Interventional Radiology offers minimally invasive procedures with less physiologic stress, fewer complications, faster recovery times, and lower morbidity and mortality rates when compared to more traditional surgical approaches. As a result, IRs are increasingly called upon to manage patients with high acuity of illness. As Interventional Radiology evolves, it will be increasingly necessary for IRs to better understand the nuances of nonprocedural patient management, particularly in the critical care setting.

Optimizing intravascular volume status is a key goal in critically ill patients. Hypovolemia can lead to hypotension, organ hypoperfusion, and shock, while volume overload can cause organ dysfunction through venous congestion. Venous congestion is most commonly recognized when volume overload overwhelms the Frank-Starling mechanism of the heart, leading to poor ventricular output and resulting venous hypertension in the pulmonary, systemic, and portal venous systems. If venous hypertension is not adequately compensated for, interstitial edema and a decrease in transcapillary arteriovenous pressure gradient can occur, both of which decrease oxygen delivery to end-organs and ultimately cause organ dysfunction.

Accurately assessing intravascular volume status is notoriously difficult—several indirect assessments are traditionally used, including physical exam findings, hemodynamic measurements, laboratory values, and imaging, although all have significant limitations and inconsistencies when used in isolation.

Recently, point-of-care ultrasound imaging methods for volume assessment have risen in popularity by providing cheap, fast, and objective evaluations. Common techniques include measurement of collapsibility of the inferior vena cava (IVC) with respiration, lung ultrasound to detect pulmonary edema, abdominal ultrasound to detect ascites, and focused cardiac ultrasound to qualitatively assess filling of the cardiac chambers. Venous Excess Ultrasound (VExUS) is a novel imaging protocol that focuses on detecting the presence and severity of volume overload that may be causing venous congestion in different organ systems. VExUS combines assessment of the IVC, hepatic, portal, and renal veins and provides a score that indicates the severity of overall systemic venous congestion. Identifying the severity of venous congestion can be particularly useful in tailoring fluid and vasopressor therapy for patients in shock, heart failure, acute kidney injury (AKI), and other conditions precipitated by hypervolemia. Here, we summarize traditional methods of assessing intravascular fluid status, review the VExUS protocol, and discuss the utility of VExUS to the clinical practice of IR.