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Targeting Aerosol Deposition in Patients With Cystic Fibrosis

2000; Elsevier BV; Volume: 118; Issue: 4 Linguagem: Inglês

10.1378/chest.118.4.1069

1931-3543

Beth L. Laube, Rajkumari N. Jashnani, Richard N. Dalby, Pamela L. Zeitlin,

Asthma and respiratory diseases

Study objective: To determine if aerosolizedmedications can be targeted to deposit in the smaller, peripheralairways or the larger, central airways of adult cystic fibrosis (CF)patients by varying particle size and inspiratory flow rate. Design: Randomized clinical trial. Setting: Outpatient research laboratory. Patients: Nine adult patients with CF. Interventions: Patients inhaled an aerosol comprised of3.68 ± 0.04 μm saline solution droplets (two visits) or1.01 ± 0.2 μm saline solution droplets (two visits) for 30 s, starting from functional residual capacity and breathing at a slow orfaster inspiratory flow rate. On all visits, the saline solution wasadmixed with the radioisotope 99mTc. Immediately afterinhalation, a gamma camera recorded the deposition pattern of theradioaerosol in the lungs. Deposition images were analyzed in terms of the inner:outer zone (I: O) ratio, a measure of deposition in an innerzone (large, central airways) vs an outer zone (small airways andalveoli). Measurements and results: For the 3.68-μmaerosol, I: O ratios averaged 2.29 ± 1.45 and 2.54 ± 1.48(p > 0.05), indicating that aerosol distribution within the lungswas unchanged while breathing at 12 ± 2 L/min vs 31 ± 5 L/min, respectively. For the 1.01-μm aerosol, I: O ratios averaged2.09 ± 0.96 and 3.19 ± 1.95 (p < 0.05), indicating thatdeposition was predominantly in the smaller airways while breathing at18 ± 5 L/min and in the larger airways while breathing at 38 ± 8L/min, respectively. Conclusions: These resultssuggest that the targeted delivery of an aerosol to the smaller, peripheral airways or the larger, central airways of adult CF patientsmay be achieved by generating an aerosol comprised of approximately1.0-μm particles and inspiring from functional residual capacity atapproximately 18 L/min and ∼ 38 L/min, respectively. To determine if aerosolizedmedications can be targeted to deposit in the smaller, peripheralairways or the larger, central airways of adult cystic fibrosis (CF)patients by varying particle size and inspiratory flow rate. Randomized clinical trial. Outpatient research laboratory. Nine adult patients with CF. Patients inhaled an aerosol comprised of3.68 ± 0.04 μm saline solution droplets (two visits) or1.01 ± 0.2 μm saline solution droplets (two visits) for 30 s, starting from functional residual capacity and breathing at a slow orfaster inspiratory flow rate. On all visits, the saline solution wasadmixed with the radioisotope 99mTc. Immediately afterinhalation, a gamma camera recorded the deposition pattern of theradioaerosol in the lungs. Deposition images were analyzed in terms of the inner:outer zone (I: O) ratio, a measure of deposition in an innerzone (large, central airways) vs an outer zone (small airways andalveoli). For the 3.68-μmaerosol, I: O ratios averaged 2.29 ± 1.45 and 2.54 ± 1.48(p > 0.05), indicating that aerosol distribution within the lungswas unchanged while breathing at 12 ± 2 L/min vs 31 ± 5 L/min, respectively. For the 1.01-μm aerosol, I: O ratios averaged2.09 ± 0.96 and 3.19 ± 1.95 (p < 0.05), indicating thatdeposition was predominantly in the smaller airways while breathing at18 ± 5 L/min and in the larger airways while breathing at 38 ± 8L/min, respectively. These resultssuggest that the targeted delivery of an aerosol to the smaller, peripheral airways or the larger, central airways of adult CF patientsmay be achieved by generating an aerosol comprised of approximately1.0-μm particles and inspiring from functional residual capacity atapproximately 18 L/min and ∼ 38 L/min, respectively.