Shock Index as a Marker for Mortality Rates in Those Admitted to the Medical Intensive Care Unit from the Emergency Department

Abstract

Objective Shock index (SI) is defined as the heart rate divided by systolic blood pressure. Studies have shown a correlation between the shock index and mortality in trauma patients in prehospital settings and in the emergency department (ED). The objective of this study was to identify the utility of SI in predicting mortality in the medical intensive care unit (MICU) patients admitted from the ED and transfers from the floor to MICU. Design We performed a retrospective analysis of adult patients admitted to the MICU at our urban trauma hospital between January 2015 through August 2015 using ED vital signs to calculate the shock index and identify inpatient deaths. Similar data were examined for inpatient transfers to the MICU. Results Nine hundred and fifty patients were included in the study; 743 had an SI ≤ 0.99 with a mortality rate of 15.9%. Two hundred and seven patients had a SI ≥ 1.00 with a mortality rate of 22.7%. A higher SI was significant for mortality. There was no statistical significance in SI and mortality rate for patients transferred from the medical floor to the ICU. Conclusions Patients with an SI ≥ 1.00 from initial ED vital signs correlated with a higher mortality rate. In patients transferred from the floor to MICU, SI ≥ 1.00 did not correlate with a higher mortality rate.