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Anticoagulants around surgery
Two things decide how an anticoagulant is interrupted — the bleeding risk of the operation and the thrombotic risk of the patient; DOACs are not bridged, warfarin is bridged only at very high thrombotic risk, and every drug has its own reversal agent.
Why it matters in the exam
The exam asks how many days warfarin is stopped and what the target INR is, when to stop apixaban, rivaroxaban and dabigatran according to kidney function and bleeding risk, who needs LMWH bridging (mechanical mitral valve, venous thrombosis in the last three months), and how each drug is reversed urgently. It also asks about the intervals before a neuraxial block and about procedures for which nothing is stopped.
The BRIDGE trial showed that in atrial fibrillation heparin bridging increases bleeding without reducing stroke — so most patients are not bridged. With DOACs the interruption time is set by kidney function, especially for dabigatran, which is mainly excreted by the kidney. In procedures with a very low bleeding risk — simple dental work, cataract surgery, small skin procedures — the anticoagulant is continued.
Before a neuraxial block the intervals are longer: 72 hours for Xa inhibitors and 120 hours for dabigatran according to ASRA. After surgery anticoagulation is restarted after 24 hours in low-bleeding-risk surgery, and after 48–72 hours in high-risk surgery. In life-threatening bleeding: warfarin — PCC with vitamin K; dabigatran — idarucizumab; Xa inhibitors — andexanet alfa or high-dose PCC; heparin — protamine.
Key points
- Interruption = bleeding risk versus thrombotic risk.
- Warfarin: 5 days, INR below 1.5; bridging only at very high thrombotic risk.
- DOAC: 24–48 hours by risk and kidney; no bridging.
- Reversal: PCC and vitamin K, idarucizumab, andexanet alfa, protamine.
- Neuraxial: Xa 72 hours, dabigatran 120 hours.
Summary table
| Drug | Stop before surgery (normal kidney) | Urgent reversal | Bridging |
|---|---|---|---|
| Warfarin | 5 days; INR below 1.5 | PCC and IV vitamin K | Only at very high thrombotic risk |
| Apixaban / rivaroxaban / edoxaban | 24 hours at low bleeding risk; 48 hours at high | Andexanet alfa or PCC | No |
| Dabigatran | 24–48 hours, longer as clearance falls | Idarucizumab | No |
| LMWH | 24 hours at a therapeutic dose; 12 prophylactic | Protamine (partial reversal) | — |
| Neuraxial block | Xa inhibitors 72 hours; dabigatran 120 hours | — | — |
A free exam question
מטופל בן 75 עם מסתם אאורטלי ( מכני הפסיק לקחת קומדין Warfarin ) ועבר לטיפול בקלקסן ( Enoxaparin ) לקראת בדיקה פולשנית. מדוע יש לחדש את הקומדין למחרת הפעולה, בחפיפה עם קלקסן? (the question as examined, in Hebrew)
- א. Protein C בעל זמן מחצית חיים ארוך יחסית לפרוטאינים האחרים
- ב. Protein C מעוכב על ידי קלקסן
- ג. Protein C מתפרק מהר יותר בשילוב שתי התרופות יחד
- ד. Protein C הוא הראשון להיפגע מקומדין
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Sources
- EHRA Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation, 2021 — Planned interventions
- ACCP / CHEST Guideline: Perioperative Management of Antithrombotic Therapy, 2022 — Bridging and interruption
- ASRA Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy, 4th edition (2018) — Neuraxial intervals
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.