Table 2 Haemodynamic and ANI variables before and after fluid challenge in positive (n = 36) and negative fluid challenge (n = 68)

Heart rate (beat.min ⁻¹ )

 Negative fluid challenges

72

[64 – 81]

71

[60 – 79]

 < 0.001

 Positive fluid challenges

67

[62 – 73]

62

[58 – 70]

 < 0.001

Mean arterial pressure (mmHg)

 Negative fluid challenges

69

[57 – 77]

67

[57 – 78]

0.807

 Positive fluid challenges

67

[60 – 71]

68

[61 – 73]

0.210

Stroke volume (ml)

 Negative fluid challenges

38

[34 – 53]

40

[36 – 55]

 < 0.001

 Positive fluid challenges

37

[33 – 43]

43

[38 – 48]

 < 0.001

Cardiac output (l.min ⁻¹ )

 Negative fluid challenges

2.8

[2.3 – 3.7]

2.9

[2.3 – 3.8]

0.222

 Positive fluid challenges

2.5

[2.0 – 3.1]

2.9

[2.3 – 3.3]

 < 0.001

PPV (%)

 Negative fluid challenges

12

[8–15]

9

[7–13]

 < 0.001

 Positive fluid challenges

11

[9–17]

8

[6–11]

 < 0.001

SVV (%)

 Negative fluid challenges

14

[11–20]

12

[9–16]

 < 0.001

 Positive fluid challenges

14

[11–17]

9

[8–12]

 < 0.001

Remifentanil dose (ng.ml ⁻¹ )

 Negative fluid challenges

4.0

[3.0 – 4.6]

4.0

[3.0 – 4.6]

-

 Positive fluid challenges

3.5

[2.7 – 4.0]

3.5

[2.7 – 4.0]

-

Propofol dose (μg.ml ⁻¹ )

 Negative fluid challenges

4.0

[3.8 – 5.0]

4.0

[3.8 – 5.0]

-

 Positive fluid challenges

3.7

[3.1 – 4.0]

3.7

[3.1 – 4.0

ANI mean (n)

 Negative fluid challenges

70

[54 – 82]

77

[58 – 86]

0.019

 Positive fluid challenges

69

[62 – 84]

79

[66 – 91]

0.005