Surgery Journey
Blood Thinners, Aspirin and Surgery
Blood Thinners, Aspirin and Your Operation
Blood thinners protect you from clots, but they increase bleeding during surgery. Every plan balances two risks: bleeding from the operation, and clotting if the medicine is stopped. The decision is made with the doctor or specialist who prescribed the medicine, and written down with dates. The golden rule: do not stop or restart any blood thinner on your own. Follow the written plan with your dates.
Which Medicines Are Blood Thinners?
Many patients do not realise one of their tablets is a blood thinner, or call it a "heart tablet". Bring all your medicines so the team can identify them. Common blood thinners include:
- Warfarin
- Apixaban, rivaroxaban, edoxaban, and dabigatran (direct oral anticoagulants)
- Aspirin
- Clopidogrel, ticagrelor, and prasugrel (antiplatelet medicines)
- Heparin injections
- Some herbal remedies also affect bleeding, so mention those too
For procedures with minimal bleeding, such as skin surgery, dental work, and cataract surgery, blood thinners are usually continued.
Your Stopping and Restarting Plan
The usual timings are below. Your bleeding risk from the operation and your clotting risk decide your personal plan, which may differ. If you take a dose by mistake after your stop date, tell the team before the operation; they may need to delay it or check a blood test.
Warfarin
- Usually stopped
- 5 days before surgery, with a blood clotting check (INR) the day before or on the morning
- Usually restarted
- 12 to 24 hours after surgery, when bleeding is controlled
Apixaban, rivaroxaban, edoxaban
- Usually stopped
- 1 day before (low or moderate bleeding risk) or 2 days before (high risk)
- Usually restarted
- 1 day after (low risk) or 2 to 3 days after (high risk)
Dabigatran, kidneys working normally
- Usually stopped
- 1 day before (low or moderate risk) or 2 days before (high risk)
- Usually restarted
- As above
Dabigatran, reduced kidney function
- Usually stopped
- 2 days before (low or moderate risk) or 4 days before (high risk)
- Usually restarted
- As above
Clopidogrel
- Usually stopped
- About 5 days before, when the team decides it must be stopped
- Usually restarted
- As agreed with your cardiologist or prescriber
Ticagrelor
- Usually stopped
- About 3 to 5 days before
- Usually restarted
- As agreed with your cardiologist or prescriber
Prasugrel
- Usually stopped
- About 7 days before
- Usually restarted
- As agreed with your cardiologist or prescriber
Aspirin for heart or stroke prevention
- Usually stopped
- Often continued through surgery, except where even small bleeding is dangerous
- Usually restarted
- Not applicable if continued
Injections While Your Tablet Is Paused: Bridging
Most people do not need heparin injections while their tablet is paused. Bridging is reserved for patients at very high clotting risk, such as those with a mechanical mitral heart valve or a stroke or clot within the previous three months. In patients with atrial fibrillation, bridging did not reduce strokes or clots in a large trial, but doubled major bleeding.
Warning: Heart Stents and Antiplatelet Medicines
If you have a coronary stent, never stop aspirin, clopidogrel, ticagrelor, or prasugrel without your cardiologist. Stopping too soon after a stent can cause a heart attack. The timing of planned surgery after a stent is also agreed with the cardiologist; see the guide on heart disease and surgery in this series.
Recovery After Surgery: Restarting and Preventing Clots
- Restart on the date in your plan, once bleeding is controlled. Make sure you know the exact day, and that you have enough medicine.
- Until your usual blood thinner is restarted, preventive heparin injections may be used, depending on your clot risk.
- Walk often to prevent clots, and expect small bruises around the wound.
- Ramadan: many people can fast on blood thinners with doses re-timed to iftar or suhoor, and warfarin needs closer INR checks because diet changes. Do not fast while recovering from surgery, and agree any change with your prescriber.
Warning Signs: When to Seek Help
Green
- What you notice
- Small bruises around the wound; slight oozing on the dressing on the first day
- What to do
- Expected. Restart your medicine on the planned date
Amber
- What you notice
- A wound that keeps oozing, or a swelling that grows; nosebleeds or bleeding gums; blood in the urine
- What to do
- Call the clinic the same day
Red
- What you notice
- Heavy bleeding that does not stop with pressure; black stools or vomiting blood; sudden weakness, numbness, or speech or vision problems; chest pain, breathlessness, or a hot, swollen calf
- What to do
- Call an ambulance or go to the emergency department now
Questions Patients Ask
Can I keep taking my blood thinner for this small procedure?
For many small procedures, such as skin surgery or dental work, yes. The team will tell you.
Do I need injections while my tablet is stopped?
Most people do not. Injections are only for people at very high risk of clots, such as those with certain heart valves.
When do I restart my blood thinner?
On the date written in your plan, usually 1 to 3 days after the operation for tablets, depending on the bleeding risk.
Full guide written by Dr. Tamer Elalfy