Nasal high flow higher than 60 L/min in patients with acute hypoxemic respiratory failure: a physiological study

Table 2 Effects of increasing NHF set flow rate on target physiologic variables

	NHF-0.5	NHF-1	NHF-1.5	ANOVA p value
Set flow rate (L/min)	35 (30–35)	65 (60–70)^a	100 (92–109)^a,b	< 0.001
PaO₂/FiO₂	194 ± 96	211 ± 106	219 ± 118	0.064
SpO₂ (%)	94 ± 2	95 ± 2	96 ± 2	0.139
Arterial pH	7.40 (7.39–7.43)	7.40 (7.39–7.41)	7.41 (7.40–7.45)	0.105
PaCO₂ ( mmHg)	36.3 ± 6.4	37.6 ± 5.3	36.2 ± 5.7	0.108
RR (bpm)	20 ± 6^c	17 ± 5	18 ± 6	0.014
Corrected MV (au/min)	46,440 ± 18,515	48,562 ± 17,781	53,870 ± 17,737	0.068
HR (bpm)	78 ± 16	76 ± 17	77 ± 16	0.391
MAP (mmHg)	76 (62–91)	73 (65–80)	74 (61–89)	0.447

NHF, nasal high flow; 0.5-1-1.5, set flow rate in L/kg PBW/min; PaO₂/FiO₂, arterial partial pressure of O₂/inspired fraction of O₂ ratio; SpO₂, peripheral oxygen saturation; PaCO₂, arterial partial pressure of CO₂; RR, respiratory rate; HR, heart rate; MAP, mean arterial pressure
^aPost hoc Dunn’s test versus NHF-0.5 (p < 0.05)
^bPost hoc Dunn’s test versus NHF-1 (p < 0.05)
^cPost hoc Bonferroni test versus NHF-1 (p < 0.05)

ISSN: 1364-8535