Neutrophilia and granulocyte colony-stimulating factor levels after cardiopulmonary bypass

The precise mechanism of neutrophilia after cardiac surgery is unknown. Granulocyte colony stimulating factor (G-CSF) can increase the number of leukocytes. The purpose of this study was to evaluate the relationship between serum G-CSF levels and peripheral blood leukocyte counts after cardiac surgery.

We prospectively studied 10 patients undergoing cardiac surgery (coronary artery bypass grafting) using cardiopulmonary bypass (CPB). Plasma G-CSF levels and neutrophil count were measured before induction of anaesthesia, at the end of surgery, and on the first postoperative day. These changes were compared with those in patients undergoing non-cardiac major surgery (control group).

At the end of surgery, G-CSF levels increased (P < 0.01) in both groups, but were higher in the control than in the cardiac group (3,250 +/- 690 vs 194 +/- 29.5 pg ml(-1), respectively, mean +/- SEM, P < 0.01). On the first postoperative day, G-CSF levels were still high in both groups, and were still higher in the control (710 +/- 179 vs 122 +/- 19.9, respectively, P < 0.01). However, neutrophilia was greater in the cardiac group than in the control. G-CSF response correlated positively with neutrophilia in the control group (r = 0.656, P < 0.05) but not in the cardiac group.

Our results indicate that changes in leukocyte count following cardiac surgery are unique to patients undergoing CPB. G-CSF plays an important role as the mediator of neutrophilia after non-cardiac surgery, but not after cardiac surgery with CPB.