Mistaken Identity: Misidentification of Other Vascular Structures as the Inferior Vena Cava and How to Avoid It

While point-of-care ultrasound (POCUS) of the inferior vena cava (IVC) is broadly perceived as having value in intravascular volume status assessment, this has not been borne out in large-scale meta-analyses containing heterogenous populations of acutely ill patients. While the limitations of IVC POCUS could be largely due to the complexity of the relationship between IVC appearance and volume status, another confounder not widely appreciated is the ease with which the aorta or right hepatic vein (RHV) can be mistaken for the IVC. While misidentification of the aorta as the IVC has been recognized elsewhere, misidentification of the RHV for the IVC has not and, in our experience, occurs frequently, even in the hands of experienced sonographers. We demonstrate how these errors occur and provide guidance on how to systematically avoid them.