Table 1 The characteristics of included patients

Male/female

19/16

136/112

1.086

0.067

Age(y)

73.15 ± 8.92

66.93 ± 7.44

1.534

0.044

BMI (kg/m²)

22.63 ± 3.25

22.23 ± 2.09

4.131

0.071

Hypertension

25(71.43 %)

72(29.03 %)

1.094

0.008

Diabetes mellitus

11(31.43 %)

60(24.19 %)

1.282

0.057

Hyperlipidemia

9(25.71 %)

52(20.97 %)

1.699

0.102

History of HF

2(5.71 %)

12(4.84 %)

1.142

0.114

Anemia

19(54.29 %)

47(18.95 %)

1.422

0.036

Hypoalbuminemia

10(28.57 %)

34(13.71 %)

1.062

0.016

Cognitive dysfunction

3(8.57 %)

19(7.66 %)

0.966

0.087

Type of fracture

1.214

0.073

Intertrochanteric fracture

16(45.71 %)

110(44.35 %)

Femoral neck fracture

19(54.29 %)

138(55.65 %)

Preoperative oxygen saturation(%)

94.64 ± 10.31

95.75 ± 10.09

9.347

0.081

Preoperative laboratory examination

White blood cell count (×10⁹ ·L^− 1)

9.03 ± 1.61

8.93 ± 1.23

1.128

0.077

Platelet count (×10⁹ ·L^− 1)

213.71 ± 84.52

210.24 ± 123.12

1.246

0.104

Red blood cell count(×10⁹ ·L^− 1)

4.73 ± 1.17

4.66 ± 1.14

1.093

0.071

Creatinine (µmol·L^− 1)

34.13 ± 14.36

33.26 ± 15.23

2.146

0.085

Alanine aminotransferase (U ·L^− 1)

18.27 ± 10.12

17.13 ± 12.56

3.108

0.063

Aspartate aminotransferase(U ·L^− 1)

19.34 ± 12.32

19.46 ± 15.30

2.997

0.102

Duration of surgery(min)

146.52 ± 66.49

112.59 ± 75.17

12.413

0.005

Methods of anesthesia

2.498

0.113

lumbar anesthesia

14(40.00 %)

105(42.34 %)

General anesthesia

21(60.00 %)

143(57.66 %)

Estimated blood loss during surgery(ml)

266.38 ± 44.52

260.14 ± 40.41

21.104

0.062

ΔHR(/min)

14.49 ± 3.12

15.18 ± 3.52

1.072

0.065

ΔSBP(mmHg)

17.62 ± 2.83

29.69 ± 4.55

5.128

0.092

ΔDBP(mmHg)

16.17 ± 2.24

15.52 ± 3.17

1.206

0.085

ΔPI(%)

3.18 ± 1.41

3.34 ± 1.28

1.299

0.106

ΔPVI(%)

3.96 ± 1.02

4.12 ± 1.21

1.384

0.059