Proper fluid management while avoiding fluid overload can be one of the most difficult parts of practicing medicine. Unfortunately, many physicians using Point of Care Ultrasound (POCUS) mainly rely on Inferior Vena Cava (IVC) measurements to predict the “Fluid Status” (either deficient or overloaded) of their patients.
If you are guilty of this, don’t worry, the majority of people are. It’s probably because you just didn’t have a better way to help assess the fluid status of your patients other than IVC measurements.
However, solely using IVC measurement has many problems. IVC measurements are inaccurate because, just like central venous pressure (CVP), they do not accurately represent your patient’s preload in the left ventricle. The IVC can also be dilated in conditions such as valvulopathies, pulmonary hypertension, or in patients with no comorbidities (such as athletes). Therefore a dilated IVC does not necessarily mean your patient is “fluid overloaded.” In addition, IVC dilation does not quantify the amount of venous congestion from other vital organs such as the lungs, liver, gut, and kidneys.
Most of us can agree that the development of venous congestion in the lungs (pulmonary edema) from fluid overload can lead to poor patient outcomes. This can be fairly easily seen using lung ultrasound or chest radiography. However, few us actually know how to evaluate other organs that can be affected by venous congestion such as the liver, gut, and kidneys. This is important because understanding early signs of venous congestion can help you limit fluid administration, look for underlying causes of right heart failure, start appropriate vasopressor therapy, and decrease the risk of significant end-organ damage such as acute kidney injury.
To help us with this, doctors William Beaubien-Souligny, Philippe Rola, Korbin Haycock, Rory Spiegal, et al developed a 4-step ultrasound protocol: the Venous Excess Ultrasound (VExUS) Score is an exam that evaluates and scores the severity of venous congestion of not just the IVC but also the liver, gut, and kidneys. You can download their VExUS book chapter at the end of this post if you wish.
Furthermore, they were able to validate the VExUS Score in a recent study and showed a correlated increased risk of AKI with an increased grade of venous congestion (SPOILER: if you read the article, the VExUS C profile performed the best and what is described in this post).
However, after going through the book chapter and the research study for our trainees (ICU fellows and residents), I found that it can seem daunting or confusing for some people to try to go through all of the material. Therefore, I wanted to write up this blog post with a Downloadable PDF VExUS Score Pocket Card and a detailed step by step approach to help make learning how to perform the VExUS Ultrasound protocol more feasible for you!
After reading this post you will:
- Have Access to Free PDF VExUS Ultrasound Score Pocket Card
- Have Access to a VExUS Ultrasound Score calculator to automatically calculate venous congestion grade
- Know exactly how to do the 4-steps of the VExUS protocol (IVC, Hepatic Vein, Portal Vein, and Intrarenal Vein Dopplers)
- Apply the VExUS ultrasound grading system criteria to your patients to help with fluid management
I want to especially thank Dr. Korbin Haycock for reviewing this material for accuracy, please follow him on Twitter! Also a shoutout to @NephroPocus on introducing me to a great VExUS diagram that I adapted into the PDF VExUS pocket Guide.
Alright, let’s get the VExUS Exam down!
You can always access the VExUS Ultrasound Score Calculator HERE as well for future reference.
When to use POCUS for Venous Congestion
Evaluation for venous congestion using Point of Care Ultrasound (VExUS POCUS) can be performed when trying to assess the fluid status of the patient. This can be especially important in our septic shock, congestive heart failure, and acute renal failure patients to help give us more data points towards starting fluids, stoping fluids, diureses, or vasopressor choice.
This exam should be done in conjunction with the clinical picture, lab values, and hemodynamic status of the patient. It should also be combined and interpreted along with cardiac ultrasound findings when possible.
The VExUS Score can give you evidence of venous congestion in the liver, gut, and kidneys to help predict early signs of end-organ damage and allow you to change/optimize your fluid management approach for your patient. It can also prompt you to look for the etiologies of your venous congestion such as causes of right heart failure.
Organs to Evaluate Using the VExUS Ultrasound Score Protocol
Below are the organs you will be evaluating using the VExUS Ultrasound Protocol (aka Protocolo Vexus). As you can see, you can get a glimpse of venous congestion from several points prior to blood entering the right heart.
- Inferior Vena Cava
- Liver (hepatic veins)
- Gut (portal veins)
- Kidneys (intrarenal veins)
- Ideally, place the machine on the patient’s right side so you can scan with your right hand and manipulate ultrasound buttons with your left hand.
- Transducer: Ideally use a curvilinear probe since it can give better resolution of the vessels, but a phased array probe can be used as well
- Preset: Abdominal
- The Indicator should be on the left side of the screen
- You must have Pulse Wave Doppler capability on your ultrasound system. Most cart-based systems have this. Unfortunately, most hand-held ultrasounds don’t have Pulse Wave Doppler.
- Head of the bed should be down
- The patient should be supine
- Have patient bend legs relax the abdominal area to facilitate scanning
VExUS Score Step 1: IVC Assessment
Acquiring the IVC view with Ultrasound:
Place the probe in the subxiphoid position and get the IVC in the long-axis view. Most people will know how to perform an IVC exam, but for a more in-depth tutorial on how to obtain the IVC view you can click HERE.
Interpretation of IVC Measurements:
Evaluate the size and collapsibility of the IVC.
If the maximum IVC diameter is <2cm, then there is no significant venous congestion (at least cardiac related). You can stop the exam here and the VExUS score is 0.
If IVC is >2cm then proceed to the next steps.
VExUS Score Step 2: HEPATIC Vein Doppler Assessment
Acquiring the Hepatic Vein View with Ultrasound:
There are three hepatic veins: the right, middle, and left hepatic veins. You can use any of these veins to evaluate for hepatic vein Doppler patterns but the middle and right hepatic are usually the most accessible since the L hepatic vein view can be obscured by bowel/stomach gas. Below is a CT figure showing approximately where you should place your probe to target specific hepatic veins. Notice that it is NOT directly midline of the patient (I made this mistake when first trying to see the hepatic veins).
So here are the step to get the Hepatic Vein Doppler Tracings:
- Get a 2-D image of the IVC and hepatic veins.
- Place color flow Doppler over the hepatic veins as they enter the IVC. You should see BLUE flow (away from probe)
- Place your pulse wave Doppler gate on a hepatic vein prior to it entering the IVC
- Initiate Pulse wave Doppler
Interpretation of Hepatic Vein Doppler findings:
The hepatic vein Doppler is composed of a systolic (S wave) and diastolic (D wave). As venous congestion increases, there will be alterations of these waves with these typical patterns:
Normal Hepatic Vein Doppler: S>D
Mild Hepatic Vein Abnormality: S<D
Severe Hepatic Vein Abnormality: S Reversal
VExUS Score Step 3: PORTAL Vein Doppler Assessment
Acquiring the Portal Vein View with Ultrasound:
I find that the portal vein is probably the easiest vein to find (compared to the hepatic and intrarenal veins). This can be done by placing your probe in the right midaxillary line.
So here are the step to get the Hepatic Vein Doppler Tracings:
- Get a 2-D image of the Right Portal Vein
- Place color flow Doppler over the Right Portal Vein. You should see RED flow (towards the probe)
- Place your pulse wave Doppler gate on the Right Portal Vein
- Initiate Pulse wave Doppler
Interpretation of VExUS Score Ultrasound Portal Vein Doppler findings:
The Portal vein Doppler is normally monophasic with little to no variation. As venous congestion increases, there will be increasing amounts of pulsatility that is observed. The Pulsatility Index = (Vmax – Vmin)/Vmax.
Portal Vein Doppler
Mild Portal Vein Abnormality
Severe Portal Vein Abnormality
VExUS Score Step 4: Intrarenal Venous Doppler Assessment
Acquiring the Intrarenal Vein View with Ultrasound:
The intrarenal vein assessment is probably the most difficult assessment to do out of all of the vessels. This is because the intrarenal veins are fairly small and the patient’s breathing patterns may limit your views. But don’t be discouraged and keep trying your best to get these views. With practice, you will get better at acquiring them.
View the kidneys on either side at the posterior axillary line. Turn on the color Doppler and then look for the Interlobar vessels. Place the pulse wave Doppler gate where you see the best color Doppler signal and activate pulse wave Doppler. TIP: You may need to adjust the color and pulse wave Doppler scale and gain to get optimal settings. I have found having the Color Doppler scale around 10-25 cm/s is ideal.
The vessels are so small that you will be able to detect BOTH the arterial and venous flow of the intrarenal vessels in the same view. For the VExUS exam, you will mainly be focusing on the venous component (the bottom portion of the Doppler tracing). Here is a brief video showing you how to do this:
Interpretation of Intrarenal Vein Doppler findings:
The Intrarenal vein Doppler pattern is usually a nice continuous monophasic flow. As venous congestion starts to increase there is a decrease in the systolic component of the wave with progression to biphasic (systolic/diastolic phases) and with renal congestion leading to complete absence of systolic flow showing only monophasic flow (only diastolic phase).
Normal Intrarenal Vein
Mild Intrarenal Vein
Severe Intrarenal Vein
The VExUS Score – Putting Everything Together
This PDF puts everything together, including how to interpret the VExUS criteria and results. Also, remember you can access the VExUS Ultrasound Score Calculator HERE at any time if you forget how to score it.
VExUS Ultrasound Score:
- Grade 0: IVC <2cm = NO Congestion
- Grade 1: IVC >2cm with any combo of Normal or Mildly Abnormal Patterns = MILD Congestion
- Grade 2: IVC >2cm and ONE severely Abnormal Pattern = MODERATE Congestion
- Grade 3: IVC >2cm and >2 Severely Abnormal Patterns = SEVERE Congestion
Obviously the VExUS Score is just another data point for your resuscitation endpoints you can obtain with Point of Care Ultrasound (POCUS). It doesn’t tell you exactly WHAT is causing the venous congestion but it can give you details of the relative severity of end-organ venous congestion your patient has. It then allows you to think about any potential underlying causes of venous congestion such as fluid overload, right heart failure, pulmonary hypertension, left ventricular dysfunction, etc. From there, you can use POCUS or other diagnostic modalities to help you elucidate and manage the underlying problems causing the venous congestion further.
I hope that was helpful and please leave any questions or comments below!
- Marik, P., Baram, M., Vahid, B. (2008). Does central venous pressure predict fluid responsiveness? A systematic review of the literature and the tale of seven mares. CHEST 134(1), 172 – 178. https://dx.doi.org/10.1378/chest.07-2331
- Beaubien-Souligny, W., Rola, P., Haycock, K., Bouchard, J., Lamarche, Y., Spiegel, R., Denault, A. (2020). Quantifying systemic congestion with Point-Of-Care ultrasound: development of the venous excess ultrasound grading system The Ultrasound Journal 12(1), 16. https://dx.doi.org/10.1186/s13089-020-00163-w
- Goldhammer, E., Mesnick, N., Abinader, E., Sagiv, M. (1999). Dilated Inferior Vena Cava: A Common Echocardiographic Finding in Highly Trained Elite Athletes Journal of the American Society of Echocardiography 12(11), 988-993. https://dx.doi.org/10.1016/s0894-7317(99)70153-7
- Book chapter: Haycock, K., Spiegel, R. (2019). Special Skills: Venous Congestion.