Table 2

NIRS variables during the vascular occlusion tests.

Blood donors

Before blood donation

After blood donation

median

IQR

median

IQR

two-tailed p-value

StO₂ rate of decrease(%/sec)

-0.19

-0.21 - -0.16

-0.19

-0.23 - -0.15

0.78

StO₂ rate of recovery (%/sec)

3.04

2.57 - 3.45

3.29

2.79 - 3.48

0.25

StO₂ delta (%)

14.0

12.0 - 15.8

13.5

12.0 - 18.0

0.36

O₂Hb rate of decrease (/sec)

-0.033

-0.043 - -0.026

-0.027

-0.055 - -0.021

0.98

O₂Hb rate of recovery (/sec)

0.59

0.50 - 0.72

0.63

0.48 - 0.74

0.59

O₂Hb delta

4.33

3.47 - 4.97

4.76

4.24 - 5.42

0.06

Control

Before rest period

After rest period (19 minutes)

median

IQR

median

IQR

two-tailed p-value

StO₂ rate of decrease (%/sec)

-0.17

-0.19 - -0.15

-0.15

-0.20 - -0.12

0.43

StO₂ rate of recovery (%/sec)

2.64

2.00 - 2.88

2.43

2.00 - 3.47

0.29

StO₂ delta (%)

12.5

11.3 - 13.3

13.5

11.5 - 15.25

0.10

O₂Hb rate of decrease (/sec)

-0.039

-0.051 - -0.026

-0.031

-0.046 - -0.020

<0.01*

O₂Hb rate of recovery (/sec)

0.49

0.39 - 0.63

0.54

0.39 - 0.69

<0.05*

O₂Hb delta

3.88

2.43 - 4.20

4.00

3.32 - 5.72

<0.01*

IQR: interquartile range, *: p < 0.05

Jeger et al. Journal of Trauma Management & Outcomes 2010 4:5   doi:10.1186/1752-2897-4-5