POCUS findings of a collapsed IVC most strongly suggest which hemodynamic state?

• A. Hypervolemia
• B. Hypovolemia
• C. Obstructive shock due to tamponade
• D. Neurogenic shock

Answer: (B)

A markedly collapsible IVC on ultrasound reflects very low preload and low right atrial pressure, which is most consistent with hypovolemia. When circulating volume is depleted, the IVC is small and shows significant collapse with inspiration because venous return is limited by the low intravascular volume. In contrast, hypervolemia tends to make the IVC distended and less collapsible due to higher venous pressures. Obstructive shock from tamponade raises right atrial pressure, typically producing a dilated, poorly responsive IVC rather than a highly collapsible one. Neurogenic shock can cause hypotension from vasodilation, but the IVC pattern is not the defining finding here. So, a highly collapsible IVC most strongly points to low circulating volume typical of hypovolemia.