Fig. 3. ( A ) Correlation plot showing the relation between end-diastolic blood volume (GEDV) and measured intrathoracic blood volume (ITBVm) in the control group (ITBVm= 1.21 × GEDV + 99; r 2= 0.89, P < 0.0001; 95% confidence interval [CI] for slope, 1.1–1.4 and 95% CI for y-intercept, 31–168). ( B ) Shock group under normovolemic ( open triangles and squares with the correlation line shown as interrupted line : ITBVm= 1.3 × GEDV + 58; r 2= 0.92, P < 0.0001; 95% CI for slope, 1.1 to 1.5 and 95% CI for y-intercept, −33 to 150) and hypovolemic conditions ( shaded triangles and squares with the correlation line shown as a solid line : ITBVm= 1.45 × GEDV + 0.6; r 2= 0.95, P < 0.0001; 95% CI for slope, 1.3 to 1.6 and 95% CI for y-intercept, −47 to 49). The differences between the slopes and intercepts of the three equations are not statistically significant.