Comparing the delivery of albuterol metered-dose inhaler via an adapter and spacer device in an in vitro infant ventilator lung model

OBJECTIVE: To compare the delivery of an albuterol metered-dose inhaler (MD I) (Ventolin) via an Aerochamber (Monaghan) with an inline adapter (Medicom p Straight Swivel) in an in vitro infant lung model. METHODS: An in vitro infant lung model was modified to compare the delivery of albuterol MDI 10 inhalations via an Aerochamber with an inline adapter. The adapter and Aerochamber were placed at the endotracheal tube. A 1000 m t intravenous bag filled with 500 mt deionized a ater was attached to a 3.5 mm endotracheal tube (10 cm length). An infant Bear Cub ventilator was use d at the following settings: positive inspiratory pressure 20 cm H2O, inter mittent mandatory ventilation 30 breaths/min, positive end expiratory press ure 4 cm H2O, and inspiratory time 0.5 second, Each device was run at least 10 times and assayed in duplicate by HPLC. An unpaired Student's t-test wa s used to analyze the statistical significance of the data. RESULTS: There was significantly greater delivery of albuterol with the Aer ochamber (19.49 +/- 7.23 mu g: 2.17% +/- 0.8%) as compared with an inline a dapter(1.0625 +/- 1.36 mu g; 0.12% +/- 0.15%) (p = 0.001). CONCLUSIONS: The Aerochamber provides a greater delivery of albuterol meter ed-dose inhalations to the lung than the inline adapter in an in vitro infa nt lung model.