Current Bronchodilator Responsiveness Criteria Underestimate Asthma in Older Adults

Bronchodilator reversibility testing in morbidly obese non-smokers: fluticasone/salmeterol efficacy versus salbutamol bronchodilator

A positive response in reversibility testing is widely used to diagnose patients with airway limitations. However, despite its simple procedure, it doesn't accurately reflect the exact airway irreversibility. This study aimed to investigate the efficacy of a bronchodilation reversibility test using salbutamol and fluticasone/salmeterol combination in obese non-smoker subjects.The study included patients without a history of obstructive lung disease or bronchodilators. A sub-classification of patients based on body mass index (BMI) was carried out into normal (< 24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (BMI ≥ 30). Spirometry measurements were performed before and after salbutamol or fluticasone/salmeterol administration.The study included 415 (49.9% male) patients with a mean age of 40.92 ± 10.86 years. Obese subjects showed a high prevalence of restrictive patterns (23.4%), with non-significantly lower spirometric values compared to normal and overweight subjects (p > 0.05). The magnitude of bronchodilation, as identified by spirometry, following fluticasone/salmeterol was higher in all participants, with a significant increase in obese subjects with a p-value of 0.013, 0.002, and 0.035 for FEV1, FEV1% predicted, and FEV1/FVC, respectively.Fluticasone/salmeterol combination increases FEV1, FEV1% of predicted, and FEV1/FVC ratio than the conventional test using salbutamol inhaler, and it can be a potential candidate for assessment of airway obstruction using reversibility test, especially among the obese population.

Small Airways Response to Bronchodilators in Adults with Asthma or COPD: A Systematic Review

BACKGROUND

Bronchodilator responsiveness (BDR) is commonly used in the diagnosis of lung disease. Although small airways dysfunction is a feature of asthma and COPD, physiological tests of small airways are not included in guidelines for BDR testing. This systematic review assessed the current evidence of BDR using small airways function in asthma and COPD.

METHODS

The systematic review used standard methodology with the protocol prospectively registered on PROSPERO (CRD42020164140). Electronic medical databases (EMBASE and Medline) were searched using related keywords. Abstracts and full texts were screened independently by two reviewers. Studies that reported the change of physiological small airways function and FEV₁ were included in the review. The revised Cochrane risk of bias tool for RCT and NIH quality assessment tool for cohort and cross-sectional studies were used to evaluate the studies.

RESULTS

A total of 934 articles were identified, with 12 meeting the inclusion criteria. Ten studies included asthma patients, 1 study included COPD patients and 1 study included both asthma and COPD. A total of 1104 participants were included, of whom 941 were asthmatic, 64 had COPD and 109 were healthy controls. Studies were heterogeneous in design including the device, dose and time intervals for BDR assessment. A small airway BDR was seen for most tests in asthma and COPD, including oscillometry (R5-20, reactance (X5), area of reactance (AX) and resonant frequency (Fres)) and Maximal Mid Expiratory Flow.

CONCLUSION

There is a measurable BDR in the small airways. However, with no consensus on how to assess BDR, studies were heterogeneous. Further research is needed to inform how BDR should be assessed, its clinical impact and place in routine clinical practice.