Preoperative use of enoxaparin increases the risk of postoperative bleeding and re-exploration in cardiac surgery patients.
OBJECTIVE
The purpose of this study was to investigate if the preoperative use of new platelet inhibitors and low-molecular-weight heparins may contribute to bleeding after cardiac surgery.


METHODS
Retrospective data review.


METHODS
University teaching hospital.


METHODS
One hundred eleven patients divided in 5 groups.


METHODS
Patients were grouped according to preoperative antithrombotic regimen: group 1, control, no agents (n=55); group 2, clopidogrel (n=9); group 3, enoxaparin (n=17); group 4, any GP IIb/IIIa inhibitor (n=14); and group 5, any drug combination (n=15). Data included cumulative mediastinal chest tube drainage, allogeneic blood transfusions, total blood donor exposures, and re-exploration.


RESULTS
Use of any drug (groups 2-5) resulted in greater total blood transfusions and donor exposure (p=0.0003) than control, especially red cells (p=0.002) and platelets (p=0.006). A greater percentage of patients on enoxaparin required mediastinal re-exploration for nonsurgical bleeding versus control (3/17 v 0/55, p=0.001). The use of enoxaparin was associated with significantly higher chest tube output after the first 24 hours postoperatively (p=0.048).


CONCLUSIONS
Newer antithrombotic agents were associated with greater transfusion rates and total donor exposures. Enoxaparin use was associated with greater overall blood loss and with higher incidence of mediastinal re-exploration. The relative risk-benefit ratio of reduced periprocedure morbidity versus increased bleeding complications has yet to be determined.
McDonald
Susan B
SB
Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Renna
Maurizio
M
Spitznagel
Edward L
EL
Avidan
Michael
M
Hogue
Charles W
CW
Moon
Marc R
MR
Barzilai
Benico
B
Saleem
Rao
R
McDonald
Jerome M
JM
Despotis
George J
GJ
D000704:Analysis of Variance; D013504:Cardiovascular Surgical Procedures / Q000009:adverse effects / Q000706:statistics & numerical data; D017984:Enoxaparin / Q000009:adverse effects* / Q000627:therapeutic use; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D015999:Multivariate Analysis; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D019106:Postoperative Hemorrhage / Q000097:blood* / Q000139:chemically induced*; D011300:Preoperative Care; D012189:Retrospective Studies; D012307:Risk Factors
D017984:Enoxaparin; D006495:Heparin, Low-Molecular-Weight; D010975:Platelet Aggregation Inhibitors