Prognostic significance of inferior vena cava volume defined by initial polytrauma CT-imaging: single-center experience of a level-1 trauma center

Background: The significance of computed tomography (CT)-based volume measurement of the inferior vena cava (IVC) in the treatment and prognosis of trauma patients is not yet fully understood. The conflicting results that have been reported may be attributable to differences in injury severity and the use of different measurement methods, including IVC index and volumetry. The purpose of this study was to determine the relationship between IVC volume and red blood cell (RBC) transfusion and mortality in intubated trauma patients who were stable enough for initial CT imaging.

Methods: A retrospective analysis was conducted on all consecutive trauma patients who underwent emergency tracheal intubation and mechanical ventilation before initial whole-body CT imaging at a level-1 trauma center over a 12-year period (2008-2019). The IVC volume was determined on initial trauma CT and included in multivariable models with demographic and diagnostic data. Associations of overall RBC transfusion, massive transfusion, 24-h mortality, and 30-day mortality were assessed using logistic regression analyses and Cox proportional hazard models.

Results: A total of 438 patients (75.3% male) with a median age of 50 years, and a median injury severity score (ISS) of 26 points were included in the analysis. Most of the patients (97.5%) had suffered from blunt trauma mechanisms. Median IVC volume was 36.25 cm³, and RBC transfusion and massive transfusion were performed in 197 and 90 patients, respectively. The 24-h and 30-day mortality rates were 7.3% and 23.3%, respectively. VCI volume was found to be independently associated with the necessity of RBC transfusion and 24-h mortality (OR 0.98, 95% CI 0.96-0.99, p = 0.01 and HR 0.96, 95% CI 0.93-0.99, p = 0.025, respectively), while associations with massive transfusion and 30-day mortality were not statistically significant in multivariable analyses.

Conclusion: Initial IVC volume may serve as a predictor of patients at risk for overall RBC transfusion requirements and 24-h mortality, suggesting the possibility of its diagnostic efficacy in short-term outcomes. Further studies are needed to confirm these findings.