Utility of Procalcitonin as a Diagnostic Tool for Sepsis in Intensive Care Units

Introduction/Objective: Sepsis is one of the leading causes of mortality in the intensive care unit (ICU). Its diagnosis is often complex and represents a real clinical challenge. The objective of this study was to evaluate the usefulness of procalcitonin (PCT) as a diagnostic marker of sepsis. Methods: This prospective cohort study included 65 patients hospitalized in the ICU. Demographic and clinical data were collected according to a specific information sheet. All patients underwent an inflammatory assessment including PCT, hypersensitive C - reactive protein (hsCRP), and complete blood count. The Sequential Organ Failure Assessment (SOFA) score was calculated. Patients were classified into septic (SOFA ≥ 2 points) and non-septic (SOFA < 2 points). The Receiver Operating Characteristic (ROC) curve was used to evaluate the diagnostic performance of inflammatory parameters. Results: Of 65 included patients, 46 had developed sepsis. Among the investigated inflammatory markers, PCT has the best discriminative capacity; its area under the curve (AUC), of 0.78, was the highest, followed by the neutrophils to lymphocytes ratio (NLR) and hsCRP with a lower but statically significant AUC. The optimal PCT threshold for sepsis diagnosis was 4.5ng/ml with a specificity of 83% and a sensitivity of 60%. A positive correlation between the PCT levels and the SOFA score was also found (p=0.002). Conclusion: This study provides additional evidence of the performance of PCT in the diagnosis of septic states in patients admitted to ICU. The newly established cut-off value provides the best balance between specificity and sensitivity. Its superiority over conventional inflammatory markers has been demonstrated.