Table 1 Demographics

Number of patients

46

51

Sex (M/F)

31/15

27/24

Weight (kg)

81.98

14.53

79.78

13.99

0.449

Height (cm)

168.00

6.77

171.35

7.47

0.023

Age

67

10.5

69

9.8

0.334

PTT (s)

27

3.93

26

4.2

0.230

Duration of operation (min)

172.74

41.85

168.09

42.03

0.587

Surgical procedure

0.286

1 segment PLIF

9

17

2 segments PLIF

23

23

3 segments PLIF

12

8

4 segments PLIF

1

3

5 segments PLIF

1

0

Surgical procedure

0.308

1 segment instrumentation

0

0

2 segments instrumentation

0

0

3 segments instrumentation

0

0

4 segments instrumentation

11

8

5 segments instrumentation

35

43

ASA I/II/III

13/21/12

9/16/26

0.042