Shock index combined with age and the Glasgow Coma Scale during the initial care of polytraumatized patients as a predictor of mortality

Objectives.

To study whether combining age and the Glasgow Coma Scale (GCS) with the shock index (SI) — SIA/G —during the initial care of polytraumatized patients can improve the ability of the SI alone to predict mortality. To compare the predictive performance of the SIA/G combination to other prognostic scales: the addition of points for the GCS, age and systolic blood pressure (GAP); the Revised Trauma Score (RTS); and the Injury Severity Score (ISS).

Methods.

Observational cohort study of patients with severe trauma admitted to the intensive care unit of a tertiary care hospital between 2015 and 2020. We calculated the SI (heart rate/systolic blood pressure), the SI/G ratio, the product of the SI and age SIA, and the combined index: SIA/G. The areas under the receiver operating characteristic curves (AUROCs) for hospital mortality and 24-hour mortality were calculated for the SIA/G combination and compared to the AUROCs for the GAP, the RTS, and the ISS.

Results.

We analyzed data for 433 patients, 47 of whom (10.9%) died. All the prognostic indexes were significantly related to mortality but the SIA/G was the best predictor of both hospital and 24-hour mortality, with AUROCs of 0.879 (95% CI, 0.83–0.93) and 0.875 (95% CI, 0.82–0.93), respectively. A score of 3.3 for the SIA/G showed 82% sensitivity and 80% specificity for hospital mortality (86% and 78%, respectively, for 24-hour mortality). The AUROCs for the GAP, RTS, and ISS indexes were lower for hospital mortality.

Conclusion. The combined SIA/G score is a better predictor in hospital of mortality in patients with multiple injuries than the SI or the traditional GAP, RTS, and ISS indexes.