Usefulness of procalcitonin for diagnosis of sepsis in the intensive care unit

INTRODUCTION: The diagnosis of sepsis in critically ill patients is challenging because traditional markers of infection are often misleading. The present study was conducted to determine the procalcitonin level at early diagnosis (and differentiation) in patients with systemic inflammatory response syndrome (SIRS) and sepsis, in comparison with C-reactive protein, IL-2, IL-6, IL-8 and tumour necrosis factor-α. METHOD: Thirty-three intensive care unit patients were diagnosed with SIRS, sepsis or septic shock, in accordance with the American College of Chest Physicians/Society of Critical Care Medicine consensus criteria. Blood samples were taken at the first and second day of hospitalization, and on the day of discharge or on the day of death. For multiple group comparisons one-way analysis of variance was applied, with post hoc comparison. Sensitivity, specificity and predictive values of PCT and each cytokine studied were calculated. RESULTS: PCT, IL-2 and IL-8 levels increased in parallel with the severity of the clinical condition of the patient. PCT exhibited a greatest sensitivity (85%) and specificity (91%) in differentiating patients with SIRS from those with sepsis. With respect to positive and negative predictive values, PCT markedly exceeded other variables. DISCUSSION: In the present study PCT was found to be a more accurate diagnostic parameter for differentiating SIRS and sepsis, and therefore daily determinations of PCT may be helpful in the follow up of critically ill patients.