Validation of the Shock Index, Modified Shock Index, and Age Shock Index for Predicting Mortality of Geriatric Trauma Patients in Emergency Departments

Abstract

The shock index (SI), modified shock index (MSI), and age multiplied by SI (Age SI) are used to assess the severity and predict the mortality of trauma patients, but their validity for geriatric patients is controversial. The purpose of this investigation was to assess predictive value of the SI, MSI, and Age SI for geriatric trauma patients. We used the Emergency Department-based Injury In-depth Surveillance (EDIIS), which has data from 20 EDs across Korea. Patients older than 65 years who had traumatic injuries from January 2008 to December 2013 were enrolled. We compared in-hospital and ED mortality of groups categorized as stable and unstable according to indexes. We also assessed their predictive power of each index by calculating the area under the each receiver operating characteristic (AUROC) curve. A total of 45,880 cases were included. The percentage of cases classified as unstable was greater among non-survivors than survivors for the SI (36.6% vs. 1.8%, P < 0.001), the MSI (38.6% vs. 2.2%, P < 0.001), and the Age SI (69.4% vs. 21.3%, P < 0.001). Non-survivors had higher median values than survivors on the SI (0.84 vs. 0.57, P < 0.001), MSI (0.79 vs. 1.14, P < 0.001), and Age SI (64.0 vs. 41.5, P < 0.001). The predictive power of the Age SI for in-hospital mortality was higher than SI (AUROC: 0.740 vs. 0.674, P < 0.001) or MSI (0.682, P < 0.001) in geriatric trauma patients.

Can the shock index be a reliable predictor of early mortality after trauma in older patients? A retrospective cohort study

“…Age SI was reported to be a significantly better predictor than SI alone for predicting mortality following traumatic injury of elderly patients. 12,16 In the present study, however, there was no significant improvement in the performance of mortality prediction using Age SI compared to SI with a cut-off ≥0.9, whereas our new method did. Although our method and Age SI both capture a mathematical interaction between age and physiological compromise, the results of our study indicated a linear relationship between the optimal SI cut-off value and age and using a simple linear regression model could be a better way to capture the effects of age on physiological compromise.…”

“…The most frequent etiology was falls (46%), followed by traffic accidents (40%). The median ISS was 13 (IQR, [9][10][11][12][13][14][15][16][17][18][19][20]. The median SI was 0.61 (IQR, 0.50-0.75), and 19,489 (13%) had an SI ≥0.9.…”

The Shock Index is not accurate at predicting outcomes in patients with upper gastrointestinal bleeding

“…These factors may explain why the Shock Index is less useful at predicting outcomes in upper GI bleeding. Further work could investigate inpatient rather than 30‐day mortality, due to possible early effects of haemodynamic compromise, or the “Age Shock Index” (age multiplied by Shock Index), which has shown increased utility compared to the Shock Index in geriatric trauma patients …”

“…Further work could investigate inpatient rather than 30-day mortality, due to possible early effects of haemodynamic compromise, or the "Age Shock Index" (age multiplied by Shock Index), which has shown increased utility compared to the Shock Index in geriatric trauma patients. 20 The administration of a blood transfusion is associated with morbidity and cost. GI bleeding accounts for 14% of blood transfusions administered in the UK.…”

The utility of the shock index in patients with acute respiratory failure

“…2 It has been used in outpatient triage of trauma patients, in emergency departments to assist in decisions regarding patient disposition, and in prognostic estimates of both short and long-term outcomes. [3][4][5] The modified shock index is the heart rate divided by the mean blood pressure and includes information based on both systolic and diastolic blood pressures; the age-adjusted shock index incorporates age into this calculation (age times the shock index) to adjust for possible change in the cardiovascular responses associated with age. 3 This editorial will briefly consider the use of the shock index in patients requiring emergent intubation in intensive care units and emergency departments.…”