Coronary artery bypass graft (CABG) surgery is associated with reperfusion syndrome and activation of inflammatory reaction (SIRS). These are more exaggerated when cardiopulmonary bypass (CPB) is used.

The aim of the study is to compare signs of SIRS (heart rate, tachypnea or hypocarbia, leukocytosis, hyperpyrexia or hypothermia) and the granulocytes subsets in peripheral blood from patients who underwent CABG surgery with or without use of CPB.

The researchers expect significant differences in SIRS criteria between both groups. If the differences will occur significant, the parameter may be used as candidate variable for a complications prediction model after CABG surgery.

Patients fulfilling inclusion criteria will be asked to sign the consent to participate in the study, the day before operation after routine preoperative anesthesiological evaluation. If included into the study they will be assigned to one of the two study groups - off-pump CABG, or CABG with CPB.

After arrival into the operating theatre 4.5 ml blood will be obtained into EDTA vials from a peripheral venous canula, placed previously for routine anesthesiologic management.

Additional blood samples will be obtained 3, 6, 12, 24 and 48 hours after the operation. Each vial will be immediately labeled with an identification number and submitted into the laboratory, where smear with May-Grunwald-Giemsa staining will be prepared. The smear will be panoptical examined for 400 consecutive leucocytes and assigned to one of the following lines: neutrophils, eosinophils, basophils, monocytes and lymphocytes. Neutrophils will be further divided into: segments, bands, metamyelocytes, myelocytes, promyelocytes, myeloblasts.

The laboratory staff will be blinded for type of operation. Differences in subsets of granulocytes between groups and timepoints wil be analysed as means by appropriate parametric or nonparametric statistical tests.

The SIRS criteria will be refered to:

1. Intraoperative variables: number of distal anastomoses, time of aorta/artery clamping, time of intraoperative hypotension, suction pump use, serum lactates;
2. Postoperative variables: serum CRP, blood products transfusion, chest tube drainage.

Inclusion Criteria:

• Elective or urgent CABG with CPB or without (off-pump CABG)
• Signed informed consent

Exclusion Criteria:

• Denied consent
• Signs of infection and/or inflammation (at least 2/4 SIRS criteria)
• Emergency operation
• Organ failure/dysfunction

Patients qualified for elective CABG with or without cardiopulmonary bypass. If possible, patient will be matched by age, sex, left ventricle ejection fraction, number of grafts, and major comorbidities (diabetes mellitus, arteriosclerosis).