In pediatric patients with cystic fibrosis (CF), bronchodilator inhalation with salbutamol is likely to have a positive short-term effect of on forced expiratory volume in 1 second (FEV1); however, due to heterogonous response, the effectiveness of this treatment should be confirmed by spirometry in individual patients. These were among the results of a Swiss study recently published in Respiration.
The use of salbutamol as a bronchodilator is controversial due to a lack of evidence showing a positive effect. In this study, researchers hypothesized that novel diagnostic tests such as multiple-breath washout and functional MRI could better elucidate such bronchodilator effects. The researchers therefore conducted a prospective, single-center study of 30 children (aged 6 to 18 years; mean age, 12.5 years) with stable CF to assess functional response to nebulized inhalation with salbutamol, using pulmonary function tests, multiple-breath washout, and matrix pencil-MRI before and after the salbutamol treatment to measure functional response.
Test results indicated that lung clearance index improved marginally (P =.111) after nebulized inhalation with salbutamol. In other measures, the percentage of lung volume with impaired fractional ventilation and relative perfusion decreased (P =.194 and P =.009, respectively), with FEV1 improving as well (P <.0001). Researchers were not able to define any clinical factors associated with the varying effect of salbutamol on patients studied.
The investigators concluded that “There is a positive short-term effect of bronchodilator inhalation on FEV1 in patients with CF, which is independent of ventilation inhomogeneity. Heterogeneous response between patients suggests that for prediction of a therapeutic effect this should be tested by spirometry in every patient individually.” They further noted that “spirometry is sufficient and [multiple-breath washout] or functional MRI is not needed to capture response.”
The researchers suggested that clinicians first establish an individual need for bronchodilators via bronchial hyperresponsiveness testing (eg, reversibility testing and bronchial provocation challenges). Although these measures cannot be obtained in infants and preschoolers, in older children, they will reduce overprescription, adverse events, and cost.
Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Kieninger E, Willers C, Röthlisberger K, et al. Effect of salbutamol on lung ventilation in children with cystic fibrosis: comprehensive assessment using spirometry, multiple-breath washout, and functional lung magnetic resonance imaging. Respiration. Published online November 22, 2021. doi:10.1159/000519751