Rapid detection of platelet inhibition and dysfunction in traumatic brain injury: A prospective observational study

Predictive value of platelet function assays in traumatic brain injury patients on antiplatelet therapy

INTRODUCTION

Traumatic brain injury (TBI) patients on antiplatelet therapy face higher mortality because of impaired platelet function, which may be treated by platelet transfusion. The value of testing platelet function in this cohort remains controversial. We aimed to evaluate the relationship between platelet function assays and outcomes in TBI patients on antiplatelet therapy receiving platelet transfusions. We hypothesized that the magnitude of change in platelet assay performance following a transfusion would predict meaningful clinical outcomes.

METHODS

A cohort of patients, aged 18 to 89 years, with a history of preinjury antiplatelet therapy or who required platelet transfusion, and who were deemed at risk for neurosurgical intervention, was selected from a prospective randomized controlled trial of platelet transfusion for TBI. Pre- and posttransfusion blood samples were drawn. Platelet hemostatic function assays (PHFAs) included thromboelastography with platelet mapping (TEG-PM) and VerifyNow. Logistic regression models assessed the association of temporal assay results with 30-day all-cause mortality, need for craniotomy, and initial and follow-up Rotterdam scores.

RESULTS

Data from 94 TBI patients (43% female) with a median age of 76 years were analyzed. The 30-day mortality rate was 14%. VerifyNow aspirin assay was able to capture increases in platelet function following a platelet transfusion in patients on aspirin (significant positive Δ = 65 aspirin response units, p < 0.001). Thromboelastography with platelet mapping parameters detected improved platelet function following transfusion, although the absolute value of changes was minimal. Thromboelastography with platelet mapping parameters predicted important clinical outcomes on logistic regression, although no significant associations with clinical outcomes were identified by the change in PHFA after transfusion or after adjusting for multiple comparisons.

CONCLUSION

Higher absolute pre- and posttransfusion values of TEG-PM were associated with decreased mortality, decreased need for neurosurgical intervention, and decreased risk of progression of hemorrhage in TBI patients taking antiplatelet agents, although neither the change in TEG-PM after transfusion nor any other PHFA value predicted outcomes.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level II.

Early Thrombocytopenia at Hospital Admission Predicts Mortality in Patients with Non-Isolated Severe Traumatic Brain Injury

Patients with severe traumatic brain injury (STBI) often experience an abnormal hemostasis that contributes to mortality and unfavorable neurological outcomes.

OBJECTIVES

We aimed to analyze epidemiologic, clinical, and laboratory factors associated with mortality in patients with STBI during the first 48 h after in-hospital admission.

METHODS

We performed an observational retrospective study of STBI patients with associated extracranial trauma [defined as Injury Severity Score (ISS) ≥ 16 with an Abbreviated Injury Scale (AIS) head and neck ≥ 3 and Glasgow Coma Scale (GCS) ≤ 8] admitted to a Level II trauma center over seven years (2015-2021). Patients were divided into two groups: survivors and dead. We assessed differences regarding demographics, trauma severity, hemodynamics, disability, need for surgery, length of stay, transfusions, need for massive transfusion protocol, and hemostatic laboratory parameters at different time points.

RESULTS

A total of 134 STBI patients were included. Patients who died were older, mostly men, and showed higher trauma severity and disability. Hemoglobin, platelets, and clotting parameters deteriorated after admission to the emergency department (ED) with significant differences between groups within the first 24 h after admission. Platelet count < 150 × 103/μL at ED arrival, GCS, and age were independent risk factors for mortality.

CONCLUSIONS

Older age, GCS, and platelet count at ED arrival were independent risk factors for mortality in STBI patients with associated extracranial trauma. Early thrombocytopenia < 150 × 103/μL at ED arrival may be used as a simple prognostic tool to early predict mortality between non-isolated STBI.

Management of Bleeding and Thrombotic Complications During Pediatric Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding the management of bleeding and thrombotic complications during pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE Consensus Conference.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

The management of bleeding and thrombotic complications of ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Twelve references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. Two good practice statements, 5 weak recommendations, and 18 consensus statements are presented.

CONCLUSIONS

Although bleeding and thrombotic complications during pediatric ECMO remain common, limited definitive data exist to support an evidence-based approach to treating these complications. Research is needed to improve hemostatic management of children supported with ECMO.

Age, admission platelet count, and mortality in severe isolated traumatic brain injury: A retrospective cohort study

BACKGROUND

We asked whether patients >50 years of age with acute traumatic brain injury (TBI) present with lower platelet counts and whether lower platelet counts are independently associated with mortality.

METHODS

We combined trauma registry and laboratory data on a retrospective cohort of all patients ≥18 years of age admitted to our Level 1 US regional trauma center 2015-2021 with severe (Head Abbreviated Injury Score [AIS] ≥3), isolated (all other AIS <3) TBI who had a first platelet count within 1 h of arrival. Age and platelet count were assessed continuously and as groups (age 18-50 vs. >50, platelet normals, and at conventional transfusion thresholds). Outcomes such as mean admission platelet counts and in-hospital mortality were assessed categorically and with logistic regression.

RESULTS

Of 44,056 patients, 1298 (3%, median age: 52 [IQR 33,68], 76.1% male) met all inclusion criteria with no differences between younger and older age groups for (ISS; 18 [14,26] vs. 17 [14,26], p = .22), New ISS (NISS; 29 [19,50] vs. 28 [17,50], p = .36), or AIS-Head (4 [3,5] vs. 4 [3,5]; p = .87). Patients aged >50 had lower admission platelet counts (219,000 ± 93,000 vs. 242,000 ± 76,000/μL; p < .001) and greater in-hospital mortality (24.5% vs. 15.6%, p < .001) than those 18-50. In multivariable regression, firearms injuries (OR9.08), increasing age (OR1.004), NISS (OR1.007), and AIS-Head (OR1.05), and decreasing admission platelet counts (OR0.998) were independently associated with mortality (p < .001-.041). Platelet transfusion in the first 4 h of care was more frequent among older patients (p < .001).

CONCLUSIONS

Older patients with TBI had lower admission platelet counts, which were independently associated with greater mortality.

The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition

BACKGROUND

Severe trauma represents a major global public health burden and the management of post-traumatic bleeding continues to challenge healthcare systems around the world. Post-traumatic bleeding and associated traumatic coagulopathy remain leading causes of potentially preventable multiorgan failure and death if not diagnosed and managed in an appropriate and timely manner. This sixth edition of the European guideline on the management of major bleeding and coagulopathy following traumatic injury aims to advise clinicians who care for the bleeding trauma patient during the initial diagnostic and therapeutic phases of patient management.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma included representatives from six European professional societies and convened to assess and update the previous version of this guideline using a structured, evidence-based consensus approach. Structured literature searches covered the period since the last edition of the guideline, but considered evidence cited previously. The format of this edition has been adjusted to reflect the trend towards concise guideline documents that cite only the highest-quality studies and most relevant literature rather than attempting to provide a comprehensive literature review to accompany each recommendation.

RESULTS

This guideline comprises 39 clinical practice recommendations that follow an approximate temporal path for management of the bleeding trauma patient, with recommendations grouped behind key decision points. While approximately one-third of patients who have experienced severe trauma arrive in hospital in a coagulopathic state, a systematic diagnostic and therapeutic approach has been shown to reduce the number of preventable deaths attributable to traumatic injury.

CONCLUSION

A multidisciplinary approach and adherence to evidence-based guidelines are pillars of best practice in the management of severely injured trauma patients. Further improvement in outcomes will be achieved by optimising and standardising trauma care in line with the available evidence across Europe and beyond.