Background: To determine the performance of delta shock index (ΔSI), a change in shock index (SI) upon arrival at the emergency room (ER) from that in the field in predicting the need for massive transfusion (MT) among adult trauma patients with stable blood pressure.

Methods: This study included data from all trauma patients aged 20 years and above who were hospitalized from January 1, 2009 to December 31, 2016 and was obtained from the registered trauma database of the hospital. Only patients who were transferred by emergency medical service from the accident site with a systolic blood pressure ≥ 90 mm Hg at the ER were included in this study. The 7,957 enrolled trauma patients were divided into 2 groups, those who had received blood transfusion ≥ 10 U (MT, n = 82) and those who had not (non-MT, n = 7,875). The odds ratios with 95% confidence intervals for associated patient conditions and the odds of need for MT by a given ΔSI were measured. The plot of specific receiver operating characteristic (ROC) curves was used to evaluate the best cutoff point that could predict the patient's probability of receiving MT.

Inclusion Criteria:

• Patients who were transferred by emergency medical service (EMS) from the field of accident and had a stable blood pressure (SBP ≥ 90 mmHg) at the ER were included

Exclusion Criteria:

• Patients who were transferred from other hospitals or arrived by private vehicles.
• Patients who had incomplete data
• Patients who had an unstable blood pressure (SBP < 90 mmHg) upon arrival at the ER were also excluded

All hospitalized trauma patients aged 20 years and above from January 1, 2009 to December 31, 2016 from the registered trauma database of the hospital.