Related Experiment Video
Updated: Oct 7, 2025

Pre-Chiasmatic, Single Injection of Autologous Blood to Induce Experimental Subarachnoid Hemorrhage in a Rat Model
Published on: June 18, 2021
Does Pre-existing Anticoagulation or Antiplatelet Therapy Increase the Risk of Traumatic Subarachnoid Hemorrhage
Tessa A Harland1,2, Tarun Prabhala1,2, AnneMarie Nardolillo1,2
1Department of Neurosurgery, Albany Medical Center, Albany, New York, USA.
Background:
Isolated traumatic subarachnoid hemorrhage (tSAH) is a common finding in mild traumatic brain injury that often results in transfer to a tertiary center. Patients prescribed blood-thinning medications (BTs) are believed to be at higher risk of clinical or radiographic worsening.
Objective:
To compare the rates of radiographic progression and need for neurosurgical intervention in patients with tSAH who are on anticoagulation (AC) and antiplatelet (AP) therapies with those who are not.
Methods:
Analysis using a retrospective cohort design identified patients older than 18 years with isolated tSAH and a Glasgow Coma Scale of 15 on admission. Clinical information including use of BTs, administration of reversal agents, radiographic progression, and need for neurosurgical intervention was collected. Patients on BTs were divided into AP, AC, and AP/AC groups based on drug type.
Results:
Three hundred eighty-four patients were included with 203 in the non-BT group and 181 in the BT group. Overall, 2.1% had worsening scans, and none required operative intervention. There was no difference in radiographic worsening between the non-BT and BT groups (2.4% vs 1.6%; P = 1.00). Crosswise comparison revealed no difference between the non-BT group and each BT subtype (AP, AP/AC, or AC). The non-BT group was more likely to have radiographic improvement than the BT group (45.8% vs 30.9%; P = .002).
Conclusion:
Neurologically intact patients on BTs with isolated tSAH are not at increased risk of radiographic progression or neurosurgical intervention. The presence of BTs should not influence management decisions for increased surveillance.
Related Concept Videos
Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
Venous Thrombosis III: Interprofessional Care
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
Venous Thrombosis IV: Nursing Management
Formation of the Platelet Plug
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...

