Shock index and its variants as predictors of mortality in severe traumatic brain injury

Reverse shock index multiplied by Glasgow coma scale (rSIG) to predict mortality in traumatic brain injury: systematic review and meta-analysis

OBJECTIVE

To determine whether the Reverse Shock Index multiplied by the Glasgow Coma Scale (rSIG) is a predictor of in-hospital mortality in patients with traumatic brain injury (TBI).

DESIGN

This is a systematic review and meta-analysis.

SETTING

A comprehensive search was conducted in five databases for studies published up to May 22, 2024, using a PECO strategy. Eight studies were identified for quantitative analysis and included in our meta-analysis.

PARTICIPANTS

The participants of the included primary studies.

INTERVENTIONS

Patients with a low rSIG as a predictor of in-hospital mortality in TBI.

MAIN VARIABLES OF INTEREST

rSIG, in-hospital mortality, TBI.

RESULTS

Our meta-analysis evaluated a total of eight observational studies encompassing 430,000 patients with TBI, observing 6,417 deaths (15%). After performing a sensitivity analysis, we found that patients with TBI and a low value of the reverse shock index multiplied by the Glasgow Coma Scale (rSIG) had a 24% higher risk of death (OR 1.24; 95% CI 1.12-1.38; I²: 96%). Furthermore, rSIG values were significantly higher in survivors compared to those who died (MD 7.72; 95% CI 1.86-13.58; I²: 99%).

Traumatic brain injury and variants of shock index

Traumatic Brain Injury is a major cause of death and long-term disability. The early identification of patients at high risk of mortality is important for both management and prognosis. Although many modified scoring systems have been developed for improving the prediction accuracy in patients with trauma, few studies have focused on prediction accuracy and application in patients with traumatic brain injury. The shock index (SI) which was first introduced in the 1960s has shown to strongly correlate degree of circulatory shock with increasing SI. In this editorial we comment on a publication by Carteri et al wherein they perform a retrospective analysis studying the predictive potential of SI and its variants in populations with severe traumatic brain injury.