We found significant differences in LCI and FRC measurements using two different gases for MBW. This may have significant implications for the future use and interpretation of LCI data in clinical trials and routine clinical care.

BackgroundFor patients with cystic fibrosis (CF), sustaining lung function through the adolescent years is crucial to slow the progressive decline that leads to significant morbidity and early mortality. This holds true for patients with high per cent predicted forced expiratory volume in 1 s (ppFEV1), as they may receive less vigilant monitoring and treatment. Early identification of lung function decline followed by aggressive treatment can lead to preservation of lung function.InterventionThe Emory+Children’s Pediatric Cystic Fibrosis Program implemented multiple quality improvement (QI) initiatives to identify and aggressively treat adolescent patients with a rapid decline in lung function. These initiatives included (1) lung zones to categorise and highlight lung function decline, (2) individual lung decline tables for quick reference, (3) a lung health algorithm to encourage uniformity, (4) a rapid decliner checklist to identify potential reasons for individual decline and (5) an automated individual patient-level data report and centre scorecard. We tested these interventions with plan–do–study–act cycles and refined as needed.ResultsImplementation of these QI initiatives resulted in overall improvement in lung function and slowing of lung function decline among adolescents with CF . This improvement could be attributed to the more standardised and proactive approach to decreases in lung function and the increased clinician attention to patients with rapid decline, especially for patients with high baseline ppFEV1.

Background Viral respiratory infections trigger pulmonary exacerbations (PEs) in children with cystic fibrosis (CF), but their clinical impact is not well understood. Methods A retrospective review of pediatric patients with CF who underwent nasopharyngeal respiratory viral panel testing during hospitalization for a PE between 2011 and 2018 was conducted. Patients were dichotomized into viral‐positive and viral‐negative groups. The results of spirometry, respiratory cultures, duration of hospitalization, and risk for subsequent PEs were analyzed. Results Ninety‐five patients had 210 hospitalizations for PE (viral‐positive = 71/210, 34%) during the study period. Rhinovirus/enterovirus was the most common virus (52/71, 73%) identified. Viral‐positive patients were younger (p < 0.001), had higher baseline forced expiratory volume in 1 s (FEV1) (p = 0.037), continued to maintain higher FEV1 at 3 and 6 months following PE (p = 0.003 and 0.002, respectively), and had a shorter duration of hospitalization (p = 0.006) compared to the viral‐negative group. There was no difference between the two groups in the rate of recovery of FEV1 at 3 and 6 months following PE (p = 0.71 and 0.405, respectively), time to the next PE (hazard ratio = 1.34, p = 0.157), number of subsequent PEs in 6 months (p = 0.99), or Pseudomonas aeruginosa (PA) acquisition (p = 0.707). Conclusions In this single pediatric CF center cohort, one‐third of PEs requiring hospitalization were associated with a viral infection, with rhinovirus/enterovirus being the most common. Viral‐positive PEs were not associated with a greater decline or delayed recovery of lung function, increased risk for PA acquisition, shortened duration to next PE, longer hospital stay, or an increase in the frequency of subsequent PEs in 6 months compared to viral‐negative PEs.