

AIM

To investigate the role of proximal MNBI in the workup of patients with chronic cough and its ability to predict PPI response.

METHODS

Demographic, clinical, endoscopy findings, impedance-pH and HRM tracings from consecutive cough patients were evaluated. MNBI was calculated at proximal and distal esophagus.

RESULTS

One hundred and sixty four patients were included. In addition to traditional variables, when considering also the PSPW index or MNBI at 3 cm or 15 cm, the proportion of patients with pathological impedance-pH monitoring significantly increased. 70/164 patients were responders, while 94 (57.3%) were non-responder to double PPI dose (p < 0.05). Patients with pathologic MNBI at 3 cm and/or 15 cm as well as those with pathologic PSPW index were characterized by a significantly higher proportion of responders than that observed among patients with normal impedance-pH variables (p < 0.001). The proportion of responders with pathological MNBI at 15 cm was significantly higher than the proportion of responders with pathological MNBI at 3 cm (82.8% vs. 64.3%, p < 0.05). At multivariable model, pathological MNBI at both 3 cm and 15 cm as well as PSPW index were associated with PPI responsiveness. The strongest association with PPI response was observed for MNBI at 15 cm.

CONCLUSIONS

The assessment of MNBI at proximal esophagus increases the diagnostic yield of impedance-pH monitoring and may represent a useful predictor of PPI responsiveness in the cumbersome clinical setting of suspected reflux-related cough.

Efficacy of Speech-language Pathology Therapy in Chronic Cough: Systematic Review With Meta-analysis

OBJECTIVES

To analyze the efficacy of speech-language pathology therapy in the self-assessment, in the cough frequency, and the vocal quality of adults with chronic cough.

METHODS

This is a systematic review with meta-analysis that answered the clinical question: "In adults with chronic cough, what is the effect of the speech-language pathology therapy in the self-assessment, in the cough frequency, and the vocal quality, compared to another intervention?" (PROSPERO 2021/CRD42021226729). An electronic search (MEDLINE, Web of Science, EMBASE, SCOPUS, Cochrane Library, and Lilacs), and a manual search (Journal of Voice, Brazilian Library of Theses and Dissertations, Open Grey and Clinical Trials) with specific search strategies was performed. The risk of bias was assessed using the Cochrane Collaboration's tool for assessing the risk of bias in randomized trials. Meta-analysis (standardized difference of means, Inverse Variance, and random effects model) and heterogeneity analysis (Chi², Tau², and I²) were performed.

RESULTS

We found 610 studies and selected three. There was an uncertain risk of detection bias. The data were heterogeneous, and there was no difference between interventions in self-perception of cough severity (z = 0.09, P = 0.930; tau² = 0.65, I² = 90%) and in the self-perception of the effects of chronic cough on health status (z = 0.30, P = 0.77; tau² = 0.99, I² = 97%). The estimated mean difference was 0.97 to cough frequency, and it was differ significantly from zero (z = 4.47, P < 0.001) but the results are heterogeneous (Chi² (1) = 22.22, P < 0.001, I² = 95%).

CONCLUSION

The speech-language pathology therapy had a greater effect size than the control interventions on cough frequency. However, in the subjects' perception, there were no differences between the interventions.

Clinical Parameters of the Speech-Language Pathology Assessment of the Chronic Cough: A Scoping Review

OBJECTIVE

to map the clinical parameters used in the speech-language pathology assessment of the chronic cough.

METHODS

a scoping review was performed to answer the clinical question: "What are the clinical parameters included in the speech-language pathology assessment of patients with chronic cough?" Evidence was searched by electronic and manual search. The electronic search included: MEDLINE, Cochrane Library, EMBASE, Web of Science, SCOPUS, and LILACS. Each database had a specific search strategy. The manual search included Journal of Voice, Chest, and Thorax, Brazilian Library of Theses and Dissertations, Open Grey, and Clinical Trials, in addition to scanning the references of the included studies. The extracted data considered information regarding the publication, sample, assessment, and measures used when assessing chronic cough.

RESULTS

the electronic search found 289 studies; the manual search found 1036 studies; 12 were selected for the present study. The most used assessments were: self-assessment (75%), aerodynamic analysis (66.67%), the perceptual auditory judgment of the voice quality (58.33%), acoustic analysis of the voice (41.67%), cough frequency, and cough threshold (41.67%) and electroglottography (25%).

CONCLUSIONS

the subjective instruments were used more frequently, while specific objective instruments, which are recent, were used less frequently. Complementary assessments such as vocal assessment, have been frequently used, also, with no other parameter. A lack of homogeneity was identified in the speech-language pathology assessment and measures of patients with chronic cough, thus, the comparison among studies and clinical analysis is difficult.

Positive effect of deep diaphragmatic breathing training on gastroesophageal reflux-induced chronic cough: a clinical randomized controlled study

BACKGROUND AND OBJECTIVE

To explore the efficacy of deep diaphragmatic breathing training (DEP) in patients with gastroesophageal reflux-induced chronic cough (GERC).

METHODS

A randomized controlled study was conducted involving 60 GERC patients who were divided into the intervention group and the control group (each with 30 patients). Both groups received routine medication treatment for GERC, while the intervention group received DEP training additionally. Both groups were evaluated by cough symptom scores, Hull airway reflux questionnaire (HARQ), gastroesophageal reflux diagnostic questionnaire (GerdQ), generalized anxiety disorder scale-7 (GAD-7), patient health questionnaire-9 (PHQ-9), Pittsburgh sleep quality index (PSQI), the Leicester cough questionnaire (LCQ), as well as capsaicin cough sensitivity testing, B-ultrasound and surface electromyography (sEMG) of the diaphragmatic muscles before and after treatment. The cough resolution rate and changes of the above indictors was compared between the two groups after eight weeks of treatment.

RESULTS

After eight weeks of treatment, cough symptoms improved in both groups, but the cough resolution rate in the intervention group of 94% was significantly higher than that in the control group of 77% (χ2 = 6.402, P = 0.041). The intervention group showed significant improvements to the control group in GerdQ (6.13(0.35) VS 6.57(0.77)), GAD-7 (0(0;1) VS 1(0;3)), PSQI (2(1;3) VS 4(3;6)), LCQ (17.19(1.56) VS 15.88(1.92)) and PHQ-9 (0(0;0) VS 0(0;3)) after treatment. Compared to control group, sEMG activity of the diaphragmatic muscle was significantly increased in the intervention group after treatment, measured during DEP (79.00(2.49) VS 74.65 (1.93)) and quiet breathing (72.73 (1.96) VS 67.15 (2.48)).

CONCLUSION

DEP training can improve cough symptoms as an adjunctive treatment in GERC patients.

TRIAL REGISTRATION

The protocol was registered in February 2, 2022 via the Chinese Clinical Trials Register ( http://www.chictr.org.cn/ ) [ChiCTR2200056246].

Validity and reliability of the Swedish version of the Leicester Cough Questionnaire in unexplained chronic cough

BACKGROUND

Cough is considered chronic when it lasts for >8 weeks. When no medical explanation can be found it is often called unexplained chronic cough (UCC), which may affect health-related quality of life (HRQOL). This study aimed to assesses the validity and reliability of the Swedish version of the Leicester Cough Questionnaire (LCQ-S) in patients with UCC.

METHODS

Seventy-six consecutively selected patients with UCC replied to: a local questionnaire; the LCQ-S; a Visual Analog Scale (VAS) for cough; the Swedish version of the Hull Airway Reflux Questionnaire (HARQ-S); and the Chemical Sensitivity Scale for Sensory Hyperreactivity (CSS-SHR). To evaluate the reproducibility of the LCQ-S, the VAS and LCQ-S were answered again after two to four weeks.

RESULTS

Seventy-four patients (17 men) answered the questionnaires at baseline. Concurrent validity for LCQ-S was regarded as moderate with the VAS for cough and HARQ-S. Internal consistency using Cronbach's alpha was high for the LCQ-S total score (0.92) and satisfactory for the LCQ-S domains (0.78-0.83). Reliability and reproducibility were analysed in 57 patients (14 men). Intra-class correlation for the LCQ-S total score and domains showed strong reliability (≥0.92), without any significant differences over time. The standard error of measurement and the smallest real difference were 1.26 and 3.49, respectively. The Bland-Altman plot showed no systematic change in the mean values.

CONCLUSIONS

The LCQ-S has good validity and reliability and can be used in clinical settings to evaluate HRQOL in Swedish-speaking adult patients with UCC.

First Exploration of the Altered Microbial Gut-Lung Axis in the Pathogenesis of Human Refractory Chronic Cough

PURPOSE

Cough represents a natural mechanism that plays an important defensive role in the respiratory tract, but in some conditions, it may become persistent, nonproductive, and harmful. In general, refractory chronic cough (RCC) occurs in about 20% of individuals; hence, we aimed to assess the presence of altered gut-lung communication in RCC patients through a compositional and functional characterization of both gut (GM) and oral microbiota (OM).

METHODS

16S rRNA sequencing was used to characterize both GM and OM composition of RCC patients and healthy controls (HC). PICRUST2 assessed functional changes in microbial communities while gas chromatography was used to evaluate fecal short-chain fatty acid levels and serum-free fatty acid (FFA) abundances.

RESULTS

In comparison with HC, RCC patients reported increased saliva alpha-diversity and statistically significant beta-diversity in both GM and OM. Also, a, respectively, significant increased or reduced Firmicutes/Bacteroidota ratio in stool and saliva samples of RCC patients has been shown, in addition to a modification of the abundances of several taxa in both GM and OM. Moreover, a potential fecal over-expression of lipopolysaccharide biosynthesis and lipoic acid metabolism pathways and several differences in serum FFA levels have been reported in RCC patients than in HC.

CONCLUSION

Since differences in both GM and OM of RCC patients have been documented, these findings could provide new information about RCC pathogenesis and also pave the way for the development of novel nutritional or pharmacological interventions for the management of RCC through the restoration of eubiotic gut-lung communication.

The Role of Bilateral Superior Laryngeal Nerve Block in Managing Refractory Chronic Cough

OBJECTIVE(S)

The aim was to investigate the utilization and efficacy of bilateral superior laryngeal nerve block in patients with refractory chronic cough.

METHODS

A retrospective chart review of 164 patients with refractory chronic cough who underwent bilateral SLN block at a single institution between November 2018 and September 2022 was performed. Demographics, comorbidities, and patient-reported outcomes including pre- and postinjection Leicester Cough Questionnaire (LCQ) scores were collected and analyzed.

RESULTS

The cohort underwent an average of 2.97 bilateral injections (range 1-22), containing either corticosteroid and local anesthetic or corticosteroid alone. Notably, 116 of 164 of patients reported an average of 67.3% reduction in their symptoms, with the treatment effect lasting 7.60 weeks on average. The average pre- and postinjection LCQ scores were 9.70 and 13.82, respectively. A lower LCQ score represents a greater impairment of health status due to cough, and the minimum important change is 1.3 points between questionnaires. The average improvement on LCQ following bilateral SLN block was 4.11 points for this cohort.

CONCLUSION

The use of in-office bilateral SLN block is an effective treatment that can be used alone or in conjunction with oral medications for the treatment of refractory chronic cough.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1773-1777, 2024.

Pulmonary dimorphic fungal infections among HIV/AIDS non-TB patients with chronic cough in Kampala, Uganda

INTRODUCTION

Dimorphic fungi cause infection following the inhalation of spores into the pulmonary system. In the lower respiratory tract, the conidia transform into yeasts, which are engulfed by alveolar macrophages and may be destroyed without disease manifestation. However, in some immunocompromised individuals, they may persist and cause active fungal disease characterized by formation of granulomas in the infected tissues, which may mimic Mycobacterium tuberculosis (MTB).

OBJECTIVE

To determine the prevalence of pulmonary dimorphic fungal infections among HIV/AIDS patients with non-TB chronic cough at Mulago National Referral and Teaching Hospital in Kampala, Uganda.

METHODS

Sputum samples were collected from 175 consented HIV/AIDS patients attending the immuno-suppression syndrome (ISS) clinic at the hospital. Upon Xpert MTB/RIF sputum testing, 21 patients tested positive for MTB, and these were excluded from further analysis. The other 154 sputum negative samples were then subjected to PCR for dimorphic fungi at MBN Clinical Laboratories. Singleplex PCR was used to detect the target sequences in selected respective genes of each dimorphic fungal species of interest. DNA amplicons were detected based on gel electrophoresis.

RESULTS

Dimorphic fungi were detected in 16.2% (25/154) of the studied population. Of these 9.1% (14/154) had Blastomyces dermatitidis and 7.1% (11/154) had Talaromyces marneffei. The remaining 84% of the studied participants had no dimorphic fungi. Histoplasma capsulatum, Coccidioides immitis and Paracoccidioides brasiliensis were not detected in any of the participants.

CONCLUSION

Dimorphic fungi (B. dermatitidis and T. marneffei) were found in 16.2% of the HIV/AIDS patients with non-TB chronic cough in Kampala, Uganda. We recommend routine testing for these pathogens among HIV/AIDS patients with chronic cough.

Characterization of Codeine Treatment Responders Among Patients with Refractory or Unexplained Chronic Cough: A Prospective Real-World Cohort Study

PURPOSE

Codeine is a narcotic antitussive often considered for managing patients with refractory or unexplained chronic cough. This study aimed to evaluate the proportion and characteristics of patients who responded to codeine treatment in real-world practice.

METHODS

Data from the Korean Chronic Cough Registry, a multicenter prospective cohort study, were analyzed. Physicians assessed the response to codeine based on the timing and degree of improvement after treatment initiation. Follow-up assessments included the Leicester Cough Questionnaire and cough severity visual analog scale at six months. In a subset of subjects, objective cough frequency was evaluated following the initiation of codeine treatment.

RESULTS

Of 305 patients, 124 (40.7%) responded to treatments based on anatomic diagnostic protocols, while 181 (59.3%) remained unexplained or refractory to etiological treatments. Fifty-one subjects (16.7%) were classified as codeine treatment responders (those showing a rapid and clear response), 57 (18.7%) as partial responders, and 62 (20.3%) as non-responders. Codeine responders showed rapid improvement in objective cough frequency and severity scores within a week of the treatment. At 6 months, responders showed significantly improved scores in cough scores, compared to non-responders. Several baseline parameters were associated with a more favorable treatment response, including older age, non-productive cough, and the absence of heartburn.

CONCLUSIONS

Approximately 60% of chronic cough patients in specialist clinics may require antitussive drugs. While codeine benefits some, only a limited proportion (about 20%) of patients may experience rapid and significant improvement. This underscores the urgent need for new antitussive drugs to address these unmet clinical needs.

Explainable artificial intelligence for cough-related quality of life impairment prediction in asthmatic patients

Explainable Artificial Intelligence (XAI) is becoming a disruptive trend in healthcare, allowing for transparency and interpretability of autonomous decision-making. In this study, we present an innovative application of a rule-based classification model to identify the main causes of chronic cough-related quality of life (QoL) impairment in a cohort of asthmatic patients. The proposed approach first involves the design of a suitable symptoms questionnaire and the subsequent analyses via XAI. Specifically, feature ranking, derived from statistically validated decision rules, helped in automatically identifying the main factors influencing an impaired QoL: pharynx/larynx and upper airways when asthma is under control, and asthma itself and digestive trait when asthma is not controlled. Moreover, the obtained if-then rules identified specific thresholds on the symptoms associated to the impaired QoL. These results, by finding priorities among symptoms, may prove helpful in supporting physicians in the choice of the most adequate diagnostic/therapeutic plan.

Neurosarcoidosis with chronic cough and Horner's syndrome

A 62-year-old man attended ophthalmology for a simple ptosis repair. He had a chronic cough, a Horner's syndrome with post-gustatory hyperhidrosis. He was referred to the respiratory and neurology teams. MR scan of his head and neck found evidence of multifocal disease at the skull base and carotid canal, and further tests identified additional deposits in the hilar lymph nodes, heart and sacrum. A transbronchial biopsy confirmed the diagnosis of sarcoidosis. His symptoms and imaging responded well to corticosteroids, but he still undergoes regular imaging. We discuss the features of Horner's syndrome, and the autonomic associations of a chronic cough.

Association of resistance training and moderate-to-vigorous physical activity with clinical outcomes in men with airflow limitation: a nationwide population-based study

Aerobic moderate-to-vigorous physical activity (MVPA) is recommended for individuals with chronic diseases. However, the association between resistance training (RT) in addition to moderate to vigorous physical activity (MVPA) and sleep duration, as well as respiratory symptoms, in patients with chronic obstructive pulmonary disease has not been thoroughly investigated. This population-based cross-sectional study used data from the Korea National Health and Nutrition Examination Survey between 2014 and 2019. A total of 61,754 individuals were identified and men with airflow limitation (FEV1/FVC < 0.7) who engaged in aerobic MVPA were selected (n = 794). Weighted percentages and odds ratio (OR) of sleep problems (≤ 5 or ≥ 9 h), chronic cough, and chronic sputum were estimated. A multivariate-adjusted complex sample logistic regression model was used to calculate ORs and 95% confidence intervals (CI). Subgroup analyses were conducted using the forced expiratory volume (FEV1) % of the predicted value (%pred) ≥ 80 vs. < 80. The percentages of sleep problems, chronic cough, and chronic sputum production were lower in men who underwent aerobic MVPA + RT than in those who underwent aerobic MVPA alone. The multivariable-adjusted OR of sleep problems was 0.44 (95% CI 0.25-0.77) in individuals undergoing aerobic MVPA + RT compared to aerobic MVPA alone. The ORs of chronic cough and sputum were 0.35 (95% CI 0.13-0.94) and 0.51 (95% CI 0.30-0.87), respectively. These associations were only significant in individuals with FEV1 < 80% pred. Compared with aerobic MVPA alone, aerobic MVPA + RT was associated with appropriate sleep duration and a decrease in chronic cough and sputum in male with airflow limitation. This was more pronounced in individuals with a FEV1 < 80% pred.

Relevant factors associated with the development of chronic cough after recovery from COVID-19

BACKGROUND

Cough is one of the symptoms of the post-COVID-19 condition. However, the factors associated with its development remain unclear. We evaluated the factors associated with chronic cough in the post-COVID-19 condition.

METHODS

In this survey, 170 individuals who previously had COVID-19 and were admitted to Aichi Hospital between October 2020 and October 2021 were included. Using self-developed questionnaires and visual analog scales, 19 symptoms, including cough, were assessed. Cough-specific quality of life (QoL), reflux-related symptoms, and abnormal laryngeal sensations were also evaluated. The patients' clinical characteristics and indices, including cough-specific QoL, at admission were extracted from their medical records. Multivariate regression analyses were conducted to determine the factors associated with cough-related outcomes, such as prevalence, QoL, and severity, in the post-COVID-19 condition.

RESULTS

The median length (range) of the survey after recovery from COVID-19 was 158 (95-467) days. Cough was prevalent (n = 41, 24 %) and often accompanied by other symptoms, including gastrointestinal symptoms. Cough-specific QoL after recovery was correlated with reflux-related symptoms and abnormal laryngeal sensations. Multivariate analyses revealed that gastrointestinal symptoms, sputum, and chronic cough before contracting COVID-19 are significant predictors of cough-related outcomes in the post-COVID-19 condition. Meanwhile, other indices including cough-specific QoL on the acute phase were not reliable predictors in the post-COVID-19 condition.

CONCLUSIONS

Cough during the post-COVID-19 condition had a negative impact on daily life activities. Gastrointestinal symptoms could play a significant role in the pathophysiology of cough in such a condition.

Pulmonary vagus nerve transection for chronic cough after video-assisted lobectomy: a randomized controlled trial

BACKGROUND

Chronic cough is common after lobectomy. Vagus nerves are part of the cough reflex. Accordingly, transection of the pulmonary branches of vagus nerve may prevent chronic cough. And there are no clear recommendations on the management of the pulmonary branches of vagus in any thoracic surgery guidelines.

METHODS

This is a single-center, randomized controlled trial. Adult patients undergoing elective video-assisted thoracoscopic lobectomy and lymphadenectomy were randomized at a 1:1 ratio to undergo a sham procedure (control group) or transection of the pulmonary branches of the vagus nerve that innervate the bronchial stump plus the caudal-most large pulmonary branch of the vagus nerve. The primary outcome was the rate of chronic cough, as assessed at 3 months after surgery in the intent-to-treat population.

RESULTS

Between 1 February 2020 and 1 August 2020, 116 patients (59.6±10.1 years of age; 45 men) were randomized (58 in each group). All patients received designated intervention. The rate of chronic cough at 3 months was 19.0% (11/58) in the vagotomy group versus 41.4% (24/58) in the control group (OR=0.332, 95% CI: 0.143-0.767; P =0.009). In the 108 patients with 2-year assessment, the rate of persistent cough was 12.7% (7/55) in the control and 1.9% (1/53) in the vagotomy group ( P =0.032). The two groups did not differ in postoperative complications and key measures of pulmonary function, for example, maximal voluntary ventilation, diffusing capacity of the lungs for carbon monoxide, and forced expiratory volume.

CONCLUSION

Transecting the pulmonary branches of vagus nerve that innervate the bronchial stump plus the caudal-most large pulmonary branch decreased the rate of chronic cough without affecting pulmonary function in patients undergoing video-assisted lobectomy and lymphadenectomy.

[Chronic cough in adult patients-evidence-based approach]

Approximately 10% of the population suffer from a cough lasting longer than 8 weeks. Compared to acute cough, which usually occurs in the context of banal respiratory tract infections, the differential diagnoses of chronic cough require an increased use of diagnostic tests and thus a structured, evidence-based approach according to current international guidelines. A targeted history (smoking status, medication, previous diseases) and ENT status are always followed by chest x‑ray and pulmonary function tests before extended diagnostics. In the case of angiotensin-converting enzyme (ACE) inhibitor use and unremarkable physical examination, a drug discontinuation test can be carried out first. In case of inconspicuous findings, a disease entity that can be treated empirically such as upper airway cough syndrome is most likely. If the cough remains unexplained, cough suppression techniques, physiotherapy or speech therapy should be sought before off-label-use of medication.

Postnasal drip and chronic cough in patients with chronic rhinitis treated with temperature-controlled radiofrequency neurolysis

OBJECTIVE

To evaluate the contribution of postnasal drip (PND) and chronic cough (CC) to symptoms of patients with chronic rhinitis treated with temperature-controlled radiofrequency (TCRF) neurolysis of the posterior nasal nerve (PNN), and correlate PND and CC scores with components of the reflective total nasal symptom score (rTNSS).

METHODS

Pooled data from three prospective studies: two single-arm studies and the index active treatment arm of a randomized controlled trial. Adult patients with baseline rTNSS ≥6 were treated with TCRF neurolysis at nonoverlapping regions of the PNN. PND and CC symptoms were evaluated on a 0 (none) to 3 (severe) scale.

RESULTS

Data from 228 patients (57.9% women, 42.1% men) were included. The mean baseline rTNSS was 8.1 (95% confidence interval [CI], 7.8-8.3), which decreased to 3.2 (95% CI, 2.9-3.5) at 6 months. At baseline, 97.4% of patients had PND and 80.3% had CC. Median baseline PND and CC symptom scores were 3 (interquartile range [IQR], 2-3) and 2 (IQR, 1-2), respectively. At 6 months, this decreased to 1 (IQR, 0-2) and 0 (IQR, 0-1), respectively, showing significant improvement from baseline (both p < 0.001). Spearman correlation coefficients with components of rTNSS (rhinorrhea, congestion, itching, sneezing) were 0.16 to 0.22 for CC and 0.19 to 0.46 for PND, indicating only a weak to moderate correlation.

CONCLUSION

PND and CC contribute to the symptomatology of chronic rhinitis and are significantly improved after TCRF neurolysis of the PNN. The inclusion of PND and CC symptoms in a chronic rhinitis assessment instrument could provide important additional information for the characterization of the disease state and outcomes after any therapeutic treatment.

Clinical and functional characteristics, possible causes, and impact of chronic cough in patients with cerebellar ataxia, neuropathy, and bilateral vestibular areflexia syndrome (CANVAS)

Cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS) is an hereditary autosomal recessive disease. Recent studies propose including chronic cough (CC) as a symptom of CANVAS. For 10 patients with CANVAS as genetically confirmed by biallelic expansion of the AAGG repeat motif (AAGGGexp) in intron 2 of replication factor C subunit 1 (RFC1), our aim was, as a multidisciplinary team, to describe clinical and functional characteristics and possible causes of CC following European Respiratory Society (ERS) recommendations, and to evaluate CC impact on quality of life (QoL) using self-administered questionnaires (Cough Severity Diary, Leicester Cough Questionnaire, Discrete Emotions Questionnaire, and EQ-5D-5L). In all 10 patients, the CC was a dry cough that developed several years prior to the neurological symptoms (mean 14.2 years); 7 patients had symptoms compatible with gastroesophageal reflux (GER), 5 with pathological GER diagnosed by 24-h esophageal pH testing, and 6 patients had impaired esophageal motility diagnosed by high-resolution esophageal manometry, most frequently ineffective peristalsis. Although further studies are required for confirmation, we conclude that CC may be a characteristic prodrome of CANVAS and may be related to GER and esophageal disorders. Furthermore, CC affects patients' QoL, especially in the psychosocial sphere.

Clinical utility of elective paediatric flexible bronchoscopy and impact on the quality of life: protocol for a single-centre, single-blind, randomised controlled trial

INTRODUCTION

Elective flexible bronchoscopy (FB) is now widely available and standard practice for a variety of indications in children with respiratory conditions. However, there are no randomised controlled trials (RCTs) that have examined its benefits (or otherwise).Our primary aim is to determine the impact of FB on the parent-proxy quality-of-life (QoL) scores. Our secondary aims are to determine if undertaking FB leads to (a) change in management and (b) improvement of other relevant patient-reported outcome measures (PROMs). We also quantified the benefits of elective FB (using 10-point Likert scale). We hypothesised that undertaking elective FB will contribute to accurate diagnosis and therefore appropriate treatment, which will in turn improve QoL and will be deemed to be beneficial from patient and doctor perspectives.

METHODS AND ANALYSIS

Our parallel single-centre, single-blind RCT (commenced in May 2020) has a planned sample size of 114 children (aged <18 years) recruited from respiratory clinics at Queensland Children's Hospital, Brisbane, Australia. Children are randomised (1:1 concealed allocation) within two strata: age (≤2 vs >2 years) and indication for FB (chronic cough vs other indications) to either (a) early arm (intervention where FB undertaken within 2 weeks) or (b) delayed (control, FB undertaken at usual wait time). Our primary outcome is the difference between groups in their change in QoL at the T2 timepoint when the intervention group has had the FB and the control group has not. Our secondary outcomes are change in management, change in PROMs, adverse events and the Likert scales.

ETHICS AND DISSEMINATION

The human research ethics committee of the Queensland Children's Hospital granted ethical clearance (HREC/20/QCHQ/62394). Our RCT is conducted in accordance with Good Clinical Practice and the Australian legislation. Results will be disseminated through conference presentations, teaching avenues, workshops, websites and publications.

REGISTRATION

Australia New Zealand Clinical Trial Registry ACTRN12620000610932.

[Effect of Preserving the Pulmonary Branch of Vagus Nerve on Postoperative Cough in Patients with Stage I Peripheral Lung Adenocarcinoma]

BACKGROUND

Cough is one of the main complications after pulmonary surgery, which seriously affects the postoperative quality of life. Preserving the pulmonary branch of vagus nerve may reduce the incidence of postoperative cough. Therefore, the aim of this study was to investigate whether preserving the pulmonary branch of the vagus nerve could reduce the incidence of postoperative chronic cough in patients with stage I peripheral lung adenocarcinoma.

METHODS

A total of 125 patients who underwent single-port thoracoscopic radical resection for lung cancer in the Department of Thoracic Surgery, The First Affiliated Hospital of University of Science and Technology of China from June 2022 to June 2023 were retrospectively selected, and divided into two groups according to whether the vagopulmonary branch was preserved during the operation, namely, the vagopulmonary branch group (n=61) and the traditional group (n=64). The general clinical data, perioperative conditions, lymph node dissection, Mandarin Chinese version of The Leicester Cough Questionnaire (LCQ-MC) scores before and 8 weeks after operation were recorded in the two groups. Both the two groups were divided into tamponade group and non-tamponade group according to whether autologous fat or gelatin sponge was tamponade after lymph node dissection. LCQ-MC scores and postoperative chronic cough of both groups were calculated.

RESULTS

The LCQ-MC score of the traditional group was significantly lower than that of the vagopulmonary branch group in physiological, psychological, social and total scores at 8 weeks after surgery, and the difference was statistically significant (P<0.05). There were more cough patients in the traditional group than the vagopulmonary branch group at 8 weeks after surgery, with significant difference (P=0.006). Subgroup analysis was conducted separately for the vagopulmonary branch group and the traditional group. Among the patients in the vagopulmonary branch group and the traditional group, the LCQ-MC scores of the non-tamponade group 8 weeks after surgery were lower than those of the tamponade group (P<0.05). There were more patients with cough in the group 8 weeks after surgery than in the tamponade group (P=0.001, P=0.024).

CONCLUSIONS

For patients with stage I peripheral lung adenocarcinoma, the preservation of the pulmonary branch of vagus nerve is safe and effective, which can reduce the incidence of postoperative chronic cough and improve the postoperative quality of life of the patients.

Research status of east Asian traditional medicine treatment for chronic cough: A scoping review

BACKGROUND

When patients continue to experience cough despite conventional treatment, East Asian traditional medicine (EATM) including herbal medicine and/or acupuncture has been frequently used. Previous systematic reviews of EATM treatment for chronic cough have been conducted mainly on herbal medicine, targeting patients with conditions that cause cough. In clinical practice, EATM interventions are not limited to herbal medicine, and considering that chronic cough is often caused by two or more conditions or unspecific causes, a comprehensive investigation is clinically relevant. We examined the current research status of EATM for chronic cough.

METHODS

Based on Arksey and O'Malley's scoping review methodological framework, a total of six English, Chinese, Korean, and Japanese electronic databases were searched on August 2022. Any clinical studies on EATM targeting chronic cough patients (regardless of their cause) were included.

RESULTS

Among 474 included studies, the study designs were mainly randomized controlled trials (72.4%), and the population was evenly distributed between children and adults. The cause of cough was not reported in most studies (56.1%). The common cause of cough was upper airway cough syndrome and post-respiratory infection (9.5%, each), followed by mixed cause (7.6%), nonspecific cause (5.9%), and gastroesophageal reflux disease (4.0%). EATM was conducted for a mean of 19.1 days, and herbal medicine was the most common (80.6%). Conventional medication was frequently used as a control (81.2%). For outcomes, the total effective rate was the most frequently utilized (94.3%), followed by cough severity (53.8%). EATM treatment showed positive outcomes in most studies.

CONCLUSIONS

In future EATM studies, it is necessary to either specify the cause of chronic cough or to report that the study was targeting nonspecific chronic cough. In addition, high-quality studies assessing the efficacy of EATM with placebo control treatment should be conducted, using validated evaluation tools.

Profiles of Cough and Associated Risk Factors in Nonhospitalized Individuals With SARS-CoV-2 Omicron Variant Infection: Cross-Sectional Online Survey in China

BACKGROUND

Cough is a common symptom during and after COVID-19 infection; however, few studies have described the cough profiles of COVID-19.

OBJECTIVE

The aim of this study was to investigate the prevalence, severity, and associated risk factors of severe and persistent cough in individuals with COVID-19 during the latest wave of the Omicron variant in China.

METHODS

In this nationwide cross-sectional study, we collected information of the characteristics of cough from individuals with infection of the SARS-CoV-2 Omicron variant using an online questionnaire sent between December 31, 2022, and January 11, 2023.

RESULTS

There were 11,718 (n=7978, 68.1% female) nonhospitalized responders, with a median age of 37 (IQR 30-47) years who responded at a median of 16 (IQR 12-20) days from infection onset to the time of the survey. Cough was the most common symptom, occurring in 91.7% of participants, followed by fever, fatigue, and nasal congestion (68.8%-87.4%). The median cough visual analog scale (VAS) score was 70 (IQR 50-80) mm. Being female (odds ratio [OR] 1.31, 95% CI 1.20-1.43), having a COVID-19 vaccination history (OR 1.71, 95% CI 1.37-2.12), current smoking (OR 0.48, 95% CI 0.41-0.58), chronic cough (OR 2.04, 95% CI 1.69-2.45), coronary heart disease (OR 1.71, 95% CI 1.17-2.52), asthma (OR 1.22, 95% CI 1.02-1.46), and gastroesophageal reflux disease (GERD) (OR 1.21, 95% CI 1.01-1.45) were independent factors for severe cough (VAS>70, 37.4%). Among all respondents, 35.0% indicated having a productive cough, which was associated with risk factors of being female (OR 1.44, 95% CI 1.31-1.57), having asthma (OR 1.84, 95% CI 1.52-2.22), chronic cough (OR 1.44, 95% CI 1.19-1.74), and GERD (OR 1.22, 95% CI 1.01-1.47). Persistent cough (>3 weeks) occurred in 13.0% of individuals, which was associated with the risk factors of having diabetes (OR 2.24, 95% CI 1.30-3.85), asthma (OR 1.70, 95% CI 1.11-2.62), and chronic cough (OR 1.97, 95% CI 1.32-2.94).

CONCLUSIONS

Cough is the most common symptom in nonhospitalized individuals with Omicron SARS-CoV-2 variant infection. Being female, having asthma, chronic cough, GERD, coronary heart disease, diabetes, and a COVID-19 vaccination history emerged as independent factors associated with severe cough, productive cough, and persistent cough.

The Therapeutic Landscape in Chronic Cough

In recent years, there has been a substantial increase in the development of antitussive therapies and the first new therapy, gefapixant has been licenced in Europe. This review describes current unlicenced treatments for chronic cough and details treatments currently in development for refractory chronic cough and cough in idiopathic pulmonary fibrosis, as well as compounds previously explored.

Brainstem processing of cough sensory inputs in chronic cough hypersensitivity

BACKGROUND

Chronic cough is a prevalent and difficult to treat condition often accompanied by cough hypersensitivity, characterised by cough triggered from exposure to low level sensory stimuli. The mechanisms underlying cough hypersensitivity may involve alterations in airway sensory nerve responsivity to tussive stimuli which would be accompanied by alterations in stimulus-induced brainstem activation, measurable with functional magnetic resonance imaging (fMRI).

METHODS

We investigated brainstem responses during inhalation of capsaicin and adenosine triphosphate (ATP) in 29 participants with chronic cough and 29 age- and sex-matched controls. Psychophysical testing was performed to evaluate individual sensitivities to inhaled stimuli and fMRI was used to compare neural activation in participants with cough and control participants while inhaling stimulus concentrations that evoked equivalent levels of urge-to-cough sensation.

FINDINGS

Participants with chronic cough were significantly more sensitive to inhaled capsaicin and ATP and showed a change in relationship between urge-to-cough perception and cough induction. When urge-to-cough levels were matched, participants with chronic cough displayed significantly less neural activation in medullary regions known to integrate airway sensory inputs. By contrast, neural activations did not differ significantly between the two groups in cortical brain regions known to encode cough sensations whereas activation in a midbrain region of participants with chronic cough was significantly increased compared to controls.

INTERPRETATION

Cough hypersensitivity in some patients may occur in brain circuits above the level of the medulla, perhaps involving midbrain regions that amplify ascending sensory signals or change the efficacy of central inhibitory control systems that ordinarily serve to filter sensory inputs.

FUNDING

Supported in part by a research grant from Investigator-Initiated Studies Program of Merck Sharp & Dohme Pty Ltd. The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck Sharp & Dohme (Australia) Pty Ltd.

Mucus Transpiration as the Basis for Chronic Cough and Cough Hypersensitivity

Chronic cough is characterized by a state of cough hypersensitivity. We analyze the process of transpiration, by which water appears to evaporate from laryngeal and tracheal mucus as from the surface of a leaf, as a potential cause of cough hypersensitivity. In this process, osmotic pressure differences form across mucus, pulling water toward the air, and preventing mucus dehydration. Recent research suggests that these osmotic differences grow on encounter with dry and dirty air, amplifying pressure on upper airway epithelia and initiating a cascade of biophysical events that potentially elevate levels of ATP, promote inflammation and acidity, threaten water condensation, and diminish mucus water permeability. Among consequences of this inflammatory cascade is tendency to cough. Studies of isotonic, hypotonic, and hypertonic aerosols targeted to the upper airways give insights to the nature of mucus transpiration and its relationship to a water layer that forms by condensation in the upper airways on exhalation. They also suggest that, while hypertonic NaCl and mannitol may provoke cough and bronchoconstriction, hypertonic salts with permeating anions and non-permeating cations may relieve these same upper respiratory dysfunctions. Understanding of mucus transpiration and its role in cough hypersensitivity can lead to new treatment modalities for chronic cough and other airway dysfunctions promoted by the breathing of dry and dirty air.

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.

Machine learning to identify chronic cough from administrative claims data

Accurate identification of patient populations is an essential component of clinical research, especially for medical conditions such as chronic cough that are inconsistently defined and diagnosed. We aimed to develop and compare machine learning models to identify chronic cough from medical and pharmacy claims data. In this retrospective observational study, we compared 3 machine learning algorithms based on XG Boost, logistic regression, and neural network approaches using a large claims and electronic health record database. Of the 327,423 patients who met the study criteria, 4,818 had chronic cough based on linked claims-electronic health record data. The XG Boost model showed the best performance, achieving a Receiver-Operator Characteristic Area Under the Curve (ROC-AUC) of 0.916. We selected a cutoff that favors a high positive predictive value (PPV) to minimize false positives, resulting in a sensitivity, specificity, PPV, and negative predictive value of 18.0%, 99.6%, 38.7%, and 98.8%, respectively on the held-out testing set (n = 82,262). Logistic regression and neural network models achieved slightly lower ROC-AUCs of 0.907 and 0.838, respectively. The XG Boost and logistic regression models maintained their robust performance in subgroups of individuals with higher rates of chronic cough. Machine learning algorithms are one way of identifying conditions that are not coded in medical records, and can help identify individuals with chronic cough from claims data with a high degree of classification value.

[Establishment of a Predictive Model for Chronic Cough after Pulmonary Resection]

BACKGROUND

Chronic cough after pulmonary resection is one of the most common complications, which seriously affects the quality of life of patients after surgery. Therefore, the aim of this study is to explore the risk factors of chronic cough after pulmonary resection and construct a prediction model.

METHODS

The clinical data and postoperative cough of 499 patients who underwent pneumonectomy or pulmonary resection in The First Affiliated Hospital of University of Science and Technology of China from January 2021 to June 2023 were retrospectively analyzed. The patients were randomly divided into training set (n=348) and validation set (n=151) according to the principle of 7:3 randomization. According to whether the patients in the training set had chronic cough after surgery, they were divided into cough group and non-cough group. The Mandarin Chinese version of Leicester cough questionnare (LCQ-MC) was used to assess the severity of cough and its impact on patients' quality of life before and after surgery. The visual analog scale (VAS) and the self-designed numerical rating scale (NRS) were used to evaluate the postoperative chronic cough. Univariate and multivariate Logistic regression analysis were used to analyze the independent risk factors and construct a model. Receiver operator characteristic (ROC) curve was used to evaluate the discrimination of the model, and calibration curve was used to evaluate the consistency of the model. The clinical application value of the model was evaluated by decision curve analysis (DCA).

RESULTS

Multivariate Logistic analysis screened out that preoperative forced expiratory volume in the first second/forced vital capacity (FEV1/FVC), surgical procedure, upper mediastinal lymph node dissection, subcarinal lymph node dissection, and postoperative closed thoracic drainage time were independent risk factors for postoperative chronic cough. Based on the results of multivariate analysis, a Nomogram prediction model was constructed. The area under the ROC curve was 0.954 (95%CI: 0.930-0.978), and the cut-off value corresponding to the maximum Youden index was 0.171, with a sensitivity of 94.7% and a specificity of 86.6%. With a Bootstrap sample of 1000 times, the predicted risk of chronic cough after pulmonary resection by the calibration curve was highly consistent with the actual risk. DCA showed that when the preprobability of the prediction model probability was between 0.1 and 0.9, patients showed a positive net benefit.

CONCLUSIONS

Chronic cough after pulmonary resection seriously affects the quality of life of patients. The visual presentation form of the Nomogram is helpful to accurately predict chronic cough after pulmonary resection and provide support for clinical decision-making.

Patient preferences for the treatment of chronic cough: a discrete choice experiment

BACKGROUND

Chronic cough is common, negatively affects quality of life and has limited treatment options. Inhibition of purinergic signalling is a promising therapeutic approach but is associated with taste-related adverse effects. Little is known about treatment preferences from the perspective of patients with chronic cough, such as trade-offs between efficacy and side effect.

METHODS

Patients with chronic cough completed an online discrete choice experiment survey in which they answered a series of questions requiring a choice between two constructed treatment options characterised by varying attribute levels. Selection of cough and taste-related attributes was informed by qualitative interviews and clinical trial data. Logit-based models were used to analyse resulting choice data.

RESULTS

The discrete choice experiment survey was completed by 472 participants with chronic cough. Among study attributes, frequency of intense cough attacks was the most important to participants, followed by taste change, frequency of night-time coughing and frequency of daytime coughing. To accept the least preferred taste disturbance of a bitter, metallic, chalky or oily taste change, participants required either: (1) elimination of night-time cough along with a slight reduction in daytime cough; (2) elimination of daytime cough along with a pronounced reduction in night-time or (3) reduction in intense cough attacks from 7 to 2 times per week. Two distinct preference patterns were identified, each placing different importance on efficacy versus side effect trade-offs.

CONCLUSIONS

Participants with chronic cough were willing to accept some taste disturbances in exchange for improved efficacy of chronic cough treatments. Knowledge of patient preferences can facilitate shared decision-making.

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.

Bronchoalveolar lavage cytology in children with chronic unexplained cough and severely neurologically impaired children

OBJECTIVE

We aimed to compare the cellular composition of bronchoalveolar lavage (BAL) fluids in children with chronic unexplained cough (group 1) and severely neurologically impaired children with chronic or recurrent respiratory problems (group 2) with the BAL cytology of children without pulmonary or systemic diseases (group 3).

METHODS

Bronchoscopy with BAL fluid analysis was performed in all subjects. Children with respiratory symptoms underwent 24-hour multichannel intraluminal impedance monitoring.

RESULTS

A significant difference was found between the groups in the total number of cells in BAL fluid cytology (191 [range, 24-12,747], 747 [range, 53-13,000], and 105 [range, 41-233] cells/μL, P = .015), in the percentage of neutrophils (21.2 [SD = 32.4], 49.4 [SD = 36.6], and 3.6 [SD = 2.4], P < .001), and in the percentage of lipid-laden macrophages (10.3 [SD = 11.4], 13.7 [SD = 15.8] and 0.44 [SD = 1.0], P < .001).

CONCLUSION

The BAL fluid cytology provides useful data for determining the cause of chronic unexplained cough and chronic or recurrent respiratory problems in severely neurologically impaired children.

Post-reflux swallow-induced peristaltic wave index: a new parameter for the identification of non-acid gastroesophageal reflux-related chronic cough

BACKGROUND

The current available diagnostic criteria for gastroesophageal reflux-related chronic cough (GERC) dominated by non-acid reflux is imperfect. The post-reflux swallow-induced peristaltic wave index (PSPWI) is a parameter reflecting esophageal clearance function.

OBJECTIVES

This study aims to investigate its diagnostic value for non-acid GERC.

DESIGN

This study sought to compare the diagnostic value of PSPWI in different types of GERC, particularly non-acid GERC, and explore the clinical significance of PSPWI in the diagnosis of non-acid GERC through diagnostic experiments.

METHODS

A retrospective analysis was performed based on 223 patients with suspected GERC who underwent multichannel intraluminal impedance-pH monitoring (MII-pH) in the outpatient clinic of our department from August 2016 to June 2021. Their clinical information, laboratory test results, and treatment responses were assessed and the underlying etiologies of chronic cough were categorized. The predictive value of the PSPWI in diagnosing different types of GERC, especially non-acid GERC, was analyzed and compared.

RESULTS

A total of 195 patients with chronic cough who met the inclusion criteria underwent MII-pH monitoring. 143 patients had a definitive diagnosis of GERC, including 98 with acid GERC and 45 with non-acid GERC. The diagnostic value of PSPWI alone was moderate for GERC with an area under the working curve (AUC) 0.760, but poor for non-acid GERC with an AUC of 0.569. However, PSPWI < 39.8% combining with acid exposure time (AET) ⩽ 6.2% demonstrated a moderate diagnostic value for non-acid GERC, with an AUC of 0.722. When PSPWI < 39.8% combined with a non-acid reflux ratio >68.75%, the diagnostic value for non-acid GERC was improved (AUCROC = 0.80 versus AUCROC = 0.722, p < 0.05), which was significantly superior to non-acid symptom index (AUCROC = 0.804 versus AUCROC = 0.550, p < 0.05) and non-acid symptom association probability (AUCROC = 0.804 versus AUCROC = 0.571, p < 0.05).

CONCLUSION

PSPWI < 39.8% and AET ⩽ 6.2% have demonstrated good diagnostic value for non-acid GERC. The diagnostic value was further improved when combined with non-acid reflux ratio >68.75%.

A comparison between a gastroesophageal reflux disease questionnaire-based algorithm and multichannel intraluminal impedance-pH monitoring for the treatment of gastroesophageal reflux-induced chronic cough

BACKGROUND

Empiric therapy with multichannel intraluminal impedance-pH monitoring (MII-pH) has been used for the initial treatment of gastroesophageal reflux-induced chronic cough (GERC). However, an algorithm based on the gastroesophageal reflux disease questionnaire (GerdQ) has the potential to achieve a simple, structured, and effective treatment approach for patients with GERC.

OBJECTIVES

This study compared the efficacy of anti-reflux therapy based on GerdQ (new structured pathway, NSP) with medical treatment after MII-pH examination (ordinary clinical pathway, OCP) in the management of GERC.

DESIGN

For the NSP, we adapted the GerdQ score to establish the basis for a treatment algorithm. For the OCP, treatment was determined using the MII-pH examination results.

METHODS

The non-inferiority (NI) hypothesis was used to evaluate NSP versus OCP.

RESULTS

Overall, the NSP and OCP-based therapeutic algorithms have similar efficacy for GERC [NI analysis: 95% confidence interval (CI), -4.97 to 17.73, p = 0.009; superiority analysis: p = 0.420]. Moreover, the cough symptom scores and cough threshold improved faster in the NSP group than in the OCP group at week 8 (p < 0.05). In the subgroup analyses using the GerdQ and GerdQ impact scale (GIS) scores, patients with low-likelihood GERC (GerdQ < 8) were more likely to benefit from OCP (NI analysis: 95% CI, -19.73 to 18.02, p = 0.213). On the other hand, in patients with high-likelihood and low-reflux impact GERC patients (GerdQ > 8 and GIS < 4), the NSP arm was not inferior to the standard treatment of OCP (NI analysis: 95% CI, -8.85 to 28.21%, p = 0.04; superiority analysis: p = 0.339), indicating that GerdQ- and GIS-guided diagnosis and management of patients with GERC could be an alternative to MII-pH management, especially in settings with reduced medical resources.

CONCLUSIONS

The use of the GerdQ algorithm should be considered when handling patients with GERC in the primary care setting.

TRIAL REGISTRATION

This research was registered in the Chinese Clinical Trials Registry (ChiCTR-ODT-12001899).

Patient-reported experiences with refractory or unexplained chronic cough: a qualitative analysis

BACKGROUND

Chronic cough, defined as a cough lasting 8 or more weeks, affects up to 10% of adults. Refractory chronic cough (RCC) is a cough that is uncontrolled despite comprehensive investigation and treatment of comorbid conditions while unexplained chronic cough (UCC) is a cough with no identifiable cause despite extensive evaluation of comorbid conditions. RCC and UCC are often poorly controlled. Understanding individuals' lived experience of the symptoms and impacts of these conditions may guide therapeutic strategies.

OBJECTIVES

The primary objectives of this study were to assess respondents' perceptions of the key symptoms of RCC and UCC and the impacts of RCC and UCC and their symptoms on well-being, health-related quality of life, work productivity, and social relationships.

DESIGN

Qualitative study.

METHODS

This study enrolled 30 adults with physician-diagnosed RCC or UCC. Two trained qualitative researchers conducted individual, in-depth telephone interviews using a semi-structured interview guide. Interviews were audio-recorded, transcribed, coded, and systematically analyzed to identify content themes.

RESULTS

A total of 15 respondents with RCC and 15 with UCC were included in the study. Many respondents had RCC or UCC for a long duration (median 9 years, range: 0-24). Half of the respondents reported having a coughing episode at least once daily. Only 40% of respondents reported that medication had improved their symptoms. In over half of the respondents, RCC or UCC hindered communication, caused embarrassment, frustration, and worry, and lowered quality of life. Perceptions of meaningful treatment benefits in RCC or UCC varied widely across respondents.

CONCLUSION

RCC and UCC remained poorly managed in many individuals and were associated with a wide range of symptoms and cough triggers that hindered daily activities and reduced emotional well-being. Understanding individuals' lived experiences may inform the development of RCC and UCC therapeutic strategies.

A 39-Year-Old Man With Refractory Chronic Cough Accompanied by Regurgitation and Belching

CASE PRESENTATION

A 39-year-old man who did not smoke was admitted to the hospital with recurrent cough for 1 year, accompanied by sputum expectoration (with a small amount of white phlegm), acid regurgitation, and belching. Nasal symptoms or other cough-related contributing factors were denied. The patient reported that his cough mainly occurred at nighttime and was aggravated in the supine position. Vomiting could occur when the cough was violent. He denied fever, dysphonia, chest tightness, wheezing, chest pain and hemoptysis, abdominal pain, and bloating. The patient had initially presented to the local hospital and underwent a chest CT scan. The chest CT scan showed slight and scattered patchy infiltration in bilateral lung fields and without other significant pulmonary lesions. Anti-infective treatment was administered but was not effective for ameliorating the cough symptoms. He then received an inhaled corticosteroid, antihistamines, antileukotriene agents, or proton pump inhibitors for 6 months. However, all these treatments failed to alleviate the patient's cough. He had a history of hypertension and hyperlipidemia for > 10 years and was treated with valsartan (an angiotensin II receptor blocker) and atorvastatin. In the past year, the patient had lost 10 kg of weight, and his current BMI was 27.72 kg/m2.

Profile of cough triggers and their relationship with capsaicin cough sensitivity in chronic cough

BACKGROUND

Cough hypersensitivity is an important part of the neurophysiology of cough, which presents with increased cough response to a lower level of stimuli or triggers. Classification of stimuli might bring about additional insight into the underlying mechanisms and management.

OBJECTIVES

This study investigated the profile of cough triggers in chronic cough patients and their relationship with capsaicin cough sensitivity.

DESIGN

This was a cross-sectional observational study.

METHODS

We enrolled patients with different causes of chronic cough from 2006 to 2021. Cough triggers were defined as cough response to chemical triggers, mechanical triggers, meal triggers, or thermal trigger. Cough sensitivity to capsaicin was evaluated by the capsaicin challenge test, which was expressed as the lowest concentration of capsaicin inducing 5 or more coughing (C5).

RESULTS

Among 1211 patients with chronic cough, 1107 (91.4%) patients reported at least one cough trigger. Chemical triggers (66.9%) were the most common cough triggers, followed by thermal exposure (50.6%), mechanical triggers (48.2%), and meal triggers (21.2%). There was no difference in the proportion of chemical triggers among different etiologies. Patients with refractory chronic cough reported the highest prevalence of cough triggers (97.1%). A higher number of meal triggers (34.9%) was associated with gastroesophageal reflux-related cough, and meal triggers and mechanical triggers were more common in refractory chronic cough. Among 254 patients who completed capsaicin challenge test, both the number of total triggers and the number of chemical triggers had a significant but mild correlation with capsaicin cough sensitivity.

CONCLUSION

Cough hypersensitivity as reflected by a variety of cough triggers is a common feature in chronic cough patients, but different etiologies present specific profiles of cough triggers, which could not be evaluated comprehensively by capsaicin cough sensitivity.

Trajectories and risk factors of persistent cough after pulmonary resection: A prospective two-center study

BACKGROUND

Persistent cough is one of the most frequent complications following lung cancer surgery. To promote optimal recovery, we conducted a study to investigate the trajectories of coughing symptoms and their impact on quality of life (QOL), as well as to identify potential risk factors of persistent cough after pulmonary resection (CAP).

METHODS

This prospective observational study assessed patients who underwent pulmonary resection for lung tumor at two medical centers in China. Persistent CAP was evaluated before surgery, at discharge, and 1, 3, and 6 months following surgery using visual analog scale (VAS), cough symptom score (CSS), and Leicester Cough Questionnaire in Mandarin Chinese (LCQ-MC). Univariate and multivariate logistic regression analyses were conducted to explore independent risk factors for persistent CAP.

RESULTS

Of the 506 enrolled patients, 130 patients were diagnosed with persistent CAP with an incidence of 25.69%. Compared to the noncough group, patients with persistent CAP reported significantly higher VAS (p < 0.001) and CSS scores (p < 0.001) and experienced worse QOL (p < 0.001) for up to 6 months, particularly at 1 month following surgery. Multivariable regression analysis revealed that a duration of anesthesia exceeding 156 min (odds ratio [OR]: 1.847, 95% confidence interval [CI]: 1.156-2.951, p = 0.010) and gastroesophageal acid reflux (GER) (OR: 3.870, 95% CI: 2.376-6.304, p < 0.001) were independent risk factors of persistent CAP.

CONCLUSION

Patients who suffer from persistent CAP face a substantial burden and diminished QOL for an extended period compared to noncough patients. Moreover, prolonged duration of anesthesia and postoperative GER are potential risk factors of persistent CAP.

Mechanisms and management of cough in interstitial lung disease

INTRODUCTION

Many patients with interstitial lung diseases (ILDs), especially fibrotic ILDs, experience chronic cough. It negatively impacts both physical and psychological well-being. Effective treatment options are limited.

AREAS COVERED

The pathophysiology of chronic cough in IPF is complex and involves multiple mechanisms, including mechanical distortion of airways, parenchyma, and nerve fibers. The pathophysiology of cough in other fibrosing ILDs is poorly understood and involves various pathways. The purpose of this review is to highlight mechanisms of chronic cough and to present therapeutic evidence for its management in the most commonly occurring diffuse fibrosing lung diseases including idiopathic pulmonary fibrosis (IPF), connective tissue disease-related interstitial lung disease (CTD-ILD), sarcoidosis-related ILD (Sc-ILD), chronic hypersensitivity pneumonitis-related ILD (CHP-ILD), and post-COVID-19-related interstitial lung disease (PC-ILD).

EXPERT OPINION

This review guides the management of chronic cough in fibrosing ILDs. In this era of precision medicine, chronic cough management should be individualized in each interstitial lung disease.

Symptomatic pericardial cysts and dilemmas in their diagnosis

Pericardial cysts (PCs) or pleuropericardial cysts are rare congenital mediastinal lesions with an approximate incidence of one in 100 000 persons. Usually, they are asymptomatic, being incidentally discovered during a routine chest imaging examination or an autopsy exam. The study involved a retrospective evaluation of clinicopathological findings in a 6-year series of PCs, treated in the Clinic of Pulmonary Diseases, Iaşi, Romania. A group of five cases of PCs, four females and one male, were evaluated. All patients displayed different symptoms, such as dyspnea, chest pain, chronic cough, fatigue, palpitation, and epigastric pain. The cystic lesions were located in the right and left cardiophrenic angle, in four cases, and in the central mediastinum in a single case. The lesions had a fluid content and a maximum diameter that ranged between 35 and 95 mm. The microscopic examination of the surgical resection tissues revealed a thin connective tissue wall without any associated smooth muscle cells. The loose connective tissue band was lined by a layer of mesothelial cells with no cellular atypia, which displayed discrete papillary projections, in one case. Although PCs are rare incidental findings, they should be considered in differential diagnoses of mediastinal cysts, especially as they are associated with non-specific symptoms. Furthermore, considering the possibility of development of severe complications, PCs should be thoroughly explored for suitable patients' management.

Managing Chronic Cough Associated with Idiopathic Pulmonary Fibrosis - Will Nalbuphine Fill an Unmet Need?

In this issue of NEJM Evidence, Maher et al.1 report the results of a randomized, controlled, 22-day treatment crossover trial comparing the antitussive effect of extended-release nalbuphine, an opioid agonist-antagonist, with placebo in a cohort of patients with definite or probable idiopathic pulmonary fibrosis (IPF). In this small, short-term trial of 38 evaluable patients, the active drug was associated with a 75.1% reduction in daytime objective cough frequency (the primary outcome) compared with a 22.6% reduction in placebo-treated patients, yielding a substantial and statistically significant 52.5 percentage point placebo-adjusted change from baseline.

A 35-Year-Old Man with Chronic Cough and Worsening Dyspnea

A 35-Year-Old Man with Chronic Cough and DyspneaA 35-year-old man presented for evaluation of chronic cough and worsening dyspnea. How do you approach the evaluation, and what is the diagnosis?

Effects of Pregabalin as a Neural Pathway Inhibitor for the Treatment of Resistant Subacute and Chronic Cough: A Pilot Clinical Trials Study

BACKGROUND

Cough hypersensitivity syndrome is one of the causes of chronic cough. Small clinical trials have suggested the effects of pregabalin as a neural pathway inhibitor in treating subacute and chronic cough resistance.

METHODS

This study is an 8-week, pilot study randomized, double-blind clinical trial on 30 patients' resistant to treatment of the underlying cause who were referred to an ultra-specialized lung clinic, Shahid Beheshti Hospital, between 2021-2022. The samples were randomly divided into control (dextromethorphan and placebo) and intervention (dextromethorphan and pregabalin). Patients were evaluated at the beginning, during, and after eight weeks of treatment, using the modified standard Leicester Cough Questionnaire (LCQ) regarding the changes and the rate of recovery compared to before Participation in the study.

FINDINGS

The quality of life score of patients eight weeks after treatment had a significant difference and was higher in the intervention group (In the pregabalin group) than in the control group (p =0.006). The recovery rate of cough in 26% of patients was equal to 70%, but others were reported up to 50%.

CONCLUSION

Pregabalin increases the quality of life in patients with subacute and chronic cough resistant to standard treatment and increases the rate of recovery in these patients.