Prediction of massive bleeding. Shock index and modified shock index

Abstract

Objective: To determine the predictive value of the Shock Index and Modified Shock Index in patients with massive bleeding due to severe trauma.

Design: Retrospective cohort.

Setting: Severe trauma patient's initial attention at the intensive care unit of a tertiary hospital.

Subjects: Patients older than 14 years that were admitted to the hospital with severe trauma (Injury Severity Score >15) form January 2014 to December 2015.

Variables: We studied the sensitivity (Se), specificity (Sp), positive and negative predictive value (PV+ and PV-), positive and negative likelihood ratio (LR+ and LR-), ROC curves (Receiver Operating Characteristics) and the area under the same (AUROC) for prediction of massive hemorrhage.

Results: 287 patients were included, 76.31% (219) were male, mean age was 43,36 (±17.71) years and ISS was 26 (interquartile range [IQR]: 21-34). The overall frequency of massive bleeding was 8.71% (25). For Shock Index: AUROC was 0.89 (95% confidence intervals [CI] 0.84 to 0.94), with an optimal cutoff at 1.11, Se was 91.3% (95% CI: 73.2 to 97.58) and Sp was 79.69% (95% CI: 74.34 to 84.16). For the Modified Shock Index: AUROC was 0.90 (95% CI: 0.86 to 0.95), with an optimal cutoff at 1.46, Se was 95.65% (95% CI: 79.01 to 99.23) and Sp was 75.78% (95% CI: 70.18 to 80.62).

Conclusion: Shock Index and Modified Shock Index are good predictors of massive bleeding and could be easily incorporated to the initial workup of patients with severe trauma.

Keywords: Escala de severidad del trauma; Escala de trauma revisado; Hemorragia masiva; Injury severity score; Massive bleeding; Massive transfussion; Modified shock index; Revised trauma score; Shock index; Transfusión masiva; Índice de shock; Índice de shock modificado.