What is the risk of Intracranial Hemorrhage (ICH) after a fall with head strike in patients on prophylactic Enoxaparin (Low Molecular Weight Heparin)?

From the Guidelines

The risk of intracranial hemorrhage (ICH) after a fall with head strike in patients on prophylactic enoxaparin is relatively low, and according to the most recent evidence, enoxaparin does not increase bleeding and may have decreased the VTE rate without an overall effect on outcome 1. Patients on prophylactic doses of enoxaparin (typically 40mg daily) have a lower bleeding risk compared to those on therapeutic anticoagulation. However, any head trauma in anticoagulated patients warrants prompt evaluation, especially with any neurological symptoms, loss of consciousness, or severe headache. If a patient on prophylactic enoxaparin experiences a head strike, they should be evaluated clinically and potentially undergo CT imaging of the brain to rule out ICH. The decision to continue or hold enoxaparin after head trauma depends on the clinical assessment, imaging results, and the indication for anticoagulation. Some key points to consider include:

• Enoxaparin's relatively short half-life (4-7 hours) is advantageous in trauma situations compared to warfarin.
• The bleeding risk is influenced by additional factors including age (higher risk >75 years), renal function, concomitant antiplatelet therapy, history of prior bleeding, and severity of the trauma.
• Protamine sulfate can partially reverse enoxaparin's effects in emergency situations, though its reversal capacity is incomplete at approximately 60-80% of the anticoagulant activity. It is essential to weigh the risks and benefits of anticoagulation in patients with a history of ICH, considering factors such as the type of hemorrhage, patient age, and indication for antithrombotic therapy 1. In general, the management of antithrombotic therapy in patients who suffer an intracranial hemorrhage should be individualized, taking into account the specific clinical scenario and the latest available evidence 1.

From the Research

Risk of Intracranial Hemorrhage (ICH) after a Fall with Head Strike

• The risk of ICH after a fall with head strike in patients on prophylactic Enoxaparin (Low Molecular Weight Heparin) is a concern, as anticoagulant and antiplatelet medications are known to increase the risk and severity of traumatic intracranial hemorrhage (tICH) 2.
• A study published in 2002 found that enoxaparin can be safely administered to most patients with intracranial hemorrhagic injuries for VTE prophylaxis, with a low rate of complications (4%) 3.
• Another study published in 2017 found a low incidence of clinically significant tICH with a ground-level fall in head trauma in patients taking an anticoagulant or antiplatelet medication, including enoxaparin, with no statistical difference in rate of tICH between antiplatelet and anticoagulants 2.
• A 2020 study found that enoxaparin is a safe prophylaxis against venous thromboembolism in patients with traumatic closed intracranial bleeding, with no patients developing clinical deterioration and/or progression of the intracranial bleeding on follow-up brain CT scans 4.
• A 2008 study found that early enoxaparin for VTE prophylaxis in patients with blunt traumatic brain injury is safe, with a low rate of bleeding complications (3.4%) and no significant increase in mortality 5.

Enoxaparin Prophylaxis and Antifactor Xa Activity

• A 2024 study found that the effects of prophylactic doses of enoxaparin on antifactor Xa activity (anti-Xa) and rotational thromboelastometry (ROTEM) parameters in critically ill patients vary, with anti-Xa values within the prophylactic range in slightly more than half of the patients 6.
• The study suggests that the dosing of low-molecular-weight heparin (LMWH) in critically ill patients may require individualization based on anti-Xa, and further studies are needed to establish a universal anti-Xa prophylactic range for LMWH 6.