Background and aim: To evaluate the diagnostic and prognostic usefulness of procalcitonin (PCT) in patients admitted to the Emergency Department (ED) with signs of infections and to assess the prognostic value of repeated measurements in predicting hospital mortality.
Materials and methods: A prospective, observational study was conducted in our 400-bed General Teaching Hospital. 261 patients arriving in ED with signs/symptoms of infection were enrolled. PCT was performed upon arrival in the ED (T0), and 5 days after antibiotic therapy (T5). Blood cultures were performed in all patients upon arrival in the ED.
Results: Mean T0 PCT value was 7.1±17.9 ng/ml, and at T5 3±9.1 ng/ml (p < 0.0001). Mean PCT in septic non-survivors was increased at T5 compared to T0 but not significantly. The PCT increase at T5 was an independent factor of mortality (OR = 1.29, p < 0.02) in septic patients. Compared to baseline mean delta % PCT decrease at T5 was 28%. Patients with a decrease delta % PCT > 28% showed a lower number of deaths, with a statistical significant difference if compared to those patients with a < 28% decrease (p < 0.004). ROC curve of delta % PCT for prediction of death has an AUC = 0.82 (p < 0.03).
Conclusions: PCT is a useful marker for diagnosis of systemic and local infections, and for prognostic stratification in patients with acute infectious diseases at their arrival in ED. PCT variations after antibiotic therapy are highly predictive for in-hospital mortality. PCT normalization during antibiotic therapy suggests a good response to infection possibly leading to less infection-related deaths.