The effect of varying inhaled oxygen concentrations of high-flow nasal cannula oxygen therapy during gastroscopy with propofol sedation in elderly patients: a randomized controlled study

Table 1 General characteristics of patients

Characteristics	Group C (n = 123)	Group H100 (n = 123)	Group H50 (n = 123)	P value
Age, yr	70(68, 72)	69(67, 71)	70(67, 72)	0.062
Sex male/female (n)	47/76	52/71	49/74	0.807
BMI, ( kg/m²)	22.8 ± 2.9	22.5 ± 2.9	22.4 ± 2.5	0.538
ASA grade (I/II)	37/86	34/89	38/85	0.844
Mallampati class ( I/II/III/IV)	108/15/0/0	105/18/0/0	103/20/0/0	0.658
Mouth opening (1/2/3)	0/8/115	0/10/113	0/11/112	0.770
Thyromental distance(I/II/III)	107/16/0	103/20/0	106/17/0	0.751
Baseline SpO₂	98(97, 99)	98(97, 99)	98(97, 98)	0.101

Values were presented as mean ± SD, a number of patients, number (%), or median (Q1, Q3). BMI: Body mass index ASA grade: American Society of Anesthesiologists physical status. Mouth opening (1)(2)(3): 1 = 1 finger, 2 = 2 fingers, 3 = 3 fingers. Thyromental distance (I)(II)(III): I > 6.5 cm, II 6–6.5 cm, III < 6 cm. Group C: nasal cannula oxygen group, Group H100: 100% of FiO₂ from HFNC group, Group H50: 50% of FiO₂ from HFNC group

ISSN: 1471-2253