title: Optimization of aerosol deposition by pressure support in children with cystic fibrosis: an experimental and clinical study.
abstract: Nebulized aerosols are commonly used to deliver drugs into the lungs of patients with cystic fibrosis (CF). The aim of this study was to assess the effectiveness of pressure-support (PS) ventilation in increasing aerosol deposition within the lungs of children with CF. An in vitro study demonstrated the feasibility of coupling a breath-actuated nebulizer to a PS device. An in vivo study was done with 18 children (ages 6 to 21 yr) with clinically stable CF, each of whom underwent both a standard and a PS-driven ventilation scan (control session and PS session, respectively). In addition, a perfusion scan was used to determine lung outlines and to construct a geometric model for quantifying aerosol deposition by radioactivity counting in MBq. Homogeneity of nebulization was evaluated from the four first-order moments of aerosol distribution in the peripheral and central lung regions. The time-activity nebulization curve was linear in all patients, with higher slopes during the PS than during the control session (0.43 +/- 0.07 [mean +/- SD] MBq/min and 0.32 +/- 0.23 MBq/min, respectively; p < 0.018). Quantitatively, aerosol deposition was about 30% greater after the PS session (4.4 +/- 2.7 MBq) than after the control session (3.4 +/- 2.1 MBq; p < 0.05). Similarly, deposition efficacy (as a percentage of nebulizer output) was significantly better during the PS session than during the control session (15.3 +/- 8.3% versus 11.5 +/- 5.7%, p < 0.05). No differences in the regional deposition pattern or in homogeneity of uptake were observed. In conclusion, our data show that driving the delivery of a nebulized aerosol by noninvasive PS ventilation enhances total lung aerosol deposition without increasing particle impaction in the proximal airways.
authors: Department of Pediatric Pulmonology, Armand Trousseau Hospital, Air Liquide Santé International, Paris, France. bfauroux@aol.com
authors: B
authors: B
authors: Fauroux
authors: E
authors: E
authors: Itti
authors: J
authors: J
authors: Pigeot
authors: D
authors: D
authors: Isabey
authors: M
authors: M
authors: Meignan
authors: G
authors: G
authors: Ferry
authors: F
authors: F
authors: Lofaso
authors: J M
authors: JM
authors: Willemot
authors: A
authors: A
authors: Clément
authors: A
authors: A
authors: Harf
mesh_terms: D000293:Adolescent; D000336:Aerosols; D002648:Child; D003131:Combined Modality Therapy; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging / Q000628:therapy*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D016014:Linear Models; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D009330:Nebulizers and Vaporizers / Q000706:statistics & numerical data; D015609:Organotechnetium Compounds; D010833:Phytic Acid; D011175:Positive-Pressure Respiration / Q000295:instrumentation* / Q000706:statistics & numerical data; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D012122:Ventilators, Mechanical
chemical_list: D000336:Aerosols; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; C026177:technetium phytate; D010833:Phytic Acid