P279 Infectious status and lung clearance index

Airflow obstruction and recurrent bacterial infections are characteristics of cystic fibrosis lung disease. During the first years of life exacerbations with Staphylococcus aureus are more common, but as lung disease progress, typical germs as Pseudomonas aeruginosa will colonize the lungs. Lung clearance index (LCI) has an increased sensitivity in diagnosing early lung disease and monitoring the degree of ventilation inhomogeneity in patients with cystic fibrosis (pwCF). Requiring only a tidal breath, the test can be performed even by children younger than 5 years old or patients in exacerbation. To evaluate the relation between LCI and infectious status in pwCF. 56 pwCF, who agreed to participate and were able to perform lung test, were included in our study. Bacteriological samples were collected to evaluate the infectious status; data about chronic infection were collected from our CF database. The pulmonary function was evaluated using LCI as an endpoint. Median age was 11 years. 25% of patients had no infection ever, and 67.8% of them were in exacerbation. 44.64% of patients had chronic infection with P. aeruginosa, 39.29% had chronic infection with S. aureus. Chronic co-infection was present in 28.57% of patients. Median LCI was 11.58. Statistically significant differences were wound between median LCI in patients who were in exacerbation vs. patients who were not in exacerbation (12.7 vs. 7.0, p = 0.006), respectively between patients with history of infection vs. patients without infection ever (12.3 vs. 8.9, p = 0.014). Patients with chronic P. aeruginosa infection, respectively chronic S. aureus infection had a higher median LCI comparative with those patients without chronic infection: 18.8 vs 9.1, p = 0.001, and 19.4 vs. 9.0, p = 0.002. Highest LCI median was obtain in patients’ group with co-infection (20.1). Lung clearance index can be used as a diagnostic tool for patients in exacerbations.