Table 3.
Studies comparing different gas flow settings for trans-nasal aerosol delivery with HFNC
| Patient | Study type | Author | Nebulizer position | Collection filter placement | Breathing pattern | Inspiratory flow (IF) | Gas flow (GF) | GF: IF | Inhaled dose (%) |
|---|---|---|---|---|---|---|---|---|---|
| Adult | In vitro | Réminiac et al., 2016 [26] | Inlet of humidifier | Trachea | Quiet breathing: Vt 500 mL, RR 15 bpm, I:E = 1:1, Ti 2 s | 15 | 30.0 | 2.0 | 6.70 |
| 45.0 | 3.0 | 3.50 | |||||||
| 60.0 | 4.0 | 3.0 | |||||||
| Distressed breathing: Vt 750 mL, RR 30 bpm, I:E = 1:1, Ti 1 s | 45 | 30.0 | 0.67 | 10.30 | |||||
| 45.0 | 1.0 | 6.70 | |||||||
| 60.0 | 1.33 | 5.10 | |||||||
| Dailey et al., 2017 [27] | Inlet of humidifier | Nasal prongs | Quiet breathing: Vt 500 mL, RR 16 bpm, I:E = 1:2, Ti 1.25 s | 24 | 10.0 | 0.42 | 26.70 ± 1.30 | ||
| 30.0 | 1.25 | 11.60 ± 1.20 | |||||||
| 50.0 | 2.08 | 3.50 ± 0.20 | |||||||
| Distressed breathing: Vt 750 mL, RR 30 bpm, I:E = 1:1, Ti 1 s | 45 | 10.0 | 0.22 | 13.0 ± 3.0 | |||||
| 30.0 | 0.67 | 33.0 ± 5.0 | |||||||
| 50.0 | 1.11 | 25.0 ± 2.0 | |||||||
| McGrath et al., 2019 [44] | Outlet of humidifier | Trachea | Quiet breathing: Vt 500 mL, RR 15 bpm, I:E = 1:1, Ti 2 s | 15 | 10.0 | 0.67 | 5.35 ± 2.81 | ||
| 40.0 | 2.67 | 2.56 ± 1.38 | |||||||
| 60.0 | 4.0 | 1.01 ± 0.26 | |||||||
| In vivo | Alcoforado et al., 2019 [42] | Inlet of humidifier | NA | Normal healthy volunteer, quiet breathing (n = 23) | NA | 10.0 | NA | 17.23 ± 6.78 | |
| 30.0 | NA | 5.71 ± 2.04 | |||||||
| 50.0 | NA | 3.46 ± 1.24 | |||||||
| Pediatric | In vitro | Ari et al., 2011 [23] | Inlet of humidifier | Nasal prong | Infant quiet breathing: Vt 100 ml, RR 20 bpm, I:E 1:2 | 6 | 3.0 | 0.5 | 10.65 ± 0.51 |
| 6.0 | 1.0 | 1.95 ± 0.50 | |||||||
| Réminiac et al., 2017 [38] | Inlet of humidifier | Trachea | Infant quiet breathing: Vt 25 mL, RR 40 bpm, I:E 1:2 | 3 | 2.0 | 0.67 | 4.15 ± 1.75 | ||
| 4.0 | 1.33 | 3.29 ± 1.70 | |||||||
| 8.0 | 2.67 | 0.52 ± 0.23 | |||||||
| Ari, 2019 [33] | Inlet of humidifier | Trachea | Child quiet breathing: Vt 250 mL, RR 20 bpm, Ti 1 s | 15 | 4.0 | 0.27 | 8.64 ± 1.20 | ||
| 6.0 | 0.40 | 5.37 ± 0.70 | |||||||
| Infant quiet breathing: Vt 100 mL, RR 30 bpm, Ti 0.7 s | 8.6 | 4.0 | 0.47 | 3.27 ± 0.40 | |||||
| 6.0 | 0.70 | 2.35 ± 0.30 | |||||||
| In vivo | Réminiac et al., 2017 [38] | Inlet of humidifier | NA | Macaque (n = 3) | NA | 2.0 | NA | 0.85 ± 0.57 | |
| 4.0 | NA | 0.49 ± 0.44 | |||||||
| 8.0 | NA | 0.09 ± 0.04 | |||||||
| Corcoran et al., 2019 [40] | After a corrugated tubing segment | NA | Infants (n = 18) | NA | 2.0 | NA | 4.50 ± 2.20 | ||
| 0.2 | NA | 33.50 ± 13.0 |
HFNC high-flow nasal cannula, Vt tidal volume, Ti inspiratory time, RR respiratory rates, I:E ratio of inspiratory to expiratory time, NA not available