The significance of platelet count in traumatic brain injury patients on antiplatelet therapy (original) (raw)

Platelet transfusion does not improve outcomes in patients with brain injury on antiplatelet therapy

Brain injury, 2018

Platelet dysfunction following traumatic brain injury (TBI) is associated with worse outcomes. The efficacy of platelet transfusion to reverse antiplatelet medication (APM) remains unknown. Thrombelastography platelet mapping (TEG-PM) assesses platelet function. We hypothesize that platelet transfusion can reverse the effects of APM but does not improve outcomes following TBI. An observational study at six US trauma centres was performed. Adult patients on APM with CT evident TBI after blunt injury were enrolled. Demographics, brain CT and TEG-PM results before/after platelet transfusion, length of stay (LOS), and injury severity score (ISS) were abstracted. Sixty six patients were enrolled (89% aspirin, 50% clopidogrel, 23% dual APM) with 23 patients undergoing platelet transfusion. Transfused patients had significantly higher ISS and admission CT scores. Platelet transfusion significantly reduced platelet inhibition due to aspirin (76.0 ± 30.2% to 52.7 ± 31.5%, p < 0.01), but h...

A prospective evaluation of platelet function in patients on antiplatelet therapy with traumatic intracranial hemorrhage

The journal of trauma and acute care surgery, 2013

Platelet transfusion is increasingly used in patients with traumatic intracranial hemorrhage (ICH) on aspirin therapy to minimize the progression of ICH. We hypothesized (null) that platelet transfusion in this cohort of patients does not improve platelet function. We performed a prospective interventional trail on patients with traumatic ICH on daily high-dose (325 mg) aspirin therapy. All patients received one pack of apheresis platelets. Blood samples were collected before and 1 hour after platelet transfusion. Platelet function was assessed using Verify Now Platelet Function Assay, and a cutoff of greater than 550 aspirin reaction units was used to define functioning platelets (FP). Twenty-eight patients were enrolled in the study. On presentation, 79% (22 of 28) of the patients had nonfunctioning platelets (NFPs), and transfusion of platelets did not improve platelet function as 81% (18 of 22) still had NFP. Of the 22 patients, 4 converted from NFP to FP after transfusion. Ther...

Survey evaluating clinical equipoise around platelet transfusion after head injury and traumatic intracranial haemorrhage (ICH) in patients on antiplatelet medications

Emergency Medicine Journal, 2021

Introduction Patients aged 60 or over account for over half of the severely injured trauma patients and a traumatic brain injury is the most common injury sustained. Many of these patients are taking antiplatelet medications but there is clinical equipoise about the role of platelet transfusion in patients with traumatic intracranial haemorrhage (ICH) taking prior antiplatelet medications. Method A prepiloted survey was designed to explore a range of clinical issues in managing patients taking antiplatelet medications admitted with a traumatic brain injury. This was sent via email to consultants and specialty registrar members of a variety of relevant UK societies and working groups in the fields of emergency medicine, critical care, neurosurgery and haematology. Results 193 responses were received, mostly from colleagues in emergency medicine, neurosurgery, anaesthesia and haematology. Respondents indicated that there is a lack of evidence to support the use of platelet transfusion...

Routine platelet transfusion in patients with traumatic intracranial hemorrhage taking antiplatelet medication: Is it warranted?

Canadian Journal of Surgery, 2022

Background: After a traumatic intracranial hemorrhage (tICH), patients often receive a platelet transfusion to reverse the effects of antiplatelet medication and to reduce neurologic complications. As platelet transfusions have their own risks, this study evaluated their effects on tICH progression, need for operations and mortality. Methods: In this retrospective study, we identified patients admitted to a level 1 trauma centre with a tICH from 2011 to 2015 who were taking acetylsalicylic acid (ASA) or clopidogrel, or both. We categorized patients into 2 groups: platelet transfusion recipients and nonrecipients. We collected data on demographic characteristics, changes in brain computed tomography findings, neuro surgical interventions, in-hospital death and intensive care unit (ICU) length of stay (LOS). We used multivariable logistic regression to compare outcomes between the 2 groups. Results: We identified 224 patients with tICH, 156 (69.6%) in the platelet transfusion group and 68 (30.4%) in the no transfusion group. There were no between-group differences in progression of bleeds or rates of neurosurgical interventions. In the transfusion recipients, there was a trend toward increased ICU LOS (adjusted odds ratio [OR] 1.59, 95% confidence interval [CI] 0.74-3.40) and in-hospital death (adjusted OR 3.23, 95% CI 0.48-21.74). Conclusion: There were no differences in outcomes between patients who received platelet transfusions and those who did not; however, the results suggest a worse clinical course, as indicated by greater ICU LOS and mortality, in the transfusion recipients. Routine platelet transfusion may not be warranted in patients taking ASA or clopidogrel who experience a tICH, as it may increase ICU LOS and mortality risk. Contexte : Après une hémorragie intracrânienne traumatique, les patients reçoivent souvent une transfusion de plaquettes pour inverser les effets des médicaments antiplaquettaires et réduire les complications neurologiques. Les transfusions de plaquettes comportent des risques particuliers; l'étude portait sur leurs effets sur la progression de l'hémorragie intracrânienne traumatique, ainsi que sur la nécessité d'une opération et la mortalité.

Platelet dysfunction as an early marker for traumatic brain induced coagulopathy in the absence of platelet inhibitors

Journal of the American College of Surgeons, 2012

Background The goal of this study is to determine the presence of platelet dysfunction in patients with traumatic brain injury (TBI). The mechanisms underlying the coagulopathy associated with TBI remain elusive. The question of platelet dysfunction in TBI is unclear. Methods This was a prospective observational study conducted at Memorial Hospital of South Bend, IN, and Denver Health Medical Center, CO. A total of 50 patients sustaining TBI, and not under treatment with anticoagulants or platelet inhibitors, were analyzed utilizing modified thromboelastography (TEG) with platelet mapping (TEG/PM), along with standard coagulation tests. Results Compared to normal controls, patients with severe TBI had a significantly increased percentage of platelet ADP and arachidonic acid (AA) receptor inhibition. Furthermore, the percentage of ADP inhibition distinguished between survivors and non-survivors in patients with TBI (Mann-Whitney test, P = 0.035). ADP inhibition correlates strongly with severity of TBI (Mann-Whitney test, P = 0.014), while AA inhibition did not. Conclusion These data indicate that early platelet dysfunction is prevalent after severe TBI, can be measured in a point-of-care setting using TEG/PM, and correlates with mortality. The mechanism responsible for this platelet dysfunction and associated implications for TBI management remains to be defined.

Utility of the Aspirin and P2Y12 Response Assays to Determine the Effect of Antiplatelet Agents on Platelet Reactivity in Traumatic Brain Injury

Neurosurgery, 2016

BACKGROUND: Premorbid antithrombotic medication may worsen intracranial injury and outcome after traumatic brain injury (TBI). Routine laboratory tests are insufficient to evaluate platelet activity. OBJECTIVE: To profile the spectrum of platelet inhibition, as measured by aspirin and P2Y12 response unit assays, in a TBI population on antiplatelet therapy. METHODS: This single-center, prospective cohort study included patients presenting to our institution between November 2010 and January 2015 with a clinical history of TBI. Serum platelet reactivity levels were determined immediately on admission and analyzed using the aspirin and P2Y12 response unit assays; test results were reported as aspirin response units and P2Y12 response units. We report congruence between assay results and clinical history as well as differences in assay results between types of antiplatelet therapy. RESULTS: A sample of 317 patients was available for analysis, of which 87% had experienced mild TBI, 7% moderate, and 6% severe; the mean age was 71.5 years. The mean aspirin response units in patients with a history of any aspirin use was 456 ± 67 (range, 350-659), with 88% demonstrating therapeutic platelet inhibition. For clopidogrel, the mean P2Y12 response unit was 191 ± 70 (range, 51-351); 77% showed therapeutic response. CONCLUSION: Rapid measurement of antiplatelet function using the aspirin and P2Y12 response assays indicated as many as one fourth of patients on antiplatelet therapy do not have platelet dysfunction. Further research is required to develop guidelines for the use of these assays to guide platelet transfusion in the setting of TBI.

Platelet Dysfunction is an Early Marker for Traumatic Brain Injury-Induced Coagulopathy

Neurocritical Care, 2013

Background The goal of this study is to determine the presence of platelet dysfunction in patients with traumatic brain injury (TBI). The mechanisms underlying the coagulopathy associated with TBI remain elusive. The question of platelet dysfunction in TBI is unclear. Methods This was a prospective observational study conducted at Memorial Hospital of South Bend, IN, and Denver Health Medical Center, CO. A total of 50 patients sustaining TBI, and not under treatment with anticoagulants or platelet inhibitors, were analyzed utilizing modified thromboelastography (TEG) with platelet mapping (TEG/PM), along with standard coagulation tests. Results Compared to normal controls, patients with severe TBI had a significantly increased percentage of platelet ADP and arachidonic acid (AA) receptor inhibition. Furthermore, the percentage of ADP inhibition distinguished between survivors and non-survivors in patients with TBI (Mann-Whitney test, P = 0.035). ADP inhibition correlates strongly with severity of TBI (Mann-Whitney test, P = 0.014), while AA inhibition did not. Conclusion These data indicate that early platelet dysfunction is prevalent after severe TBI, can be measured in a point-of-care setting using TEG/PM, and correlates with mortality. The mechanism responsible for this platelet dysfunction and associated implications for TBI management remains to be defined.

Multiplate Platelet Function Testing upon Emergency Room Admission Fails to Provide Useful Information in Major Trauma Patients Not on Platelet Inhibitors

Journal of Clinical Medicine

Platelet dysfunction is a suggested driver of trauma-induced coagulopathy. However, there is still a paucity of data regarding the impact of injury pattern on platelet function and the association of platelet dysfunction on transfusion requirements and mortality. In this retrospective cohort study, patients were grouped into those with isolated severe traumatic brain injury (TBI group), those with major trauma without TBI (MT group), and a combination of both major trauma and traumatic brain injury (MT + TBI group). Platelet function was assessed by whole blood impedance aggregometry (Multiplate®, MP). Three different platelet activators were used: adenosine-diphosphate (ADP test), arachidonic acid (ASPI test), and thrombin activated peptide-6 (TRAP test). Blood transfusion requirements within 6 h and 24 h and the association of platelet dysfunction on mortality was investigated. A total of 328 predominantly male patients (75.3%) with a median age of 53 (37–68) years and a median IS...