Anticoagulants and dentistry
Exam Pass Notes
Key Takeaways
- Assess bleeding risk for procedures in anticoagulant patients.
- May need to alter medication regimen for high-risk procedures.
- Take measures to ensure bleeding is fully stopped before patient leaves.
- Understand mechanisms of different anticoagulant and antiplatelet drugs.
- Be aware of potential drug interactions.
Overview
- Anticoagulants prevent blood clots by interfering with the clotting process.
- Antiplatelets prevent clots by stopping platelets from clumping together.
- Patients taking these medications are at higher risk of bleeding during dental procedures.
- Need to assess bleeding risk for procedures and may need to alter medication regimen.
Risk Assessment
- Pocket probing, scaling, simple extractions are low bleeding risk.
- High bleeding risk procedures: flap surgery, complex extractions, multiple extractions, adjacent extractions, biopsies, gingival recontouring.
- Antiplatelets cause more initial bleeding, anticoagulants cause clots to dislodge easier.
- Medical conditions like liver/kidney disease can also increase bleeding risk.
- Must check medical history for bleeding risks.
- Stopping medication increases clotting risk, but continuing increases bleeding risk.
Risk Management
- Do high-risk procedures early in the day/week to allow for emergencies.
- Consider staging procedures instead of all at once.
- Discuss with GP if multiple drugs or medical conditions.
- For warfarin, check INR day before, don't change dose if <4, delay if >4.
- For antiplatelets, do not change dose.
- For DOACs, miss morning dose of apixaban/dabigatran, delay PM rivaroxaban to after procedure.
- Consult specialist for injectable anticoagulants.
Achieving Hemostasis
- Must ensure bleeding fully stopped before the patient leaves.
- Consider oxidized cellulose, collagen sponge, sutures to prevent later bleeding.
- For socket bleeding: bite on pack 10 min, suture to increase pressure if needed.
- Oxidized cellulose dressing helps clotting by absorbing blood, triggering platelets.
- Should pack and suture extraction sockets for patients on anticoagulants.
Atrial Fibrillation
- Leading cause of anticoagulant use, 200,000 new cases yearly in UK.
- Causes stroke risk by erratic electrical signals in the heart causing blood to pool and clot.
- Anticoagulants reduce stroke risk to normal levels in these patients.
Deep Vein Thrombosis
- Blood clot in vein, usually leg but sometimes arm/abdomen.
- More common in over 60, overweight, smokers, prior DVT, on pill/HRT, cancer, heart failure.
- Treated with anticoagulant injection then tablets for 3+ months.
- May place filter in vena cava to catch clots if meds unsuitable.
- Different treatment in pregnancy.
Types of Blood Flow
- Clots form when injury to vessel lining.
- Abnormal clots inside vessels form with irregular flow like pooling, eddying.
- Afib causes pooling in atria.
- Known risk with immobility and artificial valves.
- Clots can cause stroke or pulmonary embolism.
- Anticoagulants prevent clots but increase bleeding risk.
Anticoagulant Mechanisms
- Clots made of fibrin protein and platelets.
- Cascade of reactions creates clotting factors from prothrombin, fibrinogen.
- Anticoagulants block different parts of clotting cascade.
- Warfarin blocks vitamin K needed to create clotting factors.
- DOACs inhibit Factor Xa to reduce thrombin burst.
- Heparin activates antithrombin to block thrombin, Factor Xa.
Anti-platelet Drug Mechanisms
- Platelets stick together to form clots.
- Aspirin blocks COX-1 in platelets, preventing aggregation.
- Clopidogrel blocks P2Y12 receptors on platelets.
Drug Interactions
- Antibiotics can interact with anticoagulants.
- NSAIDs increase bleeding risk, use paracetamol instead.
- See SDCEP and BNF guidance documents for full details.