Comparison of the trauma and injury severity score and modified early warning score with rapid lactate level (the ViEWS-L score) in blunt trauma patients

Objective: The aim of this study was to compare the predictive value of the VitalPAC Early Warning Score-lactate (ViEWS-L) score with that of the trauma and injury severity score (TRISS), which is a pre-existing risk scoring system used in trauma patients. Methods: The patients were blunt trauma victims admitted consecutively to the study hospital between 1 April 2010 and 31 March 2011, who were 15 years or older and had an injury severity score of 9 or higher. The lactate level, the ViEWS and revised trauma score upon arrival at the emergency department, and the injury severity score and TRISS were evaluated. The ViEWS-L score was calculated according to the formula: ViEWS-L=ViEWS+lactate (mmol/l). The ability to predict mortality was assessed by area under the receiver operating characteristic curve (AUC) analysis and calibration analysis. Results: A total of 299 patients were available for analysis, of whom 33 died (11.0%). The median ViEWS-L score was 3.7 (interquartile range:1.8-6.4) and the median TRISS was 96.8 (interquartile range: 93.4-98.6). The ViEWS-L score was better than TRISS at predicting hospital mortality (AUC, 0.838; 95% confidence interval, 0.771-0.906 vs. AUC, 0.734; 95% confidence interval, 0.635-0.833, P=0.031). Calibration of the ViEWS-L score (χ²=11.13, P=0.194) was good but that of TRISS was not (χ²=16.97, P=0.018). Conclusion: The prognostic value of the ViEWS-L score in terms of discrimination was better than that of TRISS in the blunt trauma patients admitted to the emergency department with an injury severity score of 9 or higher, and the ViEWS-L score showed good calibration.