The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts

INFLUENCE OF BREATHING PATTERNS, FLOW RATE AND FACE MASK ON AEROSOL DELIVERY TO SIMULATED SPONTANEOUSLY BREATHING INFANTS AND PEDIATRICS.

Hui-Ling Lin1, Arzu Ari2, Robert Harwood Harwood2, James B. Fink2, Rob Trusty3; 1Respiratory Therapy Program, Chang Gung University, Taoyuan, Taiwan; 2Division of Respiratory Therapy, Georgia State University, Atlanta, GA; 3Respiraotry Care Department, Children’s Hospital and Clinics of Minnesota, St Paul, MN

Background: Aerosol face masks have been used extensively for aerosol drug delivery to treat infants and pediatrics with airway diseases. However, aerosol delivery may be affected by various factors such as the rate of gas flow and shape of aerosol face mask . Objective: The purpose of this in vitro study was to determine the influence of breathing pattern, flow rate and face mask on aerosol drug delivery in simulated spontaneously breathing infants and pediatrics. Methods: A spontaneous lung model (ALS5000, IngMar Medical) simulating infant breathing pattern (tidal volume 100 mL, inspiratory time 0.7 second, and respiratory rate 30 breath/min) and pediatric breathing pattern (tidal volume 250 mL, inspiratory time 1.0 second, and respiratory rate 20 breath/min) was attached to collecting filter for inhaled mass collection. Two types of pediatric face mask, the OxyKid (Southmedic Inc) and the Dragon (Cardinal Health Corp.) were chosen to deliver aerosols through connected by a 22 mm ID aerosol tubing to the outlet of a high flow humidification system (OptiFlow™, Fisher & Paykel) at 3, 6, and 12 L/min. A unit-dose of 5.0 mg/2.5 mL salbutamol (GSK Corp.) was nebulized by a vibrating mesh nebulizer (Aeroneb, Aerogen Inc) at the inlet of humidifier (n = 3). Drug collected in the filter was eluted from the filter and analyzed with a spectrophotometer (Thermo Fisher Scientific) at 276 nm. Independent t- test and one-way analysis of variance with Bonferroni test were used for statistical analysis (p< 0.05) . Results: Table shows mean percent of dose inhaled ± SD. Drug delivery was influenced by breathing patterns (p = 0.004) and flow rates used in this study. The inhaled mass was significantly lower at 12 L/min than at 3 and 6 L/min (p < 0.001). No statistical difference was found between the types of face masks (p = 0.123). Conclusion: The flow rates of gas entering the mask and breathing patterns influence aerosol delivery, independent of the face mask used. Sponsored Research - None Inhaled mass %±SD among settings *significantly lower at 12 L/min than at 3 and 6 L/min (p < 0.001) #Significant in pediatric