Figure 7.

Two-graph ROC curves: sensitivity and specificity of changes in VTI, Vmax and PP during the TP according to the value of the cut-off for the detection of more than 15% increase in VTI after fluid challenge. The inconclusive zone, which is >10% of diagnosis tolerance, is represented as a shaded rectangle. ΔVTI-TP, changes in velocity-time integral during the Trendelenburg position; ΔVmax-TP, changes in peak velocity during Trendelenburg position; ΔPP-TP, changes in pulse pressure during the Trendelenburg position.