Purpose: To define whether procalcitonin should be introduced in the diagnostic criteria of sepsis.
Methods: Procalcitonin was estimated in sera of 105 critically ill patients by an immunochemiluminometric assay. Diagnosis was settled by 3 types of criteria: A, the American College of Chest Physicians/Society of Critical Care Medicine (ACCP/SCCM) 1992 criteria; B, the ACCP/SCCM criteria and concentrations of procalcitonin above 1.0 ng/mL as indicative of SIRS/sepsis; and C, the ACCP/SCCM criteria and concentrations of procalcitonin 0.5 to 1.1 ng/mL for SIRS and above 1.1 ng/mL for sepsis.
Results: Criteria A identified 50.5% of patients with SIRS, 18.1% with sepsis, 0.9% with severe sepsis and 22.9% with septic shock; respective diagnosis by criteria B were 26.7%, 9.5%, 10.5% and 25.7%; and respective diagnosis by criteria C were 19.0%, 25.7%, 9.5%, and 25.7%. Sensitivity of concentrations between 0.5 ng/mL and 1.1 ng/mL was 25.6% for Systemic Inflammatory Response Syndrome (SIRS); and above 1.1 ng/mL 92.8% for sepsis. Sepsis-related death was associated with elevated procalcitonin upon presentation of a clinical syndrome.
Conclusions: Despite the limited diagnostic value of procalcitonin for SIRS, concentrations of procalcitonin above 1.1 ng/mL are highly indicative for sepsis without, however, excluding the presence of SIRS.