Back to basics: Validation of the admission systemic inflammatory response syndrome score in predicting outcome in trauma

Background. We have previously documented that the admission systemic inflammatory response syndrome (SIRS) score, calculated with four variables-temperature, heart rate, neutrophil count, and respiratory rate-is a significant predictor of outcome in trauma (n = 4,887). The objective of this current study was to validate our previous findings in a larger trauma patient population, to analyze the predictive accuracy of the four individual components of the SIRS score (temperature, heart rate, neutrophil count, and respiratory rate), and to assess whether the admission SIRS score is an accurate predictor of intensive care unit (ICU) resource use in trauma. Methods. Prospective data were collected on 9,539 patients admitted to a Level I trauma center over a 30-month period (January 1997-July 1999). Patients were stratified by age, sex, race, and Injury Severity Score (ISS). SIRS score was calculated at admission, and SIRS was defined as a SIRS score greater than or equal to 2. Results. SIRS score was validated as a significant independent predictor of outcome in trauma by logistic regression analysis after controlling for age and ISS. Of the four SIRS variables, hypothermia (temperature < 36<degrees>C) was the most significant predictor of mortality after controlling for age and ISS. Leukocytosis (neutrophil count > 12,000/mm(3)) was the most significant predictor of total hospital length of stay. SIRS scores of greater than or equal to 2 were increasingly predictive of mortality and ICU admission by logistic regression analysis (P < 0.001). Conclusion. These data provide further validation that an admission SIRS score of : 2 is a significant independent predictor of outcome and ICU resource use in trauma. Temperature (hypothermia) is the individual component of the SIRS score with the greatest predictive accuracy. SIRS score should be calculated on all trauma admissions.