Journal of Trauma & Treatment

Cardiovascular Reserve Index Versus Shock Index Prediction of Early Trauma Deaths: Trauma-Registry Based Study

Abstract

Gabbay U, Klein Y and Stein M

Evaluation of trauma injuries is challenging as an apparently stable casualty may be eventually hemodynamically deteriorated but compensated. Shock index (SI) is bi-vital sign index proposed in 1967 for detecting severe hemodynamic deterioration. The cardio-vascular reserve index (CVRI) is a multi-vital sign index which previous studies revealed promising associations along the entire hemodynamic spectrum.

Methods: A historical prospective study was conducted utilized the Israeli National Trauma Registry of 2015. Entry point was emergency department (ED) admission, and end point was either in-hospital death or survival to discharge. Both SI and CVRI were computed from the retrieved vital signs (on ED admission). Predictability of death was evaluated by Receiver Operating Characteristics area under the curve (AUC). The study aimed to evaluate SI and CVRI predictability of early trauma death as an add-on to the existing trauma death predictors such as Glasgow Coma Score (GCS) and Revised Trauma Score (RTS).

Results: Included were 27,910 trauma casualties, mean age 54.6 years, 56% male, 98.5% survived to discharge and 1.5% died (0.2% early trauma deaths). Both SI and CVRI were found to be a moderate predictors of early death (AUC=69%) in the entire trauma population, inferior to GCS (AUC=77%), and Revised Trauma Score (RTS) (AUC=85%). However, the vast majority of casualties were scored GCS ≥ 14 including nearly half of the early deaths. In this subpopulation CVRI was a fair predictor of early death (AUC=0.74) preferable to SI (AUC=0.67). similarly, the vast majority of casualties were scored RTS ≥ 10 including nearly half of the early deaths. In this subpopulation CVRI was a fair predictor of early death (AUC=0.73) preferable to SI (AUC=0.64).

Conclusion: Both SI and CVRI were found to be moderate predictors of early trauma death, inferior to RTS and GCS. CVRI was a fair and preferable then SI in the subpopulations practically undetected either by GCS or RTS (each missed nearly half of early trauma deaths). Consideration of CVRI as a complementary measure to the existing scores may improve overall detectability of high risk casualties.