Inferior vena cava ultrasound for volume status evaluation: A conundrum

Abstract: Ultrasound evaluation of inferior vena cava (IVC) is commonly used in varied clinical settings to assess the volume status, providing insights to determine the need and adequacy of fluid resuscitation, and also provides an estimate of right atrial pressure for various echocardiographic calculations. It is relatively easy to perform and is noninvasive and widely used in hemodynamic evaluation in intensive care units. Measuring the static diameter of IVC and assessing its dynamic respiratory variability may seem simplistic. However, IVC ultrasound may be restricted by factors affecting IVC diameter and collapsibility or adequate visualization. The accurate interpretation of results requires in-depth knowledge of pathophysiology, and this may be fraught with numerous pitfalls.