Ultrasound & Chest Imaging Section
VExUS scan: The missing piece of hemodynamic puzzle?
Volume status and tailoring the correct level of fluid resuscitation is challenging for the intensivist. Determining “fluid overload,” especially in the setting of acute kidney injury, can be difficult. While a Swan-Ganz catheter, central venous pressure, or inferior vena cava (IVC) ultrasound measurement can suggest elevated right atrial pressure, the effect on organ level hemodynamics is unknown.
Abdominal venous Doppler is a method to view the effects of venous pressure on abdominal organ venous flow. An application of this is the Venous Excess Ultrasound Score (VExUS) (Rola, et al. Ultrasound J. 2021;13[1]:32). VExUS uses IVC diameter and pulse wave doppler waveforms from the hepatic, portal, and renal veins to grade venous congestion from none to severe. Studies demonstrate an association between venous congestion and renal dysfunction in cardiac surgery (Beaubien-Souligny, et al. Ultrasound J. 2020;12[1]:16) and general ICU patients (Spiegel, et al. Crit Care. 2020;24[1]:615).
This practice of identifying venous congestion and avoiding over-resuscitation could improve patient care. However, acquiring quality images and waveforms may prove to be difficult, and interpretation may be confounded by other disease states such as cirrhosis. Though it is postulated that removing fluid could be beneficial to patients with high VExUS scores, this has yet to be proven and may be difficult to prove. While the score estimates volume status well, the source of venous congestion is not identified such that it should be used as a clinical supplement to other data.
VExUS has a strong physiologic basis, and early clinical experience indicates a strong role in improving assessment of venous congestion, an important aspect of volume status. This is an area of ongoing research to ensure appropriate and effective use.
Kyle Swartz, DO
Fellow-in-Training
Steven Fox, MD
Fellow-in-Training
John Levasseur, DO