Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection which is associated with an in-hospital mortality greater than 10%.

Septic shock is a subset of sepsis with manifest circulatory dysfunction (use of vasopressors and persistent elevation of lactic acid), in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality (hospital mortality rates greater than 40%).

Currently, in addition to the use of empiric antibiotics and control of the infectious focus, intravenous fluid therapy is an essential intervention to promote hemodynamic stabilization.

 However, observational studies describe worse outcomes related to fluid overload and increased mortality and greater use of fluid-related medical interventions such as thoracentesis, paracentesis, hemodialysis, and use of diuretics in Sepsis.

Hemodynamic management in critically ill patients has traditionally focused on maintaining adequate cardiac output and arterial blood pressure by relying on fluid administration and/or vasopressor/inotropic support. However, organ perfusion is affected by other important factors, such as venous pressure, which can be overlooked.

The development of clinically significant organ congestion is susceptible to occur in patients with right ventricular failure or pulmonary hypertension, and in patients with fluid overload.

These contributors are likely to be synergistic in critically ill patients, particularly when renal dysfunction aggravates fluid retention.

A reduction of the arteriovenous gradient across vital organs may hamper adequate perfusion. Fluid overload influences tissue perfusion in the presence of venous congestion and tissue edema.

The evaluation of lung congestion with point of care ultrasound , as a signal of extravascular fluid, and, more recently,a venous excess Doppler ultrasound VExUS grading system, are parameters for the assessment of the fluid status of the patient and organ congestion.