Blood volume redistribution with aortic crossclamping

Blood volume redistribution during aortic crossclamping (AoX). This schedule depicts the reason for the decrease in venous capacity, which results in blood volume redistribution from the vasculature distal-to-aortic occlusion to the vasculature proximal-to-aortic occlusion. If the aorta is occluded above the splanchnic system, the blood volume travels to the heart, increasing preload and blood volume in all organs and tissues proximal to the clamp. However, if the aorta is occluded below the splanchnic system, blood volume may shift into the splanchnic system or into the vasculature of other tissues proximal to the clamp. The distribution of this blood volume between the splanchnic and nonsplanchnic vasculature determines changes in preload.