Procalcitonin as a biomarker for early sepsis in the emergency department

OBJECTIVES: In the critical care setting, increasing levels of midregional proadrenomedullin (MRproADM), midregional proatrial natriuretic peptide (MRproANP), procalcitonin (PCT), copeptin, and proendothelin-1 (proET-1) have been shown to be correlated with increasing severity of sepsis. The objective of this study was to investigate the utility of sepsis biomarkers in an Emergency Department (ED) population. METHODS: Through a prospective, observational pilot study, we investigated the utility of MRproADM, MRproANP, PCT, copeptin, and proET-1 in predicting a diagnosis of early sepsis in patients presenting to the ED for suspected infection. Data were analyzed using nonparametric Mann-Whitney U-tests, χ-tests, and receiver operating characteristic curves. RESULTS: Of the 66 patients enrolled in this study, 37 (56.1%) were men, with a median age of 58 years [interquartile range (IQR) 39-69 years], and 19 (28.8%) had a final diagnosis of early sepsis. A higher percentage of sepsis patients compared with no-sepsis patients met systemic inflammatory response syndrome (SIRS) criteria at initial presentation (85.7 vs. 41.3%; P<0.0001) and were admitted to the hospital (84.2 vs. 55.6%; P=0.02). PCT was higher in sepsis patients [median 0.32 ng/ml (IQR 0.19-1.17) vs. 0.18 ng/ml (IQR 0.07-0.54); P=0.04]. There were no differences between groups for MRproADM, MRproANP, copeptin, or proET-1 (P≥0.53). The C-statistic was maximized with the combination of SIRS criteria and PCT levels (0.92±0.05), which was better than PCT alone (0.67±0.08; P=0.005) or SIRS alone (0.75±0.07; P=0.04). CONCLUSION: In this pilot study, we found that the combination of SIRS criteria and PCT levels is useful for the early detection of sepsis in ED patients with suspected infection. Larger studies investigating use of PCT are necessary.