Aerosol generation in children undergoing high flow nasal cannula therapy [article]

Elliott T. Gall, Aurélie Laguerre, Michelle Noelck, Annalise Van Meurs, Jared A Austin, Byron A. Foster
2020 medRxiv   pre-print
AbstractObjectiveHigh flow nasal cannula therapy (HFNC) may increase aerosol generation, putting health care workers at increased risk of infection, including from SARS-CoV-2. This study examined whether use of HFNC increases near-field aerosols and if there is a relationship between flow rate and near-field aerosol concentrations.Patients and MethodsSubjects between 30 days and 2 years of age were enrolled. Each child received HFNC therapy at different flow rates over time. Three sampling
more » ... Three sampling stations with particle counters were deployed to measure aerosol generation and dispersion in the room: station one within 0.5 m of the subject, station two at 2 m, and station three on the other side of the room. We also measured carbon dioxide (CO2) and relative humidity. Station three (far-field) measurements were used to adjust the station one (near-field) measurements for room conditions.ResultsWe enrolled ten children ranging from 6-24 months (median 9 months), two with respiratory illness. Elevated CO2 indicated the near-field measurements were in the breathing plane of the subjects. Near-field breathing plane concentrations of aerosols with diameter 0.3 – 10 µm are elevated by the presence of the patient with no HFNC flow, relative to the room far-field, by 0.45 #/cm3. While we observed variability between subjects in their emission and dispersion of particles, we did not find an association between HFNC and near-field elevations of particle counts.ConclusionNear-patient levels of particles with diameter in the 0.3-10 µm range was not affected by the use of HFNC in healthy patients. Further study on older children and children with increased mucus production may be warranted.
doi:10.1101/2020.12.10.20245662 fatcat:3otbt3fjfnb5rd66vjf75puiy4