Interactive tool

IVC and VExUS assessment

Intended use

A decision-support tool for ultrasound assessment of venous congestion. VExUS alone cannot diagnose or rule out heart failure and does not determine treatment.

1. Inferior vena cava

Maximum IVC diameter (cm)Measure at end-expiration in the subcostal long-axis view. Minimum IVC diameter (cm)During inspiration or sniff. Respiratory context

Additional signs of markedly elevated RAP Dilated hepatic veins IVC flow reversal or spontaneous echo contrast

2. Venous Doppler (for VExUS grading)

Select the observed pattern. If a territory cannot be assessed, select “Not assessable”; the calculator will flag the grading as incomplete.

Hepatic vein Portal vein Intrarenal vein

Applied criteria

Method and limitations

Collapsibility index and RAP/CVP estimate

IVC collapsibility (%) = (maximum diameter − minimum diameter) / maximum diameter × 100. During spontaneous breathing, the calculator combines maximum diameter and inspiratory collapse (sniff) according to the 2025 ASE criteria: IVC ≤2.1 cm and collapse ≥50% suggest RAP 3 mmHg (range 0–5); IVC >2.1 cm and collapse <50% suggest RAP 15 mmHg (10–20); discordant criteria suggest an intermediate value of 8 mmHg (5–10). RAP of 20 mmHg is suggested only when IVC >2.5 cm and collapse <50% occur together with dilated hepatic veins and IVC flow reversal/spontaneous echo contrast.

Central venous pressure (CVP) is approximated by right atrial pressure (RAP), but ultrasound provides a non-invasive estimate. Collapsibility alone does not establish volume status or fluid responsiveness.

VExUS grading

The calculator applies this guide’s operational threshold: IVC ≥ 2.1 cm. VExUS 0 below the threshold; with a dilated IVC, grade 1 if no severe patterns are present, grade 2 with one severe pattern and grade 3 with at least two severe patterns. A dilated IVC with an unassessable Doppler territory produces a provisional or incomplete result.

Mild hepatic: S wave lower than D but forward; severe: systolic flow reversal.
Mild portal: pulsatility 30–<50%; severe: ≥50%.
Mild intrarenal: biphasic, pulsatile S-D flow; severe: monophasic pattern with D wave only.

Limitations

With positive-pressure ventilation, the calculator does not provide a numeric RAP/CVP estimate from the IVC alone; assess additional echocardiographic indices. Atrial fibrillation, raised intra-abdominal pressure, cirrhosis/portal hypertension, advanced kidney disease, transplantation, valvular disease, athletic conditioning and technical variability may affect measurements. VExUS describes systemic venous congestion; it does not by itself determine heart failure, hypovolaemia or the need for fluids/diuretics. Interpret alongside the full clinical and echocardiographic picture.

Selected references

References

Mukherjee M, et al. Guidelines for the Echocardiographic Assessment of the Right Heart in Adults and Special Considerations in Pulmonary Hypertension. JASE. 2025;38:141–186. doi:10.1016/j.echo.2025.01.006.
Beaubien-Souligny W, et al. Quantifying systemic congestion with Point-Of-Care ultrasound: development of the venous excess ultrasound (VExUS) grading system. Ultrasound J. 2020;12:16. doi:10.1186/s13089-020-00163-w.
Study Guide: IVC Color Doppler and VEXUS Protocol (document supplied by the user).

Disclaimer

For healthcare professionals and educational use. This tool does not replace guidelines, a complete patient assessment or clinical judgement. Calculations run in your browser; entered values are not transmitted or stored by the calculator.