Prognostic scores for early stratification of septic patients admitted to an emergency department-high dependency unit

OBJECTIVES: The aim of this study was to identify a reliable tool for the early prognostic stratification of septic patients admitted to the emergency department-high dependency unit (ED-HDU), a clinical setting providing a subintensive level of care; we also estimated the cost saving associated with HDU stay compared with ICU stay. MATERIALS AND METHODS: Mortality in Emergency Department Sepsis (MEDS), Acute Physiology Age Chronic Health Evaluation II (APACHE II), Simplified Acute Physiology Score II (SAPS II), Sequential Organ Failure Assessment (SOFA) score (SOFA-T0) and the Charlson index were calculated at ED admission. SOFA score was also calculated after 24 h (SOFA-T1). The primary outcome was 28 days mortality. RESULTS: We admitted 140 patients with severe sepsis or septic shock in our ED-HDU from June 2008 to December 2010; 135 were included in the study. One month's mortality was 29%. SOFA-T1 was significantly higher in patients who needed an ICU admission (7.5±3.8 vs. 5.3±3.0, P=0.048); it also showed the best mortality prediction ability (area under the curve 0.80, 95% confidence interval 0.70-0.91), compared with MEDS, SAPS, and APACHE score. Troponin and procalcitonin evaluated at ED admission and after 24 h did not show significant differences according to prognosis; patients with lactate more than 2 showed a higher mortality (40 vs. 22%, P=0.034). In a regression analysis adjusted for age, lactate value, and the Charlson index, SOFA-T1 (RR 1.551, 95% confidence interval 1.204-1.998, P<0.001) maintained an independent prognostic value for 28 days mortality. During the 267 days of stay at the ED-HDU, the total saving was 460 041, compared with the cost of the same period in the ICU. CONCLUSION: SOFA score is a feasible and accurate tool for an early risk stratification of septic patients admitted to the ED-HDU.