From Clinic to Recovery · First Edition
Chapter 22 — Anticoagulants and Antiplatelet Medicines
Dr. Tamer Rushdy Elalfy · 11 min read
In this chapter
Blood thinners are among the medicines most often involved in surgical errors: stopped too early, stopped too late, not restarted, or stopped without telling the cardiologist after a recent stent. Patients are often confused about which of their tablets are blood thinners and receive conflicting advice from different clinicians. The decision always balances two risks, bleeding from the operation and clotting if the medicine is stopped, and it must be made with the prescribing specialist and written down clearly for the patient. This chapter gives the principles and the usual timings; the hospital protocol and specialist advice take precedence.
Learning objectives After reading this chapter you should be able to:
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Table 22.1. Blood thinners and surgery at a glance.
| At a glance | |
|---|---|
| Minimal-bleeding procedures | Skin surgery, dental work, and cataract surgery: blood thinners are usually continued |
| Warfarin | Usually stopped 5 days before; check INR before surgery; restart within 12 to 24 hours if bleeding is controlled |
| Apixaban, rivaroxaban, edoxaban | Usually stopped 1 day before (low or moderate bleeding risk) or 2 days before (high risk); no bridging |
| Bridging with heparin injections | Only for patients at very high clotting risk |
| Antiplatelets after stents | Never stopped without the cardiologist; aspirin is often continued |
| The key counseling message | “Do not stop or restart any blood thinner on your own. Follow the written plan with your dates.” |
STEP 1 Balancing the risks and making the plan
22.1 Two risks to balance
Every plan balances the bleeding risk of the procedure against the clotting risk of the patient (Figure 22.1) [1]. Minimal-bleeding procedures, such as skin surgery, dental work, and cataract surgery, can usually be performed without stopping blood thinners. For most other procedures, the medicine is paused for a set time and restarted when bleeding is controlled. Bridging with short-acting heparin injections is reserved for patients at very high clotting risk, such as those with a mechanical mitral valve or a stroke or clot within the previous three months. In patients with atrial fibrillation, bridging during warfarin interruption did not reduce strokes or clots but doubled major bleeding in a large trial [2].
[Figure — diagram omitted in this text edition; see the figure caption below and the Word chapter file for the image]
Figure 22.1. Balancing bleeding and clotting risk when planning blood thinners around surgery.
Script: explaining the blood thinner plan “Your blood thinner protects you from clots. For this operation, the risk of bleeding means we need to pause it for a short time. We have planned exactly when to stop and when to restart, with your [cardiologist / doctor].” “Here is your plan, with the dates written in. Please do not change anything without speaking to us, and do not stop any other tablets that thin the blood unless they are on this plan.” |
22.2 Warfarin
Warfarin is usually stopped 5 days before surgery, with the INR checked the day before or on the morning of surgery, and restarted 12 to 24 hours afterward when bleeding is controlled [1]. Bridging is needed only for patients at very high clotting risk. For urgent surgery, warfarin can be reversed with vitamin K and, if needed, a prothrombin complex concentrate.
22.3 Direct oral anticoagulants
Apixaban, rivaroxaban, edoxaban, and dabigatran act quickly and wear off within days, so bridging is not needed. In the PAUSE study, a standardized plan without bridging, based on the bleeding risk of the procedure and kidney function, was associated with low rates of bleeding and stroke [3]. Table 22.2 summarizes the usual timings, and Figure 22.2 shows an example calendar that can be adapted for each patient.
Table 22.2. Usual timing for interrupting direct oral anticoagulants, based on the PAUSE study and the 2022 ACCP guideline.
| Medicine | Low or moderate bleeding risk | High bleeding risk | Restart |
|---|---|---|---|
| Apixaban, rivaroxaban, edoxaban | Omit 1 day before surgery | Omit 2 days before surgery | 1 day after (low risk); 2 to 3 days after (high risk) |
| Dabigatran, kidney function normal | Omit 1 day before | Omit 2 days before | As above |
| Dabigatran, reduced kidney function | Omit 2 days before | Omit 4 days before | As above |
[Figure — diagram omitted in this text edition; see the figure caption below and the Word chapter file for the image]
Figure 22.2. An example calendar for pausing a direct oral anticoagulant, for use with patients.
22.4 Antiplatelet medicines
Aspirin taken for heart or stroke prevention is often continued through surgery, except for procedures where even small bleeding is dangerous [1]. When a second antiplatelet medicine must be stopped, the usual intervals are about 5 days for clopidogrel, 3 to 5 days for ticagrelor, and 7 days for prasugrel [1]. Patients with coronary stents must never have antiplatelet medicines stopped without the cardiologist, and elective surgery should be timed as described in Chapter 20 [4].
Caution: common errors with blood thinners
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STEP 2 Restarting, recovery, and Ramadan
22.5 After surgery
- Restart according to the written plan, once bleeding is controlled. Record the restart date on the discharge letter.
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Clot prevention. Until the usual blood thinner is restarted, preventive heparin injections may be used according to the clot-risk assessment.
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Spinal and epidural catheters need specific timing for blood thinners; follow the anesthesia team’s instructions [5].
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Discharge. Make sure the patient knows the exact day to restart and has enough medicine.
22.6 Ramadan
Many patients taking anticoagulants can fast, with the timing of doses moved to iftar or suhoor. Warfarin needs closer INR monitoring because diet changes during Ramadan, and twice-daily medicines need a plan. Patients should not fast while recovering from surgery and should agree any changes with their prescriber.
STEP 3 Questions patients ask
“Which of my tablets are blood thinners?”
Bring all your medicines. Common blood thinners include warfarin, apixaban, rivaroxaban, edoxaban, dabigatran, aspirin, clopidogrel, ticagrelor, and prasugrel. Some herbal remedies also affect bleeding.
“Can I keep taking my blood thinner for this small procedure?”
For many small procedures, such as skin surgery or dental work, yes. We 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 [1, 2].
“I have a stent. Can I stop my clopidogrel?”
Not without your cardiologist. Stopping it too soon after a stent can cause a heart attack.
“When do I restart my blood thinner?”
On the date written in your plan, usually 1 to 3 days after the operation, depending on the bleeding risk.
“What if I forget and take a dose by mistake?”
Tell us before the operation. We may need to delay it or check a blood test.
“Can I fast in Ramadan on my blood thinner?”
Often yes, with your doses re-timed and, for warfarin, more blood tests. Not while recovering from surgery. Ask your prescriber first.
STEP 4 Risks, warning signs, and consent
22.7 Additional risks
Table 22.3. Additional risks for patients taking blood thinners. Square brackets mark figures to replace with unit data.
| Band | Risk | Typical frequency | Example wording |
|---|---|---|---|
| Less common | Bleeding needing transfusion or another procedure | Depends on the operation and medicine [unit data] | “Your blood thinner increases bleeding, which is why we pause it.” |
| Less common | Wound hematoma | [unit data] | “A collection of blood under the wound may need draining.” |
| Rare but serious | Stroke or clot while the medicine is paused | [unit data] | “Pausing your blood thinner slightly increases clot risk for a few days.” |
| Rare but serious | Stent thrombosis if antiplatelets are stopped too early | [unit data] | “This is why we never stop them without your cardiologist.” |
22.8 Checklist
Before surgery ☐ Every blood thinner identified, with the reason it is prescribed. ☐ Bleeding risk of the procedure and clotting risk of the patient assessed. ☐ Plan agreed with the prescribing specialist; cardiologist involved for stents. ☐ Bridging used only if clotting risk is very high. ☐ Written plan given with dates to stop and restart; teach-back done. ☐ Anesthesia team informed for spinal or epidural anesthesia. |
22.9 Warning signs
Table 22.4. Green, amber, and red warning signs for patients taking blood thinners.
| Level | Signs | What to do |
|---|---|---|
| Green | Small bruises around the wound Slight oozing on the dressing on the first day | Expected. Restart your medicine on the planned date. |
| Amber | A wound that keeps oozing or a swelling that grows Nosebleeds or bleeding gums Blood in the urine | Call the clinic the same day. |
| Red | Heavy bleeding that does not stop with pressure Black stools or vomiting blood Sudden weakness, numbness, speech or vision problems Chest pain, breathlessness, or a hot, swollen calf | Call an ambulance or go to the emergency department now. |
Key points
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STEP 5 Patient education guide
The following pages may be photocopied and given to patients. Complete the plan with dates, and add your unit’s name, phone numbers, and review date before use.
PATIENT GUIDE Blood Thinners and Your Operation Your personal plan, with dates. Keep it with your medicines. |
My blood thinner plan
| Details | |
|---|---|
| My blood thinner(s) | |
| Why I take it | |
| Operation date | |
| Last dose before surgery | Date: ________ Time: ________ |
| Injections while paused? | ☐ No ☐ Yes: ______________________ |
| Restart | Date: ________ Dose: ________ |
| Agreed with | ☐ Cardiologist ☐ Other: ______________ |
Golden rules
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Do not stop or restart any blood thinner on your own. Follow this plan.
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If you have a heart stent, never stop aspirin, clopidogrel, ticagrelor, or prasugrel without your cardiologist.
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Tell us about all medicines and herbal remedies.
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If you take a dose by mistake, tell us before the operation.
After your operation
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Restart on the date in your plan.
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Small bruises around the wound are normal.
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Walk often to prevent clots.
Ramadan
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Do not fast while recovering from surgery.
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Ask your prescriber before fasting. Doses may need re-timing.
Warning signs: when to get help
| Level | What you notice | What to do |
|---|---|---|
| GREEN | Small bruises; slight oozing on the first day | This is normal. Restart on your planned date. |
| AMBER | A wound that keeps oozing; a growing swelling; nosebleeds; bleeding gums; blood in your urine | Call us today. |
| RED | Heavy bleeding that will not stop; black stools or vomiting blood; sudden weakness or speech problems; chest pain; a hot, swollen leg | Call an ambulance or go to the emergency department now. |
My contacts Surgical team: ______________________ Prescriber: ______________________ Out of hours: ______________________ [Unit name] [Guide version and review date] |
References
1. Douketis JD, Spyropoulos AC, Murad MH, et al. Perioperative management of antithrombotic therapy: an American College of Chest Physicians clinical practice guideline. Chest. 2022;162(5):e207-e243.
2. Douketis JD, Spyropoulos AC, Kaatz S, et al. Perioperative bridging anticoagulation in patients with atrial fibrillation. N Engl J Med. 2015;373(9):823-833.
3. Douketis JD, Spyropoulos AC, Duncan J, et al. Perioperative management of patients with atrial fibrillation receiving a direct oral anticoagulant. JAMA Intern Med. 2019;179(11):1469-1478.
4. Thompson A, Fleischmann KE, Smilowitz NS, et al. 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM guideline for perioperative cardiovascular management for noncardiac surgery. Circulation. 2024;150(19):e351-e442.
5. Horlocker TT, Vandermeuelen E, Kopp SL, et al. Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine evidence-based guidelines (fourth edition). Reg Anesth Pain Med. 2018;43(3):263-309.
Note: references are numbered within this chapter for the pilot. Items marked in square brackets are collected in the Author Fill-in and Verification Log.