Manuscript

Original manuscript Assessment of intravascular volume status is difficult in critically ill patients. Evidence suggests that only 50% of hemodynamically unstable patients respond to a fluid challenge. Moreover, if cardiopulmonary function cannot compensate for the increase in preload, fluid loading may compromise microvascular perfusion, oxygen delivery and cause or aggravate peripheral and pulmonary edema. Inappropriate fluid expansion can increase morbidity and mortality thus making it important to accurately assess fluid responsiveness in critically ill patients. The volume responsiveness can be defined as a 15% increase in stroke volume (SV) or cardiac output (CO) after a 500-ml infusion.This study tested whether echocardiographic parameters can predict fluidresponsiveness in critically ill patients following a low volume 100-ml crystalloidsolution infusion over 1 minut