Procalcitonin for early diagnosis and differentiation of SIRS, sepsis, severe sepsis, and septic shock

Objective:To determine the value of procalcitonin (PCT) in the early diagno sis land differentiation) of patients with SIRS, sepsis, severe sepsis, and septic shock in comparison to C-reactive protein (CRP), white blood cell a nd thrombocyte count, and APACHE-II score (AP-II). Design: Prospective cohort study including all consecutive patients admitte d to the ICU with the suspected diagnosis of infection over a 7-month perio d. Patients and methods: A total of 185 patients were included: 17 patients wi th SIPS, 61 with sepsis, 68 with severe sepsis, and 39 patients with septic shock. CPP, cell counts, AS-II and PCT were evaluated on the first day aft er onset of inflammatory symptoms, Results: PCT values were highest in patients with septic shock (12.89 +/- 4 .39 ng/ml; P < 0.05 vs patients with severe sepsis). Patients with severe s epsis had significantly higher PCT levels than patients with sepsis or SIPS (6.91 +/- 3.87 ng/ml vs 0.53 +/- 2.9 ng/ml; P < 0.001, and 0.41 +/- 3.04 n g/ml; P < 0.001, respectively). AP-IT scores did not differ significantly b etween sepsis, severe sepsis and SIRS (19.26 +/- 1.62, 16.09 +/- 2.06, and 17.42 +/- 1.72 points, respectively), but was significantly higher in patie nts with septic shock (29.27 +/- 1.35, P < 0.001 vs patients with severe se psis). Neither CRP, cell counts, nor the degree of fever showed significant differences between sepsis and severe sepsis, whereas white blood cell cou nt and platelet count differed significantly between severe sepsis and sept ic shock. Conclusions: In contrast to AP-II, PCT appears to be a useful early marker to discriminate between sepsis and severe sepsis.