[Role of Procalcitonin as a Sepsis Marker]

Adequate diagnosis and therapy of sepsis is of major prognostic relevance. Besides the gold standard (blood culture diagnostics) biomarkers, e.g. serum procalcitonin (PCT), are clinically increasingly used in the diagnosis and for guiding anti-infective treatment. Recent guidelines recommend early determination of PCT. However, trauma, burns, surgical procedure, and intoxications may significantly impact PCT levels. As a rare cause, PCT producing tumors have been described and may be potentially misleading in the clinical setting. While several other constellations for increased PCT in the absence of sepsis (e.g., trauma, intoxications) have been described, it needs to be summarized that according to currently available data, sensitivity and specificity for PCT for the diagnosis of sepsis in critically ill patients is on average between 70 and 80%. Thus, PCT must be interpreted carefully in the context of medical history, physical examination, and microbiological assessment. However, the existing body of literature emphasizes the value of PCT to shorten the duration of an antibiotic treatment. So far, different cut-off values for PCT for certain infections have been identified. While different treatment algorithms have been studied, PCT-guided treatment not only enables to reduce use of antibiotics but as shown most recently may improve outcome of critically ill patients.