. 2021 Nov 14;21:367. doi: 10.1186/s12890-021-01744-8

Table 3.

Comparison of vital signs between the modified high-flow nasal cannula oxygen and the conventional oxygen therapy groups

Characteristic	Group	Pre-5 min (n = 392/396)	The lowest SpO₂, the highest respiratory rate, heart rate, and mean arterial pressure (n = 392/396)	Post-5 min (n = 392/396)	Post-10 min (n = 392/396)	Post-2 h (n = 392/396)	Post-6 h (n = 392/396)	Post-24 h (n = 392/396)	p^a
SpO₂ (%)	MHFNC	97.4 ± 1.6	94.1 ± 3.2	95.4 ± 2.3	94.7 ± 2.7	95.5 ± 1.8	95.7 ± 1.8	96.0 ± 1.7	< 0.001
	Control	97.3 ± 1.5	90.5 ± 3.8	92.1 ± 2.6	93.4 ± 2.9	95.3 ± 2.1	95.7 ± 1.9	95.9 ± 1.8	< 0.001
	p^c	0.268	< 0.001	< 0.001	< 0.001	0.348	0.869	0.493	0.003^b
Respiratory rate (bpm)	MHFNC	17 ± 5	26 ± 7	19 ± 5	19 ± 4	18 ± 3	17 ± 3	17 ± 3	< 0.001
	Control	18 ± 4	28 ± 6	21 ± 5	20 ± 4	18 ± 3	17 ± 3	17 ± 3	< 0.001
	p^c	0.196	< 0.001	< 0.001	0.005	0.693	0.694	0.973	0.001^b
Heart rate (beats/min)	MHFNC	84 ± 15	112 ± 18	94 ± 16	93 ± 16	83 ± 10	82 ± 10	81 ± 10	< 0.001
	Control	83 ± 15	116 ± 21	97 ± 18	94 ± 16	82 ± 10	81 ± 11	80 ± 10	< 0.001
	p^c	0.305	0.015	0.037	0.377	0.167	0.818	0.334	0.465^b
Mean arterial pressure (mmHg)	MHFNC	95 ± 13	108 ± 15	102 ± 14	104 ± 17	95 ± 10	94 ± 10	94 ± 9	< 0.001
	Control	94 ± 12	110 ± 18	103 ± 16	104 ± 16	96 ± 10	95 ± 10	94 ± 10	< 0.001
	p^c	0.454	0.256	0.233	0.890	0.541	0.342	0.580	0.402^b

FiO₂ the fraction of inspired oxygen, SpO₂ peripheral arterial oxygen saturation

p^a for overall comparisons of differences in each group over time

p^b for overall comparisons of differences between groups over time

p^c for comparisons of differences between groups at each time point