Shock Indices as Predictors of Outcomes in Emergency Department Patients With Emergency Severity Index Level 3.

BACKGROUND

The shock index (SI) and its derivatives, the modified shock index (MSI) and age shock index (ASI), have shown potential as prognostic tools in various clinical settings. However, their utility in predicting outcomes among Emergency Severity Index (ESI) level 3 emergency department (ED) patients remains understudied.

OBJECTIVE

This study aims to evaluate the performance of SI, MSI, and ASI in predicting length of hospital stay (LOS), in-hospital mortality, intensive care unit (ICU) admission, and readmission rates in ESI level 3 ED patients.

MATERIALS AND METHODS

This prospective cross-sectional study enrolled 250 ESI level 3 patients from the ED, aged ≥20 years, at a tertiary care hospital in Pakistan, from August 1, 2021, to January 10, 2022. SI, MSI, and ASI were calculated from triage vital signs. Logistic regression analyses assessed associations between the indices and study outcomes. Predictive performance was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

All three indices exhibited significant independent associations with mortality, even after adjusting for confounders (SI ≥1.2, OR: 11.1; MSI ≥1.0, OR: 8.82; ASI ≥36.8, OR: 12.14). ASI remained independently associated with LOS (ASI ≥36.8, OR: 3.23). ROC analyses demonstrated good predictive ability for mortality (AUC 0.84 for SI, 0.82 for ASI) and ICU admission (AUC 0.81 for SI, 0.79 for ASI).

CONCLUSIONS

Among ESI level 3 ED patients, SI ≥1.2 demonstrated strong predictive value for mortality, while ASI ≥36.8 showed moderate predictive value and was additionally associated with longer LOS. These indices, particularly the SI and ASI, may be useful adjuncts to clinical assessment for predicting mortality risk in this patient population.