Thromboembolism following multiple trauma

Mild and Severe Blood Alcohol Concentration Effects on Trauma and Traumatic Brain Injury Outcomes

INTRODUCTION

Reported outcomes for trauma patients (TPs) with elevated blood alcohol concentration (BAC) have been mixed. Previous studies suggest that positive BAC might lead to lower venous thromboembolism (VTE) rates and mortality. This study expands upon these findings by examining the association of various levels of BAC, with additional emphasis on traumatic brain injury (TBI) patients. We hypothesize that both mild and severe-BAC levels in TPs are associated with decreased risk of VTE and mortality.

METHODS

A retrospective review of the 2017 Trauma Quality Improvement Program was performed on adults (≥18 y old) screened for BAC on admission. Patients deceased on arrival and positive for drugs were excluded. We compared three groups: no-BAC, mild-BAC (0-70 mg/dL), and-severe BAC (>80 mg/dL) for associated risk of VTE and mortality.

RESULTS

From 203,535 tested patients, 118,427 (58.2%) had no-BAC, 19,813 (9.7%) had mild-BAC, and 65,295 (32.1%) had severe-BAC. The associated risk of VTE was lower for mild-BAC (odds ratios [OR] 0.69, 0.58-0.82, P < 0.001) and severe-BAC (OR 0.80, 0.72-0.89, P < 0.001). This persisted in TBI patients, with mild-BAC (OR 0.67, 0.51-0.89, P = 0.006) and severe-BAC (OR 0.75, 0.64-0.89, P < 0.001) groups exhibiting lower associated VTE risk. However, the associated mortality risk was lower only in severe-BAC patients (OR 0.90, 0.83-0.97, P = 0.009).

CONCLUSIONS

A positive BAC is linked to a reduced associated risk of VTE in TPs, including those with TBI. Notably, only the severe-BAC group demonstrated a lower associated risk of mortality. This merits future research including identification of basic science pathways that may be targeted to improve outcomes.

Budd-Chiari syndrome following abdominal trauma

We report a case of Budd-Chiari syndrome (BCS) in a 44-year-old man with inferior vena cava (IVC) thrombosis and nephrotic syndrome. This case was complicated by right atrial clot and pulmonary emboli. Endothelial injury of the IVC was the likely mechanism, following a kick from a donkey. Abdominal ultrasonography revealed a large thrombosis located in a segment of IVC near its orifice in the right atrium. Transthoracic echocardiography (TTE) revealed IVC thrombosis that extended to the right atrium; however, pulmonary emboli (PE) were not documented in TTE. Intraoperative exploration revealed multiple clots in the main and left pulmonary artery branches. The patient recovered well after open-heart surgery with resection of the right atrium, IVC, and pulmonary artery emboli. BCS should be routinely considered for patients with nephrotic syndrome.

Low Molecular Weight Heparin Is Superior for Venous Thromboembolism Prophylaxis in High-Risk Geriatric Patients

INTRODUCTION

Venous thromboembolism (VTE) is a source of preventable morbidity and mortality in critically ill trauma patients. Age is one independent risk factor. Geriatric patients embody a population at high thromboembolic and hemorrhagic risk. Currently, there is little guidance between low molecular weight heparin (LMWH) and unfractionated heparin (UFH) for anticoagulant prophylaxis in the geriatric trauma patient.

METHODS

A retrospective review was conducted at an ACS verified, Level I Trauma center from 2014 to 2018. All patients 65 years or older, with high-risk injuries and admitted to the trauma service were included. Choice of agent was at provider discretion. Patients in renal failure, or those that received no chemoprophylaxis, were excluded. The primary outcomes were the diagnosis of deep vein thrombosis or pulmonary embolism and bleeding associated complications (gastrointestinal bleed, TBI expansion, hematoma development).

RESULTS

This study evaluated 375 subjects, 245 (65%) received enoxaparin and 130 (35%) received heparin. DVT developed in 6.9% of UFH patients, compared to 3.3% with LMWH (P = .1). PE was present in 3.8% of UFH group, but only .4% in the LMWH group (P = .01). Combined rate of DVT/PE was significantly lower (P = .006) with LMWH (3.7%) compared to UFH (10.8%). 10 patients had documented bleeding events, and there was no significant association between bleeding and the use of LMWH or UFH.

CONCLUSIONS

VTE events are more common in geriatric patients treated with UFH compared to LMWH. There was no associated increase in bleeding complications when LMWH was utilized. LMWH should be considered the chemoprophylatic agent of choice in high risk geriatric trauma patients.

Racial Disparities in Administration of Venous Thromboembolism Prophylaxis After Severe Traumatic Injuries

BACKGROUND

Race is associated with differences in quality of care process measures and incidence of venous thromboembolism (VTE) in trauma patients. We aimed to investigate if racial disparities exist in the administration of VTE prophylaxis in trauma patients.

METHODS

We queried the Trauma Quality Improvement Project database from 2017 to 2019. Patients ages ≥16 years old with ISS ≥15 were included. Patients with no signs of life on arrival, any AIS ≥6, hospital length of stay <1 day, anticoagulant use before admission, or without recorded race were excluded. Patients were grouped by race: white, black, Asian, American Indian, and Native Hawaiian or Pacific Islander. The association between VTE prophylaxis administration and race was determined using a Poisson regression model with robust standard errors to adjust for confounders.

RESULTS

A total of 285,341 patients were included. Black patients had the highest rates of VTE prophylaxis exposure (73.8%), shortest time to administration (1.6 days), and highest use of low molecular weight heparin (56%). Black patients also had the highest incidence of deep vein thrombosis (2.8%) and pulmonary embolism (1.4%). Black patients were 4% more likely to receive VTE prophylaxis than white patients [adj. IRR (95% CI): 1.04 (1.03-1.05), P < .001]. American Indians were 8% less likely to receive VTE prophylaxis [adj. IRR (95% CI): .92 (.88-.97), P < .001] than white patients. No differences between white and Asian or Native Hawaiian or Pacific Islander patients existed.

DISCUSSION

While black patients had the highest incidence of DVT and PE, they had higher administration rates and earlier initiation of VTE prophylaxis. Further work can elucidate modifiable causes of these differences.

Timing of venous thromboemboli in patients with acetabular and pelvic ring fractures

PURPOSE

To determine the timing of symptomatic venous thromboemboli (VTE) in patients sustaining a pelvic and/or acetabular fracture. Secondly, to evaluate for any factors that may influence this timing.

METHODS

A retrospective cohort of 47 patients with acetabular and/or pelvic ring injuries who developed VTEs at a single academic level I trauma center were identified from 2012 to 2018. The chronology of VTE diagnosis in relation to date of injury, initial surgery, final surgery, and date of discharge was evaluated. Patients who developed VTEs were then evaluated based on known risk factors for VTE to determine if any of these affected timing.

RESULTS

Symptomatic VTEs were diagnosed in 3.8% of patients with pelvic and/or acetabular fractures. In patients who developed a thromboembolism, diagnosis occurred on average 21.5 (± 19.2), 20.7 (± 19.9), 9.8 (± 23.4), and 4.3 (± 27.6) days after injury, index procedure, final procedure, and date of discharge. 25% of patients developed VTE more than 4 weeks after their initial injury. No known risk factors effected the timing of VTE.

CONCLUSION

The 2015 OTA expert panel recommends 4 weeks of anticoagulation for orthopedic trauma patients at high risk of VTE, which may be too short a duration. In our cohort, 25% of VTEs occurred greater than 4 weeks after injury. Additional research is needed to clarify the exact duration of anticoagulation after pelvic and acetabular fractures; however, surgeons may want to consider anticoagulating patients for greater than 4 weeks.

LEVEL OF EVIDENCE

Level III-retrospective cohort.

Chest CT Findings and SARS-CoV-2 Infection in Trauma Patients-Is There a Prediction towards Higher Complication Rates?

Background: Polytrauma patients with SARS-CoV-2 infections may be associated with an increased complication rate. The main goal of this study was to analyze the clinical course of trauma patients with COVID infection and a positive CT finding. Methods: This was a retrospective in-hospital study. Polytrauma patients diagnosed with SARS-CoV-2 infections were included in our analysis. The outcome parameters were pulmonary complication during admission, pulmonary embolism, pleural effusion, pneumonia, mortality, length of stay and readmission < 30 days. Results: 48 patients were included in the study. Trauma patients in the age-adjusted matched-pair analysis with typical changes in SARS-CoV-2 infection in CT findings showed significantly more pulmonary complications in general and significantly more cases of pneumonia (complications: 56% vs. 11%, p = 0.046; pneumonia 44% vs. 0%, p = 0.023). In addition, the clinical course of polytrauma patients with SARS-CoV-2 infection showed a high rate of pulmonary complications in the inpatient course (53%). Conclusion: The results of our study show that the changes in the CT findings of trauma patients with SARS-CoV-2 infection are a good indicator of further inpatient outcomes. Similarly, polytrauma patients with a SARS-CoV-2 infection and positive CT findings are shown to have increased risk for pulmonary complications.

What happens after they survive? The role of anticoagulants and antiplatelets in IVC injuries

Background

Venous thromboembolism (VTE) after an inferior vena cava (IVC) injury is a devastating complication. Current practice involves variable use of anticoagulation and antiplatelet (AC/AP) agents. We hypothesized that AC/AP can reduce the incidence of VTE and that delayed institution of AC/AP is associated with increased VTE events.

Methods

We retrospectively reviewed IVC injuries cared for at a large urban adult academic level 1 trauma center between January 1, 2008 and December 31, 2020, surviving 72 hours. Patient demographics, injury mechanism, surgical repair, type and timing of AC, and type and timing of VTE events were characterized. Postoperative AC status during hospital course before an acute VTE event was delineated by grouping patients into four categories: full, prophylactic, prophylactic with concomitant AP, and none. The primary outcome was the incidence of an acute VTE event. IVC ligation was excluded from analysis.

Results

Of the 76 patients sustaining an IVC injury, 26 were included. The incidence of a new deep vein thrombosis distal to the IVC injury and a new pulmonary embolism was 31% and 15%, respectively. The median onset of VTE was 5 days (IQR 1–11). Four received full AC, 10 received prophylactic AC with concomitant AP, 8 received prophylactic AC, and 4 received no AC/AP. New VTE events occurred in 0.0% of full, in 30.0% of prophylactic with concomitant AP, in 50.0% of prophylactic, and in 50.0% without AC/AP. There was no difference in baseline demographics, injury mechanisms, surgical interventions, and bleeding complications.

Discussion

This is the first study to suggest that delay and degree of antithrombotic initiation in an IVC-injured patient may be associated with an increase in VTE events. Consideration of therapy initiation should be performed on hemostatic stabilization. Future studies are necessary to characterize the optimal dosing and temporal timing of these therapies.

Level of evidence

Therapeutic, level 3.

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.

A nested case-control study of risk for pulmonary embolism in the general trauma population using nationwide trauma registry data in Japan

Post-trauma patients are at great risk of pulmonary embolism (PE), however, data assessing specific risk factors for post-traumatic PE are scarce. This was a nested case–control study using the Japan Trauma Data Bank between 2004 and 2017. We enrolled patients aged ≥ 16 years, Injury Severity Score ≥ 9, and length of hospital stay ≥ 2 days, with PE and without PE, using propensity score matching. We conducted logistic regression analyses to examine risk factors for PE. We included 719 patients with PE and 3595 patients without PE. Of these patients, 1864 [43.2%] were male, and their median Interquartile Range (IQR) age was 73 [55–84] years. The major mechanism of injury was blunt (4282 [99.3%]). Median [IQR] Injury Severity Score (ISS) was 10 [9–18]. In the multivariate analysis, the variables spinal injury [odds ratio (OR), 1.40 (1.03–1.89)]; long bone open fracture in upper extremity and lower extremity [OR, 1.51 (1.06–2.15) and OR, 3.69 (2.89–4.71), respectively]; central vein catheter [OR, 2.17 (1.44–3.27)]; and any surgery [OR, 4.48 (3.46–5.81)] were independently associated with PE. Spinal injury, long bone open fracture in extremities, central vein catheter placement, and any surgery were risk factors for post-traumatic PE. Prompt initiation of prophylaxis is needed for patients with such trauma.

Thromboembolic complications among multiple injured patients with pelvic injuries: identifying risk factors for possible patient-tailored prophylaxis

Background

Patients with pelvic and/or acetabular fractures are at high risk of developing thromboembolic (TE) complications. In our study we investigate TE complications and the potential negative effects of concomitant pelvic or acetabular injuries in multiple injured patients according to pelvic/acetabular injury severity and fracture classification.

Methods

The TraumaRegister DGU® was analyzed between 2010 and 2019. Multiple injured patients with pelvic and/or acetabular fractures with ISS ≥ 16 suffering from TE complications were identified. We conducted a univariate and multivariate analysis with TE events as independent variable to examine potential risk factors and contributing factors.

Results

10.634 patients met our inclusion criteria. The overall TE incidence was 4.9%. Independent risk factors for the development of TE complications were sepsis, ≥ 10 operative interventions, mass transfusion (≥ 10 PRBCs), age ≥ 65 years and AIS_Abdomen ≥ 3 (all p < 0.001). No correlation was found for overall injury severity (ISS), moderate traumatic brain injury, additional injury to lower extremities, type B and C pelvic fracture according to Tile/AO/OTA and closed or open acetabular fracture.

Conclusions

Multiple injured patients suffering from pelvic and/or acetabular fractures are at high risk of developing thromboembolic complications. Independent risk factors for the development of thromboembolic events in our study cohort were age ≥ 65 years, mass transfusion, AIS_Abdomen ≥ 3, sepsis and ≥ 10 surgery procedures. Among multiple injured patients with acetabular or pelvic injuries the severity of these injuries seems to have no further impact on thromboembolic risk. Our study, however, highlights the major impact of early hemorrhage and septic complications on thromboembolic risk in severely injured trauma patients. This may lead to individualized screening examinations and a patient-tailored thromboprophylaxis in high-risk patients for TE. Furthermore, the number of surgical interventions should be minimized in these patients to reduce thromboembolic risk.

Guidelines for the acute care of severe limb trauma patients

GOAL

To provide healthcare professionals with comprehensive multidisciplinary expert recommendations for the acute care of severe limb trauma patients, both during the prehospital phase and after admission to a Trauma Centre.

DESIGN

A consensus committee of 21 experts was formed. A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e., pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of the quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. Few recommendations remained non-graded.

METHODS

The committee addressed eleven questions relevant to the patient suffering severe limb trauma: 1) What are the key findings derived from medical history and clinical examination which lead to the patient's prompt referral to a Level 1 or Level 2 Trauma Centre? 2) What are the medical devices that must be implemented in the prehospital setting to reduce blood loss? 3) Which are the clinical findings prompting the performance of injected X-ray examinations? 4) What are the ideal timing and modalities for performing fracture fixation? 5) What are the clinical and operative findings which steer the surgical approach in case of vascular compromise and/or major musculoskeletal attrition? 6) How to best prevent infection? 7) How to best prevent thromboembolic complications? 8) What is the best strategy to precociously detect and treat limb compartment syndrome? 9) How to best and precociously detect post-traumatic rhabdomyolysis and prevent rhabdomyolysis-induced acute kidney injury? 10) What is the best strategy to reduce the incidence of fat emboli syndrome and post-traumatic systemic inflammatory response? 11) What is the best therapeutic strategy to treat acute trauma-induced pain? Every question was formulated in a PICO (Patient Intervention Comparison Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® methodology.

RESULTS

The experts' synthesis work and the application of the GRADE method resulted in 19 recommendations. Among the formalised recommendations, 4 had a high level of evidence (GRADE 1+/-) and 12 had a low level of evidence (GRADE 2+/-). For 3 recommendations, the GRADE method could not be applied, resulting in an expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations.

CONCLUSIONS

There was significant agreement among experts on strong recommendations to improve practices for severe limb trauma patients.

Venous Thromboembolism in a Single Korean Trauma Center: Incidence, Risk Factors, and Assessing the Validity of VTE Diagnostic Tools

PURPOSE

Trauma increases the risk of venous thromboembolism (VTE) in hospitalized patients. However, the risk and incidence of VTE in Korean trauma patients are limited. Therefore, we aimed to evaluate the incidence and identify potential predictors of VTE occurrence in Korean trauma patients. Moreover, we assessed the validity of the Greenfield risk assessment profile (RAP) and the trauma embolic scoring system (TESS) in these patients.

MATERIALS AND METHODS

This retrospective cohort study used the data of trauma patients who were admitted to a regional trauma center between 2010 and 2016 and were eligible for entry into the Korea Trauma Data Bank. Clinical data were collected from hospital medical records. The patient's baseline characteristics and clinical data were compared between VTE and non-VTE groups.

RESULTS

We included 9472 patients. The overall VTE rate was 0.87% (n=82), with 56 (0.59%) events of deep vein thrombosis and 39 (0.41%) of pulmonary embolism. Multiple regression analysis revealed that variables, including VTE history, pelvic-bone fracture, ventilator use, and hospitalization period, were significant, potential predictors of VTE occurrence. This study showed that increased RAP and TESS scores were correlated with increased VTE rate, with rates of 1% and 1.5% for the RAP and TESS scores of 6, respectively. The optimal cut-off value for RAP and TESS scores was 6.

CONCLUSION

RAP and TESS, which are well-known diagnostic tools, demonstrated potentials in predicting the VTE occurrence in Korean trauma patients. Additionally, patients with pelvic-bone fractures and long-term ventilator treatment should be carefully examined for possible VTE.

Venous thromboembolism prophylaxis practices and outcomes at an Australian level-one trauma service

Background

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), is a major cause of potentially preventable morbidity and mortality amongst trauma patients. Venous thromboembolism prevalence varies from 1 to 58%, and traditionally, compliance with prophylaxis protocols is low in major trauma cohorts. This study aimed to describe VTE prevalence, prophylaxis practices and outcomes amongst VTE cases at an Australian level-one trauma centre.

Methods

A retrospective review of all VTE cases occurring in acute, major trauma admissions between 1 January 2010 and 30 June 2019 was conducted using prospectively collected registry data. Data regarding demographics, time to diagnosis, VTE prophylaxis, VTE risk assessment tool (RAT) usage and all-cause mortality were collected. Chemoprophylaxis was considered adequate if administered for 48 h prior to diagnosis. VTE cases diagnosed within 48 h of admission were excluded from prophylaxis compliance analysis. A subgroup analysis of patients with intracranial haemorrhage (ICH) was also completed.

Results

During the study period, 238 VTE events occurred in 237 patients from 7482 major trauma admissions, giving a VTE prevalence of 3.18%. The all-cause mortality rate was 8.0%. VTE chemoprophylaxis was administered for 109 of 211 eligible patients (51.7%). Of the remaining 102 VTE cases, 75 (73.5%) did not receive prophylaxis due to a documented contraindication, while 27 (26.5%) did not receive prophylaxis with no contraindication recorded. The VTE RAT was completed in 49.0% of cases.

Conclusion

Venous thromboembolism prevalence at our institution was consistent with published figures for comparable institutions. A review of compliance with prophylaxis protocols showed several potential areas for improvement.

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.

American Society of Hematology 2021 guidelines for management of venous thromboembolism: prevention and treatment in patients with cancer

BACKGROUND

Venous thromboembolism (VTE) is a common complication among patients with cancer. Patients with cancer and VTE are at a markedly increased risk for morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the prevention and treatment of VTE in patients with cancer.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The guideline development process was supported by updated or new systematic evidence reviews. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

Recommendations address mechanical and pharmacological prophylaxis in hospitalized medical patients with cancer, those undergoing a surgical procedure, and ambulatory patients receiving cancer chemotherapy. The recommendations also address the use of anticoagulation for the initial, short-term, and long-term treatment of VTE in patients with cancer.

CONCLUSIONS

Strong recommendations include not using thromboprophylaxis in ambulatory patients receiving cancer chemotherapy at low risk of VTE and to use low-molecular-weight heparin (LMWH) for initial treatment of VTE in patients with cancer. Conditional recommendations include using thromboprophylaxis in hospitalized medical patients with cancer, LMWH or fondaparinux for surgical patients with cancer, LMWH or direct oral anticoagulants (DOAC) in ambulatory patients with cancer receiving systemic therapy at high risk of VTE and LMWH or DOAC for initial treatment of VTE, DOAC for the short-term treatment of VTE, and LMWH or DOAC for the long-term treatment of VTE in patients with cancer.

A preliminary study of intensivist-performed DVT ultrasound screening in trauma ICU patients (APSIT Study)

Background

Multiple screening Duplex ultrasound scans (DUS) are performed in trauma patients at high risk of deep vein thrombosis (DVT) in the intensive care unit (ICU). Intensive care physician performed compression ultrasound (IP-CUS) has shown promise as a diagnostic test for DVT in a non-trauma setting. Whether IP-CUS can be used as a screening test in trauma patients is unknown. Our study aimed to assess the agreement between IP-CUS and vascular sonographer performed DUS for proximal lower extremity deep vein thrombosis (PLEDVT) screening in high-risk trauma patients in ICU.

Methods

A prospective observational study was conducted at the ICU of Alfred Hospital, a major trauma center in Melbourne, Australia, between Feb and Nov 2015. All adult major trauma patients admitted with high risk for DVT were eligible for inclusion. IP-CUS was performed immediately before or after DUS for PLEDVT screening. The paired studies were repeated twice weekly until the DVT diagnosis, death or ICU discharge. Written informed consent from the patient, or person responsible, or procedural authorisation, was obtained. The individuals performing the scans were blinded to the others’ results. The agreement analysis was performed using Cohen’s Kappa statistics and intraclass correlation coefficient for repeated binary measurements.

Results

During the study period, 117 patients had 193 pairs of scans, and 45 (39%) patients had more than one pair of scans. The median age (IQR) was 47 (28–68) years with 77% males, mean (SD) injury severity score 27.5 (9.53), and a median (IQR) ICU length of stay 7 (3.2–11.6) days. There were 16 cases (13.6%) of PLEDVT with an incidence rate of 2.6 (1.6–4.2) cases per 100 patient-days in ICU. The overall agreement was 96.7% (95% CI 94.15–99.33). The Cohen’s Kappa between the IP-CUS and DUS was 0.77 (95% CI 0.59–0.95), and the intraclass correlation coefficient for repeated binary measures was 0.75 (95% CI 0.67–0.81).

Conclusions

There is a substantial agreement between IP-CUS and DUS for PLEDVT screening in trauma patients in ICU with high risk for DVT. Large multicentre studies are needed to confirm this finding.

Massive Transfusion Protocol and Subsequent Development of Venous Thromboembolism: Statewide Analysis

BACKGROUND

Massive transfusion protocols (MTP) are a routine component of any major trauma center's armamentarium in the management of exsanguinating hemorrhages. Little is known about the potential complications of those that survive a MTP. We sought to determine the incidence of venous thromboembolism (VTE) following MTP. We hypothesized that MTP would be associated with a higher risk of VTE when compared with a risk-adjusted control population without MTP.

METHODS

The Pennsylvania Trauma Outcome Study database was retrospectively queried from 2015 to 2018 for trauma patients who developed VTE and survived until discharge at accredited trauma centers in Pennsylvania. Patient demographics, injury severity, and clinical outcomes were compared to assess differences in VTE development between MTP and non-MTP patients. A multivariate logistic regression model assessed the adjusted impact of MTP on VTE development.

RESULTS

176 010 patients survived until discharge, meeting inclusion criteria. Of those, 1667 developed a VTE (pulmonary embolism [PE]: 662 [0.4%]; deep vein thrombosis [DVT]: 1142 [0.6%]; PE and DVT: 137 [0.1%]). 1268 patients (0.7%) received MTP and, of this subset of patients, 171 (13.5%) developed a VTE during admission. In adjusted analysis, patients who had a MTP and survived until discharge had a higher odds of developing a VTE (adjusted odds ratio: 2.62; 95% CI: 2.13-3.24; P < .001).

DISCUSSION

MTP is a harbinger for higher risk of VTE in those patients who survive. This may, in part, be related to the overcorrection of coagulation deficits encountered in the hemorrhagic event. A high index of suspicion for the development of VTE as well as aggressive VTE prophylaxis is warranted in those patients who survive MTP.

Not all in your head (and neck): Stroke after blunt cerebrovascular injury is associated with systemic hypercoagulability

BACKGROUND

Stroke secondary to blunt cerebrovascular injury (BCVI) most often occurs before initiation of antithrombotic therapy. Earlier treatment, especially in multiply injured patients with relative contraindications to antithrombotic agents, could be facilitated with improved risk stratification; furthermore, the relationship between BCVI-attributed stroke and hypercoagulability remains unknown. We hypothesized that patients who suffer BCVI-related stroke are hypercoagulable compared with those with BCVI who do not stroke.

METHODS

Rapid thromboelastography (TEG) was evaluated for patients with BCVI-attributed stroke at an urban Level I trauma center from 2011 to 2018. Contemporary controls who had BCVI but did not stroke were selected for comparison using propensity-score matching with 20% caliper that accounted for age, sex, injury severity, and BCVI location and grade.

RESULTS

During the study period, 15,347 patients were admitted following blunt trauma. Blunt cerebrovascular injury was identified in 435 (3%) patients, of whom 28 experienced associated stroke and had a TEG within 24 hours of arrival. Forty-nine patients who had BCVI but did not suffer stroke served as matched controls. Stroke patients formed clots faster as evident in their larger angle (77.5 degrees vs. 74.6 degrees, p = 0.03) and had greater clot strength as indicated by their higher maximum amplitude (MA) (66.9 mm vs. 61.9 mm, p < 0.01). Activated clotting time was shorter among stroke patients but not significantly (113 seconds vs. 121 seconds, p > 0.05). Increased angle and elevated MA were significant predictors of stroke with odds ratios of 2.97 for angle greater than 77.3 degrees and 4.30 for MA greater than 63.0 mm.

CONCLUSION

Patients who suffer BCVI-related stroke are hypercoagulable compared with those with BCVI who remain asymptomatic. Increased angle or MA should be considered when assessing the risk of thrombosis and determining the optimal time to initiate antithrombotic therapy in patients with BCVI.

LEVEL OF EVIDENCE

Prognostic, Level III.

American Society of Hematology 2019 guidelines for management of venous thromboembolism: prevention of venous thromboembolism in surgical hospitalized patients

BACKGROUND

Venous thromboembolism (VTE) is a common source of perioperative morbidity and mortality.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about preventing VTE in patients undergoing surgery.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic reviews. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 30 recommendations, including for major surgery in general (n = 8), orthopedic surgery (n = 7), major general surgery (n = 3), major neurosurgical procedures (n = 2), urological surgery (n = 4), cardiac surgery and major vascular surgery (n = 2), major trauma (n = 2), and major gynecological surgery (n = 2).

CONCLUSIONS

For patients undergoing major surgery in general, the panel made conditional recommendations for mechanical prophylaxis over no prophylaxis, for pneumatic compression prophylaxis over graduated compression stockings, and against inferior vena cava filters. In patients undergoing total hip or total knee arthroplasty, conditional recommendations included using either aspirin or anticoagulants, as well as for a direct oral anticoagulant over low-molecular-weight heparin (LMWH). For major general surgery, the panel suggested pharmacological prophylaxis over no prophylaxis, using LMWH or unfractionated heparin. For major neurosurgery, transurethral resection of the prostate, or radical prostatectomy, the panel suggested against pharmacological prophylaxis. For major trauma surgery or major gynecological surgery, the panel suggested pharmacological prophylaxis over no prophylaxis.

High Rate of Fibrinolytic Shutdown and Venous Thromboembolism in Patients With Severe Pelvic Fracture

BACKGROUND

Trauma patients with pelvic fractures have a high rate of venous thromboembolism (VTEs). The reason for this high rate is unknown. We hypothesize that fibrinolysis shutdown (SD) predicts VTE in patients with severe pelvic fracture.

METHODS

Retrospective chart review of trauma patients who presented with pelvic fracture from 2007 to 2017 was performed. Inclusion criteria were injury severity score > 15, abdomen/pelvis abbreviated injury scale >/= 3, blunt mechanism, admission citrated rapid thrombelastography (TEG). Fibrinolytic phenotypes were defined by fibrinolysis on citrated rapid TEG as hyperfibrinolysis, physiologic lysis, and SD. Univariate analysis of TEG measurements and clinical outcomes, followed by multivariable logistic regression (MV) with stepwise selection, was performed.

RESULTS

Overall, 210 patients were included. Most patients (59%) presented in fibrinolytic shutdown. VTE incidence was 11%. There were no significant differences in fibrinolytic phenotypes or other TEG measurements between those who developed VTE and those who did not. There was a higher rate of VTE in patients who underwent pelvic external fixation or resuscitative thoracotomy. On MV, pelvic fixation and resuscitative thoracotomy were independent predictors of VTE.

CONCLUSIONS

In severely injured patients with pelvic fractures, there was a high rate of VTE and the majority presented in SD. However, we were unable to correlate initial SD with VTE. Ultimately, the high rate of VTE in this patient population supports the concept of implementing VTE chemoprophylaxis measures as soon as hemostasis is achieved.

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.

Venous thromboembolism (VTE) prophylaxis in severely injured patients: an international comparative assessment

PURPOSE

Venous thromboembolisms (VTE) are a major concern after acute survival from trauma. Variations in treatment protocols for trauma patients exist worldwide. This study analyzes the differences in the number of VTE events and the associated complications of thromboprophylaxis between two level I trauma populations utilizing varying treatment protocols.

METHODS

International multicenter trauma registry-based study was performed at the University Medical Center Utrecht (UMCU) in The Netherlands (early commencement chemical prophylaxis), and Harborview Medical Center (HMC) in the United States (restrictive early chemical prophylaxis). All severely injured patients (ISS ≥ 16), aged ≥ 18 years, and admitted in 2013 were included. Primary outcomes were VTE [deep venous thrombosis (DVT) (no screening), pulmonary embolism (PE)], and hemorrhagic complications.

RESULTS

In UMCU, 279 patients were included and in HMC, 974 patients. Overall, 75% of the admitted trauma patients in UMCU and 81% in HMC (p < 0.001) received thromboprophylaxis, of which 100% in and 75% at, respectively, UMCU and HMC consisted of chemical prophylaxis. From these patients, 72% at UMCU and 47% at HMC (p < 0.001) were treated within 48 h after arrival. At UMCU, 4 patients (1.4%) (PE = 3, DVT = 1) and HMC 37 patients (3.8%) (PE = 22, DVT = 16; p = 0.06) developed a VTE. At UMCU, a greater percent of patients with VTE had traumatic brain injuries (TBI). Most VTE occurred despite adequate prophylaxis being given (75% UMCU and 81% HMC). Hemorrhagic complications occurred in, respectively, 4 (1.4%) and 10 (1%) patients in UMCU and HMC (p = 0.570). After adjustment for age, ISS, HLOS, and injury type, no significant difference was demonstrated in UMCU compared to HMC for the development of VTE, OR 2.397, p = 0.102 and hemorrhagic complications, OR 0. 586, p = 0.383.

CONCLUSIONS

A more early commencement protocol resulted in almost twice as much chemical prophylaxis being started within the first 48 h in comparison with a more delayed initiation of treatment. Interestingly, most episodes of VTE developed while receiving recommended prophylaxis. Early chemical thromboprophylaxis did not significantly increase the bleeding complications and it appears to be safe to start early.

Optimal timing of initiation of thromboprophylaxis in spine trauma managed operatively: A nationwide propensity-matched analysis of trauma quality improvement program

BACKGROUND

Patients with spinal trauma are at high risk for venous thromboembolic events (VTE). Guidelines recommend prophylactic anticoagulation but they are unclear on timing of initiation of thromboprophylaxis. The aim of our study was to assess the impact of early versus late initiation of venous thromboprophylaxis in patients with spinal trauma who underwent operative intervention.

METHODS

We performed a 2-year (2013-2014) review of patients with isolated spine trauma (spine-Abbreviated Injury Scale score, ≥ 3 and no other injury in another body region with Abbreviated Injury Scale score, > 2) who underwent operative intervention and received thromboprophylaxis postoperatively. Patients were divided into two groups based on the timing of initiation of thromboprophylaxis: early(<48 hours) and late(≥48 hours), and were matched in a 1:1 ratio using propensity score matching for demographics, admission vitals, injury parameters, type of operative intervention, hospital course, and type of prophylaxis(low molecular weight heparin vs. unfractionated heparin). Outcomes were rates of deep vein thrombosis (DVT) and/or pulmonary embolism, red-cell transfusions, the rate of operative interventions for spinal cord decompression and mortality after initiation of thromboprophylaxis.

RESULTS

Nine thousand five hundred eighty-five patients underwent operative intervention and received anticoagulants, of which 3554 patients (early, 1,772; late, 1,772) were matched. Matched groups were similar in demographics, injury parameters, emergency department vitals, hospital length of stay, rates of inferior vena cava (IVC) filter placement and time to operative procedure. Patients who received thromboprophylaxis within 48 hours of operative intervention, unlike those who did not, were less likely to develop DVT (2.1% vs. 10.8%, p < 0. 01). However, the rate of pulmonary embolism was similar in both groups (p = 0.75). Additionally, there was no difference in postprophylaxis red cell transfusion requirements (p = 0.61), rate of postprophylaxis decompressive procedure on the spinal cord (p = 0.27), and mortality (p = 0.53).

CONCLUSION

Early VTE prophylaxis is associated with decreased rates of DVT in patients with operative spinal trauma without increasing the risk of bleeding and mortality. The VTE prophylaxis should be initiated within 48 hours of surgery to reduce the risk of DVT in this high-risk patient population.

LEVEL OF EVIDENCE

Therapeutic studies, level IV.

Acute venous thromboembolism in Indian patients of isolated proximal femur fractures

INTRODUCTION

Venous Thromboembolism (VTE) has a variable incidence in trauma patients and fatal embolism can be the very first manifestation. Proximal femur fractures result from high velocity trauma in younger age groups and could require prolonged immobilisation, which is associated with increased risk of VTE. Therefore we sought to determine the occurrance of VTE in patients with proximal femur fractures.

OBJECTIVES

The present study was initiated to assess the occurrance of deep vein thrombosis (DVT) or pulmonary embolism in isolated proximal femur fractures and identify the requirement of routine thromboprophylaxis in such patients.

METHODS

It was a prospective study conducted over a period of one and a half years. All patients, presenting with isolated proximal femur fractures were included. Patients having any other known risk factors for DVT were excluded, so that the proximal femur fracture remained their only acquired risk for DVT. All the patients were evaluated clinically and with help of diagnostic modalities like Color Doppler with compression ultrasound, D-dimer assays and CT venogram, if indicated. Patients were followed up till 8 weeks post-operatively.

RESULTS

A total of 66 patients with fractures of proximal femur were assessed, out of which there were 42 males with mean age of 48.1 years and 24 females with mean age of 58.3 years. A total of 9 cases of radiologically proved DVT were observed. Clinical DVT was seen in 5 of these cases (54%). Complete resolution of thrombus was noted in all the patients, evaluated by Color Doppler at 6 weeks, post diagnosis. Although the majority of the cases (6) occurred in patients beyond 50 years of age, this was not statistically significant.

CONCLUSION

DVT is common in patients with proximal femur fractures and the provision for screening both clinically and radiologically, should be made routine in all such patients. In case of delay in surgery and patient being bed ridden, we recommend thromboprophylaxis in this subset of trauma patients.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: prophylaxis for hospitalized and nonhospitalized medical patients

BACKGROUND

Venous thromboembolism (VTE) is the third most common vascular disease. Medical inpatients, long-term care residents, persons with minor injuries, and long-distance travelers are at increased risk.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support patients, clinicians, and others in decisions about preventing VTE in these groups.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and adult patients. The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 19 recommendations for acutely ill and critically ill medical inpatients, people in long-term care facilities, outpatients with minor injuries, and long-distance travelers.

CONCLUSIONS

Strong recommendations included provision of pharmacological VTE prophylaxis in acutely or critically ill inpatients at acceptable bleeding risk, use of mechanical prophylaxis when bleeding risk is unacceptable, against the use of direct oral anticoagulants during hospitalization, and against extending pharmacological prophylaxis after hospital discharge. Conditional recommendations included not to use VTE prophylaxis routinely in long-term care patients or outpatients with minor VTE risk factors. The panel conditionally recommended use of graduated compression stockings or low-molecular-weight heparin in long-distance travelers only if they are at high risk for VTE.

No correlation between lower extremity deep vein thrombosis and pulmonary embolism proportions in trauma: a systematic literature review

PURPOSE

To assess the effect of surveillance on deep vein thrombosis (DVT) and pulmonary embolism (PE) rates, the efficacy of chemoprophylaxis and mechanical prophylaxis, and the relationship between DVT and PE.

METHODS

A 23 year, systematic literature review was performed in PubMed. Twenty publications with > 13,000 patients were reviewed. Analyzed traits included: DVT surveillance utilization, the total number of patients included in each study, the number of patients developing DVT and/or PE, chemoprophylaxis and mechanical prophylaxis utilization. When event proportions from individual studies were combined, a weighted mean proportion was computed based on the size of each individual cohort. Combined event proportions were compared with other combined event proportions, according to differences in intervention. Inter-group event proportions were compared using Chi-Square or Fisher's exact test, as appropriate.

RESULTS

DVT rates increase with surveillance (10.7% vs. 2.5%, p < 0.001). PE rates were similar regardless of surveillance (p = 1.0). Chemoprophylaxis lowered both DVT rates (8.2% vs. 10.7%; p < 0.0001) and PE rates (1.2% vs. 1.9%; p = 0.0050). Mechanical prophylaxis did not decrease DVT rates (10.2% vs. 11.5%; p = 0.2980) or PE rates (1.7% vs. 1.6%; p = 1.0). In patients with neither chemoprophylaxis nor mechanical prophylaxis, DVT rate was 11.5%, PE was 1.6%. When chemoprophylaxis and/or mechanical prophylaxis were given, DVT rate was 8.6% (p < 0.0189) and PE was 1.3% (p = 0.4462). PE proportions were not decreased with mechanical prophylaxis or surveillance. DVT and PE rates were not associated (p = 0.7574).

CONCLUSIONS

The results suggest that PE is not associated with lower extremity DVT in adult trauma patients.

An increased tendency in fibrinogen activity and its association with a hypo-fibrinolytic state in early stages after injury in patients without acute traumatic coagulopathy (ATC)

Acute traumatic coagulopathy (ATC) diagnosed by prolongation of APTT and/or PT/INR involves alterations in platelet activity, coagulation and fibrinolysis. However, data showing the haemostatic situation in injured patients without ATC are scarce. To assess whether haemostatic impairment is also present in injured patients without ATC, ten injured patients without ATC and ten normal individuals were examined. The patients were sampled on arrival at the emergency department 0, 2, 12 h after surgical or other intervention. Thrombin generation, fibrin formation and fibrin proteolysis were determined via several laboratory methods, using tissue factor as the coagulation trigger. Thrombograms demonstrated that trauma accelerated both thrombin generation and decay. In the presence of unaffected peak thrombin levels, these two contradictory effects cancelled each other out, leading to the global endogenous thrombin potential (ETP) remaining normal. Under the mediation of normal ETP, fibrin network permeability (Ks) kept the reference levels in the two groups of subjects. Fibrinogen (FBG) activity (Clauss) rose with time from 0 to 2 h and 12 h, which significantly slowed down Clot Lysis Potential as determined by an in vitro method with exogenous t-PA. Summary: the main haemostatic impairment in the present patients concerned an increased tendency in FBG activity. Since an increase in FBG is a biomarker of acute inflammation and also predicts greater fibrin production which down-regulates fibrinolysis, we suggest that during early stages after injury, patients without ATC may suffer from worsening inflammation and confront enhancement of thrombosis risk due to dysfunction of fibrinolysis.

Decreased incidence of venous thromboembolism found in trauma patients with positive blood alcohol concentration on admission

BACKGROUND

The reported incidence of venous thromboembolism (VTE) disease in trauma is 1-58% and is considered a preventable cause of mortality. Positive blood alcohol concentration (BAC) is found in 8-45% of trauma admissions; however, its association with VTE is controversial.

OBJECTIVES

We hypothesized that a positive BAC on admission would be associated with a lower rate of VTE in a large national database of trauma patients.

METHODS

We queried the largest United States trauma registry, National Trauma Data Bank (2007-2015), for any patient with positive BAC on admission. The primary outcome was VTE and the secondary outcome was mortality. A multivariable logistic regression model was used for analysis.

RESULTS

From 2,725,032 patients (70.1% male, 29.9% female), 1,800,216 (66.1%) had a negative BAC while 924,816 (33.9%) had a positive BAC. A positive BAC was associated with lower rates of VTE (OR = 0.88, CI = 0.86-0.90, p < 0.001) and mortality (OR = 0.91, CI = 0.90-0.93, p < 0.001).

CONCLUSION

In a large national database, trauma patients with a positive BAC were associated with a lower rate of VTE compared to those with negative BAC. Additionally, trauma patients with positive BAC had a lower association with mortality. These findings remained after adjustment of well-known risk factors for VTE and mortality, respectively.

Oral Xa Inhibitors Versus Low Molecular Weight Heparin for Thromboprophylaxis After Nonoperative Spine Trauma

BACKGROUND

Thromboprophylaxis with oral Xa inhibitors (Xa-Inh) are recommended after major orthopedic operation; however, its role in spine trauma is not well-defined. The aim of our study was to assess the impact of Xa-Inh in spinal trauma patients managed nonoperatively.

METHODS

A 4-y (2013-2016) review of the Trauma Quality Improvement Program database. We included all patients with an isolated spine trauma (Spine-abbreviated injury scale ≥3 and other-abbreviated injury scale <3) who were managed nonoperatively and received thromboprophylaxis with either low molecular weight heparin (LMWH) or Xa-Inh. Patients were divided into two groups based on the thromboprophylactic agent received: Xa-Inh and LMWH and were matched in a 1:2 ratio using propensity score matching for demographics, vitals and injury parameters, and level of spine injury. Outcomes were rates of deep venous thrombosis, pulmonary embolism, and mortality.

RESULTS

We analyzed a total of 58,936 patients, of which 1056 patients (LMWH: 704, Xa-Inh: 352) were matched. Matched groups were similar in demographics, vital and injury parameters, length of hospital stay (P = 0.31), or time to thromboprophylaxis (P = 0.79). Patients who received Xa-Inh were less likely to develop a deep venous thrombosis (2.3% versus 5.7%, P < 0.01). There were no differences in the rate of pulmonary embolism (P = 0.73), postprophylaxis packed red blood cells transfusions (P = 0.79), postprophylaxis surgical decompression of spinal column (P = 0.75), and mortality rate (P = 0.77).

CONCLUSIONS

Oral Xa-Inh seems to be more effective as prophylactic pharmacologic agent for the prevention of deep venous thrombosis in patients with nonoperative spinal trauma compared to LMWH. The two drugs had similar safety profile. Further prospective trials should be performed to change current guidelines.

Optimal Timing of Initiation of Thromboprophylaxis after Nonoperative Blunt Spinal Trauma: A Propensity-Matched Analysis

BACKGROUND

Patients with spinal trauma have the highest risk of a venous thromboembolism. Although anticoagulation is recommended, its optimal timing is not well-defined. We aimed to assess the impact of early initiation of thromboprophylaxis in spinal trauma patients who were managed nonoperatively.

STUDY DESIGN

A 2-year (2013 to 2014) analysis of all isolated spinal trauma patients managed nonoperatively who received thromboprophylaxis in the American College of Surgeons Trauma Quality Improvement Program. Patients were divided into 2 groups based on timing of initiation of thromboprophylaxis: early (<48 hours) and late (≥48 hours), and were matched in a 1:1 ratio using propensity score matching for demographic characteristics, admission vitals, injury severity, level of spine injury, and type of prophylaxis. Outcomes were prevalence of deep venous thrombosis (DVT) and pulmonary embolism, packed RBC requirement, and mortality.

RESULTS

We included 20,106 patients, of which 8,552 (early, n = 4,276; late, n = 4,276) were matched. Matched groups were similar in demographic characteristics, vital and injury parameters, and type of prophylaxis. Patients in the early group were less likely to have DVT (1.7% vs 7.6%; p < 0.001) or pulmonary embolism (0.8% vs 2.2%; p < 0.001) develop compared with the late group. In addition, there was no difference in packed RBC requirement (p = 0.61) and mortality (p = 0.49). Patients who received unfractionated heparin had a similar rate of DVT (p = 0.26) and pulmonary embolism (p = 0.35) compared with those who received low-molecular-weight heparin.

CONCLUSIONS

In patients with nonoperative spinal trauma, early initiation of thromboprophylaxis is associated with decreased rates of DVT and pulmonary embolism. In addition, we did not find any association between the type of pharmacologic agents and venous thromboembolism rates. Additional prospective clinical trials should be undertaken to define guidelines for the timing of initiation of thromboprophylaxis.

Variables associated with pulmonary thromboembolism in injured patients: A systematic review

BACKGROUND

Pulmonary thromboembolism (PTE) is a dangerous complication of traumatic injury, with varied risk profiles and treatment options. This review aims to describe reported incidence and variables associated with PTE among severely injured patients.

METHODS

Searches were conducted using PubMed, Cochrane and MEDLINE. Relevant studies were identified by two independent reviewers based on predetermined inclusion criteria. Incidence of PTE was the primary outcome measure. Variables associated with PTE was the secondary outcome measure. The Newcastle-Ottawa Scale was used to assess quality of included studies.

RESULTS

There were eight studies that satisfied inclusion criteria. The diagnosed incidence of PTE in these populations ranged from 0.35 to 24%. The most common variables associated with PTE were pelvic or lower limb injury, chest injury, higher total Injury Severity Score, male sex and age. Variables that were less commonly associated with PTE were previous warfarin use, head injury, high serum lactate, soft tissue injury, more than one operation, more than three days on a ventilator, presence of a subclavian central venous catheter, need for a blood transfusion, systolic blood pressure <90mmHg, abdominal injury, presence of a deep venous thrombosis, inferior vena cava filter placement and isolated liver spleen or spinal injuries.

CONCLUSIONS

The reported incidence of PTE after major trauma is variable and dependent on inclusion criteria, diagnostic criteria and study design. Identified variables differed to those reported for venous thromboembolism in other populations. It is difficult to predict populations at risk of clinically significant PTE following injury using available evidence. Further studies linked to patient-specific variables will assist in more precise risk-stratification and interventions.

Relation of antifactor-Xa peak levels and venous thromboembolism after trauma

BACKGROUND

No previous studies have established the optimal antifactor Xa (anti-Xa) level to guide thromboprophylaxis (TPX) dosing with enoxaparin in trauma patients. We hypothesize that achieving 0.2-0.4 IU/mL anti-Xa will decrease venous thromboembolism (VTE) rates after trauma.

METHODS

This was a retrospective review of 194 intensive care unit patients sustaining blunt or penetrating trauma from January 2015 to March 2017. All received initial enoxaparin (30 mg BID subcutaneous) and mechanical devices for TPX. Peak anti-Xa levels were drawn after each third dose. The enoxaparin dose was adjusted up to a maximum of 60 mg BID subcutaneous until a peak level of 0.2-0.4 IU/mL was achieved. Data are expressed as mean ± SD if parametric or median (IQR) if not.

RESULTS

The Greenfield Risk Assessment Profile score was 9 ± 4, Injury Severity Score 23 ± 14, and hospital length of stay 19 (11-38) days. The overall VTE rate was 7.2% (n = 14), with 10 deep venous thromboses (DVT) and 5 pulmonary emboli (PE). One patient had both a DVT and PE. The median time to VTE diagnosis was 14 (7-17) days. In those diagnosed with a VTE, 50.0% (n = 7) never reached 0.2-0.4 IU/mL anti-Xa and 42.8% (n = 6) were diagnosed with a VTE after achieving these levels. Prophylactic levels were achieved initially in 64 (33.0%) patients, and achieved later in 38 (19.6%) additional patients, giving an overall prophylactic rate of 52.6% (n = 102). There were no differences in VTE (6.9% vs. 7.6%, p = 0.841), DVT (3.9% vs. 6.5%, p = 0.413), or PE (3.9% vs. 1.1%, p = 0.213) rates between those who became prophylactic and those who did not.

CONCLUSIONS

There was no difference in VTE incidence between those achieving anti-Xa peak levels of 0.2-0.4 IU/mL and those who did not. Furthermore, these levels were never achieved in some trauma patients despite repeated dosing over a >10-day period.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Perioperative bleeding and blood transfusion are major risk factors for venous thromboembolism following bariatric surgery

BACKGROUND

Morbidly obese patients are at increased risk for venous thromboembolism (VTE) after bariatric surgery. Perioperative chemoprophylaxis is used routinely with bariatric surgery to decrease the risk of VTE. When bleeding occurs, routine chemoprophylaxis is often withheld due to concerns about inciting another bleeding event. We sought to evaluate the relationship between perioperative bleeding and postoperative VTE in bariatric surgery.

METHODS

The American College of Surgeons-National Surgical Quality Improvement Program (NSQIP) dataset between 2012 and 2014 was queried to identify patients who underwent bariatric surgery. Gastric bypass (n = 28,145), sleeve gastrectomy (n = 30,080), bariatric revision (n = 324), and biliopancreatic diversion procedures (n = 492) were included. Univariate and multivariate regressions were used to determine perioperative factors predictive of postoperative VTE within 30 days in patients who experience a bleeding complication necessitating transfusion.

RESULTS

The rate of bleeding necessitating transfusion was 1.3%. Bleeding was significantly more likely to occur in gastric bypass compared to sleeve gastrectomy (1.6 vs. 1.0%) (p < 0.0001). For all surgeries, increased age, length of stay, operative time, and comorbidities including hypertension, dyspnea with moderate exertion, partially dependent functional status, bleeding disorder, transfusion prior to surgery, ASA class III/IV, and metabolic syndrome increased the perioperative bleeding risk (p < 0.05). Multivariate analysis revealed that the rate of VTE was significantly higher after blood transfusion [Odds Ratio (OR) = 4.7; 95% CI 2.9-7.9; p < 0.0001). Predictive risk factors for VTE after transfusion included previous bleeding disorder, ASA class III or IV, and COPD (p < 0.05).

CONCLUSIONS

Bariatric surgery patients who receive postoperative blood transfusion are at a significantly increased risk for VTE. The etiology of VTE in those who are transfused is likely multifactorial and possibly related to withholding chemoprophylaxis and the potential of a hypercoagulable state induced by the transfusion. In those who bleed, consideration should be given to reinitiating chemoprophylaxis when safe, extending treatment after discharge, and screening ultrasound.

High level of venous thromboembolism in critically ill trauma patients despite early and well-driven thromboprophylaxis protocol

Background

Venous thromboembolism (VTE) is one of the most common preventable causes of in-hospital death in trauma patients surviving their injuries. We assessed the prevalence, incidence and risk factors for deep venous thrombosis (DVT) and pulmonary embolism (PE) in critically ill trauma patients, in the setting of a mature and early mechanical and pharmacological thromboprophylaxis protocol.

Methods

This was a prospective observational study on a cohort of patients from a surgical intensive care unit of a university level 1 trauma centre. We enrolled consecutive primary trauma patients expected to be in intensive care for ≥48 h. Thromboprophylaxis was protocol driven. DVT screening was performed by duplex ultrasound of upper and lower extremities within the first 48 h, between 5 and 7 days and then weekly until discharge. We recorded VTE risk factors at baseline and on each examination day. Independent risk factors were analysed using a multivariate logistic regression.

Results

In 153 patients with a mean Injury Severity Score of 23 ± 12, the prevalence of VTE was 30.7%, 95 CI [23.7–38.8] (29.4% DVT and 4.6% PE). The incidence was 18%, 95 CI [14–24] patients-week. The median time of apparition of DVT was 6 days [1; 4]. The global protocol compliance was 77.8% with a median time of introduction of the pharmacological prophylaxis of 1 day [1; 2]. We identified four independent risk factors for VTE: central venous catheter (OR 4.39, 95 CI [1.1–29]), medullar injury (OR 5.59, 95 CI [1.7–12.9]), initial systolic arterial pressure <80 mmHg (OR 3.64, 95 CI [1.3–10.8]), and pelvic fracture (OR 3.04, 95 CI [1.2–7.9]).

Conclusion

Despite a rigorous, protocol-driven thromboprophylaxis, critically ill trauma patients showed a high incidence of VTE. Further research is needed to tailor pharmacological prophylaxis and balance the risks and benefits.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0315-0) contains supplementary material, which is available to authorized users.

Characterization of distinct coagulopathic phenotypes in injury: Pathway-specific drivers and implications for individualized treatment

BACKGROUND

International normalized ratio (INR) and partial thromboplastin time (PTT) are used interchangeably to diagnose acute traumatic coagulopathy but reflect disparate activation pathways. In this study, we identified injury/patient characteristics and coagulation factors that drive contact pathway, tissue factor pathway (TF), and common pathway dysfunction by examining injured patients with discordant coagulopathies. We hypothesized that patients with INR/PTT discordance reflect differing phenotypes representing contact versus tissue factor pathway perturbations and that characterization will provide targets to guide individualized resuscitation.

METHODS

Plasma samples were prospectively collected from 1,262 critically injured patients at a single Level I trauma center. Standard coagulation measures and an extensive panel of procoagulant and anticoagulant factors were assayed and analyzed with demographic and outcome data.

RESULTS

Fourteen percent of patients were coagulopathic on admission. Among these, 48% had abnormal INR and PTT (BOTH), 43% had isolated prolonged PTT (PTT-CONTACT), and 9% had isolated elevated INR (INR-TF). PTT-CONTACT and BOTH had lower Glasgow Coma Scale score than INR-TF (p < 0.001). INR-TF had decreased factor VII activity compared with PTT-CONTACT, whereas PTT-CONTACT had decreased factor VIII activity compared with INR-TF. All coagulopathic patients had factor V deficits, but activity was lowest in BOTH, suggesting an additive downstream effect of disordered activation pathways. Patients with PTT-CONTACT received half as much packed red blood cell and fresh frozen plasma as did the other groups (p < 0.001). Despite resuscitation, mortality was higher for coagulopathic patients; mortality was highest in BOTH and higher in PTT-CONTACT than in INR-TF (71%, 60%, 41%; p = 0.04).

CONCLUSIONS

Discordant phenotypes demonstrate differential factor deficiencies consistent with dysfunction of contact versus tissue factor pathways with additive effects from common pathway dysfunction. Recognition and treatment of pathway-specific factor deficiencies driving different coagulopathic phenotypes in injured patients may individualize resuscitation and improve outcomes.

LEVEL OF EVIDENCE

Prognostic/epidemiological study, level II.

Anti-Xa-guided enoxaparin thromboprophylaxis reduces rate of deep venous thromboembolism in high-risk trauma patients

BACKGROUND

Appropriate prophylaxis against venous thromboembolism (VTE) remains undefined. This study evaluated an anti-Xa-guided enoxaparin thromboprophylaxis (TPX) protocol on the incidence of VTE in high-risk trauma patients based on Greenfield's Risk Assessment Profile (RAP) score.

METHODS

This is a retrospective observational study of patients admitted to a trauma intensive care unit over a 12-month period. Patients were included if they received anti-Xa-guided enoxaparin TPX. Dosage was adjusted to a prophylactic peak anti-Xa level of 0.2 to 0.4 IU/mL. Subgroup analysis was performed on high-risk patients (RAP score ≥10) who received lower-extremity duplex ultrasound surveillance for deep vein thrombosis (DVT). Data are expressed as mean ± SD. Significance was assessed at p < 0.05.

RESULTS

One hundred thirty-one patients received anti-Xa-guided enoxaparin TPX. Four patients were excluded for age or acute VTE on admission. Fifty-six patients with RAP score of ≥10 and surveillance duplex evaluations were included in the subgroup analysis with mean age 43 ± 20 years, Injury Severity Score of 25 ± 10, and RAP score of 16 ± 4. Prophylactic anti-Xa levels were initially achieved in 34.6% of patients. An additional 25.2% required 40 to 60 mg twice daily to reach prophylactic levels; 39.4% never reached prophylactic levels. Weight, body mass index, ISS, and RAP score were significantly higher with subprophylactic anti-Xa levels. One patient developed bleeding complications (0.8%). No patient developed intracerebral bleeding or heparin-induced thrombocytopenia.Nine VTE events occurred in the high-risk subgroup, including four DVT (7.1%), all asymptomatic, and five pulmonary emboli (8.9%). The historical rate of DVT in similar patients (ISS 31 ± 12 and RAP score 16 ± 5) was 20.5%, a significant decrease (p = 0.031). Mean chest Abbreviated Injury Scale scores were significantly higher for patients developing pulmonary emboli than DVT, 3.0 ± 1.1 vs. 0.0 (p < 0.001).

CONCLUSIONS

Mean chest Abbreviated Injury Scale score was higher in patients developing pulmonary embolism. Increased weight, body mass index, ISS, and RAP score are associated with subprophylactic anti-Xa levels. Anti-Xa-guided enoxaparin dosing reduced the rate of DVT from 20.5% to 7.1% in high-risk trauma patients.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Adipose tissue location and contribution to postinjury hypercoagulability

OBJECTIVES

Obesity is associated with a hypercoagulable state at baseline and following injury. The anatomic location of adipose deposition may influence the type of thrombotic event, with visceral adipose tissue (VAT) associated with arterial thrombosis and subcutaneous adipose tissue (SAT) predisposing to venous thrombosis. We sought to determine whether adipose tissue amount and location correlated with measures of coagulation.

METHODS

All adult Level I trauma activations at our institution between January 2013 and August 2014 who underwent admission abdominal computed tomography scan and had admission rotational thromboelastometry measurements were included. Patients were excluded for history of anticoagulant use and known coagulopathy/hypercoagulable state. Admission computed tomography was used to obtain cross-sectional VAT and SAT areas at the umbilicus utilizing a novel software system; VAT and SAT measurements were associated with markers of coagulation utilizing Spearman correlation and stepwise linear regression with significance set at p < 0.05.

RESULTS

Two hundred forty-two patients met inclusion and exclusion criteria. Sixty-nine percent of patients sustained blunt injury, 79% were male, mean age was 40 years, 25% were obese or morbidly obese, and mean Injury Severity Scale score was 17. Seventeen percent of patients had acute deep venous thrombosis or pulmonary embolism during hospitalization. Neither SAT nor VAT correlated with prothrombin time, international normalized ratio, or partial thromboplastin time. Subcutaneous adipose tissue correlated positively with platelet count. Visceral adipose tissue and SAT correlated negatively with clot formation time and positively with TEM fibrinogen, α angle, maximum clot firmness, and lysis at 30 minutes; stronger correlations and greater significance were seen between SAT and these measures except for lysis at 30 minutes. Stepwise linear regression confirmed significant relationships between SAT and clot formation time, AA, and maximum clot firmness; VAT showed a significant relationship with TEM fibrinogen.

CONCLUSIONS

Increased adipose tissue correlates with relative hypercoagulability following trauma. Subcutaneous adipose tissue shows a stronger relationship with functional measures of coagulation, suggesting that SAT may be associated with hemorrhage resistance and hypercoagulability after injury.

LEVEL OF EVIDENCE

Prognostic study, level IV.

Characterizing the relationship between age and venous thromboembolism in adult trauma patients: findings from the National Trauma Data Bank and the National Inpatient Sample

BACKGROUND

Venous thromboembolism (VTE) is a tremendous burden in health care. However, current guidelines lack recommendations regarding the prevention of VTE in older adult trauma patients. Furthermore, the appropriate method of modeling of age in VTE models is currently unclear.

METHODS

Patients included in the National Trauma Data Bank (NTDB) between the years 2008 and 2014 and patients included in the National Inpatient Sample (NIS) between 2009 and 2013 were analyzed. Multiple logistic regression of VTE on age was performed.

RESULTS

Of 3,598,881 patients in the NTDB, 34,202 (1.0%) were diagnosed with VTE compared to 5405 (1.1%) of the 505,231 patients in NIS. In both the fully adjusted NTDB and NIS model, age was positively associated with odds of VTE diagnosis under 65 years (NTDB, adjusted odds ratio [aOR]: 1.018, 95% confidence interval [CI]: 1.017-1.019, P < 0.001; NIS, aOR: 1.025, 95% CI 1.022-1.027, P < 0.001). In patients aged ≥65 years, age was negatively associated with odds of VTE diagnosis in the NTDB (aOR: 0.995, 95% CI: 0.992-0.999, P = 0.006) but not in the NIS (aOR: 0.998, 95% CI 0.994-1.002, P = 0.26).

CONCLUSIONS

Incidence of VTE among adult trauma patients steadily increases with age until 65 years, after which the odds of VTE appear to level off or even slightly decrease. These findings should be applied for improved modeling of VTE in trauma patients. The mechanism behind these findings should be explored before using them to update guidelines for standardized VTE prevention in older adults.

Holistic ultrasound in trauma: An update

Holistic ultrasound is a total body examination using an ultrasound device aiming to achieve immediate patient care and decision making. In the setting of trauma, it is one of the most fundamental components of care of the injured patients. Ground-breaking imaging software allows physicians to examine various organs thoroughly, recognize imaging signs early, and potentially foresee the onset or the possible outcome of certain types of injuries. Holistic ultrasound can be performed on a routine basis at the bedside of the patients, at admission and during the perioperative period. Trauma care physicians should be aware of the diagnostic and guidance benefits of ultrasound and should receive appropriate training for the optimal management of their patients. In this paper, the findings of holistic ultrasound in trauma patients are presented, with emphasis on the lungs, heart, cerebral circulation, abdomen, and airway. Additionally, the benefits of ultrasound imaging in interventional anaesthesia techniques such as ultrasound-guided peripheral nerve blocks and central vein catheterization are described.

A simplified stratification system for venous thromboembolism risk in severely injured trauma patients

BACKGROUND

The objective of this study was to re-evaluate and simplify the Greenfield risk assessment profile (RAP) for venous thromboembolism (VTE) in trauma using information readily available at the bedside.

METHODS

Retrospective review of 1233 consecutive admissions to the trauma intensive care unit from August 2011-January 2015. Univariate analyses were performed to determine which RAP risk factors were significant contributors to VTE. Multivariable logistic regression was used to develop models for risk stratification. All results were considered statistically significant at P ≤ 0.05.

RESULTS

The study population was as follows: age 44 ± 19, 75% male, 72% blunt, injury severity score 21 ± 13, RAP score 9 ± 5, and 8% mortality. Groups were separated into +VTE (n = 104) and -VTE (n = 1129). They were similar in age, gender, mechanism, and mortality, but injury severity and RAP scores were higher in the +VTE group (all P < 0.0001). The +VTE group had more transfusions and longer time to prophylaxis (all P < 0.05). Receiving four or more transfusions in the first 24 h (odds ratio [OR], 2.60; 95% confidence interval [CI], 1.64-4.13), Glasgow coma score <8 for >4 h (OR, 2.13; 95% CI, 1.28-3.54), pelvic fracture (OR, 2.26; 95% CI, 1.44-3.57), age 40-59 y (OR, 1.70; 95% CI, 1.10-2.63), and >2-h operation (OR, 1.80; 95% CI, 1.14-2.85) predicted VTE with an area under the receiver operator curve of 0.729, which was comparable with 0.740 for the RAP score alone.

CONCLUSIONS

VTE risk in trauma can be easily assessed using only five risk factors, which are all readily available at the bedside (transfusion, Glasgow coma scale, pelvic fracture, prolonged operation, and age). This simplified model provides similar predictive ability to the more complicated RAP score. Prospective validation of a simplified risk assessment score is warranted.

New understandings of post injury coagulation and resuscitation

Coagulopathy following injury is common and it predicts poor outcomes and increased mortality. For many decades, coagulopathy in trauma was considered as an iatrogenic phenomenon, and clinical practice focused on a resuscitation strategy using large volume crystalloid and packed red blood cells. The discovery of Acute Traumatic Coagulopathy as a distinct pathophysiologic state coupled with a transition towards balanced product resuscitation has fundamentally changed the paradigm of trauma care and represents one of the most active areas of current research in the field of trauma. In this review, we examine the development and current understanding of the mechanisms, implicated mediators, and physiology of Acute Traumatic Coagulopathy, with an emphasis on the role of the activated Protein C pathway. We will also review the state of resuscitation practice including the evidence for balanced product administration and the previously under-appreciated importance of platelet count and function. Importantly, we highlight ongoing knowledge deficits in traumatic coagulopathy and resuscitation as directions for future investigation in order to facilitate further insight into these rapidly evolving fields.

Toward a More Robust Prediction of Pulmonary Embolism in Trauma Patients: A Risk Assessment Model Based on 38,000 Patients

OBJECTIVES

Pulmonary embolism (PE) is a rare but sometimes fatal complication of trauma. Risk stratification models identify patients at increased risk of PE; however, they are often complex and difficult to use. This research aims to develop a model, based on a large sample of trauma patients, which can be easily and quickly used at the time of admission to predict PE.

METHODS

This study used trauma registry data from 38,597 trauma patients. Of these, 239 (0.619%) developed a PE. We targeted demographic and injury data, prehospital information, and data on treatments and events during hospitalization. A multivariate binary logistic regression model was developed to predict the odds of developing a PE during hospitalization. The model was developed using a 50% randomly selected development subsample and then tested for accuracy using the remaining 50% validation sample.

RESULTS

We found 7 statistically significant predictors of PE, including (1) age [odds ratio (OR) = 1.01; 95% CI, 1.00-1.02; P = 0.05], (2) obesity (OR = 2.54; 95% CI, 1.29-4.99; P < 0.01), (3) injury from motorcycle accident (OR = 2.01; 95% CI, 1.25-3.22; P < 0.01), (4) arrival by helicopter (OR = 2.91; 95% CI, 1.16-7.27; P = 0.02), (5) emergency department admission pulse rate (OR = 1.01; 95% CI, 1.0-1.02; P = 0.06), (6) admission to intensive care unit (OR = 5.03; 95% CI, 3.12-8.12; P < 0.01), and (7) injury location, including thorax (OR = 1.57; 95% CI, 1.04-2.37; P = 0.03), abdomen (OR = 1.56; 95% CI, 1.04-2.33; P = 0.03), and lower extremity injuries (OR = 2.85; 95% CI, 3.12-8.12; P < 0.01). Our model was able to discriminate between predicted and actual PE events with a receiver operating characteristic area under the curve of 0.87. By identifying the top 25% high-risk patients, we were able to predict 80%-84% of pulmonary emboli.

CONCLUSIONS

This knowledge allows us to focus stronger thromboprophylactic efforts on patients at highest risk. This model can be used to rapidly identify trauma patients at high risk for PE.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Non-weight-based enoxaparin dosing subtherapeutic in trauma patients

BACKGROUND

We report our experience dosing and monitoring enoxaparin with anti-factor Xa activity (anti-FXaA) levels for venous thromboembolism prophylaxis in trauma patients (TP).

MATERIALS AND METHODS

TP receiving standard, non-weight-based dosed enoxaparin administered every 12 h for venous thromboembolism prophylaxis with peak anti-FXaA levels measured were prospectively monitored and evaluated and those whose first anti-FXaA levels ≥ or <0.2 IU/mL were compared. Anti-FXaA levels and enoxaparin dose (mg/kg actual body weight) were evaluated for correlation.

RESULTS

Of the fifty-one TP included, initial anti-FXaA levels were <0.2 IU/mL in 37 (72.5%) whose dose was lower than those within target range (0.38 [0.32-0.42] mg/kg versus 0.45 [0.39-0.48] mg/kg, P = 0.003). Thirty-seven TP achieved anti-FXaA level ≥0.2 IU/mL (23 requiring dose increases) at a dose of 0.49 [0.44-0.54] mg/kg. Correlation between dose and anti-FXaA levels for the initial 51 anti-FXaA levels (r = 0.360, P = 0.009) and for all 103 anti-XaA levels (r = 0.556, P < 0.001) was noted.

CONCLUSIONS

Non-weight-based enoxaparin dosing did not achieve target anti-FXaA levels in most TP. Higher anti-FXaA levels correlated with larger weight-based enoxaparin doses. Weight-based enoxaparin dosing (i.e., 0.5 mg/kg subcutaneously every 12 h) would better achieve target anti-FXaA levels.