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 diagnosis (and differentiation) of patients with SIRS, sepsis, severe sepsis and septic shock in comparison to C-reactive protein (CRP), white blood cell and thrombocyte count, and APACHE-II score (AP-II).

Design

Prospective cohort study including all consecutive patients admitted to the ICU with the suspected diagnosis of infection over a 7-month period.

Patients and methods

One-hundred and eight-five patients were included, 17 patients with SIRS, 61 with sepsis, 68 with severe sepsis, and 39 patients with septic shock. CRP, cell counts, AP-II and PCT were evaluated on the first day after onset of inflammatory symptoms.

Results

PCT values were highest in patients with septic shock (12.89 ± 4.39 ng/ml; P < 0.05 versus patients with severe sepsis). Patients with severe sepsis had significantly higher PCT levels compared to patients with sepsis or SIRS (6.91 ± 3.87 ng/ml versus 0.53 ± 2.9 ng/ml: P < 0.001 and 0.41 ± 3.04 ng/ml; P < 0.00l, respectively). AP-II scores did not differ significantly between 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 patients with septic shock (29.27 ± 1.35, P < 0.00l versus patients with severe sepsis). Neither CRP, cell counts nor the degree of fever showed significant differences between sepsis and severe sepsis. White blood cell count and platelet count differed significantly between severe sepsis and septic shock.

Conclusion

In contrast to AP-II, PCT appears to be a useful early marker to discriminate between sepsis and severe sepsis.