The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts

AEROSOLIZED ALBUTEROL PARTICLE SIZE DISTRIBUTION IN TWO AEROSOL DELIVERY SYSTEM CONFIGURATIONS UNDER NEONATAL VENTILATION CONDITIONS.

Jan Mazela3, Tomasz R. Sosnowski2, Arkadiusz Moskal2, Krzysztof Chmura3, Timothy J. Gregory1, Christopher Henderson1, Russell G. Clayton1; 1Discovery Laboratories, Inc., Warrington, PA; 2Chemical and Process Engineering, Warsaw University of Technology, Warsaw, Poland; 3Neonatology, Poznan University of Medical Sciences, Poznan, Poland

Background: Particle size is a critical factor in the efficient delivery of aerosolized medications to the target area of the lung. In infants receiving mechanical ventilation, particle size of aerosolized medications may be affected by the configuration of the aerosol delivery system and the ventilator circuit. A novel technology has been developed to improve the delivery of aerosolized medications to neonates receiving ventilatory support. This technology includes a proprietary aerosol delivery adaptor designed to separate aerosol flow from the ventilator bias flow. Objective: To compare the particle size distribution (PSD) of aerosolized albuterol sulfate at various locations in the ventilator circuitry using both the novel adaptor (NA) and the standard of care (SoC) T connector with a wye connector. Design/Methods: We assembled a testing system using a standard neonatal ventilator circuit, including humidification at 36 degrees C, and a bias air flow of 6L/min. Albuterol sulfate (0.5mg/mL) was aerosolized for 5 min at a flow of 2L/min of air using a Misty Finity(R) nebulizer connected at either: the T connector in the inspiratory arm of the ventilator circuit or at the NA. SoC PSD measurements were made using white-light scattering and for the NA and nebulizer, PSD measurements were made using a Spraytec spectrometer. For the ventilator circuit systems (SoC and NA), PSD was measured at the ET tube connection point and at the tip of 2.5, 3.0, and 3.5 mm ET tubes. All measurements were done in triplicate and reported at the 50th (D50) percentile. Analysis of PSD for both the SoC and NA systems was done under 2L/min inspiratory flow through the ET tubes to mimic neonatal ventilation conditions. Results: D50 was larger as it exited the nebulizer compared with D50 measured after exiting both ventilator circuit systems. D50 was statistically significantly (p < 0.05, Wilcoxon Rank-Sum) smaller in the SoC system compared with +/- SEM). Conclusions: Aerosol particle size changes after traveling through a ventilator circuit. In addition, the configuration of the aerosol delivery system affects the degree of change in particle size. These findings may reflect impaction of larger particles in the circuit that result from the influence of different flow characteristics as well as the different "points of entry" of the aerosol between the two systems. Sponsored Research - None