Figures
- FIGURE 1
High-flow nasal cannula set-up with a filter cassette with vacuum pump for sampling room air to detect SARS-CoV-2 virus and two optical particle sizers placed longitudinally at 1 foot (30.5 cm) and 3 feet (91.5 cm) away from the patient's face to measure the aerosol concentrations.
Tables
- TABLE 1
Aerosol particle concentrations of different sizes during conventional nasal cannula therapy and high-flow nasal cannula (HFNC) therapy with and without a mask
Particle size Conventional nasal cannula# versus HFNC (n=5) HFNC with versus without a mask (n=6) Concentration at 1 foot¶ Concentration at 3 feet¶ Concentration at 1 foot¶ Concentration at 3 feet¶ Conventional cannula HFNC p-value Conventional cannula HFNC p-value No mask Mask p-value No mask Mask p-value ≤0.3 µm 710 212±622 173 581 273± 513 067 0.138 743 822±658 053 570 318± 490 647 0.043 706 247± 510 591 706 611± 531 585 0.753 653 710± 460 070 633 964± 439 677 0.249 0.3–0.5 µm 29 598±25 464 22 914± 18 332 0.686 36 511±32 609 24 666± 20 414 0.08 23 020± 17 297 21 911± 17 796 0.046 23 275± 18 722 21 802± 17 307 0.173 0.5–1 µm 2821±1464 2744±1317 0.50 3966±2758 2593±1243 0.043 2575±1124 1980±1083 0.028 2380±1118 2053±1082 0.173 1–3 µm 913±368 876±436 0.345 943±499 732±316 0.043 758±348 544±274 0.028 647±295 501±252 0.028 3–5 µm 436±166 418±242 0.50 423±200 355±179 0.08 386±225 266±117 0.028 319±171 254±124 0.116 5–10 µm 205±77 194±127 0.50 152±86 142±80 0.225 197±177 129±65 0.173 135±114 107±58 0.753 Data are presented as mean±sd. #: conventional nasal cannula therapy was performed at 10–15 L·min−1; ¶: values are indicated in particles per cubic foot. 1 foot=30.5 cm.
Vol 7 Issue 1
Table of Contents
Placing a mask on COVID-19 patients during high-flow nasal cannula therapy reduces aerosol particle dispersion
