Weight-based enoxaparin thromboprophylaxis in young trauma patients: analysis of the CLOTT-1 registry.

Introduction: Optimal venous thromboembolism (VTE) enoxaparin prophylaxis dosing remains elusive. Weight-based (WB) dosing safely increases anti-factor Xa levels without the need for routine monitoring but it is unclear if it leads to lower VTE risk. We hypothesized that WB dosing would decrease VTE risk compared with standard fixed dosing (SFD). Methods: Patients from the prospective, observational CLOTT-1 registry receiving prophylactic enoxaparin (n=5539) were categorized as WB (0.45-0.55 mg/kg two times per day) or SFD (30 mg two times per day, 40 mg once a day). Multivariate logistic regression was used to generate a predicted probability of VTE for WB and SFD patients. Results: Of 4360 patients analyzed, 1065 (24.4%) were WB and 3295 (75.6%) were SFD. WB patients were younger, female, more severely injured, and underwent major operation or major venous repair at a higher rate than individuals in the SFD group. Obesity was more common among the SFD group. Unadjusted VTE rates were comparable (WB 3.1% vs. SFD 3.9%; p=0.221). Early prophylaxis was associated with lower VTE rate (1.4% vs. 5.0%; p=0.001) and deep vein thrombosis (0.9% vs. 4.4%; p<0.001), but not pulmonary embolism (0.7% vs. 1.4%; p=0.259). After adjustment, VTE incidence did not differ by dosing strategy (adjusted OR (aOR) 0.75, 95% CI 0.38 to 1.48); however, early administration was associated with a significant reduction in VTE (aOR 0.47, 95% CI 0.30 to 0.74). Conclusion: In young trauma patients, WB prophylaxis is not associated with reduced VTE rate when compared with SFD. The timing of the initiation of chemoprophylaxis may be more important than the dosing strategy. Further studies need to evaluate these findings across a wider age and comorbidity spectrum. Level of evidence: Level IV, therapeutic/care management.

Challenging Traditional Paradigms in Posttraumatic Pulmonary Thromboembolism.

Importance: Pulmonary clots are seen frequently on chest computed tomography performed after trauma, but recent studies suggest that pulmonary thrombosis (PT) and pulmonary embolism (PE) after trauma are independent clinical events. Objective: To assess whether posttraumatic PT represents a distinct clinical entity associated with the nature of the injury, different from the traditional venous thromboembolic paradigm of deep venous thrombosis (DVT) and PE. Design, Setting, and Participants: This prospective, observational, multicenter cohort study was conducted by the Consortium of Leaders in the Study of Traumatic Thromboembolism (CLOTT) study group. The study was conducted at 17 US level I trauma centers during a 2-year period (January 1, 2018, to December 31, 2020). Consecutive patients 18 to 40 years of age admitted for a minimum of 48 hours with at least 1 previously defined trauma-associated venous thromboembolism (VTE) risk factor were followed up until discharge or 30 days. Exposures: Investigational imaging, prophylactic measures used, and treatment of clots. Main Outcomes and Measures: The main outcomes of interest were the presence, timing, location, and treatment of any pulmonary clots, as well as the associated injury-related risk factors. Secondary outcomes included DVT. We regarded pulmonary clots with DVT as PE and those without DVT as de novo PT. Results: A total of 7880 patients (mean [SD] age, 29.1 [6.4] years; 5859 [74.4%] male) were studied, 277 with DVT (3.5%), 40 with PE (0.5%), and 117 with PT (1.5%). Shock on admission was present in only 460 patients (6.2%) who had no DVT, PT, or PE but was documented in 11 (27.5%) of those with PE and 30 (25.6%) in those with PT. Risk factors independently associated with PT but not DVT or PE included shock on admission (systolic blood pressure <90 mm Hg) (odds ratio, 2.74; 95% CI, 1.72-4.39; P < .001) and major chest injury with Abbreviated Injury Score of 3 or higher (odds ratio, 1.72; 95% CI, 1.16-2.56; P = .007). Factors associated with the presence of PT on admission included major chest injury (14 patients [50.0%] with or without major chest injury with an Abbreviated Injury Score >3; P = .04) and major venous injury (23 [82.1%] without major venous injury and 5 [17.9%] with major venous injury; P = .02). No deaths were attributed to PT or PE. Conclusions and Relevance: To our knowledge, this CLOTT study is the largest prospective investigation in the world that focuses on posttraumatic PT. The study suggests that most pulmonary clots are not embolic but rather result from inflammation, endothelial injury, and the hypercoagulable state caused by the injury itself.

Viscoelastic Testing and Coagulopathy of Traumatic Brain Injury.

A unique coagulopathy often manifests following traumatic brain injury, leading the clinician down a difficult decision path on appropriate prophylaxis and therapy. Conventional coagulation assays-such as prothrombin time, partial thromboplastin time, and international normalized ratio-have historically been utilized to assess hemostasis and guide treatment following traumatic brain injury. However, these plasma-based assays alone often lack the sensitivity to diagnose and adequately treat coagulopathy associated with traumatic brain injury. Here, we review the whole blood coagulation assays termed viscoelastic tests and their use in traumatic brain injury. Modified viscoelastic tests with platelet function assays have helped elucidate the underlying pathophysiology and guide clinical decisions in a goal-directed fashion. Platelet dysfunction appears to underlie most coagulopathies in this patient population, particularly at the adenosine diphosphate and/or arachidonic acid receptors. Future research will focus not only on the utility of viscoelastic tests in diagnosing coagulopathy in traumatic brain injury, but also on better defining the use of these tests as evidence-based and/or precision-based tools to improve patient outcomes.

Mechanistic determinates of the acute coagulopathy of trauma (ACoT) in patients requiring emergency surgery.

INTRODUCTION: The development of acute coagulopathy of trauma (ACoT) is associated with a significant increase in mortality. However, the contributory mechanisms behind ACoT have yet to be clearly defined. The purpose of this study was to evaluate the influence of multiple variables, including base deficit and injury severity, on development of ACoT within a subset of critically ill trauma patients. METHODS: A retrospective review of all trauma laparotomies between 01/2004-12/2009 was performed. ACoT (+) was defined as an arrival INR ≥1.5, ACoT (-) defined as INR<1.5. Univariate and multivariate analyses were performed. RESULTS: Of 1218 patients, 337 (27%) were ACoT (+) and 881 (73%) were ACoT (-) upon presentation. Groups were similar in demographics, ED fluid administration, GCS scores, and admission temperatures. Admission base deficit (8.5 vs. 4, p<0.001) and ISS (median 25 vs. 16, p<0.001) were higher in the ACoT (+) group, as were intra-operative RBC (median 4 vs. 0 U) and plasma (3 vs. 0 U) transfusions; both p<0.001. Multiple-linear regression revealed INR values were independently associated with arrival base deficit and pre-hospital fluid volumes (both p<0.001). On logistic regression, the development of ACoT (+) was associated with base deficit (OR 0.92, p=0.013) as well as ISS (OR 1.05, p<0.001). However, blunt mechanism alone was not an independent predictor of ACoT. CONCLUSION: The current study revealed that ACoT is independently associated with both shock (base deficit) and tissue injury. Additionally, tissue injury is a significant contributor to the development of early ACoT regardless of blunt or penetrating mechanism.

Screening for thoracolumbar spinal injuries in blunt trauma: an Eastern Association for the Surgery of Trauma practice management guideline.

BACKGROUND: Thoracolumbar spine (TLS) injuries have an incidence rate of 5% in blunt trauma patients. The Eastern Association for the Surgery of Trauma published Practice Management Guidelines for the Screening of Thoracolumbar Spine Fracture in 2007. The Practice Management Guidelines Committee was assembled to reevaluate the literature. METHODS: A search of the United States National Library of Medicine and the National Institutes of Health database was performed using MEDLINE through PubMed (www.pubmed.gov). The search retrieved English-language articles from March 2005 to December 2011 that referenced traumatic TLS injuries and fractures. The questions posed were the following: (1) What is the appropriate imaging modality to screen patients for TLS injuries? (2) Which trauma patients require radiographic screening for TLS injuries? (3)Does a patient who is awake and alert without distracting injuries require radiologic workup to rule out TLS injuries? RESULTS: Thirty-seven articles that referenced traumatic TLS injuries in association with screening published between March 2005 and December 2011 were collected and disseminated to the committee. Twelve were found to be relevant. Nine publications from the previous 2006 guidelines were reviewed and referenced to create and validate the updated guidelines. CONCLUSION: Practice patterns have changed regarding screening blunt trauma patients for TLS injuries. Software reformatted multidetector computed tomographic scans are more sensitive and accurate than plain films. Multidetector computed tomographic scans have become the screening modality of choice and the criterion standard in screening for TLS injuries. The literature supports a Level 1 recommendation to validate this based on a preponderance of Class II data. Patients without altered mentation or significant mechanism may be excluded by clinical examination without imaging. Patients with gross neurologic deficits or concerning clinical examination findings with negative imaging should receive a magnetic resonance imaging expediently, and the spine service should be consulted.