The management of patients receiving warfarin perioperatively remains controversial. Consensus statements are based on warfarin pharmacology, the clinical relevance of vitamin K coagulation factor levels/deficiencies, and the case reports of spinal hematoma among these patients.
There is no accepted test that predicts risk; careful preoperative assessment of risks that contribute to bleeding is necessary, including a history of easy bruisability, excessive bleeding, female gender and increased age.
NSAIDS do not appear to add increased risk for the development of spinal hematoma in patients. Use of NSAIDS alone does not create a level of risk that interferes with the performance of Neuraxial blocks.
Actual risk with use of Clopidogrel is unknown. Recommended management is based on experience and labeling precautions. Recommended dose between last dose and recommended procedures is 7 days.
The concurrent use of other medications affecting clotting, such as UFH and LMWH, may increase risk of bleeding complications.
Recent epidemiologic surveys suggest that the frequency of neurologic dysfunction resulting from hemorrhagic complications is increasing and may be as high as 1 in 3000 in some patient populations. Overall, the risk of clinically significant bleeding increases with age, associated abnormalities of the spinal cord or vertebral column, the presence of an underlying coagulopathy, difficulty during needle placement, and an indwelling neuraxial catheter during sustained anticoagulation (particularly with standard heparin or low-molecular weight heparin).
General Recommendations for Pre-Procedure Warfarin Management
- Discontinue warfarin at least 5 days before elective procedure
- Assess INR 1 to 2 days before surgery, if >1.5, consider 1-2 mg of oral vitamin K
- Reversal for urgent surgery/procedure, consider 2.5-5 mg of oral vitamin K
- Immediate reversal for emergent surgery, consider fresh-frozen plasma
Regional anaesthesia and antithrombotic agents: recommendations of the European Society of Anaesthesiology. Gogarten W, Vandermeulen E, Van Aken H, Kozek S, Llau JV, Samama CM; European Society of Anaesthesiology. Eur J Anaesthesiol. 2010 Dec;27(12):999-1015.
Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition). Horlocker TT, et.al. Reg Anesth Pain Med. 2010 Jan-Feb;35(1):64-101.
Special thanks to Anushirvan Minokadeh, MD for his expert guidance.