To define a panel of biomarkers to aid in the assessment and diagnosis of patients presenting to the Emergency Department (ED) with suspected sepsis.
Patients presenting to the ED of 10 tertiary hospitals. The inclusion criteria were: 18 years or older, and two or more SIRS criteria with confirmed or suspected infection and/or lactate > 2.5 mmol/l. The exclusion criteria were: cardiac arrest; Do Not Resuscitate order; pregnancy.
Blood samples were collected upon enrollment and the plasma was frozen at -70°C within 1 hour. Measurement of biomarkers was performed in a blinded fashion by immunoassay (Biosite). The final diagnosis was determined based on standard definitions. A search engine based on the optimization of the area under the receiver-operator curve (ROC AUC) for diagnosis of sepsis was used to select a panel of six biomarkers and to optimize a Multimarker Index (MMX). The MMX combines the individual marker values into a single index value for the sample, which is reported as the test result.
The ROC AUC (95% CI) for the sepsis panel MMX for differentiating patients with SIRS (n = 73) from those with various sepsis conditions (n = 224), SIRS from all sepsis with positive blood culture (n = 41), SIRS from severe sepsis (n = 43) and SIRS from septic shock (n = 14) are, respectively, 0.76 (0.70–0.82), 0.85 (0.79–0.92), 0.89 (0.83–0.95) and 0.95 (0.91–0.99). For comparison, the ROC AUCs obtained with CRP are 0.62 (0.54–0.70), 0.69 (0.59–0.79), 0.63 (0.53–0.74) and 0.71 (0.57–0.85); for IL-6 the values are 0.64 (0.57–0.71), 0.69 (0.59–0.80), 0.66 (0.55–0.77) and 0.63 (0.45–0.82).
The biomarker panel MMX shows clinical utility in identifying sepsis as an underlying cause in patients presenting with SIRS. Because this level of accuracy is attained based on the first blood draw, these results suggest that it may be useful in the rapid assessment and diagnosis of patients presenting to the ED. These results need to be confirmed in additional populations.