The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts

DELIVERY OF ALBUTEROL BY PRESSURIZED METERED-DOSE INHALER AND JET NEBULIZER VIA MASK WITH HIGH FLOW NASAL CANNULA IN PLACE REDUCES AEROSOL DELIVERY.

Mahmood A. Alalwan, Arzu Ari, James B. Fink, Robert Harwood, Lawrence Bryant, Meryl Sheard; Respiratory Therapy, Georgia State University, Atlanta, GA

Background: During high flow nasal cannula (HFNC) therapy, jet nebulizer or pressurized metered-dose inhaler (pMDI) may be administered by mask with the cannula in place (with HFNC) or removed. We quantified aerosol drug delivery with or without a HFNC using either pMDI or jet nebulizer. Methodology: An upper airway model of a 9 month-old infant (SAINT) with an absolute filter (Respirgard II) distal to the trachea was connected to a breathing simulator (Harvard Appartus) set to simulate pediatric parameters (Vt of 100 mL, RR of 30 breaths/min, and I:E ratio of 1: 1.4). Oxygen at 3 l/min was administered through an infant HFNC (Optiflow, Fisher & Paykel) attached to the nares of the model. Aerosol drug was administered using: 1) Misty-neb jet nebulizer (Allegiance Healthcare) powered by air at 8 l/min using pediatric aerosol facemask (B&F Medical) to deliver albuterol sulfate (2.5 mg/3 mL NS) and 2) Four actuations of Ventolin HFA pMDI (90 µg/puff) were administered via valved holding chamber with mask (AeroChamber plus with Flow-Vu). Aerosol was administered to the model with and without the HFNC in the nares (n=3). Drug was eluted from the filter and quantified using spectrophotometry (276 nm). Independent t tests were performed (p <0.05). Results: Table shows mass and % of albuterol dose (mean ± SD) deposited distal to the trachea. Removing HFNC from the nares before aerosol treatment increased drug delivery with the jet nebulizer (p = 0.024) and pMDI (p = 0.003). Deposition % was greater with pMDI than jet nebulizer, with or without nasal cannula in place. Conclusions: During HFNC therapy, aerosol delivery via mask over cannula is less efficient than removing the cannula during administration. When delivering medical aerosol by mask, the benefit of increased aerosol delivery must be weighed against the risk of lung derecruitment when nasal prongs are removed. Sponsored Research - None