POCUS in cirrhosis is a different beast. It can easily lead us astray if we don’t pay attention to the details, given the multiple anatomical and physiological alterations associated with cirrhosis that complicate interpretation. If you haven’t already, check out my previous detailed reviews on how I do POCUS in cirrhosis-AKI, as well as my general overview of extended VExUS (eVExUS). The latter expands the traditional VExUS assessment beyond the three commonly evaluated venous territories – hepatic, portal, and intrarenal veins to include additional venous Doppler sites for assessing systemic venous congestion in the setting of elevated right atrial pressure. This is particularly appealing in patients with cirrhosis, where hepatic and portal venous Doppler patterns may be altered by local structural and hemodynamic abnormalities, while intrarenal venous Doppler signals can sometimes be technically difficult to obtain.

The clinical scenario

Here, we have a patient with advanced cirrhosis and acute kidney injury who was relatively oliguric and receiving mechanical ventilation in volume-control mode with a positive end-expiratory pressure (PEEP) of 5 cm H₂O.

I started physical exam (POCUS) with a quick look at the IVC, which appeared plethoric. But as we know, IVC size doesn’t correlate all that well with right atrial pressure (RAP) in mechanically ventilated patients. Next, I looked at the internal jugular vein (IJV). The patient had just received a right IJV dialysis catheter, so I went with the left side. Interestingly, the left IJV appeared collapsed in the lower third of the neck. That made me wonder whether RAP was actually elevated at all.

Of course, there’s a catch. We generally prefer the right IJV for estimating RAP because it has a relatively straight course toward the right atrium. The left IJV drains through the longer left brachiocephalic vein, which can sometimes get compressed between the aortic arch and the thoracic cage. So, left-sided findings need to be interpreted with some caution. But with a freshly placed dialysis catheter on the right, the left side was my only practical option. I then checked the left IJV Doppler waveform, which is one of the additional venous Doppler sites included in eVExUS. Interestingly, the systolic (S) and diastolic (D) waves were almost equal in amplitude. Normally, we expect systolic predominance (S > D). Unfortunately, the IJV S/D ratio hasn’t been studied extensively in this context, but in general, patterns such as S = D, S < D, or a D-only waveform are considered abnormal. So now things are getting interesting. We had a plethoric IVC, a seemingly collapsed left IJV, and an IJV Doppler waveform that had lost its normal systolic predominance. Not exactly a straightforward picture.

Looking for other venous Doppler clues

The patient had known portal hypertension with flow reversal in the portal vein, so portal vein Doppler wasn’t going to be particularly helpful here. Looking at prior imaging, I also noticed that the hepatic vein waveform was completely blunted, which may or may not reflect changes in RAP in someone with advanced cirrhosis. I then tried to obtain an intrarenal venous Doppler waveform but couldn’t get a satisfactory signal. As you probably know, intrarenal venous Doppler can be technically challenging, even for a nephrologist!

So, what next?

While obtaining cardiac windows, I noticed that the patient had a pretty decent parasternal right ventricular (RV) inflow view. So, why not try getting an IVC Doppler waveform from there? We don’t routinely use IVC Doppler, partly because the Doppler angle is often unfavorable from the subxiphoid view, where the ultrasound beam may be nearly perpendicular to blood flow. However, the RV inflow view can sometimes provide a much better angle for sampling flow near the IVC-right atrial junction. And that’s exactly what I did. I was able to obtain a good IVC Doppler waveform, which showed systolic flow less than diastolic flow (S < D) – pay attention to EKG. Normally, we expect systolic predominance (S > D), so this was another abnormal venous Doppler finding, consistent with what I had observed in the left IJV.

Finally, I looked at the right femoral vein. The Doppler waveform was clearly pulsatile, with an increased venous stasis index (flow gaps) and an S < D pattern. This provided yet another clue pointing toward systemic venous congestion.

Putting it all together

Overall, the Doppler findings suggested systemic venous congestion. However, we don’t yet have a validated grading system for eVExUS that allows us to reliably quantify its severity. None of these waveforms looked particularly severe to me, although they were clearly abnormal. Then came the surprise! We obtained a CVP measurement through the third (infusion) lumen of the recently placed hemodialysis catheter, and it was 18 mmHg. That’s considerably higher than what I initially suspected based on the appearance of the left IJV. Even the IJV Doppler pattern (S ≈ D) might have led me to suspect only a modest elevation in RAP, certainly not something this high. We also need to remember that I was examining the left IJV, which may not reflect right atrial hemodynamics as reliably as the right IJV or superior vena cava, given the anatomical considerations discussed earlier. However, this limitation doesn’t necessarily apply to invasive CVP measurements. Regardless of whether a central venous catheter is inserted through the right or left IJV, as long as the pressure-sensing port is appropriately positioned in the SVC or proximal right atrium, it should reflect CVP, assuming proper measurement technique.

What happened after fluid removal?

We started continuous renal replacement therapy, and over the next four days, the patient achieved a ‘net’ negative fluid balance of approximately 6 liters. Urine output improved, and the dialysis catheter was subsequently removed. I repeated the POCUS examination the following day, and interestingly, all three venous Doppler waveforms had improved, along with a noticeable reduction in IVC size. At this point, the patient was still intubated but had transitioned to pressure support ventilation.

The IVC diameter had decreased considerably. You can also appreciate the somewhat unusual bottle-shaped appearance near the IVC opening, which is often seen in cirrhosis due to anatomical distortion associated with caudate lobe hypertrophy. The left IJV waveform now showed restoration of systolic predominance (S >> D). The IVC Doppler also changed from S < D to S > D. Meanwhile, the right femoral vein waveform, which was previously pulsatile with an increased stasis index, had become continuous with the expected respiratory variation. Unfortunately, I don’t have a follow-up CVP measurement to correlate with these changes, as the catheter has already been removed.

Also, TR has improved qualitatively, as shown below. As discussed in the previous post on VExUS in TR, functional TR often improves with fluid removal.

Take-home message

This case nicely illustrates how eVExUS can be useful in patients with cirrhosis, particularly when traditional VExUS components are unreliable or technically difficult to obtain. Of course, there are caveats. A single case cannot tell us how to grade congestion using eVExUS, and we certainly cannot assign a specific CVP value based on the appearance of a Doppler waveform. Instead, the key is to integrate findings from multiple venous sites rather than relying on a single vessel (like the left IJV in this case), while keeping the patient’s physiology and clinical context in mind.

Perhaps the greatest value of eVExUS here was not predicting absolute RAP but monitoring changes in venous congestion over time. While VExUS waveforms correlate with RAP, we often overlook the role of venous compliance in determining how elevated pressure translates into organ congestion. This is also why, in the original VExUS study, venous Doppler assessment outperformed CVP alone in predicting AKI associated with venous congestion.

Hope you found this case interesting! Comments welcome.