Effectiveness of low-molecular-weight heparin versus unfractionated heparin to prevent pulmonary embolism following major trauma: A propensity-matched analysis

Impact of an updated venous thromboembolism prophylaxis guideline in critically ill trauma patients on rates of venous thromboembolisms

INTRODUCTION

The objective of this analysis was to evaluate differences in incidence of venous thromboembolisms (VTE) in critically ill trauma patients between pre- and post-implementation of updated VTE prophylaxis guidelines.

METHODS

This was a pre-post analysis of critically ill trauma patients receiving pharmacologic VTE prophylaxis. Trauma patients were included if they had an intensive care unit admission during their hospitalization. The primary outcome was incidence of detected VTE and was analyzed using a Chi-Squared test. A multivariate analysis assessed the effects of guideline implementation on VTE development when controlling for confounders.

RESULTS

There were 220 patients included. There was a significant increase in low molecular weight heparin use in initial (p ​= ​0.003) and final (p ​= ​0.004) prophylactic regimens between groups. There was no significant difference in VTE incidence between the pre and post groups (6.3% vs 1.9%, p ​= ​0.10). The multivariate analysis showed guideline implementation was independently associated with an 88% reduced odds of VTE (p ​= ​0.04).

CONCLUSION

This analysis suggests the updated VTE prophylaxis guideline implementation was associated with a trend toward reduced VTE development among critically ill trauma patients.

Venous thromboembolism chemoprophylaxis after severe polytrauma: timing and type of prophylaxis matter

In this review, we provide recommendations as well as summarize available data on the optimal time to initiate venous thromboembolism chemoprophylaxis after severe trauma. A general approach to the severe polytrauma patient is provided as well as in-depth reviews of three high-risk injury subgroups: patients with traumatic brain injury, solid organ injury, and pelvic fractures.

Venous Thromboembolism Prevention in Rehabilitation: A Review and Practice Suggestions

ABSTRACT

Venous thromboembolism is a frequent complication of acute hospital care, and this extends to inpatient rehabilitation. The timely use of appropriate thromboprophylaxis in patients who are at risk is a strong, evidence-based patient safety priority that has reduced clinically important venous thromboembolism, associated mortality and costs of care. While there has been extensive research on optimal approaches to venous thromboembolism prophylaxis in acute care, there is a paucity of high-quality evidence specific to patients in the rehabilitation setting, and there are no clinical practice guidelines that make recommendations for (or against) thromboprophylaxis across the broad spectrum of rehabilitation patients. Herein, we provide an evidence-informed review of the topic with practice suggestions. We conducted a series of literature searches to assess the risks of venous thromboembolism and its prevention related to inpatient rehabilitation as well as in major rehabilitation subgroups. Mobilization alone does not eliminate the risk of venous thromboembolism after another thrombotic insult. Low molecular weight heparins and direct oral anticoagulants are the principal current modalities of thromboprophylaxis. Based on the literature, we make suggestions for venous thromboembolism prevention and include an approach for consideration by rehabilitation units that can be aligned with local practice.

Propensity weighted analysis of chemical venous thromboembolism prophylaxis agents in isolated severe traumatic brain injury: An EAST sponsored multicenter study

BACKGROUND

In patients with severe traumatic brain injury (TBI), clinicians must balance preventing venous thromboembolism (VTE) with the risk of intracranial hemorrhagic expansion (ICHE). We hypothesized that low molecular weight heparin (LMWH) would not increase risk of ICHE or VTE as compared to unfractionated heparin (UH) in patients with severe TBI.

METHODS

Patients ≥ 18 years of age with isolated severe TBI (AIS ≥ 3), admitted to 24 level I and II trauma centers between January 1, 2014 to December 31, 2020 and who received subcutaneous UH and LMWH injections for chemical venous thromboembolism prophylaxis (VTEP) were included. Primary outcomes were VTE and ICHE after VTEP initiation. Secondary outcomes were mortality and neurosurgical interventions. Entropy balancing (EBAL) weighted competing risk or logistic regression models were estimated for all outcomes with chemical VTEP agent as the predictor of interest.

RESULTS

984 patients received chemical VTEP, 482 UH and 502 LMWH. Patients on LMWH more often had pre-existing conditions such as liver disease (UH vs LMWH 1.7 % vs. 4.4 %, p = 0.01), and coagulopathy (UH vs LMWH 0.4 % vs. 4.2 %, p < 0.001). There were no differences in VTE or ICHE after VTEP initiation. There were no differences in neurosurgical interventions performed. There were a total of 29 VTE events (3 %) in the cohort who received VTEP. A Cox proportional hazards model with a random effect for facility demonstrated no statistically significant differences in time to VTE across the two agents (p = 0.44). The LMWH group had a 43 % lower risk of overall ICHE compared to the UH group (HR = 0.57: 95 % CI = 0.32-1.03, p = 0.062), however was not statistically significant.

CONCLUSION

In this multi-center analysis, patients who received LMWH had a decreased risk of ICHE, with no differences in VTE, ICHE after VTEP initiation and neurosurgical interventions compared to those who received UH. There were no safety concerns when using LMWH compared to UH.

LEVEL OF EVIDENCE

Level III, Therapeutic Care Management.

Venous thromboembolism prophylaxis and mortality in patients with spinal fractures in ICUs

BACKGROUND

Spinal fracture is a common traumatic condition in orthopaedics, accounting for 5%-6% of total body fractures, and is a high-risk factor for venous thromboembolism (VTE), which seriously affects patient prognosis.

AIM

The aim of this study was to determine the impact of VTE prophylaxis on the prognosis of patients with spinal fractures in intensive care units (ICUs) and to provide a scientific basis for clinical treatment and nursing.

DESIGN

A retrospective study of patients with spinal fractures from the multicenter eICU Collaborative Research Database.

METHOD

The outcomes of this study were ICU mortality and in-hospital mortality. Patients were divided into the VTE prophylaxis (VP) and no VTE prophylaxis (NVP) groups according to whether they had undergone VTE prophylaxis during their ICU admission. The association between groups and outcomes were analysed using Kaplan-Meier (KM) survival curve, log-rank test and the Cox proportional-hazards regression model.

RESULTS

This study included 1146 patients with spinal fractures: 330 in the VP group and 816 in the NVP group. KM survival curves and log-rank tests revealed that both ICU and in-hospital survival probabilities in the VP group were significantly higher than in the NVP group. After the Cox model was adjusted for all covariates, the hazard ratio for ICU mortality in the VP group was 0.38 (0.19-0.75); the corresponding value for in-hospital mortality in the VP group was 0.38 (0.21-0.68).

CONCLUSIONS

VTE prophylaxis is associated with reduced ICU and in-hospital mortality in patients with spinal fractures in ICUs. More research is necessary to further define specific strategies and optimal timing for VTE prophylaxis.

RELEVANCE TO CLINICAL PRACTICE

This study provides the basis that VTE prophylaxis may be associated with improved prognosis in patients with spinal fractures in ICUs. In clinical practice, an appropriate modality should be selected for VTE prophylaxis in such patients.

Multicenter study evaluating target attainment of anti-Factor Xa levels using various enoxaparin prophylactic dosing practices in adult trauma patients

STUDY OBJECTIVE

Enoxaparin is standard of care for venous thromboembolism (VTE) prophylaxis in adult trauma patients, but fixed-dose protocols are suboptimal. Dosing based on body mass index (BMI) or total body weight (TBW) improves target prophylactic anti-Xa level attainment and reduces VTE rates. A novel strategy using estimated blood volume (EBV) may be more effective based on results of a single-center study. This study compared BMI-, TBW-, EBV-based, and hybrid enoxaparin dosing strategies at achieving target prophylactic anti-Factor Xa (anti-Xa) levels in trauma patients.

DESIGN

Multicenter, retrospective review.

DATA SOURCE

Electronic health records from participating institutions.

PATIENTS

Adult trauma patients who received enoxaparin twice daily for VTE prophylaxis and had at least one appropriately timed anti-Xa level (collected 3 to 6 hours after the previous dose after three consecutive doses) from January 2017 through December 2020. Patients were excluded if the hospital-specific dosing protocol was not followed or if they had thermal burns with > 20% body surface area involvement.

INTERVENTION

Dosing strategy used to determine initial prophylactic dose of enoxaparin.

MEASUREMENTS

The primary end point was percentage of patients with peak anti-Xa levels within the target prophylactic range (0.2-0.4 units/mL).

MAIN RESULTS

Nine hospitals enrolled 742 unique patients. The most common dosing strategy was based on BMI (43.0%), followed by EBV (29.0%). Patients dosed using EBV had the highest percentage of target anti-Xa levels (72.1%). Multiple logistic regression demonstrated EBV-based dosing was significantly more likely to yield anti-Xa levels at or above target compared to BMI-based dosing (adjusted odds ratio (aOR) 3.59, 95% confidence interval (CI) 2.29-5.62, p < 0.001). EBV-based dosing was also more likely than hybrid dosing to yield an anti-Xa level at or above target (aOR 2.30, 95% CI 1.33-3.98, p = 0.003). Other pairwise comparisons between dosing strategy groups were nonsignificant.

CONCLUSIONS

An EBV-based dosing strategy was associated with higher odds of achieving anti-Xa level within target range for enoxaparin VTE prophylaxis compared to BMI-based dosing and may be a preferred method for VTE prophylaxis in adult trauma patients.

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.

Evaluation of an Association Between Enoxaparin Dose per Estimated Blood Volume and Clinically Relevant Bleeding in Low-Weight Trauma Patients

BACKGROUND

The optimal dosing for enoxaparin venous thromboembolism (VTE) prophylaxis in low-weight trauma patients is unknown. Estimated blood volume (EBV) has shown promise as a dose modifier.

OBJECTIVE

To characterize the association of enoxaparin dose per EBV with the prevalence of VTE and bleeding in low-weight trauma patients.

METHODS

This was a retrospective study of trauma patients admitted over a 4-year period. Included patients were adults weighing <60 kg who received a minimum of 3 consecutive doses of enoxaparin. The primary endpoint was a comparison of enoxaparin dose per EBV in patients experiencing bleeding and VTE. Secondary endpoints included comparisons of dose per body mass index (BMI) and total body weight (TBW) and the ability of dose per EBV to predict clinical endpoints. Subgroup analyses for patients weighing <50 kg were performed for all endpoints.

RESULTS

A total of 189 patients were included. Statistical comparisons for VTE were not performed because of low prevalence. The dose of enoxaparin per EBV was not statistically different between patients who did and did not bleed in all analyses. Doses per BMI and TBW were also not statistically different between the groups. In patients weighing <50 kg, numerically higher doses per EBV, BMI, and TBW were noted in patients that bled versus those that did not. Enoxaparin dose per EBV was not a statistically significant predictor of bleeding in logistic regression models.

CONCLUSION AND RELEVANCE

No significant associations between enoxaparin dose per EBV, BMI, or TBW and bleeding were noted in the study. Future analyses of EBV and other dose modifiers should consider inclusion of patients weighing <50 kg.

Low-molecular-weight heparin is associated with lower venous thromboembolism events than factor Xa inhibitors in patients with severe blunt trauma: a cohort study from the Trauma Quality Improvement Program

BACKGROUND

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), is a common complication of major trauma. Pharmacological VTE prophylactics are widely used, and low-molecular-weight heparin (LMWH) is recommended. Factor Xa inhibitors are increasingly being used for VTE prophylaxis in both medical and surgical patients. Evidence comparing LMWH and factor Xa inhibitors as VTE prophylactics for severe blunt trauma is lacking. This study aims to compare the efficacy and safety of factor Xa inhibitors and LMHW in VTE prophylaxis.

MATERIALS AND METHODS

Patients with severe blunt trauma who received LMWH or a factor Xa inhibitor for VTE prophylaxis in the Trauma Quality Improvement Program between 2017 and 2019 were included. The comparison was performed after using propensity score matching. The outcomes included mortality and incidence of DVT, PE, post-prophylactics haemorrhage control procedures and length of stay.

RESULTS

After 2:1 propensity score matching, 1128 patients ( n =752, LMHW group; n =376, factor Xa inhibitor group) were included in the analysis. Patients in the LMWH group had fewer VTE events than those in the factor Xa inhibitor group (DVT, 3.7% vs. 7.2%, P =0.013; PE, 0.4% vs. 3.2%, P <0.001). VTE risk was higher in the factor Xa group (DVT: odds ratio, 1.97; 95% CI, 1.12-3.44; P =0.018 and PE: odds ratio, 9.65; 95% CI, 2.91-44.12; P =0.001). The mortality rate was higher in the LMWH group; however, there was no significant difference (4.0% vs. 1.9%; P =0.075). The difference in the risk of undergoing haemorrhage control surgery after VTE prophylaxis between both groups was insignificant (0.3% vs. 0.0%; P =0.333).

CONCLUSIONS

LMWH was associated with a lower risk of VTE than factor Xa inhibitors in patients with severe blunt trauma. The mortality rate was higher in the LMWH group; however, there was no statistically significant difference observed.

Low-molecular-weight heparin is superior to unfractionated heparin in lowering the risk of venous thromboembolism after traumatic lower extremity amputation

BACKGROUND

Patients undergoing lower extremity amputation after trauma are at high risk of venous thromboembolism. Practice variations persist regarding the optimal pharmacologic agent for venous thromboembolism prophylaxis in this patient population. We aimed to compare the efficacy of unfractionated heparin versus low-molecular-weight heparin in preventing venous thromboembolism.

METHODS

Using the 2013 to 2019 American College of Surgeons Pediatric Trauma Quality Improvement Program database, all trauma patients (≥18) who underwent lower limb amputation and received venous thromboembolism thromboprophylaxis in the form of unfractionated heparin or low-molecular-weight heparin were included. We excluded patients who died within 24 hours of admission or those who received no thromboprophylaxis. The primary outcome was the rate of venous thromboembolism. Multivariable logistic regression was used to evaluate the independent relationship between the type of pharmacologic prophylaxis and the risk of venous thromboembolism.

RESULTS

A total of 4,103 patients who underwent lower extremity amputation were identified. Patients were primarily young (median age 43 years) with blunt injuries (83%). The overall rate of venous thromboembolism was 8.6%. Most (77%) patients received low-molecular-weight heparin-based prophylaxis. Compared with patients without venous thromboembolism, the venous thromboembolism cohort had a greater injury severity score (19 vs 13, P < .001), had more patients undergoing above-the-knee amputation (48% vs 36%, P < .001), and less frequently received low-molecular-weight heparin (64% vs 78%, P < .001). Multivariable analysis showed that low-molecular-weight heparin was associated with a significantly lower venous thromboembolism rate than unfractionated heparin (odds ratio: 0.65 [0.51-0.83], P < .001).

CONCLUSION

Thromboprophylaxis with low-molecular-weight heparin was found to be superior to unfractionated heparin in lowering the risk of venous thromboembolism among traumatic amputees and should be the preferred pharmacologic agent in this patient population prone to venous thromboembolism.

Retrospective evaluation of chemical venous thromboembolism prophylaxis in traumatic brain injury

Background

Traumatic brain injury (TBI) is a risk factor for venous thromboembolism (VTE) but few studies address optimal timing or choice of agent.

Materials and Methods

Retrospective review of moderate to severe TBI patients receiving chemical VTE prophylaxis (early initiation [≤ 72 h from admission], late [> 72 h to 7 days], or delayed [> 7 days]) between 2012 through 2017. Primary outcome was VTE occurrence. Secondary objectives evaluated intracranial hemorrhage (ICH) requiring cessation of prophylaxis and differences between unfractionated (UFH) and low-molecular weight heparin (LMWH).

Results

A total of 198 patients were evaluated; median age was 44 years (IQR 25-60), median Glasgow Coma Scale score 3 (IQR 3-7), and median injury severity score 27 (IQR 22-34). Ten percent of patients (n = 20) developed VTE. Median time to VTE prophylaxis was 81 h (IQR 53-152) and there was no difference in VTE incidence across all groups (p = 0.09). Intergroup comparison showed patients that received early prophylaxis had lower VTE rates (6% vs. 16%, p = 0.04) and mortality (3% vs. 15%, p = 0.02) compared to late initiation (but not delayed). There were no instances of new onset or expanded ICH requiring cessation of prophylaxis. VTE rates for patients receiving UFH only or LMWH only, 14/115 (12.2%) vs. 3/46 (6.5%), were not different (p = 0.4). Mortality was lower in the LMWH only group (0% vs. 13.0%, p<0.01).

Conclusions

Initiating VTE prophylaxis within 72 h of moderate to severe TBI appears to be safe and may be associated with lower rates of VTE and mortality.

Proceedings from the 2022 Consensus Conference to Implement Optimal Venous Thromboembolism Prophylaxis in Trauma

ABSTRACT

On May 4 and 5, 2022, a meeting of multidisciplinary stakeholders in the prevention and treatment of venous thromboembolism (VTE) after trauma was convened by the Coalition for National Trauma Research, funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health, and hosted by the American College of Surgeons in Chicago, Illinois. This consensus conference gathered more than 40 in-person and 80 virtual attendees, including trauma surgeons, other physicians, thrombosis experts, nurses, pharmacists, researchers, and patient advocates. The objectives of the meeting were twofold: (1) to review and summarize the present state of the scientific evidence regarding VTE prevention strategies in injured patients and (2) to develop consensus on future priorities in VTE prevention implementation and research gaps.To achieve these objectives, the first part of the conference consisted of talks from physician leaders, researchers, clinical champions, and patient advocates to summarize the current state of knowledge of VTE pathogenesis and prevention in patients with major injury. Video recordings of all talks and accompanying slides are freely available on the conference website ( https://www.nattrauma.org/research/research-policies-templates-guidelines/vte-conference/ ). Following this curriculum, the second part of the conference consisted of a series of small-group breakout sessions on topics potentially requiring future study. Through this process, research priorities were identified, and plans of action to develop and undertake future studies were defined.The 2022 Consensus Conference to Implement Optimal VTE Prophylaxis in Trauma answered the National Trauma Research Action Plan call to define a course for future research into preventing thromboembolism after trauma. A multidisciplinary group of clinical champions, physicians, scientists, and patients delineated clear objectives for future investigation to address important, persistent key knowledge gaps. The series of papers from the conference outlines the consensus based on the current literature and a roadmap for research to answer these unanswered questions.

Venous thromboembolism risk after spinal cord injury: A secondary analysis of the CLOTT study

INTRODUCTION

Patients with spinal cord injury (SCI) are at high risk of venous thromboembolism (VTE). Pharmacologic VTE prophylaxis (VTEppx) is frequently delayed in patients with SCI because of concerns for bleeding risk. Here, we hypothesized that delaying VTEppx until >48 hours would be associated with increased risk of thrombotic events.

METHODS

This is a secondary analysis of the 2018 to 2020 prospective, observational, cohort Consortium of Leaders in the Study of Traumatic Thromboembolism (CLOTT) study of patients aged 18 to 40 years, at 17 US level 1 trauma centers. Patients admitted for >48 hours with documented SCI were evaluated. Timing of initiation of VTEppx, rates of thrombotic events (deep vein thrombosis [DVT] and pulmonary embolism [PE]), and missed VTEppx doses were analyzed. The primary outcome was VTE (DVT + PE).

RESULTS

There were 343 patients with SCI. The mean ± SD age was 29.0 ± 6.6 years, 77.3% were male, and 78.7% sustained blunt mechanism. Thrombotic events occurred in 33 patients (9.6%): 30 DVTs (8.7%) and 3 PEs (0.9%). Venous thromboembolism prophylaxis started at ≤24 hours in 21.3% of patients and 49.3% at ≤48 hours. The rate of VTE for patients started on VTEppx ≤48 hours was 7.1% versus 12.1% if started after 48 hours ( p = 0.119). After adjusting for differences in risk factors between cohorts, starting ≤48 hours was independently associated with fewer VTEs (odds ratio, 0.45; 95% confidence interval, 0.101-0.978; p = 0.044). Unfractionated heparin was associated with a VTE rate of 21.0% versus 7.5% in those receiving enoxaparin as prophylaxis ( p = 0.003). Missed doses of VTEppx were common (29.7%) and associated with increased thrombotic events, although this was not significant on multivariate analysis.

CONCLUSION

Rates of thrombotic events in patients with SCI are high. Prompt initiation of VTEppx with enoxaparin and efforts aimed at avoiding missed doses are critical to limit thrombotic events in these high-risk patients.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Facts and Fallacy of Benchmark Performance Indicators

Efforts to improve quality in healthcare have arisen from the recognition that the quality of care delivered and resulting outcomes are highly variable. Performance benchmarking using high-quality data to compare risk-adjusted outcomes between hospitals and surgeons has been widely adopted as one means for addressing this problem. In this article we discuss the history, current state, methodologies, and potential pitfalls of benchmarking efforts to improve quality of healthcare in the United States.

Impact of Increased Enoxaparin Dosing on Anti-Xa Levels for Venous Thromboembolism Prophylaxis in Trauma Patients

INTRODUCTION

Venous thromboembolism (VTE) contributes to significant morbidity in trauma patients while increasing hospital costs and length of stay. Standard trauma prophylaxis dosing with enoxaparin 30 mg twice daily may be inadequate to prevent VTEs. The objective of this study was to compare standard dosing of enoxaparin to an increased dose of enoxaparin 40 mg twice daily for trauma patients. We hypothesized that increasing thromboprophylaxis dosing leads to an increase in therapeutic anti-Xa levels and reduced VTE rates.

METHODS

A retrospective study was performed from January 2020 to June 2021 at a Level I trauma center, following implementation of an increased enoxaparin dosing strategy. Patients with increased enoxaparin dosing were compared with those who received standard dosing. The primary outcome evaluated was the incidence of subtherapeutic anti-Xa levels. Secondary outcomes evaluated VTE rates and clinically significant bleed.

RESULTS

A total of 204 trauma patients were identified. Ninety-one patients received an increased enoxaparin dose compared to 113 who received standard dosing. The baseline demographics of both groups were similar (P > .05). Subtherapeutic levels were higher with standard dosing compared to the increased dose (50 vs 22%, P = .003). Higher VTE rates were observed with standard dosing compared to higher dosing (6.2 vs 3.3%) but with a lower incidence of major bleed (1.8 vs 4.4%). Overall annual VTE rates decreased from 1.6 to 1.3% after implementation of the increased dosing regimen.

CONCLUSIONS

This study demonstrated that an increased dosing strategy decreased rates of subtherapeutic anti-Xa levels and trended toward lower overall VTE rates in trauma.

Characterization of platelet concentrations and evaluation of risk factors for thrombocytopenia following traumatic injury

Introduction

Thrombocytopenia is common in critically ill trauma patients and can lead to potentially broad differentials, including major bleeding, hemodilution, extracorporeal circuit losses, heparin-induced thrombocytopenia, and more. Understanding the normal time course of platelet decline and recovery may delineate thrombocytopenia(HIT) secondary to traumatic injury versus other inciting factors.

Methods

This retrospective study included trauma patients admitted over a 1-year period. The primary aim was characterizing the effect of trauma on platelet concentration and thrombocytopenia incidence in the first 30 days following injury. Thrombocytopenia was defined as platelet concentration <150 × 109/L. A secondary aim was evaluating significant factors contributing to thrombocytopenia.

Results

A total of 225 patients were included. Thrombocytopenia occurred in 67.3% of patients, and a platelet decline of 50% or greater occurred in 44%. Decrease in platelet concentration was significant from day 1 to day 4 (mean ± SD, 232 ± 86 vs 142 ± 76 × 109/L; p = .001). Platelets recovered to baseline on day 8 and peaked on day 16. Packed red blood cell or platelet transfusion, continuous renal replacement therapy, and acute liver injury independently predicted a ≥50% platelet decrease. HIT was not diagnosed in any patients.

Conclusion

Platelet nadir likely occurs approximately 4 days after injury and recovers relatively quickly thereafter. More studies are needed to evaluate the magnitude of effect on thrombocytopenia by factors beyond trauma.

American Association for the Surgery of Trauma/American College of Surgeons-Committee on Trauma Clinical Protocol for inpatient venous thromboembolism prophylaxis after trauma

ABSTRACT

Trauma patients are at increased risk of venous thromboembolism (VTE), which includes both deep vein thrombosis and pulmonary embolism. Pharmacologic VTE prophylaxis is a critical component of optimal trauma care that significantly decreases VTE risk. Optimal VTE prophylaxis protocols must manage the risk of VTE with the competing risk of hemorrhage in patients following significant trauma. Currently, there is variability in VTE prophylaxis protocols across trauma centers. In an attempt to optimize VTE prophylaxis for the injured patient, stakeholders from the American Association for the Surgery of Trauma and the American College of Surgeons-Committee on Trauma collaborated to develop a group of consensus recommendations as a resource for trauma centers. The primary goal of these recommendations is to help standardize VTE prophylaxis strategies for adult trauma patients (age ≥15 years) across all trauma centers. This clinical protocol has been developed to (1) provide standardized medication dosing for VTE prophylaxis in the injured patient; and (2) promote evidence-based, prompt VTE prophylaxis in common, high-risk traumatic injuries.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level V.

Trauma Risk Score Matching for Observational Studies in Orthopedic Trauma

OBJECTIVES

To determine if matching by trauma risk score is non-inferior to matching by chronic comorbidities and/or a combination of demographic and patient characteristics in observational studies of acute trauma in a hip fracture model.

DESIGN

Retrospective cohort study SETTING: Level-1 Trauma Center PATIENTS: 1,590 hip fracture [AO/OTA 31A and 31B] patients age 55 and over treated between October 2014 and February 2020 at 4 hospitals within a single academic medical center.

INTERVENTION

Repeatedly matching randomized subsets of patients by (1) Score for Trauma Triage in Geriatric and Middle-Aged (STTGMA), (2) Charlson Comorbidity Index (CCI), or (3) a combination of sex, age, CCI and body mass index (BMI).

MAIN OUTCOME MEASUREMENTS

"Matching failures" where rate of significant differences in variables of matched cohorts exceeds the 5% expected by chance.

RESULTS

STTGMA and combination matching resulted in no "matching failures". Matching by CCI alone resulted in "matching failures" of BMI, ASA class, STTGMA, major complications, sepsis, pneumonia, acute respiratory failure, and 90-day readmission.

CONCLUSIONS

STTGMA matching in observational cohort studies is less likely to yield significant differences of demographics and outcomes than CCI matching. STTGMA matching is noninferior to matching a combination of demographic variables optimized for each treatment cohort. STTGMA matching is apt to reflect equipoise of health at admission and outcome likelihood in observational cohort studies of orthopedic trauma, while maintaining consistent weighting of demographic and injury characteristic variables that may expand the generalizability of these studies.

LEVEL OF EVIDENCE

Level III.

Efficacy and Safety of Low Molecular Weight Heparin Versus Unfractionated Heparin for Prevention of Venous Thromboembolism in Trauma Patients: A Systematic Review and Meta-analysis

PURPOSE

Trauma patients are at high risk of VTE. We summarize the efficacy and safety of LMWH versus UFH for the prevention of VTE in trauma patients.

METHODS

We searched 6 databases from inception through March 12, 2021. We included randomized controlled trials (RCTs) or observational studies comparing LMWH versus UFH for thromboprophylaxis in adult trauma patients. We pooled effect estimates across RCTs and observational studies separately, using random-effects model and inverse variance weighting. We assessed risk of bias using the Cochrane tool for RCTs and the Risk of Bias in Non-Randomized Studies (ROBINS)-I tool for observational studies and assessed certainty of findings using Grading of Recommendations, Assessment, Development and Evaluations methodology.

RESULTS

We included 4 RCTs (879 patients) and 8 observational studies (306,747 patients). Based on pooled RCT data, compared to UFH, LMWH reduces deep vein thrombosis (RR 0.67, 95% CI 0.50 to 0.88, moderate certainty) and VTE (RR 0.68, 95% CI 0.51 to 0.90, moderate certainty). As compared to UFH, LMWH may reduce pulmonary embolism [adjusted odds ratio from pooled observational studies 0.56 (95% CI 0.50 to 0.62)] and mortality (adjusted odds ratio from pooled observational studies 0.54, 95% CI 0.45 to 0.65), though based on low certainty evidence. There was an uncertain effect on adverse events (RR from pooled RCTs 0.80, 95% CI 0.48 to 1.33, very low certainty) and heparin induced thrombocytopenia [RR from pooled RCTs 0.26 (95% CI 0.03 to 2.38, very low certainty)].

CONCLUSIONS

Among adult trauma patients, LMWH is superior to UFH for deep vein thrombosis and VTE prevention and may additionally reduce pulmonary embolism and mortality. The impact on adverse events and heparin induced thrombocytopenia is uncertain.

A tale of two centers: Is low-molecular-weight heparin really superior for prevention of posttraumatic venous thromboembolism?

BACKGROUND

Low-molecular-weight heparin (LMWH) is widely used for venous thromboembolism chemoprophylaxis following injury. However, unfractionated heparin (UFH) is a less expensive option. We compared LMWH and UFH for prevention of posttraumatic deep venous thrombosis (DVT) and pulmonary embolism (PE).

METHODS

Trauma patients 15 years or older with at least one administration of venous thromboembolism chemoprophylaxis at two level I trauma centers with similar DVT-screening protocols were identified. Center 1 administered UFH every 8 hours for chemoprophylaxis, and center 2 used twice-daily antifactor Xa-adjusted LMWH. Clinical characteristics and primary chemoprophylaxis agent were evaluated in a two-level logistic regression model. Primary outcome was incidence of DVT and PE.

RESULTS

There were 3,654 patients: 1,155 at center 1 and 2,499 at center 2. The unadjusted DVT rate at center 1 was lower than at center 2 (3.5% vs. 5.0%; p = 0.04); PE rates did not significantly differ (0.4% vs. 0.6%; p = 0.64). Patients at center 2 were older (mean, 50.3 vs. 47.3 years; p < 0.001) and had higher Injury Severity Scores (median, 10 vs. 9; p < 0.001), longer stays in the hospital (mean, 9.4 vs. 7.0 days; p < 0.001) and intensive care unit (mean, 3.0 vs. 1.3 days; p < 0.001), and a higher mortality rate (1.6% vs. 0.6%, p = 0.02) than patients at center 1. Center 1's patients received their first dose of chemoprophylaxis earlier than patients at center 2 (median, 1.0 vs. 1.7 days; p < 0.001). After risk adjustment and accounting for center effects, primary chemoprophylaxis agent was not associated with risk of DVT (odds ratio, 1.01; 95% confidence interval, 0.69-1.48; p = 0.949). Cost calculations showed that UFH was less expensive than LMWH.

CONCLUSION

Primary utilization of UFH is not inferior to LMWH for posttraumatic DVT chemoprophylaxis and rates of PE are similar. Given that UFH is lower in cost, the choice of this chemoprophylaxis agent may have major economic implications.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level II; Therapeutic, level III.

Venous thromboembolic pharmacological prophylaxis in severe traumatic acute subdural hematomas: Early prophylaxis is effective and safe

BACKGROUND

The purpose of this study was to evaluate the optimal timing and type of pharmacological venous thromboembolism prophylaxis (VTEp) in patients with severe blunt head trauma with acute subdural hematomas (ASDH).

METHODS

Matched cohort study using ACS-TQIP database (2013-2016) including patients with isolated ASDH. Outcomes of matched patients receiving early prophylaxis (EP, ≤48 h) and late prophylaxis (LP, >48 h) were compared with univariable and multivariable regression analysis.

RESULTS

In 1,660 matched cases VTE complications (3.1% vs 0.5%, p < 0.001) were more common in the LP compared to the EP group. Multivariable regression analysis identified EP as an independent protective factor for VTE complications (OR 0.169, p < 0.001) but not mortality (p = 0.260). The adjusted risk for delayed craniectomy was not associated with EP compared to LP (p = 0.095). LMWH was independently associated with a lower mortality (OR 0.480, p = 0.008) compared to UH.

CONCLUSIONS

Early VTEp (≤48 h) does not increase the risk for craniectomies and is independently associated with fewer VTE complications in patients with isolated ASDH. LMWH was independently associated with a lower mortality compared to UH.

Impact of antithrombin III and enoxaparin dosage adjustment on prophylactic anti-Xa concentrations in trauma patients at high risk for venous thromboembolism: a randomized pilot trial

The impact of antithrombin III activity (AT-III) on prophylactic enoxaparin anti-factor Xa concentration (anti-Xa) is unknown in high-risk trauma patients. So too is the optimal anti-Xa-adjusted enoxaparin dosage. This prospective, randomized, pilot study sought to explore the association between AT-III and anti-Xa goal attainment and to preliminarily evaluate two enoxaparin dosage adjustment strategies in patients with subprophylactic anti-Xa. Adult trauma patients with Risk Assessment Profile (RAP) ≥ 5 prescribed enoxaparin 30 mg subcutaneously every 12 h were eligible. AT-III and anti-Xa were drawn 8 h after the third enoxaparin dose and compared between patients with anti-Xa ≥ 0.1 IU/mL (goal; control group) or anti-Xa < 0.1 IU/mL (subprophylactic; intervention group). The primary outcome was difference in baseline AT-III. Subsequently, intervention group patients underwent 1:1 randomization to either enoxaparin 40 mg every 12 h (up to 50 mg every 12 h if repeat anti-Xa < 0.1 IU/mL) (enox12) or enoxaparin 30 mg every 8 h (enox8) with repeat anti-Xa assessments. The proportion of patients achieving goal anti-Xa after dosage adjustment were compared. A total of 103 patients were included. Anti-Xa was subprophylactic in 50.5%. Baseline AT-III (median [IQR]) was 87% [80-98%] in control patients versus 82% [71-96%] in intervention patients (p = 0.092). Goal trough anti-Xa was achieved on first assessment in 38.1% enox12 versus 50% enox8 patients (p = 0.67), 84.6% versus 53.3% on second assessment (p = 0.11), and 100% vs. 54.5% on third trough assessment (p = 0.045). AT-III activity did not differ between high-risk trauma patients with goal and subprophylactic enoxaparin anti-Xa concentrations, although future investigation is warranted. Enoxaparin dose adjustment rather than frequency adjustment may be associated with a higher proportion of patients achieving goal anti-Xa over time.

Characterizing the delays in adequate thromboprophylaxis after TBI

Background

We sought to compare enoxaparin dosing for venous thromboembolism (VTE) prophylaxis in trauma patients with and without traumatic brain injury (TBI) to better understand the time and dose required to reach target anti-Xa levels. Our hypothesis was that patients with TBI have significant delays in the initiation of adequate pharmacological prophylaxis and require a higher enoxaparin dose than currently recommended.

Methods

The medical records of trauma patients who received enoxaparin dosing based on anti-Xa trough levels between August 2014 and October 2016 were reviewed. Patients were included if their anti-Xa trough level reached the target range (0.1 IU/mL to 0.2 IU/mL).

Results

A total of 163 patients had anti-Xa levels within the target range of which 41 (25.2%) had TBI. Patients with TBI had longer delays before initiating enoxaparin (7.5 days vs. 1.5 days after admission, p<0.01) and were more likely to receive unfractionated heparin prior to enoxaparin (46.3% vs. 11.5%, p<0.01). Anti-Xa levels reached the target range later in patients with TBI (11 days vs. 5 days after admission, p<0.01). Enoxaparin 40 mg two times per day was the median dose required to reach the target anti-Xa levels for both cohorts. VTE rates were higher among patients with TBI (22.0% vs. 9.0%, p=0.03). Four patients (9.8%) had progression of their intracranial hemorrhage prior to receiving enoxaparin, although none progressed during enoxaparin administration.

Conclusion

Among patients with TBI who reached target anti-Xa levels, 11 days after admission were required to reach a median enoxaparin dose of 40 mg two times per day. Unfractionated heparin was used as pharmacological prophylaxis in about half of these patients. The delay in reaching the target anti-Xa levels and the use of unfractionated heparin likely contribute to the higher VTE rate in patients with TBI.

Level of evidence

Level III, therapeutic.

Venous Thromboembolism in Trauma: The Role of Anticoagulation and Inferior Vena Cava Filters

Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality among patients with severe trauma. Historically, prophylactic inferior vena cava filters (IVCFs) were used in high-risk trauma patients with suspected risk factors for VTE, including prolonged immobilization, and concurrent contraindication to anticoagulation. Mounting data regarding the efficacy of IVCF in this cohort, as well as concerns regarding morbidity of an in situ IVCF, have challenged this practice paradigm. In this review, we discuss the comanagement of VTE and trauma, including anticoagulation and the use of IVCF.

Impact of Weight on Anti-Xa Attainment in High-Risk Trauma Patients on Enoxaparin Chemoprophylaxis

BACKGROUND

Serum anti-factor Xa (anti-Xa) concentration may guide low molecular weight heparin chemoprophylaxis in trauma patients. Higher total body weight (TBW) is a risk factor for subprophylactic anti-Xa and venous thromboembolism (VTE). The purpose of this study was to evaluate TBW differences in patients with subprophylactic versus prophylactic trough anti-Xa.

METHODS

This retrospective study included adults admitted to the trauma service who received enoxaparin chemoprophylaxis, trough anti-Xa assessment, and screening duplex ultrasound. Initial enoxaparin dose was determined per trauma team weight-tiered protocol with subsequent 10 mg increase if anti-Xa was subprophylactic. Patients were stratified into subprophylactic (anti-Xa <0.1 IU/ml) and prophylactic (anti-Xa ≥0.1 IU/mL) groups. The primary outcome was difference in TBW. Secondary outcomes were weight-adjusted enoxaparin dose (mg/kg), VTE, red blood cell (pRBC) transfusions.

RESULTS

A total of 887 patients were included with 681 (76.8%) having subprophylactic anti-Xa. The subprophylactic group had significantly younger age, higher proportion male sex, higher Injury Severity Score (ISS), higher BMI, and longer length of hospital stay. The subprophylactic group had higher TBW (median [IQR], 87.8 [74-102] kg vs. 78.9 [68-91.8] kg; P < 0.001) which equated to a lower weight-adjusted dose (0.34 [0.3-0.41] mg/kg vs. 0.38 (0.33-0.44) mg/kg; P < 0.001). There were no differences in VTE (10.4% vs. 9.2%; P = 0.71) or pRBC administration (17.0% vs. 16.0%; P = 0.81).

CONCLUSIONS

TBW is higher and weight-adjusted enoxaparin dose is lower in high-risk trauma patients with subprophylactic anti-Xa concentrations. These data suggest TBW should be considered when determining the optimal prophylactic enoxaparin dose in high-risk trauma patients.

Timely Venous Thromboembolism Prophylaxis in Trauma: A Team Approach to Process Improvement

Venous thromboembolism is a significant complication in trauma. Multisystem injury, advancing age, surgery, and blood transfusion all contribute to the risk of venous thromboembolism in trauma patients. Our Level I trauma center was identified as an outlier with compliance in timely venous thromboembolism prophylaxis in the Michigan Trauma Quality Improvement Program, a statewide collaborative for improving trauma care. The purpose of this study was to provide an evaluation of a performance improvement project to increase the timely administration of venous thromboembolism prophylaxis in admitted trauma patients. Using a Plan-Do-Study-Act method of quality improvement, we initiated a focused, goal-directed team approach that emphasized education, tracking, and feedback. This approach resulted in improved and sustained compliance rates. Resolute focus, audit, and feedback moved our center from a low- to high-performing center for timely venous thromboembolism prophylaxis.

The survival benefit of low molecular weight heparin over unfractionated heparin in pediatric trauma patients

INTRODUCTION

Venous thromboembolism (VTE) prophylaxis in pediatric patients is controversial and is mainly dependent on protocols derived from adult practices. Our study aimed to compare outcomes among pediatric trauma patients who received low molecular weight heparin (LMWH) compared to those who received unfractionated heparin (UFH).

METHODS

We performed 2 years (2015-2016) retrospective analysis of the Pediatrics ACS-TQIP database. Pediatric trauma patients (age ≤17) who received thromboprophylaxis with either LMWH or UFH were included. Patients were stratified into three age groups. Analysis of each subgroup and the entire cohort was performed. Outcome measures included VTE events (deep vein thrombosis [DVT] and pulmonary embolism [PE]), hospital and ICU length of stay (LOS) among survivors, and mortality. Propensity score matching was used to match the two cohorts LMWH vs UFH.

RESULTS

A matched cohort of 1,678 pediatric trauma patients was analyzed. A significant difference in survival, DVT events, and in-hospital LOS was seen in the age groups above 9 years. Overall, the patients who received LMWH had lower mortality (1.4% vs 3.6%, p<0.01), DVT (1.7% vs 3.7%, p<0.01), and hospital LOS among survivors (7 days vs 9 days, p<0.01) compared to those who received UFH. There was no significant difference in the ICU LOS among survivors and the incidence of PE between the two groups.

CONCLUSION

LMWH is associated with increased survival, lower rates of DVT, and decreased hospital LOS compared to UFH among pediatric trauma patients age 10-17 years.

LEVEL OF EVIDENCE

Level III Prophylactic.

STUDY TYPE

Prophylactic.

Venous thromboembolism prophylaxis in the trauma intensive care unit: an American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document

Venous thromboembolism (VTE) is a potential sequela of injury, surgery, and critical illness. Patients in the Trauma Intensive Care Unit are at risk for this condition, prompting daily discussions during patient care rounds and routine use of mechanical and/or pharmacologic prophylaxis measures. While VTE rightfully garners much attention in clinical patient care and in the medical literature, optimal strategies for VTE prevention are still evolving. Furthermore, trauma and surgical patients often have real or perceived contraindications to prophylaxis that affect the timing of preventive measures and the consistency with which they can be applied. In this Clinical Consensus Document, the American Association for the Surgery of Trauma Critical Care Committee addresses several practical clinical questions pertaining to specific or unique aspects of VTE prophylaxis in critically ill and injured patients.

Efficacy and Safety of Heparinization before Deployment of Endograft for Blunt Traumatic Aortic Injury in Severely Injured Patients

BACKGROUND

The administration of unfractionated heparin (UFH) during endovascular repair of blunt traumatic aortic injury (BTAI) is controversial. The aim of the study is to report the early outcomes of patients undergoing thoracic endovascular aortic repair (TEVAR) for BTAI, and to assess the individualized intraoperative use and dose of UFH.

METHODS

This is a retrospective analysis including consecutive patients treated with TEVAR for BTAI of the descending aorta between January 1st, 2005 and December 31st, 2018. Intraoperative use and doses of UFH were analyzed. Primary outcome included a reintervention because of new onset bleeding and/or thromboembolic complication and 30-day mortality. Technical success, injury severity score (ISS), timing of treatment, and neurologic deterioration were secondary outcome.

RESULTS

Thirty-six patients with a mean age of 47 ± 18 years, 30 males (83%), were included. Intraoperative administration of UFH was recorded in 30/36 patients (83%) with a mean dose of 4750 ± 2180 IU. Two patients had no UFH because of extensive intracranial hemorrhage or suspected relevant liver laceration, respectively; 1 died in theatre, 1 was already anticoagulated having a mechanical aortic valve, and in 2 no information about heparin use was found. During 30 days of follow-up, 3 patients died (8%; 3/36): 1 patient with completely transected aorta died on-table and 2 on the fifth postoperative day, 1 from trauma-associated brain injury and 1 with multi organ failure. No bleeding or thromboembolic complication requiring reintervention occurred in any patient during 30 days follow-up. In 3 patients partial unintentional coverage of the left common carotid artery occurred, resulting in technical success of 89% (32/36). Mean ISS was 43 ± 15. Thirty-five patients (97%) were severely injured having an ISS ≥ 25. Twenty-nine patients (81%) were treated within 24 hr and 6 patients (17%) within 1 week. No stroke or spinal cord ischemia was observed.

CONCLUSIONS

Systemic heparinization in different doses during TEVAR for BTAI can be safe with no intraoperative bleeding or thromboembolic complications in early postoperative period.

Skeletal muscle myosin and cardiac myosin attenuate heparin's antithrombin-dependent anticoagulant activity

BACKGROUND

Heparin enhances the ability of the plasma protease inhibitor, antithrombin, to neutralize coagulation factor Xa and thrombin. Skeletal muscle myosin binds unfractionated heparin.

OBJECTIVES

The aim of this study was to investigate the influence of myosin binding to heparin on antithrombin's anticoagulant activity.

METHODS

Inhibition of factor Xa and thrombin by antithrombin in the presence of different heparins and skeletal muscle myosin or cardiac myosin was studied by measuring inhibition of each enzyme's chromogenic substrate hydrolysis.

RESULTS AND CONCLUSIONS

Skeletal muscle myosin and cardiac myosin neutralized unfractionated heparin's enhancement of antithrombin's inhibition of purified factor Xa and thrombin. Skeletal muscle myosin also reduced the inhibition of factor Xa and thrombin by antithrombin in the presence of heparan sulfate. These two myosins did not protect factor Xa from antithrombin inhibition when tested in the presence of smaller heparins (eg, low molecular weight heparin, heparin pentasaccharide). This chain length dependence for skeletal muscle myosin's ability to reduce heparin's anticoagulant activity might have potential implications for therapy for patients who experience increases in plasma myosin levels (eg, acute trauma patients). In addition to the chain length, the type and extent of sulfation of glycosaminoglycans influenced the ability of skeletal muscle myosin to neutralize the polysaccharide's ability to enhance antithrombin's activity. In summary, these studies show that skeletal muscle myosin and cardiac myosin can influence antithrombin's anticoagulant activity against factor Xa and thrombin, implying that they may significantly influence the hemostatic balance involving bleeding vs clotting.

Perioperative Venous Thromboembolism Prophylaxis

Venous thromboembolism (VTE) is a preventable cause of postoperative morbidity and mortality; however, audits suggest that the use of thromboprophylaxis is underused. In this review, we describe our approach to prevention of postoperative VTE and provide guidance on how to formulate an optimal VTE prophylaxis plan. We recommend that all patients undergo thrombosis- and bleeding-risk assessment as part of their preoperative evaluation. The risk of thrombosis can be estimated based on patient- and procedure-specific factors, using validated risk-assessment models such as the Caprini score. There are no validated models to predict perioperative bleeding; however, several risk factors have been proposed. Patients should ambulate early and frequently after surgery. We recommend no additional prophylaxis in patients at very low risk of VTE (Caprini score 0). Patients at low risk of VTE (Caprini 1 to 2) are recommended to receive either mechanical or pharmacological prophylaxis. Patients at moderate (Caprini 3 to 4) to high risk of VTE (Caprini ≥5) are recommended pharmacological prophylaxis either alone or combined with mechanical prophylaxis. Patients at high risk of bleeding should receive mechanical prophylaxis until their risk of bleeding is reduced and pharmacological prophylaxis can be reconsidered. Populations for which the Caprini score has not been validated (such as orthopedic surgery) are recommended prophylaxis based on individual and procedure-specific risk factors. Prophylaxis is typically continued until the patient is ambulatory or until hospital dismissal; however, longer durations can be considered in certain circumstances (high-risk patients undergoing malignant abdominopelvic operations, bariatric operations, and certain orthopedic operations).

Direct Oral Anticoagulants Are a Potential Alternative to Low-Molecular-Weight Heparin for Thromboprophylaxis in Trauma Patients Sustaining Lower Extremity Fractures

BACKGROUND

Trauma patients are at a significant risk of venous thromboembolism (VTE), with lower extremity fractures (LEF) being independent risk factors. Use of direct oral anticoagusants (DOACs) for VTE prophylaxis is effective in elective orthopedic surgery, but currently not approved for trauma patients. The primary objective of this study was to compare the effectiveness and safety of thromboprophylaxis of DOACs with low-molecular-weight heparin (LMWH) in trauma patients sustaining LEF.

MATERIALS AND METHODS

We included adult trauma patients admitted to trauma quality improvement program participating trauma centers (between 2013 and 2016), who sustained LEF and were started on DOACs or LMWH for thromboprophylaxis after admission. Propensity score matching was performed to compare symptomatic VTE and bleeding control interventions between the groups.

RESULTS

Of 1,009,922 patients in trauma quality improvement program, 167,640 met inclusion criteria (165,009 received LMWH and 2631 received DOACs). After propensity score matching, 2280 predominantly elderly (median age: 67 y) isolated femur fracture patients (median ISS: 10) were included in each group (4560 patients in total). Symptomatic VTE occurred in 1.4% of patients in both matched groups (P = 0.992). Bleeding control interventions occurred less often in the DOAC group, albeit statistically insignificant (5.8% versus 6.0%, P = 0.772).

CONCLUSIONS

This study found similar rates of VTE and bleeding control measures for thromboprophylaxis with DOACs or LMWH in matched trauma patients with LEF. Further prospective research is warranted to consolidate the safety of DOAC thromboprophylaxis in trauma patients with LEF. Favorable oral administration and likely increased adherence could benefit this high-risk population.

Early Chemoprophylaxis in Severely Injured Trauma Patients Reduces Risk of Venous Thromboembolism

BACKGROUND

Venous thromboembolism (VTE) remains a serious complication for trauma patients. While early VTE prophylaxis has gained traction, the timing of prophylaxis remains uncertain. We hypothesized that VTE prophylaxis within 24 hours of admission would have lower VTE rates and similar rates of adverse events in seriously injured patients.

METHODS

Trauma patients were included from 32 American College of Surgeons verified Level 1 and 2 trauma centers over a 10-year period. Patients with injury severity score (ISS) <15, death or discharge within 48 hours of arrival, or who received no prophylaxis were excluded.

RESULTS

14 096 patients received VTE prophylaxis with an ISS of ≥15. Patients given prophylaxis at <24 hours had fewer VTE events and trended toward fewer serious in-hospital complications. Mortality and return to the operating room were similar across groups. Hospital and intensive care unit length of stay in the <24 hours prophylaxis group was significantly shorter when VTE prophylaxis was initiated earlier.

CONCLUSIONS

In severely injured trauma patients with ISS >15, early VTE prophylaxis within 24 hours significantly reduced the risk of VTE as compared with delayed prophylaxis. Early chemoprophylaxis was found to be efficacious in reducing the incidence of VTE; however, the safety of this practice should be evaluated by future prospective studies.

Early Anti-Xa Assay-Guided Low Molecular Weight Heparin Chemoprophylaxis is Safe in Adult Patients with Acute Traumatic Brain Injury

This study evaluated the safety of early anti-factor Xa assay–guided enoxaparin dosing for chemoprophylaxis in patients with TBI. We hypothesized that assay-guided chemoprophylaxis would be comparable in the risk of intracranial hemorrhage (ICH) progression to fixed dosing. An observational analysis of adult patients with blunt traumatic brain injury (TBI) was performed at a Level I trauma center from August 2016 to September 2017. Patients in the assay-guided group were treated with an initial enoxaparin dose of 0.5 mg/kg, with peak anti-factor Xa activity measured four hours after the third dose. Prophylactic range was defined as 0.2 to 0.5 IU/mL with a dose adjustment of ± 10 mg based on the assay result. The assay-guided group was compared with historical fixed-dose controls and to a TBI cohort from the most recent Trauma Quality Improvement Project dataset. Of 179 patients included in the study, 85 were in the assay-guided group and 94 were in the fixed-dose group. Compared with the fixed-dose group, the assay-guided group had a lower Glasgow Coma Score and higher Injury Severity Score. The proportion of severe (Abbreviated Injury Score, head ≥3) TBI, ICH progression, and venous thromboembolism rates were similar between all groups. The assay-guided and fixed-dose groups had chemoprophylaxis initiated earlier than the Trauma Quality Improvement Project group. The assay-guided group had the highest percentage of low molecular weight heparin use. Early initiation of enoxaparin anti-factor Xa assay–guided venous thromboembolism chemoprophylaxis has a comparable risk of ICH progression to fixed dosing in patients with TBI. These findings should be validated prospectively in a multicenter study.

Venous thromboembolism prophylaxis and the impact of a thrombosis service at a Canadian level 1 trauma centre

Background

Venous thromboembolism (VTE) is a common and serious complication seen in patients with trauma. Guidelines recommend the routine use of pharmacologic prophylaxis; however, compliance rates vary widely. The aim of this study was to describe the clinical practice related to VTE prophylaxis in the first 24 hours after injury at our level 1 Canadian trauma centre and the impact of a thrombosis consultation service.

Methods

We performed a retrospective review of the health records of adult patients with trauma admitted between Jan. 1, 2012, and June 30, 2013. The rate of VTE was ascertained. The use of an initial prophylactic regimen, potential contraindications to prophylaxis and involvement of the thrombosis service were determined.

Results

A total of 633 patients were included, 459 men and 174 women with a mean age of 47.4 years. The mean Injury Severity Score was 15.8. The overall VTE rate was 2.8%. A total of 514 patients (81.2%) received VTE prophylaxis, mechanical in 302 (47.7%) and pharmacologic in 231 (36.5%) (19 patients received both types). The thrombosis service was involved in the care of 164 patients (25.9%). Patients seen by the thrombosis service were more likely to receive VTE prophylaxis than those not seen by the service (145 [88.4%] v. 369 [78.7%], p < 0.01).

Conclusion

Compliance with VTE prophylaxis administration was suboptimal, and opportunities for improvement exist. The involvement of a thrombosis consultation service appears to improve compliance with VTE prophylaxis, and augmented use of this service may improve clinical outcomes.

Association of Anti-Factor Xa-Guided Dosing of Enoxaparin With Venous Thromboembolism After Trauma

Importance

The efficacy of anti-factor Xa (anti-Xa)-guided dosing of thromboprophylaxis after trauma remains controversial.

Objective

To assess whether dosing of enoxaparin sodium based on peak anti-Xa levels is associated with the venous thromboembolism (VTE) rate after trauma.

Design, Setting, and Participants

Retrospective review of 950 consecutive adults admitted to a single level I trauma intensive care unit for more than 48 hours from December 1, 2014, through March 31, 2017. Within 24 hours of admission, these trauma patients were screened with the Greenfield Risk Assessment Profile (RAP) (possible score range, 0-46). Patients younger than 18 years and those with VTE on admission were excluded, resulting in a study population of 792 patients.

Exposures

The control group received fixed doses of either heparin sodium, 5000 U 3 times a day, or enoxaparin sodium, 30 mg twice a day. The adjustment cohort initially received enoxaparin sodium, 30 mg twice a day. A peak anti-Xa level was drawn 4 hours after the third dose. If the anti-Xa level was 0.2 IU/mL or higher, no adjustment was made. If the anti-Xa level was less than 0.2 IU/mL, each dose was increased by 10 mg. The process was repeated up to a maximum dose of 60 mg twice a day.

Main Outcomes and Measures

Rates of VTE were measured. Venous duplex ultrasonography and computed tomographic angiography were used for diagnosis.

Results

The study population comprised 792 patients with a mean (SD) age of 46 (19) years and was composed of 598 men (75.5%). The control group comprised 570 patients, was older, and had a longer time to thromboprophylaxis initiation. The adjustment group consisted of 222 patients, was more severely injured, and had a longer hospital length of stay. The mean (SD) RAP scores were 9 (4) for the control group and 9 (5) for the adjustment group (P = .28). The VTE rates were similar for both groups (34 patients [6.0%] vs 15 [6.8%]; P = .68). Prophylactic anti-Xa levels were reached in 119 patients (53.6%) in the adjustment group. No difference in VTE rates was observed between those who became prophylactic and those who did not (7 patients [5.9%] vs 8 [7.8%]; P = .58). To control for confounders, 132 patients receiving standard fixed-dose enoxaparin were propensity matched to 84 patients receiving dose-adjusted enoxaparin. The VTE rates remained similar between the control and adjustment groups (3 patients [2.3%] vs 3 [3.6%]; P = .57).

Conclusions and Relevance

Rates of VTE were not reduced with anti-Xa-guided dosing, and almost half of the patients never reached prophylactic anti-Xa levels; achieving those levels did not decrease VTE rates. Thus, other targets, such as platelets, may be necessary to optimize thromboprophylaxis after trauma.

Timing of venous thromboprophylaxis in isolated severe pelvic fracture: Effect on mortality and outcomes

INTRODUCTION

Optimal timing of pharmacological thromboprophylaxis (VTEp) in patients with severe pelvic fractures remains unclear. The high risk of venous thromboembolic (VTE) complications after severe pelvic fractures supports early VTEp however concern for fracture-associated hemorrhage can delay initiation. Patients with pelvic fractures also frequently have additional injuries that complicate the interpretation of the VTEp safety profiles. To minimize this problem, the study included only patients with isolated severe pelvic fractures.

MATERIALS AND METHODS

The Trauma Quality Improvement Program was used to collect patients with blunt severe pelvic fractures (AIS > 3) who received VTEp with unfractionated heparin (UH) or low-molecular-weight heparin (LMWH). Patients with head, chest, spine, and abdominal injuries AIS > 3, or those with angio or operative intervention prior to VTEp were excluded. The study population was stratified according to timing of VTEp, early (<48 h) and late (>48 h). Outcomes included in-hospital mortality and VTE.

RESULTS

2752 patients were included in the study. Overall, 2007 patients (72.9%) received early VTEp, while 745 (27.1%) received late VTEp. LMWH was administered in 2349 (85.4%) and UH in 403 (14.6%). Late VTEp was associated with significantly higher incidence of VTE (4.3% vs. 2.2%, p = 0.004). Logistic regression identified late VTEp as an independent risk factor for VTE (OR 1.93, p = 0.009) and mortality (OR 4.03, p = 0.006). LMWH was an independent factor protective for both VTE and mortality (OR 0.373, p < 0.001, OR 0.266, p = 0.009, respectively).

CONCLUSION

In isolated severe pelvic fractures, early VTEp is independently associated with improved survival and fewer VTE. LMWH may be preferred over UH for this purpose.

Diagnostic and therapeutic approach in adult patients with traumatic brain injury receiving oral anticoagulant therapy: an Austrian interdisciplinary consensus statement

There is a high degree of uncertainty regarding optimum care of patients with potential or known intake of oral anticoagulants and traumatic brain injury (TBI). Anticoagulation therapy aggravates the risk of intracerebral hemorrhage but, on the other hand, patients take anticoagulants because of an underlying prothrombotic risk, and this could be increased following trauma. Treatment decisions must be taken with due consideration of both these risks. An interdisciplinary group of Austrian experts was convened to develop recommendations for best clinical practice. The aim was to provide pragmatic, clear, and easy-to-follow clinical guidance for coagulation management in adult patients with TBI and potential or known intake of platelet inhibitors, vitamin K antagonists, or non-vitamin K antagonist oral anticoagulants. Diagnosis, coagulation testing, and reversal of anticoagulation were considered as key steps upon presentation. Post-trauma management (prophylaxis for thromboembolism and resumption of long-term anticoagulation therapy) was also explored. The lack of robust evidence on which to base treatment recommendations highlights the need for randomized controlled trials in this setting.

Anticoagulant prophylaxis against venous thromboembolism following severe traumatic brain injury: A prospective observational study and systematic review of the literature

OBJECTIVES

Venous thromboembolism (VTE) is a serious complication following severe traumatic brain injury (TBI), however, anticoagulant prophylaxis remains controversial due to concerns of intracranial hemorrhage (ICH) progression. We examined anticoagulant prophylaxis practice patterns at a major trauma centre and determined risk estimates for VTE and ICH progression classified by timing of anticoagulant initiation.

PATIENTS AND METHODS

A 1-year prospective analysis of consecutive patients with severe TBI admitted to a Level-I trauma centre was conducted. In addition, we systematically reviewed the literature to identify studies on VTE and anticoagulant prophylaxis after severe TBI.

RESULTS

64 severe TBI patients were included. 83% of patients received anticoagulant prophylaxis, initiated ≥3d post-TBI in 67%. The in-hospital VTE incidence was 16% and there was no significant difference between patients who received early (<3d) versus late (≥3d) prophylaxis (10% vs. 16%). Rates of ICH progression (0% vs. 7%) were similar between groups. Our systematic review identified 5 studies with VTE rates ranging from 5 to 10% with prophylaxis, to 11-30% without prophylaxis. The effect of timing of anticoagulant prophylaxis initiation on ICH progression was not reported in any study.

CONCLUSION

VTE is a common complication after severe TBI. Anticoagulant prophylaxis is often started late (≥3d) post-injury. Randomized trials are justifiable and necessary to provide practice guidance with regards to optimal timing of anticoagulant prophylaxis.

A Systematic Review of the Risks and Benefits of Venous Thromboembolism Prophylaxis in Traumatic Brain Injury

BACKGROUND

Patients suffering from traumatic brain injury (TBI) are at increased risk of venous thromboembolism (VTE). However, initiation of pharmacological venous thromboprophylaxis (VTEp) may cause further intracranial hemorrhage. We reviewed the literature to determine the postinjury time interval at which VTEp can be administered without risk of TBI evolution and hematoma expansion.

METHODS

MEDLINE and EMBASE databases were searched. Inclusion criteria were studies investigating timing and safety of VTEp in TBI patients not previously on oral anticoagulation. Two investigators extracted data and graded the papers' levels of evidence. Randomized controlled trials were assessed for bias according to the Cochrane Collaboration Tool and Cohort studies were evaluated for bias using the Newcastle-Ottawa Scale. We performed univariate meta-regression analysis in an attempt to identify a relationship between VTEp timing and hemorrhagic progression and assess study heterogeneity using an I 2 statistic.

RESULTS

Twenty-one studies were included in the systematic review. Eighteen total studies demonstrated that VTEp postinjury in patients with stable head computed tomography scan does not lead to TBI progression. Fourteen studies demonstrated that VTEp administration 24 to 72 hours postinjury is safe in patients with stable injury. Four studies suggested that administering VTEp within 24 hours of injury in patients with stable TBI does not lead to progressive intracranial hemorrhage. Overall, meta-regression analysis demonstrated that there was no relationship between rate of hemorrhagic progression and VTEp timing.

CONCLUSIONS

Literature suggests that administering VTEp 24 to 48 hours postinjury may be safe for patients with low-hemorrhagic-risk TBIs and stable injury on repeat imaging.

Comparison between CT and MRI in the assessment of pulmonary embolism: A meta-analysis

OBJECTIVE

Besides pulmonary arteriography, a number of imaging techniques, such as magnetic resonance imaging (MRI) and computed tomography (CT), were adopted in the detection of identifying pulmonary embolism (PE). However, the contrast of sensitivity and specificity in these methods was studied little in a statistical way. To compare the effects of MRI and CT, this study used a series of methods to analyze data in included researches.

METHODS

A comprehensive computer search was conducted through internet up to July 2016. The quality assessment was performed by the Quality Assessment Tool for Diagnostic Accuracy Studies, version 2 tool. The diagnostic value of comparison between MRI and CT was evaluated by using the pooled estimate of sensitivity, specificity, and summary receiver operating characteristic (SROC) curve. In addition, sensitivity analysis and bias analysis were applied to ensure the accuracy of the results.

RESULTS

Ten studies with 590 cases were involved in the study. Only 2 trials had high risk regarding bias while other trials were supposed to be at low risk of applicability. Heterogeneity existed in analysis of both CT and MRI. The pooled sensitivity of CT was 0.90 (95% CI: 0.85-0.93), pooled specificity was 0.88 (95% CI: 0.77 to 0.95), the pooled sensitivity of MRI was 0.92 (95% CI: 0.89-0.94), and pooled specificity was 0.91 (95% CI: 0.77-0.97). The Q index of sensitivity and specificity for CT and MRI were 71.38, 19.67, 47.14, and 12.35, respectively. The SROC curve area under the curve of CT and MRI were 0.94 (95% CI: 0.91-0.96) and 0.93 (95% CI: 0.91-0.95), respectively.

CONCLUSION

This meta-analysis demonstrates that MRI has better sensitivity and specificity in detecting subsegmental artery PE. MRI is a relatively better detection technique for PE. This conclusion is consistent with many published researches.

Anti-Factor Xa measurements in acute care surgery patients to examine enoxaparin dose

BACKGROUND

The purpose of this study was to determine if fixed dose enoxaparin prophylaxis provided effective anticoagulation for acute care surgery patients and to examine whether a real-time enoxaparin dose adjustment algorithm optimized anticoagulation.

METHODS

Acute care surgical patients placed on enoxaparin prophylaxis 30 mg twice daily were recruited prospectively. Peak steady state aFXa levels were drawn with a goal peak aFXa range of 0.2-0.4 IU/ml. A real time dose adjustment algorithm was implemented for patients with out-of-range levels.

RESULTS

Fifty five patients were included. 56.4% of patients had low aFXa levels (<0.2 IU/mL). Real-time enoxaparin dose adjustment significantly increased the proportion of patients who achieved in-range peak aFXa levels, compared to standard dosing (74.5% vs 41.8%, p < 0.001). Patients with initial inadequate peak aFXa levels had a higher rate of 90-day post-operative VTE, although not statistically significant (16.1% vs. 8.3%, p = 0.50).

CONCLUSION

The majority of acute care surgery patients receive inadequate VTE prophylaxis with fixed enoxaparin dosing.

Timing of femoral shaft fracture fixation following major trauma: A retrospective cohort study of United States trauma centers

BACKGROUND

Femoral shaft fractures are common in major trauma. Early definitive fixation, within 24 hours, is feasible in most patients and is associated with improved outcomes. Nonetheless, variability might exist between trauma centers in timeliness of fixation. Such variability could impact outcomes and would therefore represent a target for quality improvement. We evaluated variability in delayed fixation (≥24 hours) between trauma centers participating in the American College of Surgeons (ACS) Trauma Quality Improvement Program (TQIP) and measured the resultant association with important clinical outcomes at the hospital level.

METHODS AND FINDINGS

A retrospective cohort study was performed using data derived from the ACS TQIP database. Adults with severe injury who underwent definitive fixation of a femoral shaft fracture at a level I or II trauma center participating in ACS TQIP (2012-2015) were included. Patient baseline and injury characteristics that might affect timing of fixation were considered. A hierarchical logistic regression model was used to identify predictors of delayed fixation. Hospital variability in delayed fixation was measured using 2 approaches. First, the random effects output of the hierarchical model was used to identify outlier hospitals where the odds of delayed fixation were significantly higher or lower than average. Second, the median odds ratio (MOR) was calculated to quantify heterogeneity in delayed fixation between hospitals. Finally, complications (pulmonary embolism, deep vein thrombosis, acute respiratory distress syndrome, pneumonia, decubitus ulcer, and death) and hospital length of stay were compared across quartiles of risk-adjusted delayed fixation. We identified 17,993 patients who underwent definitive fixation at 216 trauma centers. The median injury severity score (ISS) was 13 (interquartile range [IQR] 9-22). Median time to fixation was 15 hours (IQR 7-24 hours) and delayed fixation was performed in 26% of patients. After adjusting for patient characteristics, 57 hospitals (26%) were identified as outliers, reflecting significant practice variation unexplained by patient case mix. The MOR was 1.84, reflecting heterogeneity in delayed fixation across centers. Compared to hospitals in the lowest quartile of delayed fixation, patients treated at hospitals in the highest quartile of delayed fixation suffered 2-fold higher rates of pulmonary embolism (2.6% versus 1.3%; rate ratio [RR] 2.0; 95% CI 1.2-3.2; P = 0.005) and required greater length of stay (7 versus 6 days; RR 1.15; 95% CI 1.1-1.19; P < 0.001). There was no significant difference with respect to mortality (1.3% versus 0.8%; RR 1.6; 95% CI 1.0-2.8; P = 0.066). The main limitations of this study include the inability to classify fractures by severity, challenges related to the heterogeneity of the study population, and the potential for residual confounding due to unmeasured factors.

CONCLUSIONS

In this large cohort study of 216 trauma centers, significant practice variability was observed in delayed fixation of femoral shaft fractures, which could not be explained by differences in patient case mix. Patients treated at centers where delayed fixation was most common were at significantly greater risk of pulmonary embolism and required longer hospital stay. Trauma centers should strive to minimize delays in fixation, and quality improvement initiatives should emphasize this recommendation in best practice guidelines.