High-flow nasal cannula oxygen therapy during anesthesia recovery for older orthopedic surgery patients: A prospective randomized controlled trial

Table 1 Preoperative baseline characteristics of the patients based on grouping

Characteristic	Conventional mask group (n = 30)	HFNCO group (n = 30)	P value
Age (yr)	72.8 ± 5.7	72.5 ± 4.3	0.778
Sex
Male	9 (30)	10 (33.3)	0.781
Female	21 (70)	20 (66.7)
Weight (kg)	62.4 ± 10.5	63.1 ± 8.0	0.756
BMI	25.1 ± 3.8	25.3 ± 3.5	0.793
ASA
II	15 (50)	21 (70)	0.114
III	15 (50)	9 (30)
Operation type			0.320
TKA	18 (60)	13 (43.3)
Spinal surgery	6 (20)	11 (36.7)
Others	6 (20)	6 (20)

Data are presented as mean ± SD or n (%). ASA: American Society of Anesthesiologists; BMI: Body mass index; HFNCO: High-flow nasal cannula oxygen; TKA: Total knee arthroplasty.