Preoperative Patients on Coumadin

If you work in surgery or with the elderly - anticoagulation is an every day part of life. INRs, PTs, PTTs, etc... it is important to know what measures what and what reversal agents (if any) are available. Let's talk about Coumadin today.

Scenario: 79 yo patient is coming in for a surgical procedure, but he is on Coumadin. You did your due diligence and had them stop it about 5 days pre-op, but their INR is still 1.6 on preoperative blood work. What are your next steps?

Generally if you are going to bring someone to the OR you'd like their INR to be less than 1.5. If it is higher, you would consider a reversal agent.

Your 1st option for reversal is Vit K. 

• PO is most predictable and is preferred to IV if rapid reversal is not needed. PO Vit K lowers INR in about 24-48 hours. 
• IV works in approximately 12-24 hrs, but you run a greater risk of anaphylaxis and it must be administered over a longer period of time (approx 20 minutes). 

Your 2nd option for reversal is Fresh Frozen Plasma (FFP).

• FFP is more expensive than Vit K, but works within 12 hrs. FFP replaces clotting factors.

So, even though you did your due diligence, why was the INR still high? There are several reasons that can delay the drop of a patient's INR:

1. Age - Elderly pts
2. Malignancy (active)
3. Liver disease
4. CHF, unstable
5. Meds that keep Coumadin around in the blood (check their med list)

Sources:

Ansell, J, Hirsh, J, Poller, L, et al. The pharmacology and management of the vitamin K antagonists: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126:204S. 

Normalization of INR After Stopping Coumadin: http://www.fpnotebook.com/mobile/HemeOnc/Surgery/PrprtvAntcgltn.htm