Systemic inflammatory response syndrome after extracorporeal circulation: a predictive algorithm for the patient at risk.

INTRODUCTION: Perioperative systemic inflammatory response syndrome (SIRS) remains a catastrophe in cardiac surgery and adequate patient screening is still lacking. We present a prospective trial starting with preoperative data collection. For the first time, the postoperative outcomes of patients after open-heart surgery are evaluated to predict a hazard-constellation for the patient at risk of developing SIRS.

METHODS: Of 2315 patients undergoing cardiac surgery over a 2-year period, 107 were considered likely to develop perioperative SIRS based on a high-risk stratification; 12 of them actually developed SIRS and were recruited for this study. Another 20 uneventful consecutive patients served as controls. Blood samples were collected from before the induction of anaesthesia until the morning of the second postoperative day and were analysed for complement, cytokines, adhesion-molecules, endothelin-1 (ET-1), plasminogen-activatorinhibitor (PAI), the coagulation and fibrinolysis cascade and routine laboratory analysis.

RESULTS: Significant preoperative differences were observed in leukocytes, lymphocytes, alkaline phosphatase,ICAM-3 and VCAM-1 (p<0.05). Significant positive correlations were found for ET-1 and lactate in the SIRS group. The increase in these parameters was correlated with a prolonged duration of extracorporeal circulation. The best predictive combination for SIRS consisted of alkaline phosphatase, ET-1, ICAM-1, -2, -3, VCAM-1 and ELAM-1.

CONCLUSIONS: The results suggest a new theory regarding the development of perioperative SIRS. It is not the extracorporeal circulation itself that represents the main trigger, but rather an a priori activation of the endothelial cells, lymphocytes and leukocytes. This activation impairs the microcirculation and finally leads to multi-organ failure. The current data allow the identification of the patient at risk and can thus influence the individual operative schedule.