title: Preoperative use of enoxaparin increases the risk of postoperative bleeding and re-exploration in cardiac surgery patients.
abstract: 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.
authors.affiliation: Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Susan B
authors.initials: SB
authors.lastname: McDonald
authors.forename: Maurizio
authors.initials: M
authors.lastname: Renna
authors.forename: Edward L
authors.initials: EL
authors.lastname: Spitznagel
authors.forename: Michael
authors.initials: M
authors.lastname: Avidan
authors.forename: Charles W
authors.initials: CW
authors.lastname: Hogue
authors.forename: Marc R
authors.initials: MR
authors.lastname: Moon
authors.forename: Benico
authors.initials: B
authors.lastname: Barzilai
authors.forename: Rao
authors.initials: R
authors.lastname: Saleem
authors.forename: Jerome M
authors.initials: JM
authors.lastname: McDonald
authors.forename: George J
authors.initials: GJ
authors.lastname: Despotis
mesh_terms: 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
chemical_list: D017984:Enoxaparin; D006495:Heparin, Low-Molecular-Weight; D010975:Platelet Aggregation Inhibitors