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 lev els may distinguish between bacterial infections and a non-bacterial system ic inflammation. We investigated the influence of ECC, ECC modified by appl ication of aprotinin, systemic inflammation, and bacterial infection on the PCT values. Methods: 20 CABG patients were randomized and divided in two g roups. Group A served as the control group, while group B perioperatively r eceived 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 w as no significant elevation of PCT in group A or B at any time, in sepsis p atients 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 pa tients 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 influe nce on the secretion of PCT, A systemic bacterial infection caused a signif icant 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 ba cterial sepsis by means of PCT.