Circuit 3, station 7

Treating a Patient Taking Warfarin

Patients on warfarin or other vitamin K antagonist medication with an INR below 4 are recommended to continue treatment and not to interrupt the dose of the anticoagulant.

Dental treatments that have a high or low risk of causing bleeding complications:

• Verify the patient’s INR status for no more than 24 hours prior to the procedure. If the patient’s INR is stable it can be verified no more than 72 hours prior to the procedure:
• When a patient has an NRI higher than 4, treatment should be postponed until the NRI is reduced or stabilised. If the patient needs urgent treatment refer to secondary dental care.
• Patients with IRN less than 4 should be managed taking into consideration the general advice for the management of bleeding risk. And:
• Assess the possibility of limiting the initial treatment area.
• For higher risk cases with hemorrhagic complications, if possible, plan to perform the procedures in stages.

Treating a Patient Taking an Injectable Anticoagulant

If the patient is taking a prophylactic dose of low molecular weight heparin, it is not necessary to interrupt the medication with the anticoagulant.

Dental treatments with a high or low risk of bleeding complications:

• Determine if the patient is taking a high or low prophylactic dose.
• Consult with the specialist or prescriber to clarify doubts in cases of patients taking a very high dose.
• Patients with low prophylactic dose are recommended to be treated following the general advice to avoid bleeding. And:
• Assess the possibility of limiting the initial treatment area.
• For higher risk cases with postoperative bleeding complications, plan to perform the procedures in stages if possible.
• Strongly consider suturing and packing.

Treating a Patient Taking an Anti-platelet Drug(s)

Patients receiving single or double anti-platelet doses can receive treatment without interrupting their medication.

Care for the patient following the general advice for the management of bleeding risks. And:

If the patient is taking aspirin only:

• Cases with a higher risk of postoperative bleeding complications, if possible, plan to perform the procedures in steps.
• Take into account local hemorrhagic measures to achieve haemostasis.

If the patient is taking another single anti-platelet drug or dual anti-platelet drugs:

• Be aware bleeding may be prolonged (up to 60 minutes).
• Assess the possibility of limiting the initial treatment area.
• For higher risk cases with postoperative bleeding complications, plan to perform the procedures in stages if possible.
• Strongly consider suturing and packing.

Treating a patient taking an anticoagulant and anti-platelet drug combination

Patients who have combined treatment of anticoagulants with anti-platelet drugs and need to perform dental procedures have the possibility of suffering bleeding with a high or low risk of complication:

• Assess drug interaction, general health status and potential bleeding risks in consultation with the patient’s specialist or prescriber.

Drug interactions between anticoagulants or anti-platelet drugs and other medications

• It is important to keep in mind that the prescription of any medication to patients taking anticoagulants or anti-platelet drugs can generate interactions that affect coagulation levels.

Treatment with anticoagulant or anti-platelet drugs has raised concerns about the high risk of bleeding complications in patients undergoing invasive dental procedures. For many years, many dentists have been widely aware of the use of anticoagulants such as warfarin, and the anti-platelet drugs aspirin and clopidogrel, and the well-established guidelines for the dental care of patients taking these drugs. There are other anticoagulants that have been available in the UK since 2008 (the DOACs* or Direct Oral Anticoagulants; namely apixaban, dabigatran, rivaroxaban and edoxaban) and anti-platelet agents (prasugrel and ticagrelor) that are in increasing use. The lack of certainty in the field of dentistry about treatment with these new drugs has led to different advice on how to obtain the right treatment for patients. There is also a lack of information on dental patients who have infrequent treatment with injectable low-molecular-weight heparins (LMWHs).

Assessing Bleeding Risk

Before performing any dental treatment on a patient taking anticoagulants or anti-platelet drugs, it is important to assess the risk of bleeding. This also allows assessment of the risk of bleeding triggered by the dental procedure, as well as the patient’s individual level of bleeding risk, which may be affected by anticoagulants or anti-platelet medications and the patient’s other medical conditions and medications.

In addition to bleeding complications in dental procedures it should always be noted that existing evidence and clinical experience indicates that serious adverse bleeding is rare.

The percentage of bleeding after dental procedures requiring haemostatic measures for patients who have maintained their peri-operative oral anticoagulant therapy has been estimated to be approximately 4%.

Which Dental Procedures Have the Highest Bleeding Risk?

Care for patients taking anticoagulants or anti-platelet agents who require dental treatments that include procedures in the first category should be straightforward, and these patients can be managed according to standard practice, taking care not to cause bleeding. Take extra care and attention to patients who have invasive procedures that have bleeding risks. 

Haemorrhagic complications are known to be continuous or excessive bleeding that has not been controlled from the beginning with the recommended haemostatic measures. When the term “higher risk” is used, it does not mean that dental treatments are high risk. Dental procedures classified as low or high risk are considered a relatively minor bleeding risk from a broader field of medical surgical procedures. All dental professionals should use their clinical judgment and make sure, before performing a dental procedure that may cause bleeding in a patient taking anticoagulants or anti-platelet agents, that there is sufficient confidence and skill in the procedure and the management of peri-operative bleeding should it occur.

Bleeding risks for dental procedures

Dental procedures that are unlikely to cause bleeding: 

• Local anaesthesia by infiltration, intraligamentary or mental nerve block
• Local anaesthesia by inferior dental block or other regional nerve blocks
• Basic periodontal examination (BPE)
• Supragingival removal of plaque, calculus and stain
• Direct or indirect restorations with supragingival margins
• Endodontics – orthograde
• Impressions and other prosthetics procedures
• Fitting and adjustment of orthodontic appliances

Dental procedures that are likely to cause bleeding:

• Low risk of post-operative bleeding complications:

• Simple extractions (1-3 teeth, with restricted wound size)
• Incision and drainage of intra-oral swellings
• Detailed six-point full periodontal examination
• Root surface debridement (RSD)
• Direct or indirect restorations with subgingival margins

Higher risk of post-operative bleeding complications:

• Complex extractions, adjacent extractions that will cause a large wound or more than 3 extractions at once.
• Flap raising procedures including:

– Elective surgical extractions

– Periodontal surgery

– Preprosthetic surgery

– Periradicular surgery

– Crown lengthening

– Dental implant surgery

– Gingival recontouring

– Biopsies

Local anaesthesia should be delivered using an aspirating syringe and should include a vasoconstrictor, unless contraindicated. Note that other methods of local anaesthetic delivery are preferred over regional nerve blocks, whether the patient is taking an anticoagulant or not.

There is no evidence to suggest that an inferior dental block performed on an anticoagulated patient poses a significant risk of bleeding. However, for patients taking warfarin, if there are any indications that the patient has an unstable INR, or other signs of excessive anticoagulation, an INR should be requested before the procedure to ensure <4 before proceeding.

Although a BPE can result in some bleeding from gingival margins, this is considered extremely unlikely to lead to complications.

Simple extractions refers to those that are expected to be straightforward without surgical complications.

Complex extractions refers to those that may be likely to have surgical complications.

Consideration should be given to the extent and invasiveness of the individual procedure. Some may be less invasive and could be treated as low risk.

Main medical conditions associated with increased bleeding risk

• Chronic kidney disease – platelet dysfunction
• Liver disease e.g. alcoholic liver disease, hepatitis (viral, autoimmune) – reduces coagulation factor production; reduces platelet numbers and function from associated splenomegaly and alcohol excess is toxic to the bone marrow and reduces platelet counts
• Haematological malignancies – platelet and platelet dysfunction
• Active or recent chemotherapy/radiotherapy (defined as < 3-months) – fewer platelets from pancytopenia
• NYHA Heart Failure III or IV – associated liver dysfunction
• Platelet disorders (congenital or acquired) – fewer platelet count/dysfunction
• Connective tissue disorders – vascular fragility and platelet dysfunction

In the case of medically complex patients the likely impact on bleeding risk should be determined, consult with the primary care physician to determine the extent of the disease and how it affects dental treatment.

Main drug groups associated with increased bleeding risk

• Other anticoagulants or anti-platelet drugs.

Effect: Patients can be on dual, multiple or combined anti-platelet or anticoagulant therapies. These patients are likely to have a higher risk of bleeding complications than those on single drug regimes.

• Cytotoxic drugs or drugs associated with bone marrow suppression e.g. leflunamide, hydroxychloroquine, sulfasalazine, penicillamine, gold, methotrexate, azathioprine, mycophenolate.

Effect: These can reduce platelet numbers and/or impair liver function affecting production of coagulation factors.

• Biologic immunosuppression therapies e.g. infliximab, adalimumab, etanercept, tocilizumab, certolizumab, abatacept, anakinra.

Effect: These can cause thrombocytopenia and/or impair liver function.

• Non-steroidal anti-inflammatory drugs (NSAIDs) e.g. aspirin, ibuprofen, diclofenac and naproxen.

Effect: Impair platelet function to various extents.

• Drugs affecting the nervous system:

• Selective serotonin re-uptake inhibitors (SSRIs)
• Serotonin and noradrenaline re-uptake inhibitors (SNRIs)
• Carbamazepine

Effect: SSRIs and SNRIs have the potential to impair platelet aggregation and, although unlikely to be clinically significant in isolation, may in combination with other anti-platelet drugs, increase the bleeding time.

Carbamazepine can affect both liver function and bone marrow production of platelets. Patients most at risk are those recently started on this medication or following dose adjustment.

Be aware that patients may also be taking non-prescribed aspirin, and this anti-platelet agent can in effect convert a prescribed monotherapy into a dual therapy.

Patients with inflammatory bowel disease or autoimmune/rheumatological conditions are commonly prescribed these drugs.

For the management of patients taking these additional medications, the patient’s prescribing clinician, specialist or general medical practitioner could be consulted in order to assess the likely impact on bleeding risk.

Be aware that some herbal and complementary medicines may affect bleeding risk, either on their own or when in combination with other anticoagulants or anti-platelet drugs. These include St. John’s Wort, Ginkgo biloba and garlic.

Advice for Assessing Bleeding Risk

The following advice for good patient management is based on clinical experience and expert opinion.

• Determine whether the risk of each treatment is positive or negative and how high or low the bleeding complication may be.
• When taking a medical history it is important to ask the patient if he/she is taking or has taken anticoagulants or anti-platelet agents or any other drug prescribed by the patient’s specialist physician.

• The patient should have been informed by the physician about the type of drugs he/she is taking and the importance of notifying the dentist about the use of anticoagulants or anti-platelet drugs.
• In some cases patients may be unaware that their medication is an anticoagulant or anti-platelet drug.
• Patients taking non-prescription medications such as NSAIDs may be at increased risk of bleeding.
• Monitor the patient’s health status prior to the appointment to verify that there is no alteration that could affect the treatment and postpone it. This can be verified through a call or message.

• Ask the patient if he/she is taking an anticoagulant or anti-platelet drug and whether it is lifelong or time-limited.

• If the treatment with anticoagulants has a limited duration, it is better to wait until the patient finishes taking the medication to perform the dental treatment.

• Ask the patient about medical history and any medical conditions.

• Kidney, liver or bone marrow diseases may affect coagulation and platelet function in patients with some conditions.

• Ask the patient if he/she has suffered bleeding and what type of bleeding (e.g. severe and continuous bleeding requiring hospitalisation, bleeding from other wounds, spontaneous bleeding, and easy bruising, etc.).

• A history of bleeding from dental or surgical procedures is an indicator to determine the possibility of bleeding and complications after treatment.

Ensure that the patient is referred to a specialist. Full details of the patient’s anticoagulant medication should be included when referring a patient.

General advice for managing bleeding risk

The following advice for good patient management is based on clinical experience and expert opinion.

A patient who is taking an anticoagulant or anti-platelet medication and requires dental treatment that is unlikely to cause bleeding:

• The patient should be treated following the usual procedures, taking care not to cause bleeding.

A patient who is taking anticoagulant or anti-platelet medications and requires a dental procedure that has the potential to cause bleeding, with a low or high risk of bleeding complications:

• It is advisable to delay non-urgent invasive dental treatments whenever possible when the patient is taking anticoagulants or platelet anti-aggregants of limited duration until the medication has been completed.

• In cases where there is a dental emergency and the patient is taking anticoagulants in preparation for surgery, it is necessary to contact the surgical advisor to suspend treatment.
• Patients with acute deep vein thrombosis or pulmonary embolism take high doses of apixaban or rivaroxaban during the first 1 to 3 weeks of treatment. It is advisable to take this into account in order to delay any dental procedure likely to cause bleeding until the patient is taking the standard dose.

• Consult with the specialist physician to assess the risks when the patient is taking any medication or suffers from any disease that may trigger bleeding 

• Consulting with the patient and the specialist physician in advance could avoid missed appointments and travel.

• In cases where you need to consult on procedures, contact a more experienced colleague, ideally in your own centre or clinic.

• Most patients can be treated as usual, only in exceptional situations the patient may be required to be referred.

• All questions about the patient’s medication should be direct to the prescribing physician. 

• Whenever possible plan treatments during the early hours of the day and week to allow sufficient time to treat prolonged bleeding or rebleeding episodes, should one occur.

• Give the patient all the instructions prior to treatment (e.g. the steps to follow to do the INR test or any modification of his medication regimen).

• Written pre-treatment instructions or electronic devices serve to reduce unnecessary appointments and travel.

• Perform each treatment as atraumatically as possible by applying appropriate local measures and only when complete haemostasis has been achieved can the patient be discharged.

• To reduce the possibility that a treatment may cause bleeding and the patient may have to go to the emergency room, it is important to make sure that the tissues are sutured and well packed.

• It is necessary to highlight measures to prevent complications and to avoid travel time to emergency care as a cause for concern (e.g. limitation of the initial treatment area, staggering of treatment, haemostatic measures and post-treatment follow-up).

• If it is not contraindicated to recommend the patient to take paracetamol, it works to relieve pain instead of NSAIDs such as aspirin, ibuprofen, diclofenac or naproxen.

• Provide the patient with post-treatment instructions and emergency contact information.

Only with the cardiologist’s instructions can anticoagulant or anti-platelet therapy be discontinued in the following cases:

• Patients with prosthetic metal heart valves or coronary stents.
• Patients who have had a pulmonary embolism or deep vein thrombosis in the last three months.
• Patients on anticoagulant therapy for cardioversion.