Inferior Vena Cava Ultrasonography for Volume Status Evaluation: An Intriguing Promise Never Fulfilled

The correct determination of volume status is a fundamental component of clinical evaluation as both hypovolaemia (with hypoperfusion) and hypervolaemia (with fluid overload) increase morbidity and mortality in critically ill patients. As inferior vena cava (IVC) accounts for two-thirds of systemic venous return, it has been proposed as a marker of volaemic status by indirect assessment of central venous pressure or fluid responsiveness. Although ultrasonographic evaluation of IVC is relatively easy to perform, correct interpretation of the results may not be that simple and multiple pitfalls hamper its wider application in the clinical setting. In the present review, the basic elements of the pathophysiology of IVC behaviour, potential applications and limitations of its evaluation are discussed.

Automated summary

Correct determination of volume status is crucial in clinical evaluation for critically ill patients, as both hypovolaemia and hypervolaemia increase morbidity and mortality. The inferior vena cava (IVC) has been proposed as a marker of volume status by indirect assessment of central venous pressure or fluid responsiveness. However, the interpretation of ultrasonographic evaluation of the IVC is complex and there are limitations to its clinical application.