Demystifying Venous Excess Ultrasound (VExUS): Image Acquisition and Interpretation

Summary

Point-of-care ultrasound (POCUS) is often used to assess the hemodynamic circuit and detect the presence of venous congestion. The Venous Excess Ultrasound (VExUS) scoring system was developed to aid clinicians in predicting the impact of venous congestion on organ dysfunction. This article aims to describe VExUS image acquisition and interpretation.

Abstract

Providers in many medical specialties must accurately assess the hemodynamic circuit to deliver appropriate patient care. Venous congestion is increasingly implicated in a range of multiorgan complications. However, hemodynamic assessment remains challenging because of the complex physiology involved and inconsistent diagnostic accuracy of conventional bedside tools and physical exam maneuvers. While right heart catheterization is regarded as the gold standard for measuring systemic venous pressure, it is invasive and not easily repeatable, and thus, there remains a need for non-invasive alternatives. Even point-of-care ultrasound examinations of the internal jugular vein or inferior vena cava have significant limitations in terms of accuracy of intravascular volume assessment and correlation with central venous pressure. To improve bedside clinicians' accuracy at assessing venous congestion, a protocol was developed and validated that utilizes pulsed-wave (PW) Doppler signals of veins in the liver and kidney to grade the degree of venous congestion present in patients. Although this scoring system, called Venous Excess Ultrasound (VExUS), is being increasingly adopted within certain subspecialties of medicine, such as nephrology and critical care, it remains underutilized in medicine as a whole. This is likely due, at least in part, to knowledge gaps and lack of training in this emerging modality. To address this educational gap, this article will describe VExUS image acquisition and interpretation.

Introduction

Assessment of the hemodynamic circuit at the bedside is fundamental to the daily care of acutely ill patients. The deleterious effects of fluid overload are increasingly recognized even outside of more obvious clinical syndromes such as heart failure, and there are now multiple studies showing that positive fluid balance is associated with increased mortality¹. There is a growing body of evidence that shows that even low levels of venous congestion are associated with organ dysfunction². Similarly, timely decongestion is associated with improved outcomes³. This multiorgan, dynamic circuit involves....

Protocol

All procedures performed in studies involving human participants adhered to the ethical standards of the institutional research committee and the Declaration of Helsinki, including its later amendments or comparable ethical standards. Written informed consent was obtained from the human participants. The scanning technique encompassed transducer selection, machine settings, patient positioning, B-mode scanning, and image acquisition. Patients with unclear volume status, suspected venous congestion, heart failure, acute kidney injury (AKI), and/or chronic kidney disease (CKD) were included in the study, while those with end-stage kidney disease on dialysis, known cirrh....

Results

The first step to the VExUS exam involves imaging the inferior vena cava (IVC) to determine if there are signs of elevated right atrial pressures that would qualify the patient for the remainder of the exam. When imaging the IVC, it is important to view it from both the longitudinal and transverse perspectives to see the vessel in its maximal dimension. If the IVC is greater than 2 cm in its maximal anteroposterior diameter, then the remainder of the examination can be performed.

The next step.......

Discussion

Critical steps
VExUS was developed in post-cardiac surgery patients to quantify venous congestion non-invasively, but the utility has expanded for its use to assist in the evaluation of venous congestion and assessment of fluid status in multiple clinical contexts. To perform the exam properly, several critical steps must be considered. First, to maximize the diagnostic yield of the exam, one must consider the requirements of the VExUS exam when selecting a transducer and preset²³. .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
5500P Ultrasound System	Philips	HC795143	Used to obtain a subset of the Figures and Videos
Affiniti 70 Ultrasound System	Philips	HC795210	Used to obtain a subset of the Figures and Videos
Curvilinear Transducer (C1-5-D)	GE	5409287-R	1-5 MHz, also called the abdominal probe
Curvilinear Transducer (C5-1)	Philips	HC989605412041	2-5 MHz, also called the abdominal probe
Curvilinear Transducer (C5-1)	SonoSite	https://www.sonosite.com/products/ultrasound-transducers/c5-1	1-5 MHz, also called the abdominal probe
Curvilinear Transducer (C5-2s)	Mindray	https://lysis.cc/products/mindray-c5-2s	1-5 MHz, also called the abdominal probe
Edge 1 Ultrasound Machine	SonoSite		Used to obtain a subset of the Figures and Videos
Handheld Probe (Butterfly iQ3)	Butterfly	https://www.butterflynetwork.com/iq3?srsltid=AfmBOorvY6WqHGbdeWW gtefztEJa8pt_xbwSOc6hQuB2s-Kb0wRlsCLR	Used to obtain a subset of the Figures and Videos
LOGIQ P9 Ultrasound System	GE	H42752LS	Used to obtain a subset of the Figures and Videos
Lumify Handheld Ultrasound	Philips		Used to obtain a subset of the Figures and Videos
Phased-Array Transducer (3Sc-D)	GE	https://services.gehealthcare.in/gehcstorefront/p/5863286	1-5 MHz, also called the cardiac probe
Phased-Array Transducer (P4-2s)	Mindray	https://lysis.cc/products/mindray-p4-2s	1-5 MHz, also called the cardiac probe
Phased-Array Transducer (P5-1)	SonoSite	https://www.sonosite.com/in/products/ultrasound-transducers/p5-1	1-5 MHz, also called the cardiac probe
Phased-Array Transducer (S4-1)	Philips	HC989605389271	1-5 MHz, also called the cardiac probe
TE7 Max Ultrasound System	Mindray	https://www.mindray.com/na/products/ultrasound/point-of-care/te-series/te-7-max-portable-ultrasound-machine/	Used to obtain a subset of the Figures and Videos