Venous thromboembolism during combat operations: a 10-y review

Outpatient prescription medications during the first year following combat-related amputations and traumatic brain injury: A retrospective study

BACKGROUND

Prescription medications are an essential element of military amputation care programs.

OBJECTIVES

To analyze (1) outpatient prescription medications following combat-related amputations, (2) longitudinal changes in prescription activity during the first year postinjury, and (3) patient characteristics associated with prescription medications.

DESIGN

Retrospective study of military casualty records and outpatient prescription medications. Clinicians identified 13 medication categories based on American Hospital Formulary Service classifications.

SETTING

Military amputation rehabilitation program.

PATIENTS

1651 service members who sustained major limb amputations during 2001-2017.

MAIN OUTCOMES MEASURES

Prescription medication category, days' supply, opioid dosage.

RESULTS

During the first year postinjury, patients averaged 65 outpatient prescriptions (new or refills, SD = 43.3) and 8 (SD = 1.9) of 13 medication categories. Nearly all patients (99%) had opioid prescriptions averaging high dosages with variation by patient characteristics and postinjury time. At least 84% of patients had prescriptions for one or more central nervous system, gastrointestinal, psychotherapeutic, immune/anti-infective and/or nonopioid analgesic medications. Prescriptions declined from the first (92%) to fourth (73%) quarter postinjury. Many patients had prescription opioids (51%), central nervous system medications (43%), or psychotherapeutic medications (32%) during the fourth quarter. In regression models, multiple factors including White race/ethnicity (relative risk [RR] = 1.16; 95% confidence interval [CI]: [1.06-1.28], p = .001), injury severity, traumatic brain injury, upper limb amputation (RR = 0.90; CI: [0.83-0.99], p = .020), multiple amputation (RR = 1.12 CI: [1.03-1.22], p = .008), phantom limb syndrome, chronic pain, and posttraumatic stress disorder were significantly associated with prescriptions (p's < .05).

CONCLUSIONS

Amputation care providers manage a high volume and wide range of prescription medications including multiple central nervous system drugs. The results show significant variation in prescription practices by patient characteristics and time postinjury. These findings can help optimize the benefits and reduce the risks of prescription medications and indicate areas for future research.

A 20-year retrospective analysis of deep venous thrombosis and pulmonary embolism among combat casualties requiring damage-control laparotomy at US military Role 2 surgical units

BACKGROUND

Combat casualties receiving damage-control laparotomy at forward deployed, resource-constrained US military Role 2 (R2) surgical units require multiple evacuations, but the added risk of venous thromboembolism (VTE) in this population has not been defined. To fill this gap, we retrospectively analyzed 20 years of Department of Defense Trauma Registry data to define the VTE rate in this population.

METHODS

Department of Defense Trauma Registry from 2002 to 2023 was queried for US military combat casualties requiring damage-control laparotomy at R2. All deaths were excluded in subsequent analysis. Rates of VTE were assessed, and subgroup analysis was performed on patients requiring massive transfusion.

RESULTS

Department of Defense Trauma Registry (n = 288) patients were young (mean age, 25 years) and predominantly male (98%) with severe (mean Injury Severity Score, 26), mostly penetrating injury (76%) and high mortality. Venous thromboembolism rate was high: 15.8% (DVT, 10.3%; pulmonary embolism, 7.1%). In the massively transfused population, the VTE rate was even higher (26.7% vs. 10.2%, p < 0.001).

CONCLUSION

This is the first report that combat casualties requiring damage-control laparotomy at R2 have such high VTE rates. Therefore, for military casualties, we propose screening ultrasound upon arrival to each subsequent capable echelon of care and low threshold for initiating thromboprophylaxis.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Traumatic lower extremity amputation as a risk factor for venous thromboembolism

BACKGROUND

This study aimed to evaluate whether lower extremity (LE) amputation among civilian casualties is a risk factor for venous thromboembolism.

METHODS

All patients with severe LE injuries (AIS ≥3) derived from the ACS-TQIP (2013-2020) were divided into those who underwent trauma-associated amputation and those with limb salvage. Propensity score matching was used to mitigate selection bias and confounding and compare the rates of pulmonary embolism (PE) and deep vein thrombosis (DVT).

RESULTS

A total of 145,667 patients with severe LE injuries were included, with 3443 patients requiring LE amputation. After successful matching, patients sustaining LE amputation still experienced significantly higher rates of PE (4.2% vs. 2.5%, p ​< ​0.001) and DVT (6.5% vs. 3.4%, p ​< ​0.001). A sensitivity analysis examining patients with isolated major LE trauma similarly showed a higher rate of thromboembolic complications, including higher incidences of PE (3.2% vs. 2.0%, p ​= ​0.015) and DVT (4.7% vs. 2.6%, p ​< ​0.001).

CONCLUSIONS

In this nationwide analysis, traumatic lower extremity amputation is associated with a significantly higher risk of VTE events, including PE and DVT.

Pharmacologic Considerations for Antimicrobials and Anticoagulants after Burn Injury

Derangements in pharmacokinetics and pharmacodynamics (PK/PD) of burn patients are poorly understood and lacking consistent data. This leads to an absence of consensus regarding pharmacologic management of burn patients, complicating their care. In order to effectively manage burn critical illness, knowledge of pharmacologic parameters and their changes is necessary. It is also imperative that the clinician understands how these changes will affect drug dosing. A common practice is to increase antibiotic dosing and/or frequency; however, this may not be necessary and doses should be adjusted to patient- and drug-specific parameters. Additionally, monitoring assays for antibiotic levels as well as coagulation factors can be useful for adjusting dosages to best treat the patient. This review focuses on alterations in PK/PD as well as other physiologic changes after burn injury, with special reference to care in military and austere settings.

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.

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.

American Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary for Limb Salvage or Early Amputation

Clinical Practice Guideline for Limb Salvage or Early Amputation is based on a systematic review of current scientific and clinical research. The purpose of this clinical practice guideline is to address treatment for severe lower limb trauma below the distal femur by either amputation or limb salvage by providing evidence-based recommendations for key decisions that affect the management of patients with lower extremity trauma. This guideline contains 11 recommendations to evaluate the decision factors important for limb salvage versus early amputation. In addition, the work group highlighted the need for better research in the treatment and the shared decision making process of high-energy lower extremity trauma.

Trauma-induced coagulopathy

Uncontrolled haemorrhage is a major preventable cause of death in patients with traumatic injury. Trauma-induced coagulopathy (TIC) describes abnormal coagulation processes that are attributable to trauma. In the early hours of TIC development, hypocoagulability is typically present, resulting in bleeding, whereas later TIC is characterized by a hypercoagulable state associated with venous thromboembolism and multiple organ failure. Several pathophysiological mechanisms underlie TIC; tissue injury and shock synergistically provoke endothelial, immune system, platelet and clotting activation, which are accentuated by the 'lethal triad' (coagulopathy, hypothermia and acidosis). Traumatic brain injury also has a distinct role in TIC. Haemostatic abnormalities include fibrinogen depletion, inadequate thrombin generation, impaired platelet function and dysregulated fibrinolysis. Laboratory diagnosis is based on coagulation abnormalities detected by conventional or viscoelastic haemostatic assays; however, it does not always match the clinical condition. Management priorities are stopping blood loss and reversing shock by restoring circulating blood volume, to prevent or reduce the risk of worsening TIC. Various blood products can be used in resuscitation; however, there is no international agreement on the optimal composition of transfusion components. Tranexamic acid is used in pre-hospital settings selectively in the USA and more widely in Europe and other locations. Survivors of TIC experience high rates of morbidity, which affects short-term and long-term quality of life and functional outcome.

Outpatient Pharmacy Prescriptions During the First Year Following Serious Combat Injury: A Retrospective Analysis

INTRODUCTION

Limited research has analyzed the full range of outpatient medication prescription activity following serious combat injury. The objectives of this study were to describe (1) outpatient medication prescriptions and refills during the first 12 months after serious combat injury, (2) longitudinal changes in medication prescriptions during the first-year postinjury, and (3) patient characteristics associated with outpatient prescriptions.

MATERIALS AND METHODS

This was a retrospective analysis of existing health and pharmacy data for a random sample of U.S. service members who sustained serious combat injuries in the Iraq and Afghanistan conflicts, 2010-2013 (n = 381). Serious injury was defined by an Injury Severity Score (ISS) of 9 or greater. These patients typically participate in military rehabilitation programs (eg, amputation care) where prescription medications are essential. Data sources were the Expeditionary Medical Encounter Database for injury-specific data, the Pharmacy Data Transaction Service for outpatient medication prescriptions and refills, and the Military Health System Data Repository for diagnostic codes of pain and psychological disorders. Military trauma nurses reviewed casualty records to identify types of injuries. Using the American Hospital Formulary Service Pharmacologic-Therapeutic Classification system, clinicians identified 13 categories of prescription medications (eg, opioid, psychotherapeutic, immunologic) for analysis. Multivariable negative binomial and logistic regression analyses evaluated significant associations between independent variables (eg, blast injury, traumatic brain injury [TBI], ISS, limb amputation, diagnoses of chronic pain, or psychological disorders) and prescription measures (ie, number or category of medication prescriptions). We also describe longitudinal changes in prescription activity postinjury across consecutive quarterly intervals (91 days) during the first-year postinjury.

RESULTS

During the first-year postinjury, patients averaged 61 outpatient prescriptions, including all initial prescriptions and refills. They averaged eight different categories of medications, primarily opioid, immunologic, gastrointestinal/genitourinary, central nervous system (CNS), nonopioid analgesic, and psychotherapeutic medications (representing 82% of prescriptions) during the first year. Prescription activity generally declined across quarters. There was still substantial prescription activity during the fourth quarter, as 79% of patients had at least one prescription. From 39 to 49% of patients had fourth-quarter prescriptions for opioid, CNS, or psychotherapeutic medications. Longitudinally, we found that 24-34% of patients had an opioid, CNS, or psychotherapeutic prescription during each of the final three quarters. In multivariable analysis, ISS, limb amputation (particularly bilateral amputation), and diagnoses of chronic pain and post-traumatic stress disorder (PTSD) were associated with significantly higher counts of individual and multiple medication prescriptions. TBI was associated with significantly lower numbers of prescriptions for certain medications.

CONCLUSIONS

This is one of the first studies to provide a systematic analysis of outpatient medication prescriptions following serious combat injury. The results indicate substantial prescription activity from multiple medication categories throughout the first-year postinjury. Diagnoses of chronic pain, PTSD, and limb amputation and ISS were associated with significantly higher counts of prescriptions overall and more prescription medication categories. This study provides initial evidence to better understand medication prescription activity following serious combat injury. The results inform future research on medication prescription practices and planning for rehabilitation.

Early Detection of Deep Venous Thrombosis in Trauma Patients

Background

This study was performed to determine whether trauma patients are at an increased risk of developing deep venous thrombosis (DVT) within the first 48 hours of hospitalization.

Materials and methods

A retrospective review was performed using a prospectively maintained database of patients admitted to a trauma center during a five-year time period. Patients hospitalized for greater than 48 hours who received a screening venous duplex for DVT were included in the study.

Results

There were 1067 venous duplex scans obtained, 689 (64.5%) within the first 48 hours of admission (early DVT group), 378 (35.4%) after the first 48 hours (late DVT group). Only 142 (13.2%) patients had a positive duplex scan for DVT, 55 (early group), 87 (late group). Comorbid conditions of congestive heart failure (P = 0.02), pelvic fractures (P = 0.04), and a lower initial systolic blood pressure on presentation (p = 0.04) were associated with early DVT. Head trauma (P < 0.01), mechanical ventilation (P < 0.001), and transfusion of blood products (P < 0.001), were predictors of DVT in the late group.

Conclusions

Trauma patients are at an increased risk of developing venous thrombosis early in the hospital course due to comorbidities associated with trauma. Whereas, venous thrombosis in trauma patients diagnosed after the first 48 hours of hospitalization appears to be associated with prolonged patient immobility.

Trauma Embolic Scoring System in military trauma: a sensitive predictor of venous thromboembolism

Introduction

Clinical decision support tools capable of predicting which patients are at highest risk for venous thromboembolism (VTE) can assist in guiding surveillance and prophylaxis decisions. The Trauma Embolic Scoring System (TESS) has been shown to model VTE risk in civilian trauma patients. No such support tools have yet been described in combat casualties, who have a high incidence of VTE. The purpose of this study was to evaluate the utility of TESS in predicting VTE in military trauma patients.

Methods

A retrospective cohort study of 549 combat casualties from October 2010 to November 2012 admitted to a military treatment facility in the USA was performed. TESS scores were calculated through data obtained from the Department of Defense Trauma Registry and chart reviews. Univariate analysis and multivariate logistic regression were performed to evaluate risk factors for VTE. Receiver operating characteristic (ROC) curve analysis of TESS in military trauma patients was also performed.

Results

The incidence of VTE was 21.7% (119/549). The median TESS for patients without VTE was 8 (IQR 4–9), and the median TESS for those with VTE was 10 (IQR 9–11). On multivariate analysis, Injury Severity Score (ISS) (OR 1.03, p=0.007), ventilator days (OR 1.05, p=0.02), and administration of tranexamic acid (TXA) (OR 1.89, p=0.03) were found to be independent risk factors for development of VTE. On ROC analysis, an optimal high-risk cut-off value for TESS was ≥7 with a sensitivity of 0.92 and a specificity of 0.53 (area under the curve 0.76, 95% CI 0.72 to 0.80, p<0.0001).

Conclusions

When used to predict VTE in military trauma, TESS shows moderate discrimination and is well calibrated. An optimal high-risk cut-off value of ≥7 demonstrates high sensitivity in predicting VTE. In addition to ISS and ventilator days, TXA administration is an independent risk factor for VTE development.

Level of evidence

Level III.

Evaluation of Military Use of Tranexamic Acid and Associated Thromboembolic Events

Importance

Since publication of the CRASH-2 and MATTERs studies, the US military has included tranexamic acid (TXA) in clinical practice guidelines. While TXA was shown to decrease mortality in trauma patients requiring massive transfusion, improper administration and increased risk of venous thromboembolism remain a concern.

Objective

To determine the appropriateness of TXA administration by US military medical personnel based on current Joint Trauma System clinical practice guidelines and to determine if TXA administration is associated with venous thromboembolism.

Design, Setting, and Participants

This cohort study of US military casualties in US military combat support hospitals in Afghanistan and a single US-based tertiary military treatment facility within the continental United States was conducted from 2011 to 2015, with follow-up through initial hospitalization and readmissions.

Exposures

Data collected for all patients included demographic information as well as Injury Severity Score; receipt of blood products, TXA, and/or a massive transfusion; and admission hemodynamics.

Main Outcomes and Measures

Variance from guidelines in TXA administration and venous thromboembolism. Tranexamic acid overuse was defined as a hemodynamically stable patient receiving TXA but not a massive transfusion, underuse was defined as a patient receiving a massive transfusion but not TXA, and TXA administration was considered delayed when given more than 3 hours after injury.

Results

Of the 455 identified patients, 443 (97.4%) were male, and the mean (SD) age was 25.3 (4.8) years. A total of 173 patients (38.0%) received a massive transfusion, and 139 (30.5%) received TXA in theater. Overuse occurred in 18 of 282 patients (6.4%) and underuse in 46 of 173 (26.6%) receiving massive transfusions, and delayed administration was found in 6 of 145 patients (4.3%) receiving TXA. Overuse increased at 3.3% per quarter (95% CI, 4.0-9.9; P < .001; R2 = 0.340) and underuse decreased at -4.4% per quarter (95% CI, -4.5 to -3.6; P < .001; R2 = 0.410). Tranexamic acid administration was an independent risk factor for venous thromboembolism (odds ratio, 2.58; 95% CI, 1.20-5.56; P = .02).

Conclusions and Relevance

Military medical personnel decreased missed opportunities to appropriately use TXA but also increased overuse. In addition, TXA administration was an independent risk factor for venous thromboembolism. A reevaluation of the use of TXA in combat casualties should be undertaken.

Prevention of Deep Venous Thromboembolism

The nature of many combat wounds puts patients at a high risk of developing deep venous thrombosis (DVT) and pulmonary embolism (PE), which fall under the broader disease category of venous thromboembolism (VTE). In addition to the hypercoagulable state induced by trauma, massive injuries to the extremities, prolonged immobility, and long fixed wing transport times to higher echelons of care are unique risk factors for venous thromboembolism in the combat-injured patient. These risk factors mandate aggressive prophylaxis for DVT and PE that can effectively be achieved by the use of lower extremity sequential compression devices and low dose unfractionated heparin or low molecular weight heparin. In addition, inferior vena cava filters are often used for PE prophylaxis when chemical DVT prophylaxis fails or is contraindicated. The following Department of Defense (DoD) Joint Trauma System (JTS) Clinical Practice Guideline (CPG) discusses the current recommendations for the prevention of DVT and PE including the use of inferior vena cava filters (IVCFs).

The impact of septic stimuli on the systemic inflammatory response and physiologic insult in a preclinical non-human primate model of polytraumatic injury

BACKGROUND

Established animal trauma models are limited in recapitulating the pathophysiology of human traumatic injury. Herein, we characterize the physiologic insult and inflammatory response in two clinically relevant non-human primate (NHP) trauma models.

METHODS

Mauritian Cynomolgus Macaques underwent either a laparoscopic closed abdomen liver injury (laparoscopic 60% left-lobe hepatectomy) in an established uncontrolled severe hemorrhage model (THM), or a polytrauma hemorrhage model (PHM) involving combined liver and bowel injury, uncontrolled severe hemorrhage as well as an open full-thickness cutaneous flank wound. Fixed volume resuscitation strategies were employed in the THM and goal directed resuscitation was used in the PHM. Complete peripheral blood and critical clinical chemistry parameters, serum biomarkers of systemic inflammation, tissue perfusion parameters, as well as survival, were compared between the models throughout the 2-week study period.

RESULTS

NHPs in both the THM (n = 7) and the PHM (n = 21) demonstrated tissue hypoperfusion (peak lactate 6.3 ± 0.71 mmol/L) with end organ injury (peak creatinine 3.08 ± 0.69 mg/dL) from a similar liver injury (60% left hemi-hepatectomy), though the PHM NHPs had a significantly higher blood loss (68.1% ± 12.7% vs. 34.3% ± 2.3%, p = 0.02), lower platelet counts (59 ± 25 vs. 205 ± 46 K/uL, p = 0.03) and a trend towards higher mortality (90.5% vs. 33.3%, p = 0.09). The inflammatory response was robust in both models with peak cytokine (IL-6 > 6000-fold above baseline) and peak leukocyte values (WBC 27 K/uL) typically occurring around t = 240 min from the time of hepatic injury. A more robust systemic inflammatory response was appreciated in the PHM resulting in marked elevations in peak serum IL-6 (7887 ± 2521 pg/mL vs.1076 ± 4833 pg/mL, p = 0.02), IL-1ra (34,499 ± 5987 pg/mL vs. 2511 ± 1228 pg/mL, p < 0.00), and IL-10 (13,411 pg/mL ± 5598 pg/mL vs. 617 pg/mL ± 252 pg/mL, p = 0.03).

CONCLUSION

This comparative analysis provides a unique longitudinal perspective on the post-injury inflammatory response in two clinically relevant models, and demonstrates that the addition of septic stimuli to solid organ injury increases both the hemorrhagic insult and inflammatory response.

Preinjury statin use and thromboembolic events in trauma: a 10-year retrospective evaluation

BACKGROUND

Traumatic injury is well known to increase the risk of venous thromboembolic events (VTEs), occurring in up to 58% of trauma patients. Statin medications have significant anti-inflammatory properties and have been shown to reduce the risk of VTE. We hypothesized that trauma patients who received statin medication before injury would have a lower incidence of VTE after injury.

METHODS

A 10-y retrospective review identified all patients admitted to our trauma service with an injury severity score >9 and an intensive care unit stay of >3 d. This population was categorized as either "statin recipient" (SR) or "statin naïve," with subsequent categorical division by occurrence of VTE. Our primary outcome measure was the occurrence of documented VTE in both statin naïve and SR subjects.

RESULTS

A total of 2519 trauma patients were included with 97 (3.8%) developing VTE. Pretrauma statin use in males remained as an independent predictor of VTE (odds ratio = 2.25, 95% confidence interval = 1.25-4.04, P < 0.01). The median time to VTE onset was 3 d longer in SRs (10.0 d; confidence interval = 7.3-12.7, P < 0.05).

CONCLUSIONS

Pretrauma statin use does not appear to have a protective benefit of VTE prevention in trauma patients, as we have shown pretrauma SR male trauma patients to have a twofold increased incidence of VTE. However, when considering the 3 d longer median time to VTE onset found in SRs, we consider the protective benefit of statin use reported in the current literature as likely attributable to this observed delayed onset.

Surveillance and Early Management of Deep Vein Thrombosis Decreases Rate of Pulmonary Embolism in High-Risk Trauma Patients

BACKGROUND

Venous duplex ultrasound (VDU) is the modality of choice for surveillance of venous thromboembolism (VTE), but there is controversy about its appropriate implementation as a screening method. We hypothesize that VDU surveillance in trauma patients at high risk for VTE decreases the rate of pulmonary embolism (PE).

STUDY DESIGN

One thousand two hundred and eighty-two trauma ICU admissions were screened with Greenfield's Risk Assessment Profile from August 2011 to September 2014. Four hundred and two patients were identified as high risk for VTE (Risk Assessment Profile ≥10). Those who received weekly VDU to evaluate for deep vein thrombosis (n = 259 [64%]) were compared with those who did not (n = 143 [36%]). Parametric data are reported as mean ± SD and nonparametric data are reported as median (interquartile range). Statistical significance was determined at an α level of 0.05.

RESULTS

The overall study population was 47 ± 19 years old and 75% were male, 78% of injuries were blunt mechanism, Injury Severity Score was 28 ± 13, Risk Assessment Profile was 14 ± 4, and mortality was 14.3%. Deep vein thrombosis rate was 11.6% (n = 30) in the surveillance group vs 2.1% (n = 3) in the non-surveillance group (p < 0.001). Deep vein thromboses detected in the surveillance group were managed with systemic anticoagulation (43%) or with IVC filter placement (57%). In the surveillance group, the PE rate was 1.9% (n = 5) vs 7.0% (n = 10) in the non-surveillance group (p = 0.014).

CONCLUSIONS

Trauma patients at high risk for VTE and who received VDU surveillance and early management of deep vein thrombosis have decreased rates of pulmonary embolism.

Risk of pulmonary embolism with repair or ligation of major venous injury following penetrating trauma

BACKGROUND

There are many benefits of repair over ligation of major venous injuries (MVIs) following penetrating trauma, but the risk of pulmonary embolism (PE) is not well defined. We hypothesized that rates of PE are comparable between repair and ligation of MVI.

METHODS

All penetrating trauma patients with MVI requiring an operation from 2003 to 2012 (n = 158) were retrospectively reviewed. Propensity scores were based on a logistic regression model using patient and injury characteristics. A 1:1 fixed ratio nearest neighbor matching was performed to compare outcomes of the repair and ligation cohorts. Data are reported as mean ± SD if parametric, or median (interquartile range) if not, and compared using a t test, Mann-Whitney U-test, χ2, or Fisher's exact test, as appropriate.

RESULTS

The population was 89% male, age 32 ± 12 years, 74% gunshot wound, Injury Severity Score of 19 ± 13, length of stay of 9 (18) days, 3.8% PE, and a mortality of 21.5%. Repair was performed in 37% (n = 59), ligation was performed in 60% (n = 94), and 3% required both. With ligation versus repair, ligation patients were generally more critically injured; 48-hour survival was 78% versus 93% (p = 0.0083), initial Glasgow Coma Scale (GCS) score was 12 ± 5 versus 14 ± 3 (p = 0.003), initial base excess was -9 ± 8 versus -5 ± 5 mEq/L (p = 0.003), more packed red blood cells were transfused (12 (14) U vs. 9 (12) U; p = 0.032), and major arterial injury was more likely (86% vs. 42%, p < 0.001), but the PE rate was identical (5.9%) in propensity-matched cohorts. In those who developed a PE, all were receiving standard thromboprophylaxis.

CONCLUSION

Following penetrating trauma, the risk of PE between repair and ligation of MVI is comparable.

LEVEL OF EVIDENCE

Epidemiologic study, level III.