title: Perioperative clopidogrel and postoperative events after hip and knee arthroplasties.
abstract: BACKGROUND
  Hip and knee arthroplasties are widely performed and vascular disease among patients having these procedures is common. Clopidogrel is a platelet inhibitor that decreases the likelihood of thrombosis. It may cause intraoperative and postoperative bleeding, but its discontinuation increases the risk of vascular events. There is currently no consensus regarding the best perioperative clopidogrel regimen that balances these concerns.
  
  
  OBJECTIVE
  We determined (1) the relationship between time of perioperative clopidogrel administration and postoperative bleeding-related events after hip and knee arthroplasties and (2) patient characteristics or surgical factors that may predict these events.
  
  
  METHODS
  We retrospectively queried our inpatient pharmacy database for patients who received clopidogrel from 2007 to 2009 and identified 116 patients who underwent hip or knee arthroplasty. We recorded the time of perioperative clopidogrel administration, bleeding-related postoperative events, patient characteristics, and surgical factors.
  
  
  RESULTS
  Patients who withheld clopidogrel 5 or more days before hip or knee arthroplasty had lower rates of reoperation for infection and antibiotics prescribed for the surgical wound. Postoperative events did not vary with timing of clopidogrel resumption after surgery. Advanced age, an American Society of Anesthesiologists (ASA) score of 4, and revision surgery predicted increased readmission, reoperation for hematoma or infection, antibiotic use, and death.
  
  
  CONCLUSIONS
  Holding clopidogrel for at least 5 days before hip or knee arthroplasty may lower the rate of bleeding-related events. We found no increase in events when patients resumed clopidogrel immediately after surgery. Advanced age, ASA score of 4, and revision surgery may be risk factors for bleeding-related events.
  
  
  METHODS
  Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopedics, New England Baptist Hospital, Tufts University School of Medicine, 125 Parker Hill Avenue, Boston, MA 02120, USA.
authors.forename: Sumon
authors.initials: S
authors.lastname: Nandi
authors.forename: Mehran
authors.initials: M
authors.lastname: Aghazadeh
authors.forename: Carl
authors.initials: C
authors.lastname: Talmo
authors.forename: Claire
authors.initials: C
authors.lastname: Robbins
authors.forename: James
authors.initials: J
authors.lastname: Bono
mesh_terms: D000367:Age Factors; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000401:mortality; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000401:mortality; D000077144:Clopidogrel; D016208:Databases, Factual; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D059035:Perioperative Period; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D019106:Postoperative Hemorrhage / Q000209:etiology*; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine