Abstract: The search identified 11 studies, but we only included one study enrolling infants with cystic fibrosis under six months of age and diagnosed through newborn screening (170 enrolled); participants were followed until they were five years old (data from 157 children). The study compared outcomes following therapy directed by bronchoalveolar lavage for pulmonary exacerbations with standard treatment based on clinical features and oropharyngeal cultures. We considered this study to have a low risk of bias; however, the statistical power to detect a significant difference in the prevalence of Pseudomonas aeruginosa was limited due to the prevalence (of Pseudomonas aeruginosa isolation in bronchoalveolar lavage samples at five years age) being much lower in both the groups compared to that which was expected and which was used for the power calculation. The sample size was adequate to detect a difference in high-resolution computed tomography scoring. The quality of evidence for the key parameters was graded as low except high-resolution computed tomography scoring and cost of care analysis, which were graded as moderate quality. At five years of age, there was no clear benefit of bronchoalveolar lavage-directed therapy on lung function z scores or nutritional parameters. Evaluation of total and component high-resolution computed tomography scores showed no significant difference in evidence of structural lung disease in the two groups. In addition, this study did not show any difference between the number of isolates of Pseudomonas aeruginosa per child per year diagnosed in the bronchoalveolar lavage-directed therapy group compared to the standard therapy group. The eradication rate following one or two courses of eradication treatment was comparable in the two groups, as were the number of pulmonary exacerbations. However, the number of hospitalizations was significantly higher in the bronchoalveolar lavage-directed therapy group, but the mean duration of hospitalizations was significantly less compared to the standard therapy group. Mild adverse events were reported in a proportion of participants, but these were generally well-tolerated. The most common adverse event reported was transient worsening of cough after 29% of procedures. Significant clinical deterioration was documented during or within 24 hours of bronchoalveolar lavage in 4.8% of procedures. This review, limited to a single, well-designed randomized controlled study, shows no clear evidence to support the routine use of bronchoalveolar lavage for the diagnosis and management of pulmonary infection in pre-school children with cystic fibrosis compared to the standard practice of providing treatment based on results of oropharyngeal culture and clinical symptoms. No evidence was available for adult and adolescent populations.

Plain-language summary: We searched for studies of people of any age, but this review only includes one study in which 170 babies with cystic fibrosis, aged less than six months, were divided into two groups completely at random. One group was given antibiotics based on samples taken by bronchoscopy and the other group based on samples taken from throat. The investigators measured outcomes at five years of age. A total of 157 children completed the study. This study did not show any difference between the groups in terms of lung function, weight, body mass index or in the score calculated by a CT scan of the lungs at five years of age. There were no differences in how many children in each group had an infection with Pseudomonas aeruginosa at five years of age, or per year of follow up, or how often a child was unwell with respiratory symptoms. Children in the bronchoscopy group were admitted to hospital more often although admissions were generally shorter than the other group. There was no difference in the overall cost of care between the two groups. Side effects reported during, and after bronchoscopy, were not serious; the most common side effect was increased coughing (in one third of children). There is currently not enough evidence to support the regular use of bronchoscopy to diagnose and treat lung infections in children with cystic fibrosis. Evidence was limited to only one well-designed study. Overall quality of evidence was of low (for most outcomes) to moderate quality (for high-resolution computed tomography scoring and cost of care analysis). Quality limitations were due to fewer children taking part in the study than the statisticians thought were needed to show true results for some outcomes. Since the treatment of a first infection with Pseudomonas aeruginosa is highly successful, larger and longer studies are needed to detect small differences between the groups. Conducting such large studies is extremely difficult. Also, the study only included young children and we do not know if the results would be the same in other age groups.