What is the relationship between Aspirin (acetylsalicylic acid) and subdural hematoma?

From the Guidelines

Aspirin should be discontinued in patients with a subdural hematoma, especially in the elderly, due to the increased risk of bleeding and worsening of the hematoma. The use of antiplatelet agents, such as aspirin, is associated with a higher risk of intracranial hemorrhage (ICH) after mild head trauma, as reported in a recent study published in the Annals of Emergency Medicine 1. This study suggests that patients on antiplatelet agents, particularly the elderly, may require observation if repeat CT scanning is avoided, highlighting the need for caution when managing patients with subdural hematoma who are taking aspirin.

When a patient on aspirin develops a subdural hematoma, the medication should be stopped immediately and not restarted until cleared by a neurosurgeon, typically after the hematoma has resolved (usually 4-12 weeks). Aspirin inhibits platelet function and increases bleeding risk, which can worsen an existing subdural hematoma or increase the risk of rebleeding. For patients who require antiplatelet therapy for conditions like coronary artery disease, alternative management strategies should be discussed with both neurosurgery and cardiology. Key considerations include:

• The risk of recurrent bleeding versus the risk of thrombotic events
• The need for frequent neuroimaging surveillance when aspirin therapy is restarted
• The importance of having a caregiver to assist with discharge care instructions and provide a safe environment during recovery, especially for patients requiring ongoing physical or cognitive assistance.

In emergency situations where a patient with a subdural hematoma has recently taken aspirin, platelet transfusions may be considered to reverse the antiplatelet effect, particularly before surgical intervention, as suggested by the study by Tauber et al, cited in the clinical policy endorsed by the Emergency Nurses Association 1. Ultimately, the decision to manage aspirin therapy in patients with subdural hematoma requires careful consideration of the individual patient's risk factors and medical history.

From the Research

Aspirin and Subdural Hematoma: An Overview

• Aspirin use has been associated with an increased risk of subdural hematoma, a type of brain bleed characterized by the accumulation of blood beneath the dura matter 2, 3, 4.
• The incidence of subdural hematomas varies widely depending on the age of the patient population, with older patients being at higher risk 3, 4.
• Dual antiplatelet therapy with aspirin and clopidogrel has been shown to increase the risk of intracranial hemorrhage, including subdural hematoma, in patients undergoing percutaneous coronary intervention 2.

Risk of Subdural Hematoma with Aspirin Use

• A meta-analysis of randomized trials found that aspirin use increases the relative risk of subdural hematoma by 1.5-fold, although the absolute increased rate associated with aspirin therapy is very low for most people 3.
• Another study found that the incidence of subdural hematoma during aspirin therapy is low, but varies widely depending on the age of the patient population, ranging from 0.02 per 1000 patient-years for primary prevention trials of middle-aged health professionals to 1 to 2 per 1000 patient-years for older patients with atrial fibrillation 4.

Management of Subdural Hematoma in Patients on Aspirin

• The management of subdural hematoma in patients on aspirin therapy is challenging, as resuming treatment can lead to recurrence of bleeding, while suspension or stopping of treatment can increase the risk of thrombotic events 2, 5.
• A case report suggests that individuals with chronic subdural hematoma who require antiplatelet therapy can still receive the medication after undergoing a bilateral middle meningeal artery embolization 6.
• Another study found that patients requiring reinitiation of antiplatelet therapy and/or anticoagulation therapy after traumatic subdural hematoma are at elevated risk of thrombotic/thromboembolic events, but not unplanned hematoma evacuation, and should be followed closely until treatment is restarted 5.