RT Journal Article
SR Electronic
T1 Exhaled air dispersion during high flow nasal cannula therapy <em>versus</em> CPAP <em>via</em> different masks
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 1802339
DO 10.1183/13993003.02339-2018
A1 David S. Hui
A1 Benny K. Chow
A1 Thomas Lo
A1 Owen T.Y. Tsang
A1 Fanny W. Ko
A1 Susanna S. Ng
A1 Tony Gin
A1 Matthew T.V. Chan
YR 2019
UL http://erj.ersjournals.com/content/early/2019/01/16/13993003.02339-2018.abstract
AB Question High flow nasal cannula (HFNC) is an emerging therapy for respiratory failure but the extent of exhaled air dispersion during treatment is unknown. We examined exhaled air dispersion during HFNC therapy versus CPAP on a human patient simulator (HPS) in an isolation room with 16 air changes·h−1.Methods HPS was programmed to represent different severity of lung injury. CPAP was delivered at 5–20 cmH2O via nasal pillows (Respironics Gel or ResMed Swift FX) or oronasal mask (Quattro, ResMed). HFNC, humidified to 37°C, was delivered at 10–60 L·min−1 to the HPS. Exhaled airflow was marked with intrapulmonary smoke for visualisation and revealed by laser light-sheet. Normalised exhaled air concentration was estimated from the light scattered by the smoke particles. Significant exposure was defined when there was ≥20% normalised smoke concentration.Results [mean(sd)]In normal lung condition, exhaled air dispersion, along the sagittal plane, increased from 186 (34) to 264 (27) mm and from 207(11) to 332 (34) mm when CPAP was increased from 5 to 20 cmH2O via Respironics and ResMed nasal pillows, respectively. Leakage from the oronasal mask was negligible. Exhaled air distances increased from 65 (15) to 172 (33) mm when HFNC was increased from 10 to 60 L·min−1. Air leakage to 620 mm occurred laterally when HFNC and the interface tube became loose.Conclusion Exhaled air dispersion during HFNC therapy and CPAP via different interfaces is limited provided there is good mask interface fitting.FootnotesThis manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.Conflict of interest: Dr. Hui has nothing to disclose.Conflict of interest: Dr. Chow has nothing to disclose.Conflict of interest: Mr. Lo has nothing to disclose.Conflict of interest: Dr. Tsang has nothing to disclose.Conflict of interest: Dr. Ko has nothing to disclose.Conflict of interest: Dr. Ng has nothing to disclose.Conflict of interest: Dr. Gin has nothing to disclose.Conflict of interest: Dr. Chan has nothing to disclose.