An Investigation of Nebulized Bronchodilator Delivery Using a Pediatric Lung Model of Spontaneous Breathing
BACKGROUND: The literature lacks comparative data on nebulizer aerosol delivered via mask versus T-piece, to spontaneously breathing pediatric subjects. PURPOSE: To compare total inhaled drug mass delivered via standard pediatric aerosol mask versus via T-piece, with increasing distance.
METHODS: We used a sample of 5 nebulizers, operated under manufacturers' conditions, with a standard pediatric aerosol mask and with a T-piece capped at one end, at 0 cm, 1 cm, and 2 cm from an inhalation filter placed at the inlet of a pediatric test lung. Inhaled drug mass was analyzed with
spectrophotometry. Aerosol particle size was measured separately from the breathing simulations, using a laser particle sizer to determine fine-particle mass (particles < 4.7 μm) and fine-particle fraction as percent of total mass. The fine-particle fraction was used to estimate
the fine-particle mass. RESULTS: The mean ± SD values for inhaled drug mass as a percentage of nominal dose, at 0 cm, 1 cm, and 2 cm, with the mask were 2.88 ± 0.79%, 1.61 ± 0.65%, and 1.3 ± 0.42%, respectively, and with the T-piece were 4.14 ± 1.37%, 3.77
± 1.04%, and 3.47 ± 0.64%, respectively. There was a statistically greater inhaled drug mass with T-piece than with mask, overall (p < 0.01), and a significant decrease with mask or T-piece as distance increased (p < 0.01). The difference between mask and T-piece for inhaled
drug mass at 2 cm was statistically significant (p < 0.018). The mean ± SD values for fine-particle mass estimated as a percentage of total drug mass at 0, 1, and 2 cm, with the mask were 1.39 ± 0.36%, 0.78 ± 0.29%, and 0.64 ± 0.20%, respectively, and with the
T-piece were 2.1 ± 0.63%, 1.84 ± 0.45%, and 1.71 ± 0.27%, respectively. CONCLUSION: Inhaled drug mass was greater with T-piece than with a standard pediatric aerosol mask under the conditions studied.
Document Type: Research Article
Department of Respiratory Care, University of Texas Health Science Center at San Antonio, 7703 Floyd C Drive, Mail Code 6248, San Antonio TX 78229-3900;, Email: firstname.lastname@example.org
Cardiac Intensive Care Unit, Children's Health Care of Atlanta at Egleston, Atlanta, Georgia
Cardiopulmonary Care Sciences, Georgia State University, Atlanta, Georgia
Publication date: January 1, 2006
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