Complications related to deep venous thrombosis prophylaxis in trauma: a systematic review of the literature

What Constitutes High Risk for Venous Thromboembolism? Comparing Approaches to Determining an Appropriate Threshold

Background

Guidelines recommend pharmacological venous thromboembolism (VTE) prophylaxis only for high-risk patients, but the probability of VTE considered "high-risk" is not specified. Our objective was to define an appropriate probability threshold (or range) for VTE risk stratification and corresponding prophylaxis in medical inpatients.

Methods

Patients were adults admitted to any of 10 Cleveland Clinic Health System hospitals between December 2020 and August 2021 (N = 41,036). Hospital medicine physicians and internal medicine residents from included hospitals were surveyed between June and November 2023 (N = 214). We compared five approaches to determining a threshold: decision analysis, maximizing the sensitivity and specificity of a logistic regression model, deriving a probability from a point-based model, surveying physicians' understanding of VTE risk, and deriving a probability from physician behavior. For each approach, we determined the probability threshold above which a patient would be considered high-risk for VTE. We applied each threshold to the Cleveland Clinic VTE risk assessment model (CCM) and calculated the percentage of the 41,036 patients in our cohort who would be considered eligible for prophylaxis due to their high-risk status. We compared these hypothetical prophylaxis rates with physicians' observed prophylaxis rates.

Results

The different approaches yielded thresholds ranging from 0.3% to 5.4%, corresponding inversely with hypothetical prophylaxis rates of 0.2% to 75%. Multiple thresholds clustered between 0.52% to 0.55%, suggesting an average hypothetical prophylaxis rate of approximately 30%, whereas physicians' observed prophylaxis rates ranged from 48% to 76%.

Conclusions

Multiple approaches to determining a probability threshold for VTE prophylaxis converged to suggest an optimal threshold of approximately 0.5%. Other approaches yielded extreme thresholds that are unrealistic for clinical practice. Physicians prescribed prophylaxis much more frequently than the suggested rate of 30%, indicating opportunity to reduce unnecessary prophylaxis. To aid in these efforts, guidelines should explicitly quantify high-risk.

Use of Thromboprophylaxis after Autologous Breast Reconstruction: A Cost-Effective Break-Even Analysis

BACKGROUND

Postoperative venous thromboembolism (VTE) is a major source of morbidity and mortality. The use of thromboprophylaxis among surgeons is not well studied in autologous breast reconstruction. The purpose of this study was to determine the rate of VTE in patients with breast cancer undergoing autologous breast reconstruction and to compare the cost-effectiveness of postoperative chemoprophylactic agents.

METHODS

The TriNetX National Health Research Network database was used to identify patients with breast cancer who underwent autologous breast reconstruction surgery between 2002 and 2022. The incidence of VTE within the first 30 days of surgery was calculated. A break-even analysis was performed to determine the break-even rate of VTE at which a chemoprophylactic agent would be cost-effective.

RESULTS

A cohort of 8221 patients was identified in this study. The rate of VTE was significantly higher in those without anticoagulation (4.0%) compared with those who received anticoagulation (2.6%) ( P = 0.0008). The break-even analysis for heparin and enoxaparin cost-effectiveness yielded absolute risk reductions of 0.73% and 1.63% for high-risk patients requiring 30 days of therapy and 0.20% and 0.43% for moderate-risk patients requiring 7 days of therapy, respectively.

CONCLUSIONS

The use of thromboprophylaxis significantly lowered the risk of VTE within 30 days after autologous breast reconstruction. Heparin appeared to be more cost-effective at preventing VTE compared with enoxaparin for both high- and moderate-risk patients. The presented model holds potential for other institution-specific variables that can be easily applied by plastic surgeons to determine the cost-effectiveness of any therapy.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Deep Vein Thrombosis Prophylaxis in Orthopedic Surgery

Deep vein thrombosis (DVT) is a complex and multifactorial process arising from a variety of factors, including recent surgical procedures, traumatic events, and periods of prolonged immobility. The extended period of stasis post-orthopedic surgery places patients at a notably high risk of developing DVT, and DVT-related pulmonary embolism (PE) ranks as the third most common cause of death in orthopedic surgery patients. This review examines the multifaceted risk factors contributing to the development of DVT in orthopedic patients. Additionally, it addresses the importance of DVT prophylaxis in orthopedic settings, the efficacy and safety of various prophylactic methods encompassing both mechanical and pharmacological approaches, and the economic dimensions of DVT prophylaxis, including scrutiny of cost-effectiveness and the exploration of strategies for optimization.

A systematic review of venous thromboembolism mechanical prophylaxis devices during surgery

PURPOSE

Hospitalisation and surgery are major risk factors for venous thromboembolism (VTE). Intermittent pneumatic compression (IPC) and graduated compression stockings (GCS) are common mechanical prophylaxis devices used to prevent VTE. This review compares the safety and efficacy of IPC and GCS used singularly and in combination for surgical patients.

METHODS

Ovid Medline and Pubmed were searched in a systematic review of the literature, and relevant articles were assessed against eligibility criteria for inclusion along PRISMA guidelines.

RESULTS

This review is a narrative description and critical analysis of available evidence. Fourteen articles were included in this review after meeting the criteria. Results of seven studies comparing the efficacy of IPC versus GCS had high heterogeneity but overall suggested IPC was superior to GCS. A further seven studies compared the combination of IPC and GCS versus GCS alone, the results of which suggest that combination mechanical prophylaxis may be superior to GCS alone in high-risk patients. No studies compared combination therapy to IPC alone. IPC appeared to have a superior safety profile, although it had a worse compliance rate and the quality of evidence was poor. The addition of pharmacological prophylaxis may make mechanical prophylaxis superfluous in the post-operative setting.

CONCLUSION

IPC may be superior to GCS when used as a single prophylactic device. A combination of IPC and GCS may be more efficacious than GCS alone for high-risk patients. Further high-quality research is needed focusing on clinical relevance, safety and comparing combination mechanical prophylaxis to IPC alone, particularly in high-risk surgical settings when pharmacological prophylaxis is contraindicated.

Prevalence of preoperative deep vein thrombosis in long bone fractures of lower limbs: a systematic review and meta-analysis

BACKGROUND

There is a paucity of data regarding the prevalence of preoperative deep vein thrombosis (DVT) in patients with long bone (including femur, tibia and fibula) fractures of the lower limbs. We performed a meta-analysis to address the issue.

METHODS

Electronic databases, including PubMed, EMBASE, the Web of Science, the Cochrane Library, the VIP database, CNKI, and the Wanfang database, were systematic searched for original articles that reported the prevalence of preoperative DVT in long bone fractures of the lower limbs from January 2016 to September 2021. The prevalence of preoperative DVT was pooled using random-effects models, and subgroups were established according to study type, detection method, sample size and fracture site.

RESULTS

Twenty-three articles reporting on 18,119 patients were eligible. The overall pooled preoperative DVT prevalence was 24.1% (95% CI 19.3-28.8%). In different subgroups, the preoperative DVT prevalences were 18.2-27.3%, 15.2-28.6%, 23.1-24.9%, 18.2-26.0% and 23.2-23.4% for different study designs, sample sizes, age groups, detection methods and fracture sites, respectively.

CONCLUSIONS

Despite the heterogeneity among studies, this systematic review suggests that the prevalence of preoperative DVT, which may seriously affect the prognosis of patients, is high. Therefore, greater efforts should be devoted to the improvement of screening and prevention strategies for preoperative DVT in lower-extremity long bone fractures.

LEVEL OF EVIDENCE

Level III. Trial Registration The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database with the registration number CRD42022324706.

Early start of thromboprophylaxis does not increase risk of intracranial hematoma progression in multiply injured patients with traumatic brain injury

BACKGROUND

Venous thromboembolism (VTE) in severely injured patients with severe traumatic brain injury (TBI) is a risk during the clinical course. Data on the safety of an early initiation of pharmacological VTE prophylaxis in severely injured patients with concomitant severe TBI is sparse.

METHODS

Admissions to our level-1-trauma center between January 2015 and December 2018 were screened. Patients suffering from severe TBI (Abbreviated Injury Scale (AIS) of the head ≥3) and at least one further AIS ≥ 3 in any other body region were included. Demographic data, thromboembolic events, and progression of the intracranial hemorrhage were extracted from the patient's charts. According to the first application of pharmacological thromboprophylaxis (VTEp), patients were categorized either to the early, the late (later than 24 h) or the no therapy group.

RESULTS

In 79 patients (early: n = 35, late: n = 29, no therapy: n = 15) the Injury Severity Score (ISS) was 36.7 ± 12.7 points (AIS_head 4.1 ± 0.8). No differences were found regarding the progression of the intracranial hemorrhage after initiation of the VTE prophylaxis (adj. p = 0.8). The VTE rate was low (n = 1, 1.6%).

CONCLUSION

In severely injured patients with severe TBI, the early administration of pharmacological thromboprophylaxis did not result in a higher rate of intracranial hematoma progression.

Trauma-induced pulmonary thromboembolism: What's update?

Trauma-induced pulmonary thromboembolism is the second leading cause of death in severe trauma patients. Primary fibrinolytic hyperactivity combined with hemorrhage and consequential hypercoagulability in severe trauma patients create a huge challenge for clinicians. It is crucial to ensure a safe anticoagulant therapy for trauma patients, but a series of clinical issues need to be answered first, for example, what are the risk factors for traumatic venous thromboembolism? How to assess and determine the status of coagulation dysfunction of patients? When is the optimal timing to initiate pharmacologic prophylaxis for venous thromboembolism? What types of prophylactic agents should be used? How to manage the anticoagulation-related hemorrhage and to determine the optimal timing of restarting chemoprophylaxis? The present review attempts to answer the above questions.

Identification of hypercoagulability with thrombelastography in patients with hip fracture receiving thromboprophylaxis

Background:

Venous thromboembolism (VTE) is the second most common complication after hip fracture surgery. We used thrombelastography (TEG), a wholeblood, point-of-care test that can provide an overview of the clotting process, to determine the duration of hypercoagulability after hip fracture surgery.

Methods:

In this prospective study, consecutive patients aged 51 years or more with hip fractures (trochanteric region or neck) amenable to surgical treatment who presented to the emergency department were eligible for enrolment. Thrombelastography, including calculation of the coagulation index (CI) (combination of 4 TEG parameters for an overall assessment of coagulation) was performed daily from admission until 5 days postoperatively, and at 2 and 6 weeks postoperatively. All patients received 28 days of thromboprophylaxis. We used single-sample t tests to compare mean maximal amplitude (MA) values (a measure of clot strength) to the hypercoagulable threshold of greater than 65 mm, a predictor of in-hospital VTE.

Results:

Of the 35 patients enrolled, 11 (31%) were hypercoagulable on admission based on an MA value greater than 65 mm, and 29 (83%) were hypercoagulable based on a CI value greater than 3.0; the corresponding values at 6 weeks were 23 (66%) and 34 (97%). All patients had an MA value greater than 65 mm at 2 weeks. Patients demonstrated normal coagulation on admission (mean MA value 62.2 mm [standard deviation (SD) 6.3 mm], p = 0.01) but became significantly hypercoagulable at 2 weeks (mean 71.6 mm [SD 2.6 mm], p < 0.001). There was a trend toward persistent hypercoagulability at 6 weeks (mean MA value 66.2 mm [SD 3.8 mm], p = 0.06).

Conclusion:

More than 50% of patients remained hypercoagulable 6 weeks after fracture despite thromboprophylaxis. Thrombelastography MA thresholds or a change in MA over time may help predict VTE risk; however, further study is needed.

Venous Thromboembolism Chemoprophylaxis in Burn Patients: A Literature Review and Single-Institution Experience

Hospitalized burn patients meet the criteria for Virchow's triad (endothelial damage, hypercoagulability, and stasis), predisposing them to venous thromboembolism (VTE). Although the disease burden of VTE suggests a need for prevention in this population, unreliable reported VTE rates, costly and complicated prophylaxis regimens, and chemoprophylaxis risks have prevented the establishment of a universal protocol. This paper reviews thromboprophylaxis practices both in the literature and at our own institution. A systematic review was conducted according to PRISMA guidelines identifying studies pertaining to VTE chemoprophylaxis in burn patients. Additionally, medical records of patients admitted to an American Burn Association-verified burn center between June 2015 and June 2019 were retrospectively reviewed for demographics, chemoprophylaxis, and presence of VTE defined as either deep vein thrombosis (DVT) or pulmonary embolism (PE). Thirty-eight studies met inclusion criteria. In the 12 studies that reported VTE incidence, rates ranged widely from 0.25% to 47.1%. The two largest retrospective studies (n = 33,637 and 36,638) reported a VTE incidence of 0.61% and 0.8% in populations with unknown or inconsistently recorded chemoprophylaxis. Throughout the literature, prevention protocols were mixed, though a trend toward using dose-adjusted subcutaneous low molecular weight heparin based on serum anti-factor Xa level was noted. At our burn center, 1,068 patients met study criteria. At-risk patients received a simple chemoprophylaxis regimen of 5000U of subcutaneous unfractionated heparin every 8 hours. No routine monitoring tests were performed to limit cost. Nine cases of DVT and two cases of PE were identified with an incidence of 0.84% and 0.19%, respectively, and a total VTE incidence of 1.03%. Only one patient developed heparin-induced thrombocytopenia (HIT). No cases of other heparin-associated complications were observed. VTE incidence rates reported in the literature are wide-ranging and poorly capture the effect of any one chemoprophylaxis regimen in the burn population. Our center uses a single, safe, and cost-effective protocol effecting a low VTE rate comparable to that of large national retrospective studies.

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.

Effect of Compression Devices on Preventing Deep Vein Thrombosis Among Adult Trauma Patients: A Systematic Review

BACKGROUND

Trauma is the leading cause of death in Americans up to 44 years old each year. Deep vein thrombosis (DVT) is a significant condition occurring in trauma, and prophylaxis is essential to the appropriate management of trauma patients. The incidence of DVT varies in trauma patients, depending on patients' risk factors, modality of prophylaxis, and methods of detection. However, compression devices and arteriovenous (A-V) foot pumps prophylaxis are recommended in trauma patients, but the efficacy and optimal use of it is not well documented in the literature.

OBJECTIVES

The aim of this study was to review the literature on the effect of compression devices in preventing DVT among adult trauma patients.

METHODS

We searched through PubMed, CINAHL, and Cochrane Central Register of Controlled Trials for eligible studies published from 1990 until June 2014. Reviewers identified all randomized controlled trials that satisfied the study criteria, and the quality of included studies was assessed by Cochrane risk of bias tool.

RESULTS

Five randomized controlled trials were included with a total of 1072 patients. Sequential compression devices significantly reduced the incidence of DVT in trauma patients. Also, foot pumps were more effective in reducing incidence of DVT compared with sequential compression devices.

DISCUSSION

Sequential compression devices and foot pumps reduced the incidence of DVT in trauma patients. However, the evidence is limited to a small sample size and did not take into account other confounding variables that may affect the incidence of DVT in trauma patients. Future randomized controlled trials with larger probability samples to investigate the optimal use of mechanical prophylaxis in trauma patients are needed.

Three cases of heparin-induced thrombocytopenia associated with polytrauma

Case

We present three cases in which patients that had suffered polytrauma developed heparin-induced thrombocytopenia after the start of heparin treatment for thrombosis. All three patients had high injury severity scores and required major surgery. They all started receiving unfractionated heparin for deep venous thrombosis with or without an asymptomatic pulmonary embolism. The patients were clinically diagnosed with heparin-induced thrombocytopenia after their platelet counts fell or exhibited a delayed recovery.

Outcome

Heparin-induced thrombocytopenia and the associated thromboses were successfully treated by discontinuing all forms of heparin treatment and administering argatroban followed by warfarin.

Conclusion

Early recognition and clinical diagnosis of heparin-induced thrombocytopenia is necessary for clinicians in cases in which severely injured trauma patients show reductions or delayed recovery in their platelet counts in combination with thrombosis after starting heparin treatment.

Fibrinolytic activity of endothelial cells from different venous beds

BACKGROUND

Little is known about the molecular biology of endothelial cells from different venous vascular beds. As a result, our treatment of deep vein thrombosis and pulmonary artery embolism remain identical. As an initial step in understanding venous thromboembolic disease in the trauma and surgical patients, this study sought to investigate the balance between coagulation and fibrinolysis in the pulmonary and deep venous vascular beds and how trauma might influence this balance.

MATERIALS AND METHODS

Confluent human iliac vein endothelial cells (HIVECs) and human pulmonary artery endothelial cells (HPAECs), were cultured in the absence or presence of tumor necrosis factor (TNFα; 10 ng/mL) for 24 h. The expression of mediators of coagulation and fibrinolysis were determined by Western blot analysis, and plasminogen activator activity was determined by a fibrin clot degradation assay.

RESULTS

After TNFα stimulation, there was decreased expression of endothelial protein C receptor and thrombomodulin in both HIVECs and HPAECs. TNFα stimulation increased urokinase plasminogen activator expression in both HIVECs and HPAECs. There was an increase in the expression of tissue plasminogen activator and plasminogen activator inhibitor-1 in response to TNFα in HPAECs, but not in HIVECs. There was significantly greater clot degradation in the presence of both the conditioned media and cell extracts from HIVECs, when compared with HPAECs.

CONCLUSIONS

HPAECs and HIVECs react differently in terms of fibrinolytic potential when challenged with a cytokine associated with inflammation. These findings suggest that endothelial cells from distinct venous vascular beds may differentially regulate the fibrinolytic pathway.

Managing behavioral health needs of veterans with traumatic brain injury (TBI) in primary care

Traumatic brain injury (TBI) is a frequent occurrence in the United States, and has been given particular attention in the veteran population. Recent accounts have estimated TBI incidence rates as high as 20 % among US veterans who served in Afghanistan or Iraq, and many of these veterans experience a host of co-morbid concerns, including psychiatric complaints (such as depression and post-traumatic stress disorder), sleep disturbance, and substance abuse which may warrant referral to behavioral health specialists working in primary care settings. This paper reviews many common behavioral health concerns co-morbid with TBI, and suggests areas in which behavioral health specialists may assess, intervene, and help to facilitate holistic patient care beyond the acute phase of injury. The primary focus is on sequelae common to mild and moderate TBI which may more readily present in primary care clinics.

Profilaxia medicamentosa da trombose venosa profunda em pacientes submetidos à cirurgia do trauma em um hospital universitário

CONTEXTO: Anualmente, milhões de pessoas são vítimas de trauma no mundo. Além de suas consequências sociais e econômicas, muitos dos pacientes necessitam de tratamento cirúrgico, gerando, portanto, maiores riscos à vida. O tromboembolismo venoso, consequência da trombose venosa profunda, é uma importante causa de morbimortalidade em pós-operatórios e pode ser evitado com profilaxia adequada. OBJETIVO: Avaliar a utilização da profilaxia medicamentosa para trombose venosa profunda em pacientes submetidos à cirurgia do trauma de emergência, em um hospital-escola. MÉTODOS: Estudo transversal analítico, com 153 pacientes internados no Hospital Universitário Cajuru, em Curitiba, no Paraná, durante dois meses. Foram analisados prospectivamente prontuários de pacientes que necessitaram de cirurgia devido a trauma. O estudo incluiu pacientes classificados como alto e médio risco para trombose venosa profunda e avaliou-se a realização, ou não, da profilaxia medicamentosa. A análise estatística foi feita de forma descritiva. RESULTADOS: Dos 153 pacientes incluídos no estudo, 99 (64,7%) foram classificados como alto risco para trombose venosa e 54 (35,3%) como médio, sendo que 144 (94%) não receberam profilaxia medicamentosa. Dos nove (6%) pacientes que receberam profilaxia medicamentosa, um foi estratificado como médio risco e os outros oito de alto risco. Dos pacientes que receberam profilaxia, em apenas quatro a orientação foi adequada. CONCLUSÕES: A profilaxia para trombose venosa não é realizada de maneira rotineira nos pacientes de médio e alto risco para trombose venosa profunda que são submetidos à cirurgia do trauma e, quando realizada, muitas vezes é inadequada.

Hypercoagulability in porcine hemorrhagic shock is present early after trauma and resuscitation

INTRODUCTION

The understanding of coagulopathy associated with trauma continues to evolve. Trauma patients are frequently coagulopathic early after injury and become hypercoagulable within days of injury. Thrombelastography (TEG) allows real-time evaluation of the coagulation status of patients. We hypothesized that TEG will identify post-traumatic hypercoagulable state in our porcine model of hemorrhagic shock and resuscitation.

METHODS

Fourteen male Yorkshire pigs were sedated, instrumented, and splenectomized via laparotomy. Eight of these animals underwent a shock protocol consisting of a pulmonary contusion via captive bolt gun, 35% hemorrhage and two liver fractures. Vitals, hemodynamics, physiologic parameters and TEG were measured at baseline, after shock and at intervals after injury thru 72 h post-injury.

RESULTS

Animals undergoing surgery and instrumentation demonstrated the same hypercoagulable patterns as animals that received shock, injury, and resuscitation. In this model, hypercoagulability was present in both groups at 4 h after injury and continued for 72 h post-injury (increased angle and maximum amplitude, P < 0.05, compared to baseline). Statistically significant differences between the groups were noted at both 16 and 48 h post-injury.

CONCLUSIONS

Hypercoagulability is present early after surgical intervention and trauma. This finding has implications for use of deep venous thrombosis (DVT) prophylaxis in trauma patients.

Deep vein thrombosis prophylaxis in trauma patients

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are known collectively as venous thromboembolism (VTE). Venous thromboembolic events are common and potentially life-threatening complications following trauma with an incidence of 5 to 63%. DVT prophylaxis is essential in the management of trauma patients. Currently, the optimal VTE prophylaxis strategy for trauma patients is unknown. Traditionally, pelvic and lower extremity fractures, head injury, and prolonged immobilization have been considered risk factors for VTE; however it is unclear which combination of risk factors defines a high-risk group. Modalities available for trauma patient thromboprophylaxis are classified into pharmacologic anticoagulation, mechanical prophylaxis, and inferior vena cava (IVC) filters. The available pharmacologic agents include low-dose heparin (LDH), low molecular weight heparin (LMWH), and factor Xa inhibitors. Mechanical prophylaxis methods include graduated compression stockings (GCSs), pneumatic compression devices (PCDs), and A-V foot pumps. IVCs are traditionally used in high risk patients in whom pharmacological prophylaxis is contraindicated. Both EAST and ACCP guidelines recommend primary use of LMWHs in trauma patients; however there are still controversies regarding the definitive VTE prophylaxis in trauma patients. Large randomized prospective clinical studies would be required to provide level I evidence to define the optimal VTE prophylaxis in trauma patients.

Thromboembolic prophylaxis with low-molecular-weight heparin in patients with blunt solid abdominal organ injuries undergoing nonoperative management: current practice and outcomes

BACKGROUND

Low-molecular-weight heparins (LMWHs) are effective in preventing thromboembolic complications after trauma. In the nonoperative management (NOM) of blunt solid abdominal organ injuries, the timing of the administration of LMWH remains controversial because of the unknown risk for bleeding.

METHODS

Retrospective study including patients aged 15 years or older who sustained blunt splenic, liver, and/or kidney injuries from January 2005 to December 2008. Patients were stratified according to the type and severity of organ injuries. NOM failure rates and blood transfusion requirements were compared between patients who got LMWH early (≤3 days), patients who got LMWH late (>3 days), and patients who did not receive LMWH.

RESULTS

Overall, 312 (63.8%) patients with solid organ injuries had NOM attempted. There were 154 splenic, 144 liver, and 65 kidney injuries (1.2 organs injured per patient). Forty-one patients (13.2%) received LMWH early, 70 patients (22.4%) received LMWH late, and 201 (64.4%) patients did not receive LMWH. The early LMWH group was less severely injured compared with the late LMWH group. However, the distribution of the risk factors for failure of NOM (high-grade injury, large amount of hemoperitoneum, and contrast extravasation) was similar between the three LMWH groups. Overall, 17 of 312 patients (5.4%) failed NOM (7.8% spleen, 2.1% liver, and 3.1% kidney). All but one failure occurred before LMWH administration. After adjustment for demographic differences, the overall blood transfusion requirements for the early LMWH group was significantly lower when compared with patients with late LMWH administration (3.0±5.3 units vs. 6.4±9.9 units; adjusted p=0.027). Pulmonary embolism and deep venous thrombosis occurred in four patients. The mortality rate for patients with splenic, liver, and kidney injuries was 3.2% and did not differ with LMWH application.

CONCLUSION

In patients with solid abdominal organ injuries undergoing NOM, early use of LMWH does not seem to increase failure rates or blood transfusion requirements.