VExUS Simulator

Change right atrial pressure, rhythm and pitfalls, then watch the hepatic, portal and intrarenal venous Doppler respond.

IVC max diameter2.5 cmOver 2 cm
Hepatic veinS reversalSevere
Portal vein PVPF41%Mild
Intrarenal veinBiphasicMild
2VExUS grade 2One severe waveform

Hepatic vein

Right coronal view, PW gate 1 to 2 cm from the HV to IVC junction
Normal color: blue, away from probeSevere
HV PW antegrade below baseline
40 cm/s

Portal vein

Coronal view, gate distal in the main portal vein, away from hepatic artery aliasing
Normal color: red, toward probeMild
PV PW hepatopetal above baseline
40 cm/s

Intrarenal vein

Coronal view, gate on an interlobar vessel, abdominal preset
Artery redVein blueMild
IRA above IRV below baseline
15 cm/s

Hepatic vein

  • A and V are retrograde (above baseline); S and D are antegrade (below).
  • A follows the P wave, S follows the QRS, V is end systole, D follows the T wave.
  • Normal S > D. Mild: S < D, still below baseline. Severe: S reversed above baseline.
  • Pitfalls: AF causes S < D without high RAP. Cirrhosis blunts phasicity. Structural TR keeps S reversed even after decongestion.

Portal vein

  • Normal flow is continuous and toward the probe (red), because sinusoids dampen RAP.
  • PVPF = (Vmax − Vmin) / Vmax × 100.
  • Under 30% normal, 30 to 50% mild, 50% or more severe.
  • Pitfalls: lean people and athletes can be pulsatile normally; cirrhosis can raise or mask pulsatility.

Intrarenal vein

  • Use interlobar veins, abdominal preset, scale below 20 cm/s.
  • Normal: continuous. Mild: biphasic with distinct S and D. Severe: monophasic, D only.
  • The arterial waveform above baseline times the cardiac cycle.
  • Hardest view to obtain; not studied in CKD or renal transplant.

Grading

  • IVC 2 cm or less: grade 0, Doppler not graded.
  • IVC over 2 cm and no severe waveform: grade 1.
  • One severe waveform: grade 2. Two or more: grade 3.
  • VExUS shows congestion, not volume responsiveness. Interpret with cardiac POCUS and the clinical picture.