Table 2.

Primary and secondary endpoints in the two treatment groups

	HFNO group	Venturi mask group	P value
	(n = 52)	(n = 48)
Primary endpoint
Number (%) of patients requiring mechanical ventilation	8 (15 %)	4 (8 %)	0.36
Noninvasive mechanical ventilation	6a	3a
Invasive mechanical ventilation	4	2
Secondary endpoints, median [25th–75th percentile]
Discomfort VAS scoreb at 120 min	3 [1–5]	3 [0–5]	0.88
Dyspnea VAS scoreb at 120 min	3 [2 – 6]	3 [1–6]	0.87
Thirst VAS scoreb at 120 min	6 [3–8]	6 [5 – 9]	0.40
Respiratory rate at 120 min, breaths/min	25 [22–29]	25 [21–31]
Heart rate at 120 min, beats/min	98 [90–110]	99 [83–112]	0.43

HFNO high-flow nasal oxygen, VAS visual analogue scale

^aTwo patients in the HFNO group and one patient in the Venturi mask group received noninvasive ventilation followed by invasive mechanical ventilation

^bAll three VASs ranged from 0 (absence of discomfort, dyspnea, or thirst) to 10 (worst possible discomfort, dyspnea, or thirst)