Table 5.

Comparisons of the results with collecting filter placed at trachea vs nasal cannula in adult in vitro studies

Studies	Population	Breathing pattern	HFNC flow (L/min)	Inhaled dose (%)
				Trachea	Nasal cannula
Réminiac et al., 2016 [26], and Dailey et al., 2017 [27]	Adult	Distressed breathing Vt 750 mL, RR 30 bpm, I:E = 1:1, Ti 1 s, inspiratory flow 45 L/min	30	10.3	13.0 ± 3.0
			45	6.7	33.0 ± 5.0
			60	5.1	25.0 ± 2.0
Bennett et al., 2019 [32], and Dailey, 2017 [27]	Adult	Quiet breathing: Vt 500 mL, RR 15 bpm, I:E = 1:1, Ti 2 s, inspiratory flow 15 L/min	10	5.4 ± 2.8	26.7 ± 1.3

HFNC high flow nasal cannula, Vt tidal volume, RR respiratory rates, Ti inspiratory time, I:E ratio of inspiratory time to expiratory time