IVC ultrasound

Revision as of 15:07, 7 March 2015 by Neil.m.young (talk | contribs) (Redo and ref table)

Background

  • Though contriversal, IVC measurement by ultrasound can estimate volume status and fluid responsiveness
    • There is moderate evidence to support that IVC diameter is consistently low in hypovolemia vs euvolemia[1]
    • It is suggested that IVC change can estimate fluid responsiveness with a Sn 0.78 and Sp 0.86[2]
  • 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 or estimation can be made in 2D with IVC in longitudinal axis

Measurements

Correlations Between IVC Size and CVP[3]

IVC (cm) Respiratory Change CVP (cm H2O)
<1.5 Total collapse 0-5
1.5-2.5 >50% collapse 6-10
1.5-2.5 <50% collapse 11-15
>2.5 <50% collapse 16-20
>2.5 No change >20

Measure 2cm from IVC/RA junction or 1cm from IVC/hepatic vein junction

See Also

References

Dawson, M. Mallin, M. Introduction To Bedside Ultrasound: Volumes 1 and 2.Emergency Ultrasound Solutions. 2012 Inkling File

  1. Dipti A, et al. Role of inferior vena cava diameter in assessment of volume status: a meta-analysis. AJEM. 2012; 30:1414-1419.
  2. Zhang Z, et al. Ultrasonographic measurement of the respiratory variation in the inferior vena cava diameter is predictive of fluid responsiveness in critically ill patients: systematic review and meta-analysis. Ultrasound Med Biol. 2014. May; 40(5):845-53.
  3. Goldflam K, et al. Focus on: Inferior vena cava ultrasound. ACEP News. June 2011.