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Background and objective: Inhalational challenge with dry mannitol powder may potentially induce cough by two mechanisms: airway bronchoconstriction or laryngeal irritation. This prospective observational study investigated laryngeal and bronchial components of cough induced by mannitol challenge. Methods: We recruited consecutive patients referred for clinical mannitol challenge. The Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ) was administered. Throughout testing, coughs were audio‐recorded to derive a cough frequency index per time and dose of mannitol. Relationships between cough indices, laryngeal hypersensitivity and bronchial hyperresponsiveness (BHR) were examined. Participants were classified by cough characteristics with k‐means cluster analysis. Results: Of 90 patients who underwent challenge, 83 completed both the questionnaire and challenge. Cough frequency was greater in patients with abnormal laryngeal hypersensitivity (p = 0.042), but not in those with BHR. There was a moderate negative correlation between coughs per minute and laryngeal hypersensitivity score (r = −0.315, p = 0.004), with lower LHQ scores being abnormal. Cluster analysis identified an older, female‐predominant cluster with higher cough frequency and laryngeal hypersensitivity, and a younger, gender‐balanced cluster with lower cough frequency and normal laryngeal sensitivity. Conclusion: Cough frequency during mannitol challenge in our cohort reflected laryngeal hypersensitivity rather than BHR. Laryngeal hypersensitivity was more often present among older female patients. With the incorporation of cough indices, mannitol challenge may be useful to test for laryngeal hypersensitivity as well as BHR. Cough commonly occurs during bronchoprovocation testing with mannitol. In this study, higher cough frequency in patients undergoing mannitol provocation was associated with laryngeal hypersensitivity, but not bronchial hyperresponsiveness. Greater cough frequency was found in older female patients. Mannitol provocation may be a useful test for laryngeal hypersensitivity. [ABSTRACT FROM AUTHOR]

Background and objective: E-cigarette use has become increasingly prevalent, but there is some evidence demonstrating potential harms with frequent use. We aimed to identify the profiles of e-cigarette users from a regional community in Australia and investigate the associations of e-cigarettes with respiratory symptoms and lung function. Methods: A total of 519 participants completed a cross-sectional study. Exposure to ecigarettes was collected via a validated questionnaire. Respiratory symptoms were evaluated via a self-reported questionnaire and lung function measured with spirometry and forced oscillation technique (FOT). Linear and logistic regression models were fitted to investigate the associations between e-cigarettes and outcomes, while controlling for confounders such as tobacco smoking. Results: Of the 519 participants, 46 (9%) reported e-cigarette use. Users tended to be younger (mean x SD 45.2 x 14.5 vs. 55.3 x 16.0 years in non-users), concurrently using tobacco products (63% vs. 12% in non-users), have a mental health diagnosis (67% vs. 37% in non-users) and have self-reported asthma (63% vs. 42% in nonusers). After controlling for known confounders, chest tightness (OR = 2.4, 95% CI 1.2-4.9, p = 0.02) was associated with e-cigarette use. Spirometry was not different after adjustment for confounding. However, FOT showed more negative reactance and a greater area under the reactance curve in e-cigarette users than non-users. Conclusion: E-cigarette use was associated with increased asthma symptoms and abnormal lung mechanics in our sample, supporting a potential health risk posed by these products. Vulnerable populations such as young adults and those with mental health conditions have higher usage, while there is high concurrent tobacco smoking. [ABSTRACT FROM AUTHOR]

Background: Spirometry forms the foundation investigation for the diagnosis and monitoring of common pulmonary conditions. However, potential variation in spirometry interpretation for airflow obstruction may impact subsequent clinical management. Aim: To audit spirometry interpretation practices for airflow obstruction in Thoracic Society of Australia and New Zealand accredited laboratories. Methods: Thirty‐nine accredited complex lung function laboratories were invited to participate in an online survey. The survey enquired about demographics, definition of lower limit of normal range for spirometry parameters, spirometric parameters used for identifying airflow obstruction, spirometric definition of airflow obstruction, definition of significant bronchodilator response and chosen spirometry reference equations. Results: Thirty‐six laboratories provided complete responses (response rate, 92%). To define the lower limit of normal, 26 of 36 used the 5th percentile, 7 of 36 used a fixed cut‐off and 3 used other. Twenty‐nine laboratories utilised forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) as the sole parameter to identify airflow obstruction, 3 of 36 used FEV1/FVC and FEF25–75%, and 4 used other. To define airflow obstruction, 25 of 36 laboratories used FEV1/FVC < 5th percentile, 9 of 36 used a fixed cut‐off (FEV1/FVC < 0.7, 6/36; FEV1/FVC < 0.8, 2/36; FEV1/FVC < 0.75, 1/36) and 2 of 36 used other. Twenty‐six laboratories defined a significant bronchodilator response as an increase of at least 200 mL and 12% in FEV1 and/or FVC, 9 of 36 used ≥200 mL and ≥ 12% increase in FEV1 only, and 1 used other criteria. Reference equations utilised for interpretation of spirometry data included: Quanjer 2012 Global Lung Initiative (16/36), the third National Health and Nutritional Examination Survey (8/36), European Community of Coal and Steel (8/36) and other (4/36). Conclusions: Significant heterogeneity in spirometry interpretation for airflow obstruction exists across Australian and New Zealand accredited lung function laboratories. Lack of standardisation may translate into clinically appreciable differences for the diagnosis and management of common respiratory conditions. Ongoing discussion regarding formal standardisation is required. [ABSTRACT FROM AUTHOR]