RT Journal Article SR Electronic T1 Airway surface liquid concentrations of aztreonam lysine for inhalation in children with cystic fibrosis: A modeling study JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P2114 VO 42 IS Suppl 57 A1 Cedric Van Holsbeke A1 Aukje Bos A1 Wim Vos A1 Jan De Backer A1 Hettie Janssens A1 Harm Tiddens YR 2013 UL http://erj.ersjournals.com/content/42/Suppl_57/P2114.abstract AB IntroductionThe mechanics of inhaled antibiotics in obstructed airways are not well known. It is possible that local areas with concentration below the minimal inhibitory concentration (10xMIC90, 128µg/ml for P. Aeruginosa) exist, causing undertreated parts of the lung. To optimize inhaled therapy, knowledge about antibiotic concentrations throughout the lung should be known. Local deposition characteristics of inhaled Aztreonam lysine (AZLI) were simulated using Functional Respiratory Imaging.MethodsAirways and lungs were segmented from a retrospective dataset of 40 in- and expiratory CT-scans of children with cystic fibrosis (CF) between 5 and 17 years. FRI simulations were performed that simulated the nebulisation of 75mg AZLI through PARI eFlow® with minimal/median/maximal reported aerodynamic diameters (MMAD) and different thicknesses of airway surface liquid (ASL). Figure 1 shows local concentrations in the central airways and lung.ResultsIn Figure 2, it is shown how many lobes are being undertreated.ConclusionParts of the CF-lung receive concentrations < 10xMIC90 with inhaled antibiotics, such as AZLI.