What is VExUS?

What is POCUS?

Point-of-care ultrasound (POCUS) is ultrasound performed by the treating clinician, at the bedside, to answer a specific question in real time — rather than a full study done in a radiology department and reported later.

It has spread quickly because handheld and portable scanners made imaging available wherever the patient is: the ward, the emergency department, the ICU, and increasingly the primary-care clinic. The clinician scans, interprets, and acts in the same encounter. POCUS does not replace formal imaging; it extends the physical exam with questions like is there fluid here, is this vessel dilated, how is this organ perfusing.

What is VExUS?

VExUS — Venous Excess UltraSound — is a POCUS protocol that grades how congested the venous side of the circulation is, on a scale from 0 to 3.

Most bedside tools estimate whether a patient needs more fluid. VExUS looks at the opposite problem: too much fluid backing up into the veins and organs. That backward pressure — venous congestion — is now recognised as a driver of organ injury, especially of the kidneys, in heart failure, cardiorenal syndrome and critical illness.

The four measurements

VExUS combines one size measurement with three Doppler waveforms. Doppler shows the direction and pattern of blood flow, and congestion distorts these patterns in characteristic ways.

1 · IVC diameter — the gate

The inferior vena cava (IVC) is the large vein returning blood to the heart. If it is under 2 cm, there is no meaningful systemic congestion and the score is grade 0 — the Doppler patterns are not even scored. A dilated IVC (≥ 2 cm) is what "opens" the grading.

2 · Hepatic vein

Sampled where a liver vein joins the IVC. Normally the systolic (S) wave is at least as large as the diastolic (D) wave. As congestion worsens the S wave shrinks, and in severe congestion it reverses direction entirely.

3 · Portal vein

Normally near-continuous flow. Congestion makes it pulsatile. This is quantified as a pulsatility fraction: under 30% is normal, and ≥ 50% is severe.

4 · Intrarenal (interlobar) vein

The small veins inside the kidney. Normal flow is continuous. As pressure rises the trace breaks into two phases (biphasic), and in severe congestion into a single diastolic-only phase (monophasic).

How the grade is built

Once the IVC is dilated, the grade depends on how many of the three veins show a severe pattern. Mild abnormalities do not push the grade higher than 1.

A "severe pattern" means any one of: hepatic systolic reversal, portal pulsatility ≥ 50%, or intrarenal monophasic flow.

Why it matters clinically

Higher VExUS grades are associated with a greater risk of congestion-related organ injury, particularly acute kidney injury. Clinicians use the grade in settings such as:

• Cardiorenal syndrome — deciding whether it is safe to keep removing fluid.
• Decompensated heart failure — tracking how congestion changes as diuretics take effect.
• Critical care and after cardiac surgery — the setting where the score was first validated.

Because it is quick and repeatable, its real strength is following a trend: scanning again after treatment to see whether congestion is actually resolving, rather than relying on weight and clinical gestalt alone.

Limitations

VExUS is one input, not a verdict. It needs an adequate acoustic window and is harder to interpret in atrial fibrillation, advanced liver or kidney disease, and difficult body habitus. It grades congestion — it does not, on its own, tell you the cause or the treatment. It always belongs inside the full clinical picture.