Assessment of the effect of cannula choice and gas flow rate on aerosol delivery during high flow nasal therapy

Louise Sweeney¹, Mary Joyce¹, Gavin Bennett¹ & Ronan MacLoughlin¹

¹Aerogen, IDA Business Park, Dangan, Galway, Ireland

Summary

Non-invasive Nasal High Flow therapy is increasingly used across a variety of patient populations. This study evaluated the effects of gas flow rates across a range of nasal cannulas (adult and junior) and head models using the Airvo™ 2   high flow system in conjunction with the Aerogen solo ® vibrating mesh nebuliser. A 2 mL dose of albuterol sulphate (1 mg/mL) was nebulised to determine % dose distal to the trachea for both an adult and paediatric (5 year old) head model (available online: www.rddonline.com). A total of three adult cannulas and two paediatric cannulas were used in this study.The Aerogen Solo nebuliser was positioned in the Airvo™ 2   nebuliser adapter at the humidification chamber. Tracheal dose (dose delivered to a filter beyond the trachea) was characterised by quantifying the mass of drug captured on a filter placed distal to the head models during simulated High Flow Nasal Therapy. Results for tracheal dose were expressed as the percentage of the nominal dose placed in the nebuliser’s medication cup. Statistically significant differences in tracheal dose were observed across the range of gas flows under test for each individual cannulas. There was also a significant difference between all three adult cannulas for each individual gas flow rate, with the exception of 30 & 60LPM. There was no significant difference between the junior cannulas for the individual gas flow rates. In addition, increasing gas flow rates were associated with a reduced tracheal dose.