Small airways are relevant to the pathophysiology of asthma. We investigated whether in asthmatic patients with normal forced expiratory volume in the 1st second (FEV₁) values, impulse oscillometry system (IOS), as a measure of small airway function, contributed additional information to spirometry either at baseline or after bronchodilator, and whether it was related to the disease control. The fall in resistance from 5 to 20 Hz (R5‐R20) and reactance at 5 Hz (X5) by IOS and spirometry measures of small airway function (forced expiratory flow at 25‐75% [FEF_25‐75] and forced vital capacity/slow inspiratory vital capacity [FVC/SVC]) at baseline and after 400 micrograms of salbutamol were prospectively measured in 33 asthmatic patients (18 women; age range, 18‐66 years). Disease control was assessed by the Asthma Control Test (ACT). R5‐R20 but not X5 values were significantly related to FEF_25‐75 and FVC/SVC values (p < 0.05 for both correlations). When the bronchodilator response was assessed, no correlation was found among IOS and spirometry changes. ACT scores were related to R5‐R20, FEF_25‐75, and FVC/SVC values (p < 0.01 for all correlations). In asthmatic patients with normal FEV₁ values, R5‐R20 values were related to spirometry measures of small airway function. However, when the bronchodilator response was assessed, IOS and spirometry provided quite different results. Moreover, small airway dysfunction, as assessed by IOS and spirometry, was associated with poor disease control and history of asthma exacerbations. The results of this study confirm the value of IOS, as an investigative tool, and suggest that in asthmatic patients with normal FEV₁ values and poor disease control, small airway function should be investigated.

We investigated whether a relationship between small airways dysfunction and bronchial hyperresponsiveness (BHR), expressed both in terms of ease of airway narrowing and of excessive bronchoconstriction, could be demonstrated in asthma. 63 (36 F; mean age 42 yr ± 14) stable, mild-to-moderate asthmatic patients (FEV1 92% pred ±14; FEV1/FVC 75% ± 8) underwent the methacholine challenge test (MCT). The degree of BHR was expressed as PD20 (in μg) and as ∆FVC%. Peripheral airway resistance was measured pre- and post-MCT by impulse oscillometry system (IOS) and expressed as R5-R20 (in kPa sL−1). All patients showed BHR to methacholine (PD20 < 1600 μg) with a PD20 geometric (95% CI) mean value of 181(132–249) μg and a ∆FVC% mean value of 13.6% ± 5.1, ranging 2.5 to 29.5%. 30 out of 63 patients had R5-R20 > 0.03 kPa sL−1 (>upper normal limit) and showed ∆FVC%, but not PD20 values significantly different from the 33 patients who had R5-R20 ≤ 0.03 kPa sL−1 (15.8% ± 4.6 vs 11.5% ± 4.8, p < 0.01 and 156(96–254) μg vs 207 (134–322) μg, p = 0.382). In addition, ∆FVC% values were significantly related to the corresponding pre- (r = 0.451, p < 0.001) and post-MCT (r = 0.376, p < 0.01) R5-R20 values. Our results show that in asthmatic patients, small airway dysfunction, as assessed by IOS, is strictly associated to BHR, expressed as excessive bronchoconstriction, but not as ease of airway narrowing.

Pulmonary hyperinflation has the potential for significant adverse effects on cardiovascular function in COPD. The aim of this study was to investigate the relationship between dynamic hyperinflation and cardiovascular response to maximal exercise in COPD patients.

A clinical interpretation of the Randomized Evaluation of COVID-19 Therapy (RECOVERY) study was performed to provide a useful tool to understand whether, when, and to whom dexamethasone should be administered during hospitalization for COVID-19. A post hoc analysis of data published in the preliminary report of the RECOVERY study was performed to calculate the person-based number needed to treat (NNT) and number needed to harm (NNH) of 6 mg dexamethasone once daily for up to 10 days vs. usual care with respect to mortality. At day 28, the NNT of dexamethasone vs. usual care was 36.0 (95%CI 24.9–65.1, p < 0.05) in all patients, 8.3 (95%CI 6.0–13.1, p < 0.05) in patients receiving invasive mechanical ventilation, and 34.6 (95%CI 22.1–79.0, p < 0.05) in patients receiving oxygen only (with or without noninvasive ventilation). Dexamethasone increased mortality compared with usual care in patients not requiring oxygen supplementation, leading to a NNH value of 26.7 (95%CI 18.1–50.9, p < 0.05). NNT of dexamethasone vs. usual care was 17.3 (95%CI 14.9–20.6) in subjects 7 days. Dexamethasone is effective in male subjects < 70 years that require invasive mechanical ventilation experiencing symptoms from >7 days and those patients receiving oxygen without invasive mechanical ventilation; it should be avoided in patients not requiring respiratory support.

Background: Cough is an important defense mechanism, whose main function is to remove mucus and/or foreign bodies from the airways. In patients with multiple sclerosis (MS), respiratory muscle function may be affected and cough may be impaired. Objectives: Respiratory muscle strength and voluntary cough efficacy were determined in MS patients and controls, and the relationship between cough efficacy and patients’ degree of disability was investigated. Methods: We recruited 27 MS patients (age: 41 ± 11 years; 18 females) with mild-to-moderate disability, Expanded Disability Status Scale (EDSS) score range: 1–7, and 20 healthy controls (age: 37 ± 11 years; 12 females). The maximal inspiratory (PIMAX) and expiratory (PEMAX) pressures, maximal whistle mouth pressures (PMOW), cough peak flows (CPF), cough expiratory volumes (CEV) and cough gastric pressures (PGA) were measured in all subjects. Results: In MS patients, the EDSS score was significantly related to CPF, PEMAX, PMOW, cough PGA, PIMAX and CEV (p < 0.01, each correlation). The receiver-operating characteristic curve showed that an EDSS score ≧5.5 was consistent with impaired cough (CPF ≤5.6 l/s), with a sensitivity of 0.85 and a specificity of 0.95 (area under curve 0.90, p < 0.001). CPF was related to and predicted by PEMAX, PMOW, cough PGA and PIMAX in MS patients (p < 0.01 each correlation), but not in controls. Conclusions: MS can affect voluntary cough efficacy and respiratory muscle strength, which are inversely related to the patients’ degree of disability. In addition, this study shows that CPF is a measure of clinical relevance in MS patients.