IVC ultrasound

Revision as of 23:06, 5 March 2015 by Kghaffarian (talk | contribs) (clarified techniques, added info about mmode)

Background

  • Inferior vena cava measurement by ultrasound to estimate volume status
  • Measure both absolute diameter of IVC and percent collapse during inspiration of spontaneously breathing patients
  • can use as a dynamic assessment after intervention (giving fluids)
  • Unclear if applicable to intubated patients

Technique

  • Use curvilinear (abdominal) probe or phased array (cardiac) probe
  • In subxyphoid cardiac view (epigastric), fan probe laterally to view the IVC draining into the right atrium
    • may start with subxyphoid view, place right atrium in center of screen and rotate probe 90 degrees clockwise to find IVC
  • use M-mode to measure IVC collapse during inspiration

Measurements

IVC  % Collapse during inspiration^ CVP
<1.5cm >50% 0-5
1.5-2.5cm >50% 5-10
1.5-2.5cm <50% 10-15
>2.5cm Little phasicity 15-20

^Measure ~2cm from IVC/RA junction

  • Can ask patient to sniff or valsalva to evaluate collapse

See Also