Table 1 Patient baseline characteristics

Sex, female, n (%)

48 (64.9)

49 (66.2)

27 (84.4)

0.112

Age, y, mean (SD)

69.24 (5.3)

69.18 (5.9)

69.52 (4.9)

0.958

Weight, kg, mean (SD)

64.49 (10.4)

67.89 (9.4)

65.44 (8.0)

0.094

Body mass index, kg m⁻², mean (SD)

24.54 (3.5)

25.62 (3.1)

25.70 (2.2)

0.068

ASA physical status, n (%)

0.923

 I

0 (0.0)

0 (0.0)

0 (0.0)

 II

53 (71.6)

51 (68.9)

23 (71.9)

 III

21 (28.4)

23 (31.1)

9 (28.1)

Comorbidities, n (%)

 Hypertension

33 (44.6)

41 (55.4)

20 (62.5)

0.184

 Diabetes

13 (17.6)

11 (14.9)

8 (25.0)

0.455

 Coronary heart disease

9 (12.2)

9 (12.2)

6 (18.8)

0.610

 Cerebrovascular disease

2 (2.7)

6 (8.1)

0 (0.0)

0.185

 Others

15 (20.3)

14 (18.9)

6 (18.8)

0.973

History of operation, n (%)

44 (59.5)

47 (63.5)

23 (71.9)

0.476

History of anesthesia, n (%)

43 (58.1)

47 (63.5)

23 (71.9)

0.398

Preoperative complications, n (%)

 Pruritus, n (%)

3 (4.1)

4 (5.4)

2 (6.3)

0.905

 Nausea, n (%)

2 (2.7)

1 (1.4)

0 (0.0)

 > 0.999

 Vomiting, n (%)

1 (1.4)

1 (1.4)

0 (0.0)

 > 0.999

 Headache, n (%)

1 (1.4)

1 (1.4)

0 (0.0)

 > 0.999

 Low back pain, n (%)

8 (10.8)

9 (12.2)

2 (6.3)

0.659