Trendelenburg maneuver is performed to predict fluid responsiveness. Responders are defined by an increase in stroke volume over 15% after infusion of 500ml of crystalloid solution.

In the Trendelenburg position, the body is laid supine, or flat on the back with the feet higher than the head by 15-30 degrees. The venous return increases in the trendelenburg position which in turn increases the stroke volume.

responders are defined by stroke volume increases over 15% after volume expansion of 500ml crystalloid

nonresponders are defined by stroke volume increases less than 15% after volume expansion of 500ml crystalloid