Introduction: Traumatic intracranial hemorrhage may present with concomitant coagulopathy. This state is often further complicated by the increasingly common use of anticoagulant and antiplatelet medications. The development of point of care (POC) assays to help rapidly identify hypocoagulable states in the acute setting is a crucial step in guiding treatment of traumatic brain injury (TBI) patients. We examined the role of rapid thromboelastography (r-TEG) and Verify Now Aspirin Assay (VN-ASA) in the assessment of platelet inhibition following TBI.
Methods: Retrospective review of coagulation profiles obtained on admission was conducted in 49 TBI patients. All patients were assessed by both r-TEG and VN-ASA regardless of history of aspirin use. Platelet dysfunction was determined by mean amplitude (MA) levels lower than 52mm on r-TEG or by therapeutic VN-ASA <550 ARU. Thrombocytopenia was defined as < 100,000 platelets/uL.
Results: Analysis of 49 patients (median age 67 years; 62% male) was completed, of which approximately half (n=24) reported ASA intake. Therapeutic VN-ASA suggestive of platelet dysfunction was found in 83% (20/24) of patients taking ASA, but also in 32% (8/25) of non-takers. Conversely, only 10% (5/49) of patients demonstrated reduced MA on r-TEG (3 patients in the ASA group). Four of these patients were also found to have therapeutic VN-ASA.
Conclusions: While r-TEG serves as an invaluable tool in rapidly assessing coagulopathy secondary to coagulation factor deficiency or fibrinolysis, it appears to have poor sensitivity for platelet dysfunction, particularly when driven by intake of ASA. However, VN-ASA demonstrated high sensitivity in our cohort and may be combined with r-TEG to improve POC assessment of coagulation status in the acute setting. Standardization of these POC assays on admission in TBI may help guide patient resuscitation and determine suitability for surgical intervention in place of conventional coagulation tests.
Patient Care: To better help determine underlyng coagulopathy in TBI patients using POC assays
Learning Objectives: 1) Identify the benefits and limitations of POC assays in assessing various aspects of clot formation
2) Understand the potential for obtaining incomplete or incorrect history from the patient or family which may significantly impact treatment decisions.
3) Understand the application of POC coagulation assays in guiding decisions regarding resuscitation and/or surgical intervention