Effect of extending the time after bronchodilator administration on identifying bronchodilator responsiveness in a pediatric pulmonary clinic.

American Thoracic Society/European Respiratory Society (ATS/ERS) spirometry interpretation guidelines recommend ≥15 min between pre- and post-bronchodilator testing to evaluate for a bronchodilator response. We aimed to lengthen the time between albuterol administration and post-bronchodilator testing to adhere to ATS/ERS guidelines and evaluated if lengthening this wait time would increase the percentage of patients classified as bronchodilator responsive. We compared the proportion of patients with a positive bronchodilator response between two groups of children with asthma, one group in which post-bronchodilator administration wait times were not standardized (pre-intervention) to another in which the wait time was extended to 15 min to adhere to ATS/ERS standards (post-intervention). We also determined the effect of this intervention on clinic appointment duration. The analysis included 271 patients (145 pre-intervention and 126 post-intervention). The average wait time in the pre-intervention group was 6.5 ± 2.1 (mean ± SD) minutes compared to 16.2 ± 3.2 min (P < 0.001) post intervention, and clinic times increased from 83.0 ± 29.6 min to 91.7 ±22.5 min (P < 0.007) from the pre- to post-intervention group, respectively. In adjusted regression analysis, there was no significant change in FEV1 % predicted between the two groups. In a busy pediatric pulmonary clinic, while we successfully lengthened time between albuterol administration and post-bronchodilator testing in the vast majority of patients, no difference was seen in the percentage of patients classified as bronchodilator responsive. Results from this study appear to question the ATS/ERS recommended 15 min post-bronchodilator administration wait time for children.

Cogen JD ，DiBlasi RM ，Gibson RL ，Debley JS ... -  《-》

Diagnostic Accuracy of Bronchodilator Response for Asthma in a Population of South China.

Zhang S ，Hu C ，Lu R ，Niu R ，Hu X ，Qin L ，He R ，Feng J ... -  《-》

Comparison of bronchodilator response in patients with asthma and healthy subjects using spirometry and oscillometry.

Impulse oscillometry (IOS) is an effort-independent and patient-friendly pulmonary function technique, but limited data are available that correlate the bronchodilator response using spirometry and IOS in adult asthmatic and healthy subjects. To compare spirometry and IOS in ongoing bronchodilator response. The study was a prospective evaluation of patients with asthma and healthy subjects attending screening at a research unit in a university teaching hospital. Reversibility testing was carried out using standardized American Thoracic Society/European Respiratory Society (ATS/ERS) criteria after administering 400 μg salbutamol by AccuhalerTM. Impulse oscillometry measurements (resistance at 5 Hz [R5], resistance at 20 Hz [R20], reactance at 5 Hz [X5]) and spirometry (forced expiratory volume in 1 second [FEV(1)], forced vital capacity [FVC], forced expiratory flow from 25% to 75% of vital capacity [FEF(25-75)]) were recorded pre and postbronchodilator. Ninety-five asthmatic and 61 healthy subjects underwent screening. Mean percent (standard error of the mean [SEM]) baseline prebronchodilator FEV(1) was 83.99 (2.23) for patients with asthma, and 99.25 (1.72) for healthy subjects. Baseline percent predicted IOS indices in the group with asthma were 162.22 (7.5) for R5; 154.73 (4.71) for R20; and 441.72 (173.86) for X5. In healthy volunteers, corresponding values were 111.01 (3.96), 127.75 (4.12), and -229.80 (125.75). R5 was the only IOS measure that showed correlation with spirometry (FEV(1)) in both groups. The mean percent (SEM) predicted postbronchodilator change in FEV(1) and R5 in patients with asthma was 6.35 (0.65) and -33.78 (4.43); correspondingly in healthy subjects it was 2.24 (0.32) and -14.91 (2.48). A negative correlation was demonstrated (r = -0.40, P < .001 between the 2 indices in patients with asthma. Linear regression modeling demonstrated that 1 unit change in %FEV(1) corresponds to a 2.5% change in %R5. Low-frequency IOS as R5 and spirometry as FEV(1) correlate in patients with asthma and healthy subjects, with changes that can be predicted by linear regression.

Nair A ，Ward J ，Lipworth BJ 《-》

Dose Response to Transnasal Pulmonary Administration of Bronchodilator Aerosols via Nasal High-Flow Therapy in Adults with Stable Chronic Obstructive Pulmonary Disease and Asthma.

There has been increasing interest in transnasal pulmonary aerosol administration, but the dose-response relationship has not been reported. To determine the accumulative bronchodilator dose at which patients with stable mild-to-moderate asthma and chronic obstructive pulmonary disease (COPD) achieve similar spirometry responses before and after bronchodilator tests using albuterol via a metered dose inhaler with a valved holding chamber (MDI + VHC). Adult patients who met ATS/ERS criteria for bronchodilator responses in pulmonary function laboratory were recruited and consented to participate. After a washout period, patients received escalating doubling dosages (0.5, 1, 2, and 4 mg) of albuterol in a total volume of 2 mL delivered by vibrating mesh nebulizer via a nasal cannula at 37°C with a flow rate of 15-20 L/min using a Venturi air entrainment device. Spirometry was measured at baseline and after each dose. Titration was stopped when an additional forced expiratory volume in 1 second (FEV1) improvement was <5%. 42 patients (16 males) with stable mild-to-moderate asthma (n = 29) and COPD (n = 13) were enrolled. FEV1 increment after a cumulative dose of 1.5 mg of albuterol via nasal cannula at 15-20 L/min was similar to 4 actuations of MDI + VHC (0.34 ± 0.18 vs. 0.34 ± 0.12 L, p = 0.878). Using ATS/ERS criteria of the bronchodilator test, 33.3% (14/42) and 69% (29/42) of patients responded to 0.5 and 1.5 mg of albuterol, respectively. With a nasal cannula at 15-20 L/min, transnasal pulmonary delivery of 1.5 mg albuterol resulted in similar bronchodilator response as 4 actuations of MDI + VHC.

Li J ，Zhao M ，Hadeer M ，Luo J ，Fink JB ... -  《-》

Evaluation of the magnitude of the bronchodilator response in children and adolescents with asthma.

Bussamra MH ，Cukier A ，Stelmach R ，Rodrigues JC ... -  《CHEST》