Does CT evidence of a flat inferior vena cava indicate hypovolemia in blunt trauma patients with solid organ injuries?

BACKGROUND: Nonoperative management for selective patients with solid organ injuries from blunt trauma has gained wide acceptance. However, for trauma surgeons, it is often difficult to estimate a patient's circulatory volume. Some authors have proposed that the presence of a collapsed inferior vena cava (IVC) on computed tomography (CT) scan correlates with inadequate circulatory volume. Our aim was to verify whether CT evidence of a flat IVC (FI) is an indicator of hypovolemia in blunt trauma patients with solid organ injuries.
METHODS: We conducted a retrospective chart review of all blunt trauma patients with solid organ injuries admitted to our Medical Center from July 2003 to September 2006. Of the 226 patients reviewed, 29 had CT evidence of FI. We compared Injury Severity Scores, hemodynamic parameters, fluid and blood transfusion requirements, mortality rate, and hospital course between patients with (FI group) and without FI (non-FI [NFI] group).
RESULTS: The FI group had higher rates of intensive care unit admission and mortality, in addition to longer intensive care unit stays, when compared with the NFI group. In addition, the patients in the FI group needed larger amounts of fluid and blood transfusions and presented lower hemoglobin levels during the first week of admission; furthermore, the majority deteriorated to a state of shock in the emergency department.
CONCLUSIONS: CT evidence of FI is a good indicator of hypovolemia and an accurate predictor for prognosis in trauma patients with blunt solid organ injuries.