Study of Venous Return Changes During Volume Expansion Using 500 mL Crystalloid Fluid Challenge in Critically Ill Patients

What this Trial Is About

Researchers are studying how fluids affect heart function in critically ill patients who need volume expansion. The study focuses on how fluids increase the mean systemic filling pressure Pms and central venous pressure CVP, which together influence venous return and cardiac output. The goal is to understand why only some of the fluids given actually improve heart function by increasing the pressure difference between Pms and CVP. The study involves a fluid challenge where 500 mL of crystalloid fluid is given to patients who already have invasive or minimally invasive hemodynamic monitoring. The mean systemic filling pressure is measured using a brief blood flow interruption technique with a blood pressure cuff on the arm. Measurements of Pms, CVP, and cardiac index are taken before, during, and after fluid administration at specific intervals corresponding to 150 mL, 250 mL, 500 mL infused, and one hour after completion. Participants are critically ill adults admitted to the intensive care unit who need volume expansion. During the study, continuous monitoring of cardiac function and pressures will be done. Researchers will evaluate changes in the venous return gradient, cardiac index, and other hemodynamic measures over time. The study aims to classify patients as fluid responders based on changes in stroke volume. This observational study will help improve understanding of fluid effectiveness in critical care settings.

Assessment of Venous Return During Volume Expansion: a Prospective Observational Study