Management of the anticoagulated patient in the dental clinic

In dental practice, it is crucial to know how to manage patients taking oral anticoagulants to ensure that the procedures performed are safe. Whether for cardiovascular pathologies or other disorders related to thromboembolic risk, oral anticoagulants are essential in the treatment of patients, but their use presents challenges in dental surgery due to the risk of bleeding.

What are oral anticoagulants and what are they used for?

Oral anticoagulants are drugs that are administered orally and interfere with the blood clotting process, which is why they are used in patients with conditions such as atrial fibrillation (AF), deep vein thrombosis (DVT) or pulmonary embolism (PE), among others.

These act on different phases, preventing the excessive formation of fibrin and, therefore, the creation of dangerous clots that could obstruct blood vessels and cause damage to vital organs such as the heart, lungs or brain.

Prevalence of anticoagulated patients

The use of oral anticoagulants has increased in recent years, amounting to between 10% and 15% of adults, many of them being patients over 65 years of age. The prevalence continues to increase due to longer life expectancy and more diagnosed diseases for which these drugs are required, so a high percentage of patients requiring dental care are also anticoagulated.

Physiology of blood coagulation

Blood coagulation is a process carried out by our body to prevent excessive blood loss after an injury or wound. It involves different biochemical events that end up forming a fibrin clot to seal the damaged blood vessels. This can be divided into two phases:

Primary hemostasis

First phase of coagulation in which vasoconstriction, the narrowing of blood vessels at the site of injury, occurs. Platelets cluster at the site to form a temporary plug to stop the bleeding.

Secondary hemostasis

A series of plasma proteins numbered I to XIII, called coagulation factors, are activated to form fibrin, which intertwines and creates a mesh that stabilizes the clot and makes it more durable to stop bleeding.

This two-phase process is known as the coagulation cascade, as the factors are activated sequentially, one after the other. Oral anticoagulants mainly affect the second phase.

Types of oral anticoagulants

There are two main types of oral anticoagulants used in clinical dental practice:

• Vitamin K antagonists (VKA)
• Direct oral anticoagulants (ACOD).

Vitamin K antagonists

Warfarin and acenocoumarol have been used for many years. VKAs inhibit the synthesis of coagulation factors II, VII, IX and X, which are vitamin K-dependent. However, they require constant monitoring of coagulation values by laboratory tests such as the INR (International Normalized Ratio) to ensure that levels are within the safe range.

Direct oral anticoagulants

Such as rivaroxaban, apixaban and dabigatran. These are newer drugs that directly affect thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban and edoxaban). They are more predictable, have a faster onset of action and require less monitoring. They also have fewer interactions with food and other drugs, and are easier to use in elderly and polymedicated patients, although they should be used with great care in cases of renal failure.

What is INR and what are the optimal values for treatments in the dental clinic?

The INR (International Normalized Ratio) is a standardized measure used to evaluate blood coagulation in patients receiving oral anticoagulants, especially vitamin K antagonists. It compares the patient's prothrombin time (PT) with a normal reference value to adjust the anticoagulant dose and maintain a balance between avoiding clots and preventing excessive bleeding.

• Normal INR (1.0) is the value in people without anticoagulant treatment.
• Therapeutic INR (2.0 - 3.0) is a common range in patients with atrial fibrillation, deep vein thrombosis or pulmonary embolism. It is usually safe for most dental procedures.
• INR 3.5 - 4.0 requires greater caution in invasive procedures, which may require medication adjustments or additional measures to control bleeding.
• INR > 4.0 indicates an elevated risk of bleeding, so surgeries should be postponed until the INR is in a safe range.

Protocols for the care of patients with anticoagulants

When a patient takes anticoagulants, the risk of bleeding during dental surgery increases. As dentists, protocols should be followed to prevent this from happening, starting with a preoperative assessment in which the INR is measured 24 to 72 hours before surgery to see what range it is in. If it is less than or equal to 3.5, no changes in medication should be made, while a higher INR may require adjustments.

During surgery, techniques are used to minimize tissue damage, applying local anesthesia with vasoconstrictor to reduce bleeding. It is advisable to opt for resorbable sutures to avoid having to remove them and minimize tissue manipulation after surgery.

In patients treated with VKA, especially when the INR is higher than 3.5, bridging therapy can be used, replacing anticoagulants with low-molecular-weight heparin (LMWH). In patients on OACD, temporary discontinuation of anticoagulation usually depends on the type of surgery. For minor procedures, discontinuation is generally not necessary, whereas, in invasive surgeries, 1 or 2 doses may be discontinued earlier, depending on the risk of bleeding.

Post-surgical recommendations

After surgery, local hemostatic agents can be used, applying pressure to the area with gauze containing tranexamic acid, to help stop the bleeding. The patient should follow a soft and cold diet so as not to irritate the wound, and analgesics such as paracetamol or diclofenac are recommended. The important thing is to avoid aspirin or NSAIDs.

The patient should be educated to identify warning signs, such as bruising, continuous bleeding or difficulty breathing. In these cases, a physician should be consulted as soon as possible. Careful oral hygiene and, in some cases, antibiotics to prevent infection are also recommended. In minor procedures, such as simple extractions, the patient can resume taking his or her anticoagulant a few hours later.

Before handling an anticoagulated patient, the dental practice should analyze the patient's health status in detail and plan the procedure accordingly to reduce risks, especially with elderly patients. By following the steps set out in the protocols, safe dental treatment can be provided.