How long prior to orthopedic surgery should deep venous thrombosis (DVT) prophylaxis be initiated?

Updated: Jan 28, 2021
  • Author: David A Forsh, MD; Chief Editor: Vinod K Panchbhavi, MD, FACS, FAOA, FABOS, FAAOS  more...
  • Print


In Europe, it is common practice to begin anticoagulant prophylaxis 10-12 hours before surgery. In North America, the practice is to begin treatment 12-24 hours following surgery. The ninth edition of the ACCP guidelines suggested that for most major elective orthopedic surgical procedures, the first dose of LMWH may be administered either before or after surgery, [10] though meta-analyses suggest little advantage for preoperative initiation.

A study by Bergqvist and Hull seemed to suggest that starting a half-dose of anticoagulation 6 hours after surgery may deliver more effective prophylaxis without a significant increase in bleeding risk. [65] Patients with a high risk of bleeding should have the first postoperative dose delayed 12-24 hours after surgery. In a meta-analysis of 33 trials, Leonardi et al reported an approximately 3% rate of bleeding complications from DVT prophylaxis in which the bleeding was severe enough to require a change of care. [66]

For additional information, see Deep Venous Thrombosis, and Pulmonary Embolism.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!