Impact on survival of whole-body computed tomography before emergency bleeding control in patients with severe blunt trauma

Abstract

Introduction: Whole-body computed tomography (CT) has gained importance in the early diagnostic phase of trauma care. However, the diagnostic value of CT for seriously injured patients is not thoroughly clarified. This study assessed whether preoperative CT beneficially affected survival of patients with blunt trauma who required emergency bleeding control.

Methods: This retrospective study was conducted from January 2004 to December 2010 in two tertiary trauma centers in Japan. The primary inclusion criterion was patients with blunt trauma who required emergency bleeding control (surgery or transcatheter arterial embolization). CT before emergency bleeding control was performed at the attending physician's discretion based on individual patient condition (for example, hemodynamic stability or certain abnormalities in the primary survey). We assessed covariates associated with 28-day mortality with multivariate logistic regression analysis and evaluated standardized mortality ratio (SMR, ratio of observed to predicted mortality by Trauma and Injury Severity Score (TRISS) method) in two subgroups of patients who did or did not undergo CT.

Results: The inclusion criterion was fulfilled by 152 patients with a median Injury Severity Score of 35.3. During the early resuscitation phase, 132 (87%) patients underwent CT and 20 (13%) did not. Severity of injury was significantly higher in the non-CT versus CT group patients. Observed mortality rate was significantly lower in the CT versus non-CT group (18% vs. 80%, P <0.001). Multivariate adjustment for the probability of survival (Ps) by TRISS method confirmed CT as an independent predictor for 28-day mortality (adjusted OR, 7.22; 95% CI, 1.76 to 29.60; P = 0.006). In the subgroup with less severe trauma (TRISS Ps ≥50%), SMR in the CT group was 0.63 (95% CI, 0.23 to 1.03; P = 0.066), indicating no significant difference between observed and predicted mortality in the CT group. In contrast, in the subgroup with more severe trauma (TRISS Ps <50%), SMR was 0.65 (95% CI, 0.41 to 0.90; P = 0.004) only in the CT group, whereas the difference between observed and predicted mortality was not significant in the non-CT group, suggesting a possible beneficial effect of CT on survival only in trauma patients at high risk of death.

Conclusion: CT performed before emergency bleeding control might be associated with improved survival, especially in severe trauma patients with TRISS Ps of <50%.

Figures

Figure 1

Patient flow diagram. CPA, cardiopulmonary arrest.

Figure 2

Outcome analysis for calculation of standardized mortality ratio (SMR) on the basis of the Trauma and Injury Severity Score (TRISS) method. All patients were divided into two groups on the basis of TRISS Ps. The gray columns represent observed mortality rates, the blue bars represent predicted mortality rates, and the whisker bars represent the 95% confidence range. Ps, probability of survival

Figure 3

Outcome analysis for calculation of standardized mortality ratio (SMR) on the basis of shock index (SI) value. The patients who underwent CT scanning were divided into two groups on the basis of their SI value. The gray columns represent observed mortality rates, the blue bars represent predicted mortality rates, and the whisker bars represent the 95% confidence range.