Diagnostic Value of Procalcitonin: the Influence of Cardiopulmonary Bypass, Aprotinin, SIRS, and Sepsis

BACKGROUND: The reasons for a systemic inflammatory response syndrome (SIRS) following ECC are not yet fully understood. Procalcitonin (PCT) blood levels may distinguish between bacterial infections and a non-bacterial systemic inflammation. We investigated the influence of ECC, ECC modified by application of aprotinin, systemic inflammation, and bacterial infection on the PCT values. METHODS: 20 CABG patients were randomized and divided in two groups. Group A served as the control group, while group B perioperatively received a high dose of aprotinin. Blood samples for measurement of PCT were taken 6 times perioperatively. Furthermore, blood samples were taken from 20 preoperatively comparable patients who suffered from bacterial infection (n = 10) (group C) or a SIRS (n = 10) (group D) after ECC; in these groups PCT was determined daily after the onset of inflammation. RESULTS: There was no significant elevation of PCT in group A or B at any time. In sepsis patients a significant elevation of PCT was seen, with the peak level of 18.6+/-6.3 ng/ml on the second day after diagnosis; the PCT level of SIRS patients remained constantly low (<0.9 ng/ml). CONCLUSIONS: In this study it was demonstrated that ECC and the use of aprotinin did not have any influence on the secretion of PCT. A systemic bacterial infection caused a significant increase of PCT, whereas PCT values remained normal in case of a SIRS. So it seems to be possible to distinguish between a primary SIRS and a bacterial sepsis by means of PCT.