VExUS (Venous Excess Ultrasound Score)

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VExUS (Venous Excess Ultrasound Score)

VExUS is a point-of-care ultrasound (POCUS)-based scoring system used to quantify systemic venous congestionand predict organ dysfunction (especially congestive nephropathy) in critically ill patients.

It integrates:

  • IVC size (macro congestion)
  • Doppler patterns in venous systems (micro congestion transmission)

Why VExUS? (Core Concept)

Traditional markers (CVP, edema, weight gain) are:

  • Late
  • Non-specific
  • Poor predictors of organ congestion

VExUS assesses backward failure (venous congestion):

Pathophysiological Cascade

↑ RA pressure → ↑ IVC pressure → transmission to:

  • Hepatic veins → liver congestion
  • Portal vein → splanchnic congestion
  • Renal veins → ↓ GFR → AKI

 This is congestive nephropathy

Although enthusiasm has grown in other aspects like sepsis, heart failure etc but  systematic reviews conclude that evidence remains heterogeneous and further validation is needed before universal adoption.

 

VExUS Technique 

  1. Position the patient supine (or slightly head-up if needed).
  2. Ask the patient to breathe normally.
  3. Locate the target vessel.
  4. Ask:“Breathe out normally… now hold your breath.”—measure at end-expiration(Reason- Primarily to reduce organ motion and obtain a stable Doppler signal,A short end-expiratory breath-hold minimizes respiratory effects so that the waveform primarily reflects the cardiac cycle, which is what VExUS evaluates.)
  5. Record 3–5 cardiac cycles (about 2–5 seconds).
  6. Resume normal breathing.

A. Inferior Vena Cava (IVC)

Measurement:

  • Subcostal long-axis
  • 1–2 cm from RA junction

Interpretation:

IVC

Meaning

< 2 cm + collapsible

Low RA pressure

> 2 cm + non-collapsible

High RA pressure

 VExUS requires dilated IVC (>2 cm) to proceed further(original VExUS protocol-Beaubien-Souligny)

But is this always true?No.

Clinical experience and later studies have identified situations where the IVC may be <2 cm but organ venous Doppler is still abnormal.

This is why many POCUS experts no longer rely exclusively on the IVC gatekeeper.

 

B. Hepatic Vein Doppler

Sample Right hepatic vein Near IVC—Pulse-wave Doppler

Normal Pattern(TRIPHASIC):S wave > D wave(forward flow)

followed by A wave

Congestion Pattern:

Pattern

Finding

Mild

S < D

Severe

S reversal

Why hepatic vein changes first?

It drains directly into IVC.No capillary bed.Therefore First organ affected.

ANATOMY AND IDENTIFICATION

The portal triad contains:

  • Portal vein
  • Hepatic artery
  • Common bile duct

Feature

Hepatic Vein

Portal Vein

Hepatic Artery

Blood flow

Liver → IVC

Portal system → Liver

Aorta → Liver

Direction

Away from liver

Towards liver

Towards liver

Wall

Thin, indistinct

Thick echogenic wall

Thin, difficult to see

Size

Largest

Large

Smallest

PW Doppler

Triphasic

Continuous monophasic

Pulsatile arterial

Respiratory variation

Marked

Mild

Minimal

Cardiac pulsatility

Very marked

Minimal normally

Present

Branching

Converge into IVC

Branch throughout liver

Travels with portal vein

ROLE OF ECG

ECG event

Cardiac event

Hepatic vein Doppler

P wave

Atrial contraction

A-wave reversal (small retrograde flow)

QRS complex

Ventricular systole begins

S-wave starts(Systolic Forward Flow)

T wave

End of systole

Transition to D-wave

Early diastole

Tricuspid valve opens

D-wave(Diastolic Forward Flow)

Without ECG, it can be difficult to determine whether the reversed wave is truly the systolic (S) wave or another component. ECG confirms its timing.

 

C. Portal Vein Doppler

Normal:Continuous, monophasic flow

Abnormal:Pulsatile flow (due to RA pressure transmission)

Portal Pulsatility Fraction (PPF):

PPF=(Vmax −Vmin)/Vmax  ×100

PPF

Severity

< 30%

Normal

30–50%

Mild

> 50%

Severe

D. Intrarenal Vein Doppler

Obtained from Interlobar vein

Normal:Continuous venous flow

Congestion:

Pattern

Interpretation

Biphasic

Moderate

Monophasic (discontinuous)

Severe

Direct reflection of renal venous hypertension

 

VExUS Grading System

 Only applied when IVC is dilated

Grade

Criteria

Grade 0

IVC normal

Grade 1

IVC dilated + mild Doppler changes

Grade 2

IVC dilated + 1 severe abnormal Doppler

Grade 3

IVC dilated + ≥2 severe Doppler abnormalities

Severe abnormalities:

  • Hepatic vein → S reversal
  • Portal vein → PPF > 50%
  • Renal vein → monophasic flow

Clinical Significance 

A. Acute Kidney Injury (AKI)

  • Strong predictor of congestive AKI
  • Better than CVP

 Especially in:

  • Post-cardiac surgery
  • Septic patients with fluid overload

B. Fluid Management in ICU

Scenario

Role of VExUS

Fluid resuscitation

Avoid over-resuscitation

Shock

Differentiate hypovolemia vs congestion

De-resuscitation

Guide diuretics/ultrafiltration

Grade

Management

0–1

Fluids if needed

2

Caution → avoid overload

3

Active decongestion (diuretics/CRRT)

C. Heart Failure

  • Detect subclinical congestion
  • Guide diuretic therapy

D. Perioperative Medicine

  • Predict post-op AKI
  • Optimize fluid balance

Limitations

  • Not a direct measure of volume status.
  • Elevated RAP from severe TR, pulmonary hypertension, RV dysfunction, or mechanical ventilation can alter waveforms independent of excess body fluid.
  • Portal hypertension and chronic liver disease may confound portal vein interpretation.
  • Technically challenging in obesity, abdominal wounds, dressings, bowel gas, or poor acoustic windows.
  • Requires training in Doppler acquisition and interpretation.
  • Should never be used in isolation to decide on fluids or diuretics; integrate with clinical examination, echocardiography, lung ultrasound, perfusion markers, urine output, and laboratory data.