Fig. 3

The pre-operative and post-operative blood haemoglobin concentration for conventional perfusion management and perfusion management using the pressure field. The dashed line is the line of identity where post-operative and pre-operative haemoglobin are equal. Shaded region gives the 95% confidence interval. a The slope (p < 0.001) and intercept (p < 0.001) of the two groups was different. That is, the pressure field group was closer than the conventional group to the line of unity where post-operative haemoglobin is equal to pre-operative haemoglobin. b Plot showing the significant (p < 0.001) pre-operative/post-operative blood haemoglobin concentration interaction with sex. Within each sex the difference in conventional or pressure field approach remains. Regression coefficients are provided in Table 2