Procalcitonin as a prognostic biomarker of severe sepsis and septic shock

To evaluate the tendency of the plasma concentration and clearance of procalcitonin (PCT-c) as biomarkers of prognosis of patients with severe sepsis and septic shock, compared to another early prognosis marker, the number of SIRS criteria at sepsis diagnosis.

We conducted a prospective, observational, cohort study, with patients with severe sepsis and septic shock. The serum procalcitonin was determined at diagnosis of sepsis and after 24 and 48 hours. Demographic data, APACHE IV, SOFA score on arrival, number of SIRS criteria at diagnosis, site of infection and microbiological results were recorded.

Twenty-eight patients were included, 19 clinical and nine surgical. In 13 (46.4%) the source of sepsis was pulmonary, abdominal in seven (25.0%), urinary in five (17.9%) and soft tissue in three cases (10.7%). Fifteen patients had severe sepsis and 13 septic shock. Overall mortality was 17.9% (five patients), three with septic shock. Twenty-eight PCT determinations were performed at sepsis diagnosis, 27 after 24 hours and 26 after 48 hours. The initial concentration was not significantly different between survivors and non-survivors groups, but the differences between the two groups after 24 and 48 hours were statistically significant. There was no difference in the number of SIRS criteria. The 24-hour procalcitonin clearance proved to be significantly higher in the group of survivors (-3.0 versus -300.0, p = 0.028). Although the 48-hour procalcitonin clearance has shown to be higher in the group of survivors when compared to non-survivors, the difference did not reach statistical significance.

Persistently high procalcitonin concentrations in plasma, as well as reduced 24-hours PCT clearence, were associated with a significant increase in mortality in patients with severe sepsis and septic shock.