Purpose: The precise mechanism of neutrophilia after cardiac surgery is unk
nown. 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 card
iac surgery.
Methods: We prospectively studied 10 patients undergoing cardiac surgery (c
oronary artery bypass grafting) using cardiopulmonary bypass (CPB). Plasma
G-CSF levels and neutrophil count were measured before induction of anaesth
esia, at the end of surgery, and on the first postoperative day. These chan
ges were compared with those in patients undergoing non-cardiac major surge
ry (control group).
Results: At the end of surgery, G-CSF levels increased (P < 0.01) in both g
roups, 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 th
e first postoperative day, G-CSF levels were still high in both groups, and
were still higher in the control (7 10 +/- 179 vs 122 +/- 19,9, respective
ly, P < 0.0 1). 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.
Conclusions: Our results indicate that changes in leukocyte count following
cardiac surgery are unique to patients undergoing CPB. G-CSF plays an impo
rtant role as the mediator of neutrophilia after non-cardiac surgery, but n
ot after cardiac surgery with CPB.