Clinical Practice Guideline: Chronic Cough

The diagnostic value of combined pulmonary function test and exhaled nitric oxide monitoring in cough variant asthma with or without gastroesophageal reflux disease: a retrospective study

INTRODUCTION

This study aimed to investigate the effect of fractional exhaled nitric oxide (FeNO), a marker of airway inflammation, together with small airway function tests in diagnosing cough variant asthma (CVA), particularly in patients with gastroesophageal reflux disease (GERD).

METHODS

This retrospective cohort study included adult patients with chronic cough for more than eight weeks who were divided into a CVA group and a control group. Participants underwent pulmonary function tests and FeNO measurements. Statistical tests and ROC curve analysis were used to assess diagnostic accuracy.

RESULTS

CVA patients had higher FeNO levels than controls, regardless of with or without GERD. There were no significant differences in FEV1, FVC, and FEV1/FVC ratio between the control and CVA groups, but CVA patients had significantly lower MEF25, MEF50, MEF75, and MMEF values. FeNO was negatively correlated with MEF50, MEF75, and MMEF. The AUC of FeNO in diagnosing CVA was 0.862. Combining FeNO with MMEF resulted in the highest diagnostic accuracy (AUC = 0.909). The diagnostic benefits of FeNO and FeNO + MMEF were similar in GERD patients.

CONCLUSION

Combining FeNO with small airway function tests, especially MMEF, can improve the diagnostic accuracy of CVA, while FeNO and FeNO + MMEF performed similar diagnostic accuracy in patients with GERD.

CLINICAL TRIAL NUMBER

Not applicable.

Narrative review of relationship between chronic cough and laryngopharyngeal reflux

Gastroesophageal reflux disease (GERD) as a possible cause of chronic cough is known for decades. However, more than 75% of patients with extraoesophageal symptoms do not suffer from typical symptoms of GERD like pyrosis and regurgitations and have negative upper gastrointestinal endoscopy. For such a condition term laryngopharyngeal reflux (LPR) was introduced and is used for more than two decades. Since the comprehensive information on relationship between chronic cough and LPR is missing the aim of this paper is to summarize current knowledge based on review of published information during last 13 years. Laryngopharyngeal reflux is found in 20% of patients with chronic cough. The main and recognized diagnostic method for LPR is 24-h multichannel intraluminal impedance-pH (MII-pH) monitoring, revealing reflux episodes irritating the upper and lower respiratory tract mucosa. The treatment of LPR should be initiated with dietary and lifestyle measures, followed by proton pump inhibitor (PPI) therapy and other measures. Despite progress, more research is needed for accurate diagnosis and targeted therapies. Key areas for exploration include biomarkers for diagnosis, the impact of non-acid reflux on symptom development, and the efficacy of new drugs. Further studies with a focused population, excluding other causes like asthma, and using new diagnostic criteria for LPR are essential. It's crucial to consider LPR as a potential cause of unexplained chronic cough and to approach diagnosis and treatment with a multidisciplinary perspective.

Endobronchial angioleiomyoma: Diagnostic difficulties of a rare lung neoplasm

Angioleiomyoma is a benign soft-tissue tumor that rarely develops in the respiratory tract. Here, we report a case of a 51-year-old female with an angioleiomyoma developed in the left lobar bronchial branch and extended to the left principal bronchus, causing nonspecific symptoms, and not visible on the chest X-ray examination. The suspected diagnosis was established by high-resolution computed tomography and confirmed by the histological evaluation of the endoscopically removed lesion.

[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.

Contribution of Symptomatic, Herbal Treatment Options to Antibiotic Stewardship and Microbiotic Health

Epithelial surfaces in humans are home to symbiotic microbes (i.e., microbiota) that influence the defensive function against pathogens, depending on the health of the microbiota. Healthy microbiota contribute to the well-being of their host, in general (e.g., via the gut-brain axis), and their respective anatomical site, in particular (e.g., oral, urogenital, skin, or respiratory microbiota). Despite efforts towards a more responsible use of antibiotics, they are often prescribed for uncomplicated, self-limiting infections and can have a substantial negative impact on the gut microbiota. Treatment alternatives, such as non-steroidal anti-inflammatory drugs, may also influence the microbiota; thus, they can have lasting adverse effects. Herbal drugs offer a generally safe treatment option for uncomplicated infections of the urinary or respiratory tract. Additionally, their microbiota preserving properties allow for a more appropriate therapy of uncomplicated infections, without contributing to an increase in antibiotic resistance or disturbing the gut microbiota. Here, herbal treatments may be a more appropriate therapy, with a generally favorable safety profile.