Abstract
BACKGROUND: Several hemodynamic parameters have been promoted to help establish a rapid diagnosis of hemorrhagic shock, but they have not been well validated in the pregnant population. In this study, we examined the association between three measures of shock and early blood transfusion requirements among pregnant trauma patients. METHODS: This study included 81 pregnant trauma patients admitted to a level 1 trauma center (2010-2015). In separate logistic regression models, we tested the relationship between exposure variables-initial systolic blood pressure (SBP), shock index (SI), and rate over pressure evaluation (ROPE)-and the outcome of transfusion of blood products within 24 hours of admission. To test the predictive ability of each measure, we used receiver operating characteristic (ROC) curves. RESULTS: A total of 10% of patients received blood products in the patient cohort. No patients had an initial SBP≤90, so the SBP measure was excluded from analysis. We found that patients with SI>1 were significantly more likely to receive blood transfusions compared with patients with SI<1 (OR 10.35; 95% CI 1.80 to 59.62), whereas ROPE>3 was not associated with blood transfusion compared with ROPE≤3 (OR 2.92; 95% CI 0.28 to 30.42). Furthermore, comparison of area under the ROC curve for SI (0.68) and ROPE (0.54) suggested that SI was more predictive than ROPE of blood transfusion. CONCLUSION: We found that an elevated SI was more closely associated with early blood product transfusion than SBP and ROPE in injured pregnant patients. LEVEL OF EVIDENCE: Prognostic, level III.