Utility of Delta Shock Index in Predicting Mortality and Clinical Outcomes at a Rural Level One Trauma Center

Abstract

Introduction

Shock index (SI) is useful in assessing hemodynamic status and predicting outcomes. Delta shock index (ΔSI), measuring changes in SI over time, highlights its dynamic role in predicting patient deterioration and mortality risk. This study hypothesizes that ΔSI in the rural setting has a predictive value in patient outcomes.

Methods

Study data from January 2017 to July 2023 was obtained from the trauma registry at a rural Level 1 trauma center. This study employed SI (HR/SBP) based on vital signs collected at the transfer facility, scene, and trauma bay (TB). Delta SI, the change seen in SI from TB arrival compared to earlier measurements, was computed, and patients were stratified into two groups based on ΔSI values: those with positive ΔSI (+ΔSI) and those with zero or negative ΔSI. The primary outcome examined was mortality, alongside secondary outcomes such as hospital length of stay (HLOS), ICU length of stay (ILOS), and blood transfusions.

Results

Patients with +ΔSI were older, had longer HLOS and ILOS, and higher injury severity scores. Patients with +ΔSI were more likely to have increased mortality rates (6.8% vs. 3.6%, P < 0.001) and blood transfusions (14.5% vs. 9.7%, P < 0.001). Multivariable logistic regression further validated +ΔSI significantly increasing odds of early mortality (OR 2.061, P = 0.008) and in-hospital death (OR 1.465, P = 0.002).

Discussion

Positive ΔSI is associated with negative patient outcomes, including early and overall mortality. The results show the predictive value of ΔSI in a rural environment.