The collapsed inferior vena cava: CT evidence of hypovolemia.

In a review of 100 patients undergoing abdominal CT for blunt abdominal trauma, seven had flattening of the infrahepatic inferior vena cava at multiple levels. In six of these patients, emergency surgery was required to control major hemorrhage. Three patients had hypotension documented during or shortly after abdominal CT. Five patients had major intraabdominal injuries, and one patient had massive hemorrhage from facial lacerations. The severity of the blood loss was not fully appreciated clinically in five of the six patients before CT. The seventh patient had no clinical evidence of significant blood loss; in this case the flattened inferior vena cava probably was related to a normal variant. In a group of 100 patients scanned for nonacute conditions, none had flattening of the infrahepatic inferior vena cava at multiple levels. Presence of a collapsed inferior vena cava may be CT evidence of significant hypovolemia from major blood loss and should prompt careful hemodynamic and central venous pressure monitoring.