Risk factors for venous thromboembolism in critically ill trauma patients who cannot receive chemical prophylaxis

doi:10.1016/j.injury.2011.10.006

Injury

Volume 44, Issue 1, January 2013, Pages 80-85

https://doi.org/10.1016/j.injury.2011.10.006 Get rights and content

Abstract

Background

Standard venous thromboembolism (VTE) prevention for critically ill trauma patients includes sequential compression devices and chemical prophylaxis. When contraindications to anticoagulation are present, prophylactic inferior vena cava filters (IVCF) may be used to prevent pulmonary emboli (PE) in high-risk patients, but specific indications are lacking. We sought to identify independent predictors of VTE in critically-ill trauma patients who cannot receive chemical prophylaxis in order to identify a subset of patients who may benefit from aggressive screening and/or prophylactic IVCF placement.

Methods

All trauma patients in the surgical ICU from 2008 to 2009 were prospectively followed. Patients with an ICU length of stay ≥2 days who had contraindications to prophylactic anticoagulation were included. Screening duplex exams were obtained within 48 h of admission and then weekly. CT-angiography for PE was obtained if clinically indicated. Patients were excluded if they did not receive a duplex or if they had a post-injury VTE prior to ICU admission. Data regarding VTE rates (lower extremity [LE] DVT or PE), demographics, past medical history (PMH), injuries, and surgeries were collected. Univariate and multivariable analyses were performed to identify independent predictors of VTE with a p < 0.05.

Results

411 trauma patients with a mean age of 48 (SD 22) years and 8 (SD 9) ICU days were included. 72% were male and the mean ISS was 22 (SD 13). 30 (7.3%) patients developed VTE: 28 (6.8%) with LEDVT and 2 (0.5%) with PE. Risk factors for VTE with a p < 0.2 on univariate analysis included: PMH of DVT, injury severity score (ISS), extremity fractures (Fx), and a pelvis or LE extremity Fx repair. After logistic regression, only PMH of DVT (OR = 22.6) and any extremity Fx (OR = 2.4) remained as independent predictors.

Conclusion

VTE occur in 7% of critically injured trauma patients who cannot receive chemical prophylaxis. Aggressive screening and/or prophylactic IVCF placement may be considered in patients with a PMH of DVT or extremity fractures when anticoagulation is prohibited.

Introduction

Deep venous thrombosis (DVT) and pulmonary embolism (PE), collectively known as venous thromboembolism (VTE), continue to significantly impact the morbidity and mortality of hospitalised patients. DVT rates range from 11.8% to 70% in prospectively-screened, critically-injured trauma patients with contraindication for prophylaxis.1, 2 Historically, PE occur in 2% of trauma patients and have been cited as the most common, preventable cause of hospital death.2, 4 In addition, PE represent up to 37% of all post surgical VTEs.³

The routine prophylaxis of VTE is part of standard critical care. Low-dose unfractionated heparin (LDH) and low molecular weight heparin (LMWH) are recognised as effective methods of anticoagulation.⁴ Mechanical prophylaxis, in the form of sequential compression devices (SCDs), is frequently used in lieu of or in addition to pharmacological prevention. The American College of Chest Physicians suggests early use of LMWH and SCDs for DVT prophylaxis in major trauma patients as long as contraindications are not present.⁴

Contraindications for chemical prophylaxis consist of significant bleeding risk (including severe intracranial haemorrhage or critical spinal injury), recent or imminent surgery, renal insufficiency, anaemia, recent history of GI haemorrhage, active peptic ulcer disease, or liver disease.4, 5 Trauma patients frequently present with one or more of these contraindications. In these cases, it is recommended that mechanical prophylaxis be used with chemoprophylaxis commencing as soon as the contraindication resolves.⁴ In addition, SCDs are recognised as an acceptable form of DVT prophylaxis when anticoagulants cannot be administered and screening duplex ultrasound exams should be considered in high-risk patients when VTE prophylaxis is considered sup-optimal.⁴

Given that two out of three PEs occur within the first week of injury, withholding chemical prophylaxis due to contraindications compromises the prevention of PE and its associated mortality during the most crucial period.⁶ Currently, IVCFs are sometimes used in patients with contraindications to VTE prophylaxis to prevent PE even prior to the development of lower extremity DVT (LEDVT). This practice is referred to as “prophylactic IVCF placement”. Despite being used in 4% of trauma patients, studies analysing the safety and efficacy of IVCFs have produced mixed results.7, 8, 9, 10, 11, 12, 13 Although IVCFs have been associated with up to a seven-fold decrease in the occurrence of PE,¹⁴ several studies have shown no benefit.10, 11 Retrieval of temporary IVCFs is also of special concern due to the lifestyle demands of a young trauma population. Whilst the success rate of filter removal has reached 97%, overall filter removal rates range from 22% to 78% due to lack of follow-up and contraindications.8, 9, 15 In addition, IVCFs may be associated with complications that include fracture, migration, and the formation of VTE within the filter itself.5, 8, 10

Due to uncertainty regarding the efficacy, safety, and retrievability of IVCFs, it is imperative that vena cava filtration be used only in high-risk patients. The Eastern Association for the Surgery of Trauma (EAST) Practise Management Guidelines Work Group established a level-3 recommendation for prophylactic IVCF only in “very-high-risk trauma patients” who are not candidates for DVT prophylaxis and present with immobilizing injuries.¹⁶ At present, there are no level-1 or level-2 recommendations for prophylactic vena cava filtration (prior to the development of a VTE) in critically injured patients. Guidelines from the Institute for Clinical Systems Improvement state that IVCFs are not appropriate for routine use but are indicated in any type of patient with a VTE and contraindications to anticoagulation, failure of adequate anticoagulation to treat a progressive VTE, or a history of pulmonary hypertension.⁵ Given this, it is fair to say that a trauma patient who develops a LEDVT or PE and can not receive therapeutic anticoagulation would have an indication for IVCF insertion. This study was designed to find independent predictors of LEDVT or PE in critically-injured trauma patients who cannot receive chemical prophylaxis in order to identify a subset of patients with a significantly increased risk of VTE who may benefit from aggressive screening and/or prophylactic IVCF placement. Whilst only aggressive screening is recommended in these cases by the American College of Chest Physicians,⁴ practise patterns vary in trauma centers and some centers do employ the use of prophylactic IVCF under similar circumstances.¹⁵ The ability to elucidate risk factors for VTE in trauma patients who cannot receive adequate chemical prophylaxis may help centers to focus these additional resources on the patients who have the greatest chance to benefit from them.

Section snippets

Methods

All adult patients on the surgical intensive care unit (SICU) service at an academic, level-1 trauma center were prospectively followed from January 2008 to December 2009. VTE prophylaxis was administered according to a pre-established protocol. This included SCDs, which were applied bilaterally to the lower extremities as early as possible. When indicated, 30 mg LMWH [Enoxaparin, Sanofi-aventis, Bridgewater, NJ] was subcutaneously administered twice-daily. LMWH was held due to the following

Results

Over the two-year study period, the SICU service followed 1269 adult patients. Nine hundred eighteen of these were trauma patients and they had an LEDVT rate of 4% and a PE rate of 0.3%. Of these 918 patients, 411 met the criteria for the study by having an ICU length of stay ≥2 days, by having a duplex prior to leaving the ICU, and by not receiving chemical prophylaxis within the first 5 days of admission or prior to an LEDVT (Fig. 1).

The 411 included patients had an average age of 48(SD 22)

Discussion

Trauma patients represent a unique population when considering the treatment and prevention of VTE. Whilst chemical prophylaxis is recommended after major trauma, many patients have contraindications to any form of anticoagulation and their only option is mechanical prophylaxis. In these cases prophylactic IVCF placement may be utilised to prevent PE, but specific indications are lacking. Our study used strict selection criteria and found that 45% of trauma patients did not receive chemical

Conclusions

Recent studies continue to demonstrate that one in four PEs leads to mortality, making it the most preventable cause of death in hospitals.²⁰ Trauma patients are particularly prone to VTE and anticoagulation is frequently contraindicated in these patients. In the current study, 7.3% of critically injured trauma patients who could not receive chemical prophylaxis developed a LE DVT or PE. Despite mixed data regarding the safety and retrievability of prophylactic IVCFs and the absence of level-1

Funding disclosure

There is no funding to disclose.

Conflict of interest statement

There are no financial or personal conflicts to disclose.

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Cited by (29)

Worth looking! venous thromboembolism in patients who undergo preperitoneal pelvic packing warrants screening duplex
2020, American Journal of Surgery
Citation Excerpt :
VTEp initiation earlier than 48 h may reduce VTE rates, but often, this is not possible in the multiply injured patient population, as they frequently have injuries that may be worsened by VTEp initiation, such as intracranial hemorrhage or solid organ injury. Malinoski et al. reported a 7% VTE rate in critically-ill trauma patients who could not receive VTEp.23 Our practice is to initiate VTEp as soon as bleeding is controlled, which in this patient cohort lead to the majority of our patients being initiated on enoxaparin VTEp within 48 h with an average of <1 missed doses.
Venous thromboembolism (VTE) in patients with major pelvic fractures who undergo preperitoneal pelvic packing (PPP) has not been investigated. We hypothesized that patients who undergo PPP are at high risk for VTE, thus early prophylactic anticoagulation and screening duplex are warranted.
All patients requiring PPP from 2015 to 2019 were reviewed. Management and outcomes were analyzed.
During the study period, 79 patients underwent PPP. Excluding the early deaths, 17 patients had deep venous thrombosis (DVT) and 6 had pulmonary emboli (PE); 4 patients had both DVT/PE. Overall mortality was 15%. Thirty-two patients underwent screening duplex within 72 h of admission and 10 were positive for DVT.
Patients with complex pelvic trauma undergoing PPP have a 23% incidence of DVT and an additional 8% incidence of PE. 31% of screening ultrasounds are positive. The overall mortality was 15%. With a high incidence of VTE in this patient population, we recommend screening duplex ultrasounds.
Guidelines for the prevention of venous thromboembolism in hospitalized patients with pelvi-acetabular trauma
2020, Journal of Clinical Orthopaedics and Trauma
Venous thromboembolism is a dreaded complication leading to increased morbidity and mortality in patients having pelvi-acetabular fractures.
These evidence based guidelines aim to provide the decision making ability in the prevention of venous thromboembolism in patients with pelvi-acetabular trauma planned for operative or non operative treatment.
The patients were subclassified into 5 categories. The PICO framework was used to devise research questions in each category. The systematic reviews were performed for each research question. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess outcomes of critical interest. The guideline panel consisting of expert members of different subspecialties, analyzed the evidence and made recommendations.
The guideline panel proposed 21 recommendations. There are five recommendations in category 1 to 3, two recommendations in category 4 and four recommendations in category 5.
In pelvi-acetabular fractures there is strong evidence to suggest that thromboprophylaxis should be given. It should be initiated as early as possible after control of hemorrhage. The chemical prophylaxis is the preferred mode and LMWH is the preferred agent of choice. The mechanical methods can be used as an adjunct. The routine prophylactic use of IVC filters is not recommended. However, the use of retrievable IVC filters in high risk patients with established VTE in preoperative period can be considered. The use of newer directly acting oral anticoagulants is gaining importance.
Elevated risk of venous thromboembolism among post-traumatic brain injury patients requiring pharmaceutical immobilization
2020, Journal of Clinical Neuroscience
Traumatic brain injury (TBI) patients are known to have a high rate of venous thromboembolism (VTE), and additional neuromuscular blockade or barbiturate coma therapy has the theoretical risk of exacerbating baseline hemostasis and elevating the incidence of thromboembolic events. We conducted a single-institution retrospective review of patients surviving severe TBI, as determined by need for intracranial pressure (ICP) monitoring, who further required paralytics or barbiturate therapy to maintain ICP control. Patients were administered VTE prophylaxis as clinically appropriate. Predictors for VTE were subsequently determined with univariate and logistic multivariate regression analyses. The main cohort includes 144 patients, 34 of whom received pharmaceutical immobilization for ICP control. Mean ISS and GCS at intake were 31.9 and 5.2, respectively. Among those receiving vs not-receiving paralytics and/or barbiturate therapy, there was a statistical difference of 12/34 (35.3%) vs 18/110 (16.4%, p = 0.0280) in VTE events, at a mean time greater than two weeks from the time of trauma. Multivariate logistics regression indicated 3.2 times increased odds of developing a VTE (log odds = 1.17, p = 0.023). No pediatric patients were positive for an event (0/12 vs 7/22, p = 0.0356), and infections were only documented among those with VTE (0/22 vs 4/12, p = 0.0107). Overall, paralytics and barbiturate therapy were correlated with a higher incidence of VTE among TBI patients. Although the need for ICP control will outweigh an increase in thromboembolic risk, there is value for increased surveillance and screening during the prolonged inpatient stay of these patients.
Practice Variation in Vena Cava Filter Use Among Trauma Centers in the NTDB
2020, Journal of Surgical Research
Agreement regarding indications for vena cava filter (VCF) utilization in trauma patients has been in flux since the filter's introduction. As VCF technology and practice guidelines have evolved, the use of VCF in trauma patients has changed. This study examines variation in VCF placement among trauma centers.
A retrospective study was performed using data from the National Trauma Data Bank (2005-2014). Trauma centers were grouped according to whether they placed VCFs during the study period (VCF+/VCF−). A multivariable probit regression model was fit to predict the number of VCFs used among the VCF+ centers (the expected [E] number of VCF per center). The ratio of observed VCF placement (O) to expected VCFs (O:E) was computed and rank ordered to compare interfacility practice variation.
In total, 65,482 VCFs were placed by 448 centers. Twenty centers (4.3%) placed no VCFs. The greatest predictors of VCF placement were deep vein thrombosis, spinal cord paralysis, and major procedure. The strongest negative predictor of VCF placement was admission during the year 2014. Among the VCF+ centers, O:E varied by nearly 500%. One hundred fifty centers had an O:E greater than one. One hundred sixty-nine centers had an O:E less than one.
Substantial variation in practice is present in VCF placement. This variation cannot be explained only by the characteristics of the patients treated at these centers but could be also due to conflicting guidelines, changing evidence, decreasing reimbursement rates, or the culture of trauma centers.
ACR Appropriateness Criteria <sup>®</sup> Radiologic Management of Venous Thromboembolism-Inferior Vena Cava Filters
2019, Journal of the American College of Radiology
Citation Excerpt :
The use of IVC filters in trauma patients remains controversial. However, an increasing number of authors advocate for filter placement in patients that cannot be anticoagulated [19,20,67]. Other authors have argued that filters confer no benefit to these patients and that as soon as hemostasis is achieved (within 36 hours in most patients), pharmacologic prophylaxis should begin [68-71].
Venous thromboembolism (VTE)—deep vein thrombosis and pulmonary embolism—is a common cause of morbidity and mortality. The mainstay of VTE prophylaxis and therapy is anticoagulation. In select patients with VTE, inferior vena cava (IVC) filters are used to prevent pulmonary embolism by trapping emboli as they pass from the lower extremity venous system through the IVC. These guidelines review the indications for placement of IVC filters in acute and chronic VTE, as well as the indications for retrieval of implanted IVC filters.
The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
Preinjury statin use and thromboembolic events in trauma: a 10-year retrospective evaluation
2018, Journal of Surgical Research
Citation Excerpt :
Evaluation of varying incidence rates through examination of population attributes, as well as VTE risk factors and severity of injury, is of paramount importance to ensure accurate result application. While the strongest evidence to date for the protective benefit of statin medication is derived from the JUPITER trial published by Glynn et al., their study population consisted of healthy subjects without screening for VTE risk; therefore, when evaluating VTE, DVT, and PE rates within the control group of 0.32, 0.20, and 0.12 events per 100-person years, respectively, the lower incidence found in published literature is likely attributable to the nontrauma study population.6,9 With further evaluation of additional risk factors for VTE within our trauma population, we observed the characteristics within the SR population of a higher overall medical acuity.
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.
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.
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).
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.

View all citing articles on Scopus

¹: Deceased.

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Risk factors for venous thromboembolism in critically ill trauma patients who cannot receive chemical prophylaxis

Abstract

Background

Methods

Results

Conclusion

Introduction

Section snippets

Methods

Results

Discussion

Conclusions

Funding disclosure

Conflict of interest statement

Chest

J Thromb Haemost

Injury

A prospective study of venous thromboembolism after major trauma

N Engl J Med

Prevention of venous thromboembolism after injury: an evidence-based report. Part I. Analysis of risk factors and evaluation of the role of vena caval filters

J Trauma

Incidence of symptomatic venous thromboembolism after different elective or urgent surgical procedures

Thromb Haemost

Pulmonary embolism and deep venous thrombosis in trauma: are they related?

Arch Surg

Current trends in vena caval filtration with the introduction of a retrievable filter at a level I trauma center

J Trauma

Inferior vena cava filters in trauma patients: efficacy, morbidity, and retrievability

J Trauma

Vena caval filters for the prevention of pulmonary embolism

Cochrane Database Syst Rev

Prophylactic inferior vena cava (IVC) filter placement may increase the relative risk of deep venous thrombosis after acute spinal cord injury

J Trauma

Long-term follow-up of trauma patients with permanent prophylactic vena cava filters

J Trauma