Procalcitonin as a diagnostic marker for sepsis/septic shock in the emergency department; a study based on Sepsis-3 definition.

INTRODUCTION: The recent definition of sepsis was modified based on a scoring system focused on organ failure (Sepsis-3). It would be a time-consuming process to detect the sepsis patient using Sepsis-3. Procalcitonin (PCT) is a well-known biomarker for diagnosing sepsis/septic shock and monitoring the efficacy of treatment. We conducted a study to verify the predictability of PCT for diagnosing sepsis based on Sepsis-3 definition.

MATERIALS & METHODS: This is a retrospective cohort study. The patients whose PCT was measured on the emergency department (ED) arrival and had final diagnosis related infection were enrolled. The patients were categorized by infection, sepsis, or septic shock followed by Sepsis-3 definition. "Pre-septic shock" was defined when a patient was initially diagnosed with sepsis, following which his/her mean arterial blood pressure decreased to under 65 mmHg refractory to fluid resuscitation and there was need for vasopressor use during ED admission. Receiver operating characteristics (ROC) curve and area under the curve (AUC) analysis were performed to verify sensitivity and specificity of PCT.

RESULTS: 866 patients were enrolled in the final analysis. There are 287 cases of infection, 470 cases of sepsis, and 109 cases of septic shock. An optimal cutoff value for diagnosing sepsis was 0.41 ng/dL (sensitivity: 74.8% and specificity: 63.8%; AUC: 0745), septic shock was 4.7 ng/dL (sensitivity: 66.1% and specificity: 79.0%; AUC: 0.784), and "pre-septic shock" was 2.48 ng/dL (sensitivity: 72.8%, specificity: 72.8%, AUC: 0.781), respectively.

CONCLUSION: PCT is a reliable biomarker to predict sepsis or septic shock according to the Sepsis-3 definitions.