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

Venous Thrombus Embolism in Polytrauma: Special Attention to Patients with Traumatic Brain Injury

Venous thrombus embolism (VTE) is common after polytrauma, both of which are considered significant contributors to poor outcomes and mortality. Traumatic brain injury (TBI) is recognized as an independent risk factor for VTE and one of the most common components of polytraumatic injuries. Few studies have assessed the impact of TBI on the development of VTE in polytrauma patients. This study sought to determine whether TBI further increases the risk for VTE in polytrauma patients. A retrospective, multi-center trial was performed from May 2020 to December 2021. The occurrence of venous thrombosis and pulmonary embolism from injury to 28 days after injury was observed. Of 847 enrolled patients, 220 (26%) developed DVT. The incidence of DVT was 31.9% (122/383) in patients with polytrauma with TBI (PT + TBI group), 22.0% (54/246) in patients with polytrauma without TBI (PT group), and 20.2% (44/218) in patients with isolated TBI (TBI group). Despite similar Glasgow Coma Scale scores, the incidence of DVT in the PT + TBI group was significantly higher than in the TBI group (31.9% vs. 20.2%, p < 0.01). Similarly, despite no difference in Injury Severity Scores between the PT + TBI and PT groups, the DVT rate was significantly higher in the PT + TBI group than in the PT group (31.9% vs. 22.0%, p < 0.01). Delayed anticoagulant therapy, delayed mechanical prophylaxis, older age, and higher D-dimer levels were independent predictive risk factors for DVT occurrence in the PT + TBI group. The incidence of PE within the whole population was 6.9% (59/847). Most patients with PE were in the PT + TBI group (64.4%, 38/59), and the PE rate was significantly higher in the PT + TBI group compared to the PT (p < 0.01) or TBI (p < 0.05) group. In conclusion, this study characterizes polytrauma patients at high risk for VTE occurrence and emphasizes that TBI markedly increases the incidence of DVT and PE in polytrauma patients. Delayed anticoagulant therapy and delayed mechanical prophylaxis were identified as the major risk factors for a higher incidence of VTE in polytrauma patients with TBI.

Retrievable Inferior Vena Cava Filters-Use, Removal, and Removal Techniques

The use of retrievable inferior vena cava filters is on the rise, but there is an inadequate number of these filters being removed even if their use as a prophylactic for venous thromboembolism is no longer indicated. Complications with retrievable filters that remain in the patient for an extended duration include examples such as filter tilt and embedding into the caval wall. This raises concerns for whether the filter is properly functioning and for consequent sequelae, including recurrent thrombosis, stenosis, or inferior vena cava perforation. With these complications, there are also challenges to retrieving these filters via the standard techniques and thus more advanced techniques are required. Both standard and advanced techniques, their uses, and possible risks of these methods are also discussed.

Upper Extremity Deep Venous Thrombosis Risk Factors, Associated Morbidity and Mortality in Trauma Patients

BACKGROUND

The literature on upper extremity deep venous thrombosis (UEDVT) is not as abundant as that on lower extremities. This study aimed to identify the risk factors for UEDVT, associated mortality and morbidity in trauma patients and the impact of pharmacological prophylaxis therein.

METHODS

A 3-year retrospective review of patients admitted to a Level 1 trauma center was conducted. Patients aged 18 years or older who had experienced a traumatic event and had undergone an upper extremity ultrasound (UEUS) were included in the study. Multiple logistic regression was used to identify independent risk factors that contributed to UEDVT.

RESULTS

A total of 6,607 patients were admitted due to traumatic injuries during the study period, of whom 5.6% (373) had at least one UEUS during their hospitalization. Fifty-six (15%) were diagnosed with an UEDVT, as well as three non-fatal pulmonary emboli (PE) and four (7.1%) deaths, p = 0.03. Pharmacological prophylaxis with low-molecular-weight heparin (LMWH) or unfractionated heparin showed a protective effect against UEDVT; among the patients positive for UEDVT, 14 of 186 patients (7.5%) received LMWH, while 42 of 195 (21.5%) did not receive LMWH (p < 0.001). Multiple logistic regression revealed that the presence of upper extremity fractures, peripherally inserted central catheter (PICC) lines, and traumatic brain injury (TBI) were independent risk factors for UEDVT.

CONCLUSIONS

UEDVT are associated with a higher mortality. The presence of upper extremity fractures, PICC lines, and TBI were independent risk factors for UEDVTs. Further, pharmacological prophylaxis reduces the risk of UEDVT.

Venous thromboembolism risk stratification in trauma using the Caprini risk assessment model

INTRODUCTION

The Caprini risk assessment model is widely used for venous thromboembolism (VTE) but has limited data in trauma. The study objective was to determine if the Caprini risk assessment model could effectively risk stratify trauma patients.

MATERIALS AND METHODS

We performed a retrospective review of trauma patients aged ≥18 years, admitted for greater than 24 h at a level one trauma center from January 1, 2018, to December 31, 2018. Demographic and clinical data were analyzed to generate Caprini scores. Multiple logistic regression assessed odds of inpatient VTE.

RESULTS

A total of 1279 patients met study eligibility, with a total of 33 VTE (2.6%). When comparing those with VTE to those without, the mean age was lower (52.5 vs 59.5, p = 0.06, respectively), sex distribution was similar, but mean body mass index was higher (30.2 vs 27.4, p = 0.019, respectively). The mean Caprini score was 9.9, and 75.5% had a score >4, the traditional Caprini high-risk cutoff. The VTE group had a higher mean Injury Severity Score (17.8 vs 12.6, p = 0.011), and mean Caprini score (16.4 vs 9.8, p < 0.001). Multiple logistic regression found Caprini score, not Injury Severity Score, was associated with higher odds of VTE (adjusted odds ratio 1.06, 95% confidence interval 1.02-1.10), after adjusting for Injury Severity Score, any missed doses of VTE chemoprophylaxis, and VTE prophylaxis type.

CONCLUSIONS

Higher Caprini scores are associated with elevated odds of inpatient VTE within hospitalized trauma patients. These data support using the Caprini risk assessment model in the trauma population, which may aid in risk stratification.

When is It Safe to Start VTE Prophylaxis After Blunt Solid Organ Injury? A Prospective Study from a Level I Trauma Center

BACKGROUND

The optimal timing of VTE prophylaxis initiation after blunt solid organ injury is controversial. Retrospective studies suggest initiation ≤48 h is safe. This prospective study examined the safety and efficacy of early VTE prophylaxis initiation after nonoperative blunt solid organ injury.

METHODS

All patients >15 years of age presenting after blunt trauma (12/01/16-11/30/17) were prospectively screened. Patients were included if solid organ injury (liver, spleen, kidney) was diagnosed on admission CT scan and nonoperative management was planned. ED deaths, transfers, patients with pre-existing bleeding disorders or home antiplatelet/anticoagulant medications, and those who did not receive VTE prophylaxis were excluded. Demographics, injury/clinical data, type/timing of VTE prophylaxis initiation, and outcomes were collected. Patients were dichotomized into study groups based on VTE prophylaxis initiation time: Early (≤48 h) vs Late (>48 h after admission). Prophylaxis initiation was at the discretion of the attending trauma surgeon. The primary study outcome was VTE event rate. Secondary outcomes included hospital length of stay (LOS), intensive care unit (ICU) LOS, need for and volume of post-prophylaxis blood transfusion, need for delayed (post-prophylaxis) interventional radiology (IR) or operative intervention, failure of nonoperative management, and mortality. Outcomes were compared with univariate analysis. Multivariate analysis with logistic regression determined independent predictors of late VTE prophylaxis initiation.

RESULTS

After exclusions, 118 patients were identified. Median ISS was 22 [IQR 14-26]. Median AAST grade of injury was 2 [IQR 2-3] for liver, 2 [IQR 1-3] for spleen, and 3 [IQR 2-3] for kidney. Compared to late prophylaxis patients (n = 57, 48%), early prophylaxis patients (n = 61, 52%) had significantly fewer DVTs (n = 0, 0% vs n = 5, 9%, p = 0.024) but similar rates of PE (n = 2, 3% vs n = 3, 5%, p = 0.672). TBI was the only significant risk factor for late prophylaxis (OR 0.22, p = 0.015). No patient in either group required delayed intervention (operative or IR) for bleeding. There was no difference in volume of post-prophylaxis blood transfusion.

CONCLUSIONS

In this prospective study of patients with nonoperative blunt solid organ injuries, early (≤48 h) initiation of VTE prophylaxis resulted in a lower incidence of DVTs without an associated increase in bleeding or need for intervention. Early initiation of VTE prophylaxis is likely to be safe and beneficial for patients with blunt solid organ injury.

Asymptomatic Trauma Patients Screened for Venous Thromboembolism Have a Higher Risk Profile with Lower Rate of Pulmonary Embolism: A Five-Year Single-Institution Experience

Deep vein thrombosis (DVT) is linked to reimbursements and publicly reported metrics. Some hospitals discourage venous duplex ultrasound (VDUS) screening in asymptomatic trauma patients because they often find higher rates of DVT. We aim to evaluate the association between lower extremity (LE) VDUS screening and pulmonary embolism (PE) in trauma patients. Trauma patients admitted to an urban Level-1 trauma center between 2010 and 2015 were retrospectively analyzed. We characterized the association of asymptomatic LE VDUSs with PE, upper extremity DVT, proximal LE DVT, and distal LE DVT by univariate and multivariable logistic regression controlling for confounders. Of the 3959 trauma patients included in our study—after adjusting for covariates related to patient demographics, injury, and procedures—there was a significantly lower likelihood of PE in screened patients (odds ratio (OR) = 0.02, P < 0.001) and a higher rate of distal LE DVT (OR 11.1, P = 0.004). Screening was not associated with higher rates of proximal LE DVTafter adjustment for covariates (OR = 1.8, P = 0.193). PE was associated with patient transfer status, pelvis fracture, and spinal procedures in unscreened patients. After adjusting for covariates, we have shown that LE VDUS asymptomatic screening is associated with lower rates of PE in trauma patients and not associated with higher rates of proximal LE DVT. Our detailed institutional review of a large cohort of trauma patients over five years provides support for ongoing asymptomatic screening and better characterizes venous thromboembolism outcomes than similarly sized purely administrative data reviews. As a retrospective cohort study with a large sample size, no loss to follow-up, and a population with low heterogeneity, this study should be considered as level III evidence for care management.

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.

Inferior Vena Cava Filters: Current Indications, Techniques, and Recommendations

The vena cava filter (VCF) is intended to prevent the progression of deep venous thrombosis to pulmonary embolism. Recently, the indications for VCF placement have expanded, likely due in part to newer retrievable inferior vena caval filters and minimally invasive techniques. This article reviews the available VCFs, the indications for use, the techniques for placement, and possible outcomes and complications.

Are too many inferior vena cava filters used? Controversial evidences in different clinical settings: a narrative review

The use of inferior vena cava filters to prevent pulmonary embolism is increasing mainly because of indications that appear to be unclearly codified and recommended. The evidence supporting this approach is often heterogeneous, and mainly based on observational studies and consensus opinions, while the insertion of an IVC filter exposes patients to the risk of complications and increases health care costs. Thus, several proposed indications for an IVC filter placement remain controversial. We attempt to review the proof on the efficacy and safety of IVC filters in several "special" clinical settings, and assess the robustness of the available evidence for any specific indication to place an IVC filter.

Unfractionated heparin versus low-molecular-weight heparin for venous thromboembolism prophylaxis in trauma

BACKGROUND

Venous thromboembolism (VTE) is a common complication in trauma patients. Pharmacologic prophylaxis is utilized in trauma patients to reduce their risk of a VTE event. The Eastern Association for the Surgery of Trauma guidelines recommend use of low-molecular-weight heparin (LMWH) as the preferred agent in these patients. However, there is literature suggesting that unfractionated heparin (UFH) is an acceptable, and less costly, alternative VTE prophylaxis agent with equivalent efficacy in trauma patients. We examined data from the Michigan Trauma Quality Improvement Program to perform a comparative effectiveness study of UFH versus LMWH on outcomes for trauma patients.

METHODS

We conducted an analysis of the Michigan Trauma Quality Improvement Program data from January 2012 to December 2014. The data set contains information on date, time, and drug type of the first dose of VTE prophylaxis. Thirty-seven thousand eight hundred sixty-eight patients from 23 hospitals were present with an Injury Severity Score of 5 or greater and hospitalization for more than 24 hours. Patients were excluded if they died within 24 hours or received no pharmacologic VTE prophylaxis or agents other than UFH or LMWH while admitted to the hospital. We compared patients receiving LMWH to those receiving UFH. Outcomes assessed were VTE event, pulmonary embolism, deep vein thrombosis, and mortality during hospitalization. We used a generalized estimating equation approach to fit population-averaged logistic regression models with the type of first dose of VTE prophylaxis as the independent variable. Unfractionated heparin was considered the reference value. Timing of the first dose of VTE prophylaxis was entered into the model in addition to standard covariates. Odds ratios were generated for each of the dependent variables of interest.

RESULTS

The analysis cohort consisted of 18,010 patients. Patients administered LMWH had a decreased risk of mortality (odds ratio, 0.64; confidence interval, 0.49-0.83), VTE (odds ratio, 0.67; confidence interval, 0.53-0.84), pulmonary embolism (odds ratio, 0.53; confidence interval, 0.35-0.79), and deep vein thrombosis (odds ratio, 0.73; confidence interval, 0.57-0.95) when compared with UFH following risk adjustment and accounting for hospital effect. The reduced risk of a VTE event for patients receiving LMWH was most pronounced for patients in the lower injury-severity categories.

CONCLUSIONS

In our examination of VTE prophylaxis drug effectiveness, LMWH was found to be superior to UFH in reducing the incidence of mortality and VTE events among trauma patients. Therefore, LMWH should be the preferred VTE prophylaxis agent for use in hospitalized trauma patients.

LEVEL OF EVIDENCE

Therapeutic, level III.

Money well spent? A cost and utilization analysis of prophylactic inferior vena cava filter placement in high-risk trauma patients

BACKGROUND

Inferior vena cava filters (IVCF) for venous thromboembolic prophylaxis in high-risk trauma patients is a controversial practice. Utilization of IVCF prophylaxis was evaluated at a level 1 trauma center. Daily cost of IVCF prophylaxis, time to IVCF, duration between IVCF and chemoprophylaxis, and number of patients needed to treat (NNT) to prevent pulmonary embolism (PE) was calculated.

METHODS

A retrospective review of prophylactic IVCF over a 5-year period (2010-2014). Demographic, physiologic, injury, procedural, and outcome data were abstracted from the administrative trauma database. Medicare fees and days without chemoprophylaxis were used to determine daily IVCF cost. NNT was calculated using PE events in a cohort without IVCF.

RESULTS

Over the 5-year period, 146 patients with mean age 56.3 y (SD ± 24.2), 67.8% male, underwent prophylactic IVCF. Predominant mechanisms of injuries were falls (45.9%) and motor vehicle accidents (20.5%) with median Injury Severity Score of 25 (intraquartile range [IQR] 16-29) and head Abbreviated Injury Score of 3 (IQR 3-5). Most common operative interventions required in 24.7% were orthopedic (25.3%) and neurosurgical (21.9%). Median time to IVCF was 78 h (IQR 48-144). Most common IVCF indications were closed head injury (48.6%) and spinal injuries (30.8%). Median time to administration of chemoprophylaxis was 96 h after IVCF (IQR 24-192) in 57.5%. Median IVCF cost was $759/d (IQR $361-$1897) compared with $4.32 for chemoprophylaxis. PE occurred in 0.26% without IVCF. PE did not occur with prophylactic IVCF. Estimated NNT was 379 (95% CI 265, 661).

CONCLUSIONS

Prophylactic IVCF placement is a costly practice with relatively low benefit. Anticipated time without chemoprophylaxis and patient criteria should be considered before routine IVCF placement.

The high-risk polytrauma patient and inferior vena cava filter use

OBJECTIVES

The aim of this study was to assess the impact on practice of vena cava filter insertion guidelines (Eastern Association for the Surgery of Trauma: practice management guidelines).

DESIGN

The study was performed at a level 1 trauma centre with data from the 'Trauma Audit and Research Network' cross-referenced to hospital data.

RESULTS

A total of 1138 specific 'high-risk' major trauma patients were identified over a 6-year period. The mean age was 46 years (18-102) and the male to female ratio was 3.3:1. The average Injury Severity Score was 23.6 (4-75). The overall DVT rate was 2.6% and the PE rate was 1.8%. A retrievable IVC filter was inserted in 42 cases (3.8%). The filter retrieval rate was 23.8% at a mean of 68.5days (4-107). Only one complication was reported of a breakthrough PE despite filter. Applying the EAST guidelines to this cohort would have suggested filter insertion in 279 (24.6%) cases. The kappa concordance value between observed practice and the 'EAST filter group' was 0.103 (poor). The PE rate in the 'EAST filter group' was 2.2% vs 1.6% in the 'no filter group' (p=0.601, no statistical difference) and the observed odds ratio was 0.814 (95% CI 0.413, 1.602).

CONCLUSION

The EAST guidelines are useful but may be overestimating the need for filter insertion.

Increased Enoxaparin Dosing for Venous Thromboembolism Prophylaxis in General Trauma Patients

Objective: To review the evidence regarding increased enoxaparin dosing for venous thromboembolism (VTE) prophylaxis in the general trauma patient population. Data Sources: A search of MEDLINE databases (1946 to October 2016) was conducted using the search terms enoxaparin, thromboembolism prophylaxis, venous thromboembolism, trauma, anti-factor Xa, and weight-based dosing. Additional references were identified from a review of literature citations. Study Selection and Data Extraction: Search results were limited to English-language studies conducted in humans. Trials that included only obese patients or nontrauma patients were excluded. Data Synthesis: A total of 7 trials (958 patients) explored the use of increased dosing of enoxaparin for VTE prophylaxis in trauma patients. Patients were divided by enoxaparin dosing strategies: standard dosing of 30 mg twice daily (BID; n = 509), higher initial dosing regimen (n = 216), or dosing based on anti-FXa level adjustments (n = 233). The majority of the 42 total VTE events (64.3%) occurred in the standard dosing regimen. Within each group, VTE was reported in 5.3% of patients in the standard dosing group, 3.2% in the higher initial dosing group, and 4% in the anti-FXa adjustment group. Initial subtherapeutic anti-FXa levels occurred in 33% to 92% of standard dose patients and 9% to 39% of higher initial dose patients. The average weight-based dose required to achieve a therapeutic level ranged between 0.43 and 0.54 mg/kg/dose BID. The overall rate of bleeding was low, with 3 incidents (0.37%) reported. Conclusion: Standard-dose enoxaparin prophylaxis may not be optimal for the general trauma patient population. Weight-based enoxaparin dosing (0.5 mg/kg/dose BID) is an option in trauma patients considered to be at a lower risk of bleeding complications.

Vena Caval Filters: A Review for Intensive Care Specialists

Venous thromboembolism (VTE) is a common complication among patients in the intensive care unit. While anticoagulation remains standard therapy, vena caval filters are an important alternative when anticoagulation is contraindicated. To determine the safety and efficacy of vena caval filters in the treatment of VTE, a comprehensive review of the English-language medical literature was performed. Except for one randomized controlled trial, the literature supporting the use of vena caval filters consists almost exclusively of case series, which in many instances are limited by incomplete and short follow-up. While case series suggest that filters function effectively in the prevention of pulmonary embolism (2%-4% symptomatic pulmonary embolism [PE], fatal PE < 2%), recent higher quality studies indicate that filters may not provide significant additional protection to that provided by anticoagulation alone. Furthermore, filters are associated with a 2- fold increase in the incidence of recurrent DVT. Until randomized comparative studies are available, the safety and efficacy of all the available devices should be considered to be roughly equivalent. Since filters do not inhibit continued clot formation, all filter patients should receive anticoagulation for durations appropriate for their thrombotic disorder. Although extended anticoagulation may prevent thrombotic complications associated with filter placement, this strategy has yet to be experimentally tested. While many additional indications for vena caval filter use have been proposed (VTE in cancer patients, PE prophylaxis in trauma patients, etc), well-designed clinical trials demonstrating their efficacy in these situations are lacking. Further development of temporary/retrievable filters, which offer the potential to avoid the long-term complications of permanent filters, should be a research priority. Until additional data are available, vena caval filters should generally be restricted to patients with VTE who cannot receive anticoagulation.

Optional Vena Cava Filters: What, Why, and When

Optional vena cava filters can used to provide either short-term or permanent protection from pulmonary embolism. These devices have recently become available for clinical use in the United States. However, there remains a paucity of data about these devices and their outcomes. This article reviews current and future devices, the rationale behind non-permanent caval filtration, and the generally accepted guidelines for their clinical application.

Preventing Venous Thromboembolism in the Critically Ill — Can We do More?

Pulmonary embolism is the most common preventable cause of hospital death; and of all the different patient groups, the critically ill are particularly at risk of venous thromboembolism. Most critically ill patients have multiple risk factors. Clinical trials have shown that the use of low molecular weight heparin (LMWH) is safer than unfractionated heparin in this population. Further trials are required to look at the risks and benefits of dose adjusting LMWH at the extremes of weight, in patients with renal failure and those on antiplatelet agents. Heparin-induced thrombocytopenia is still a risk with LMWHs so a safer anticoagulant such as fondaparinux and even the new oral anticoagulants merit trials. Further evidence is also needed for the use of graduated compression stockings and pneumatic devices.

Posttraumatic edema of the lower extremities: evaluation of the lymphatic vessels with magnetic resonance lymphangiography

OBJECTIVE

To assess for the first time the morphology of the lymphatic system in patients with posttraumatic edema of the lower extremities by magnetic resonance (MR) imaging using the interstitial lymphangiography technique

MATERIALS AND METHODS

Six patients with posttraumatic edema in eight of their 12 lower extremities were examined by MR lymphangiography. Eighteen mL of gadoteridol and one mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MR lymphangiography, a 3D-spoiled gradient-echo sequence was used.

RESULTS

In five of the eight (63%) traumatized lower extremities, enlarged lymphatic vessels were detected, with the largest diameter measuring 5 mm. Additionally, a fast lymphatic outflow was observed in seven of the eight (88%) traumatized legs with enhancement of the inguinal lymph nodes already in the first image acquisition 15 minutes after contrast material injection. In two of the eight (25%) traumatized lower extremities, an extensive network of collateral lymphatic vessels was detected at the level of the calf. In both extremities, lymphatic collateralization involved not only the epifascial but also the subfascial lymphatic system. In one patient, who sustained a trauma of the left lower leg with tibial fracture, a small aneurysmatic widening of 7 mm could be detected at the middle level of the calf.

CONCLUSION

MR lymphangiography is a safe and accurate minimal-invasive imaging modality for the evaluation of the lymphatic circulation in patients with posttraumatic edema of the lower extremities. If the extent of lymphatic damage is unclear at the initial clinical examination or requires a better definition for optimal therapeutic planning, MR lymphangiography is able to identify the anatomic and physiological derangements and to establish an objective baseline.

Thromboprophylaxis in patients with pelvic and acetabular fractures: A short review and recommendations

The management of thromboprophylaxis in patients with pelvic and acetabular fractures remains a highly controversial topic within the trauma community. Despite anticoagulation, venous thromboembolism (VTE) remains the most common cause of surgical morbidity and mortality in this high-risk patient group. Although various thromboprophylactic regimes are employed, evidence relating to the most effective method remains unclear. Controversies surrounding screening, the use of prophylactic inferior vena cava filters (IVCF) and chemothromboprophylaxis in polytraumatised patients, particularly those with pelvic and acetabular fractures, form the basis of considerable debate. With the absence of a well-designed clinical trial and the presence of ongoing controversies within the literature, this review will explore current treatment options available to trauma surgeons and highlight differing scientific opinions, providing an update on the role of screening and current available preventative measures. We cover existing as well as recent advances in chemical thromboprophylactic agents and discuss external mechanical compression devices, the usefulness of serial duplex ultrasonography and the role of extended chemothromboprophylaxis on discharge. The evidence behind prophylactic IVCF is also considered, along with reported complication profiles. We conclude with a proposed protocol for use in major trauma centres, which can form the basis of local policy for the prevention of VTE in trauma patients with pelvic and acetabular fractures.

Platelets are dominant contributors to hypercoagulability after injury

BACKGROUND

Venous thromboembolic (VTE) disease has a high incidence following trauma, but debate remains regarding optimal prophylaxis. Thrombelastography (TEG) has been suggested to be optimal in guiding prophylaxis. Thus, we designed a phase II randomized controlled trial to test the hypothesis that TEG-guided prophylaxis with escalating low-molecular weight heparin (LMWH), followed by antiplatelet therapy would reduce VTE incidence.

METHODS

Surgical intensive care unit trauma patients (n = 50) were randomized to receive 5,000 IU of LMWH daily (control) or to TEG-guided prophylaxis, up to 5,000 IU twice daily with the addition of aspirin, and were followed up for 5 days. In vitro studies were also conducted in which apheresis platelets were added to blood from healthy volunteers (n = 10).

RESULTS

Control (n = 25) and TEG-guided prophylaxis (n = 25) groups were similar in age, body mass index, Injury Severity Score, and male sex. Fibrinogen levels and platelet counts did not differ, and increased LMWH did not affect clot strength between the control and study groups. The correlation of clot strength (G value) with fibrinogen was stronger on Days 1 and 2 but was superseded by platelet count on Days 3, 4, and 5. There was also a trend in increased platelet contribution to clot strength in patients receiving increased LMWH. In vitro studies demonstrated apheresis platelets significantly increased clot strength (7.19 ± 0.35 to 10.34 ± 0.29), as well as thrombus generation (713.86 ± 12.19 to 814.42 ± 7.97) and fibrin production (274.03 ± 15.82 to 427.95 ± 16.58).

CONCLUSION

Increased LMWH seemed to increase platelet contribution to clot strength early in the study but failed to affect the overall rise clot strength. Over time, platelet count had the strongest correlation with clot strength, and in vitro studies demonstrated that increased platelet counts increase fibrin production and thrombus generation. In sum, these data suggest an important role for antiplatelet therapy in VTE prophylaxis following trauma, particularly after 48 hours.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Comparing clinical predictors of deep venous thrombosis versus pulmonary embolus after severe injury: a new paradigm for posttraumatic venous thromboembolism?

BACKGROUND

The traditional paradigm is that deep venous thrombosis (DVT) and pulmonary embolus (PE) are different temporal phases of a single disease process, most often labeled as the composite end point venous thromboembolism (VTE). However, we theorize that after severe blunt injury, DVT and PE may represent independent thrombotic entities rather than different stages of a single pathophysiologic process and therefore exhibit different clinical risk factor profiles.

METHODS

We examined a large, multicenter prospective cohort of severely injured blunt trauma patients to compare clinical risk factors for DVT and PE, including indicators of injury severity, shock, resuscitation parameters, comorbidities, and VTE prophylaxis. Independent risk factors for each outcome were determined by cross-validated logistic regression modeling using advanced exhaustive model search procedures.

RESULTS

The study cohort consisted of 1,822 severely injured blunt trauma patients (median Injury Severity Score [ISS], 33; median base deficit, -9.5). Incidence of DVT and PE were 5.1% and 3.9%, respectively. Only 9 (5.7%) of 73 patients with a PE were also diagnosed with DVT. Independent risk factors associated with DVT include prophylaxis initiation within 48 hours (odds ratio [OR], 0.57; 95% confidence interval [CI], 0.36-0.90) and thoracic Abbreviated Injury Scale (AIS) score of 3 or greater (OR, 1.82; 95% CI, 1.12-2.95), while independent risk factors for PE were serum lactate of greater than 5 (OR, 2.33; 95% CI, 1.43-3.79) and male sex (OR, 2.12; 95% CI, 1.17-3.84). Both DVT and PE exhibited differing risk factor profiles from the classic composite end point of VTE.

CONCLUSION

DVT and PE exhibit differing risk factor profiles following severe injury. Clinical risk factors for diagnosis of DVT after severe blunt trauma include the inability to initiate prompt pharmacologic prophylaxis and severe thoracic injury, which may represent overall injury burden. In contrast, risk factors for PE are male sex and physiologic evidence of severe shock. We hypothesize that postinjury DVT and PE may represent a broad spectrum of pathologic thrombotic processes as opposed to the current conventional wisdom of peripheral thrombosis and subsequent embolus.

Thromboprophylaxis for trauma patients

BACKGROUND

Trauma is a leading causes of death and disability in young people. Venous thromboembolism (VTE) is a principal cause of death. Trauma patients are at high risk of deep vein thrombosis (DVT). The incidence varies according to the method used to measure the DVT and the location of the thrombosis. Due to prolonged rest and coagulation abnormalities, trauma patients are at increased risk of thrombus formation. Thromboprohylaxis, either mechanical or pharmacological, may decrease mortality and morbidity in trauma patients who survive beyond the first day in hospital, by decreasing the risk of VTE in this population.A previous systematic review did not find evidence of effectiveness for either pharmacological or mechanical interventions. However, this systematic review was conducted 10 years ago and most of the included studies were of poor quality. Since then new trials have been conducted. Although current guidelines recommend the use of thromboprophylaxis in trauma patients, there has not been a comprehensive and updated systematic review since the one published.

OBJECTIVES

To assess the effects of thromboprophylaxis in trauma patients on mortality and incidence of deep vein thrombosis and pulmonary embolism. To compare the effects of different thromboprophylaxis interventions and their effects according to the type of trauma.

SEARCH METHODS

We searched The Cochrane Injuries Group Specialised Register (searched April 30 2009), Cochrane Central Register of Controlled Trials 2009, issue 2 (The Cochrane Library), MEDLINE (Ovid) 1950 to April (week 3) 2009, EMBASE (Ovid) 1980 to (week 17) April 2009, PubMed (searched 29 April 2009), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED) (1970 to April 2009), ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S) (1990 to April 2009).

SELECTION CRITERIA

Randomized controlled clinical trials involving people of any age with major trauma defined by one or more of the following criteria: physiological: penetrating or blunt trauma with more than two organs and unstable vital signs, anatomical: people with an Injury Severity Score (ISS) higher than 9, mechanism: people who are involved in a 'high energy' event with a risk for severe injury despite stable or normal vital signs. We excluded trials that only recruited outpatients, trials that recruited people with hip fractures only, or people with acute spinal injuries.

DATA COLLECTION AND ANALYSIS

Four authors, in pairs (LB and CM, EF and RC), independently examined the titles and the abstracts, extracted data, assessed the risk of bias of the trials and analysed the data. PP resolved any disagreement between the authors.

MAIN RESULTS

Sixteen studies were included (n=3005). Four trials compared the effect of any type (mechanical and/or pharmacological) of prophylaxis versus no prophylaxis. Prophylaxis reduced the risk of DVT in people with trauma (RR 0.52; 95% CI 0.32 to 0.84). Mechanical prophylaxis reduced the risk of DVT (RR = 0.43; 95% CI 0.25 to 0.73). Pharmacological prophylaxis was more effective than mechanical methods at reducing the risk of DVT (RR 0.48; 95% CI 0.25 to 0.95). LMWH appeared to reduce the risk of DVT compared to UH (RR 0.68; 95% CI 0.50 to 0.94). People who received both mechanical and pharmacological prophylaxis had a lower risk of DVT (RR 0.34; 95% CI 0.19 to 0.60)

AUTHORS' CONCLUSIONS

We did not find evidence that thromboprophylaxis reduces mortality or PE in any of the comparisons assessed. However, we found some evidence that thromboprophylaxis prevents DVT. Although the strength of the evidence was not high, taking into account existing information from other related conditions such as surgery, we recommend the use of any DVT prophylactic method for people with severe trauma.

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

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.

The use of prophylactic inferior vena cava filters in trauma patients: a systematic review

INTRODUCTION

Pulmonary embolisms (PE) are an often preventable cause of late morbidity and mortality after trauma. Although there is evidence for the use of therapeutic inferior vena cava (IVC) filters (defined as IVC filters implanted in those with proven deep venous thrombosis [DVT] in order to prevent PE), there is not as much evidence to support the use of prophylactic IVC filters. Thus, we undertook a systematic review of the literature to assess the following in prophylactic IVC filters: efficacy in PE reduction, prevalence of filter-related complications and the indications for use.

MATERIALS AND METHODS

After screening 249 studies, 24 studies met inclusion criteria for qualitative synthesis.

RESULTS

Overall, the literature is supportive of the use of prophylactic IVC filters in high-risk poly-trauma patients who may have contraindications to DVT prophylaxis. Filter-associated complications are uncommon and, when they do occur, tend to be of limited clinical significance. Limited data, mostly in the form of case series, supports a reduction in PE and PE-related mortality. There has been increasing use of retrievable filters as well as the ability to safely retrieve them at longer intervals.

CONCLUSION

Despite the addition of a few matched-control studies, the literature is still plagued by a lack of high quality data, and therefore the true efficacy of prophylactic IVC filters for prevention of PE in trauma patients remains unclear. Further studies are required to determine the true role of prophylactic IVC filters in trauma patient.

Oral thromboprophylaxis in pelvic trauma: a standardized protocol

BACKGROUND

Thromboprophylaxis for deep vein thrombosis (DVT) after lower-extremity trauma could include rivaroxaban, an oral medication that does not need laboratory monitoring.

OBJECTIVE

To assess rivaroxaban's efficacy in preventing DVTs after pelvic trauma compared to its historical incidence.

MATERIALS AND METHODS

All patients admitted with pelvic fractures in a 12-month period followed a standardized thromboprophylaxis protocol: 1) rivaroxaban 10 mg/day within 24 h of injury or upon hemodynamic stability; 2) pre-operative, post-operative, and 30-day extremity ultrasound; 3) ventilation-perfusion scintigraphy for clinical signs of pulmonary embolus; and 4) a 45-, 90-, and 120-day re-evaluation. Rivaroxaban administration ceased the day of surgery and restarted 12 h post-operatively or upon hemodynamic stability, continuing for 30 days. Excluded patients had severe neurological or hepatosplenic injuries, heparin hypersensitivity, or hemodynamic instability.

RESULTS

Of 113 patients assessed, 84 patients (66 males), average age 46.6 years (range 19-69 years), were included. They had isolated pelvic trauma (n = 37), associated lower limb injuries (n = 47), average Injury Severity Score 21.4 (range 16-50), and average Glasgow Coma Scale score 13.6 (range 9-15). Patients receiving thromboprophylaxis soon after their fracture (n = 64) had a lower incidence of DVT than those receiving delayed thromboprophylaxis (n = 20) (p = 0.02). One patient (1.2%) died from a pulmonary embolus; 13 had asymptomatic below-the-knee DVTs. Rivaroxaban did not increase intra- or post-operative bleeding in surgical wounds.

CONCLUSIONS

DVT incidence after pelvic fractures is reduced by administering antithrombotics within 24 h of injury or, if the patient is hemodynamically unstable, 24 h after stabilization. Rivaroxaban is a safe and effective method of providing this thromboprophylaxis.

Vena cava interruption

Anticoagulation has been proven to be effective in preventing and treating deep vein thrombosis and pulmonary embolus. However, many critically ill patients are unable to receive anticoagulation or suffer recurrent venous thromboembolism despite adequate treatment. This article examines the use of vena cava filters in the critically ill. Indications for, techniques, and complications of vena cava filter insertion are reviewed. The importance of vena cava filters with the option to be retrieved and bedside insertion in the intensive care unit is emphasized.

Optional inferior vena cava filters in the trauma patient

Trauma patients are at exceedingly high risk of development of venous thromboembolism (VTE) including deep venous thrombosis and pulmonary embolism (PE). The epidemiology of VTE in trauma patients is reviewed. PE is thought to be the third major cause of death after trauma in those patients who survive longer than 24 hours after onset of injury. In fact, patients recovering from trauma have the highest rate of VTE among all subgroups of hospitalized patients. Various prophylactic and surveillance methods have been evaluated and found helpful in certain situations, but VTE complications can occur despite such measures. Therapeutic and prophylactic uses of inferior vena cava (IVC) filters in trauma patients are reviewed. Prophylactic IVC filter use is revealed to be a controversial subject with valid arguments on both sides of the issue. With the lack of prospective randomized trials of IVC filter use in trauma, it is impossible to make evidence-based recommendations. Unfortunately, two sets of guidelines are available for insertion of filters in trauma patients, with conflicting recommendations. The introduction of retrievable IVC filters seems to offer a unique solution for VTE protection in the trauma patient population, which often consists of younger members of our population. Lastly, current generations of FDA-approved retrieval filters are discussed.

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.

Prophylaxis for venous thromboembolism: guidelines translated for the clinician

Venous thromboembolism is a major cause of morbidity and mortality worldwide and most often affects hospitalized postoperative surgical and medical patients. Venous thromboembolism prophylaxis undoubtedly improves the care of these patients, as demonstrated by the current literature and guidelines. Failure to prescribe prophylaxis when indicated, however, remains a vital health care concern. The American College of Chest Physicians (ACCP) published their most recent guidelines regarding venous thromboembolism prophylaxis in 2008. In this review, we aim to summarize the most recent ACCP prophylaxis guidelines with practical application and interpretation for the practicing physician. Here we present the most practical information from these guidelines and summarize essential recommendations in key tables. We will briefly review the grading system used in the guidelines for the level of evidence and the strength of the recommendation. We will then discuss the recommendations for prophylaxis in the various patient populations described in these guidelines including general and orthopedic surgery, gynecologic surgery, urologic surgery, thoracic surgery, neurosurgery, trauma, medical conditions, cancer patients, and critical care. In addition, we will discuss recent clinical trials regarding novel anticoagulants for venous thromboembolism prophylaxis and share some conclusions.

Results of the CONTROL trial: efficacy and safety of recombinant activated Factor VII in the management of refractory traumatic hemorrhage

BACKGROUND

Traumatic coagulopathy contributes to early death by exsanguination and late death in multiple organ failure. Recombinant Factor VIIa (rFVIIa, NovoSeven) is a procoagulant that might limit bleeding and improve trauma outcomes.

METHODS

We performed a phase 3 randomized clinical trial evaluating efficacy and safety of rFVIIa as an adjunct to direct hemostasis in major trauma. We studied 573 patients (481 blunt and 92 penetrating) who bled 4 to 8 red blood cell (RBC) units within 12 hours of injury and were still bleeding despite strict damage control resuscitation and operative management. Patients were assigned to rFVIIa (200 μg/kg initially; 100 μg/kg at 1 hour and 3 hours) or placebo. Intensive care unit management was standardized using evidence-based trauma "bundles" with formal oversight of compliance. Primary outcome was 30-day mortality. Predefined secondary outcomes included blood products used. Safety was assessed through 90 days. Study powering was based on prior randomized controlled trials and large trauma center databases.

RESULTS

Enrollment was terminated at 573 of 1502 planned patients because of unexpected low mortality prompted by futility analysis (10.8% vs. 27.5% planned/predicted) and difficulties consenting and enrolling sicker patients. Mortality was 11.0% (rFVIIa) versus 10.7% (placebo) (p = 0.93, blunt) and 18.2% (rFVIIa) versus 13.2% (placebo) (p = 0.40, penetrating). Blunt trauma rFVIIa patients received (mean ± SD) 7.8 ± 10.6 RBC units and 19.0 ± 27.1 total allogeneic units through 48 hours, and placebo patients received 9.1 ± 11.3 RBC units (p = 0.04) and 23.5 ± 28.0 total allogeneic units (p = 0.04). Thrombotic adverse events were similar across study cohorts.

CONCLUSIONS

rFVIIa reduced blood product use but did not affect mortality compared with placebo. Modern evidence-based trauma lowers mortality, paradoxically making outcomes studies increasingly difficult.

Deep vein thrombosis in major trauma

Major trauma patients are at increased risk of developing deep vein thrombosis (DVT). Certain injuries may be associated with an increased DVT risk, though definitive evidence regarding specific risk factors is lacking. The role of mechanical thromboprophylaxis in major trauma remains unclear and these methods are often contraindicated in lower limb injuries. Low molecular weight heparin is effective in reducing DVT frequency in major trauma with acceptable haemorrhagic complications. Evidence regarding the efficacy of thromboprophylaxis specifically in major trauma patients is lacking. However, recently published guidelines from the National Institute for Health and Clinical Excellence appear to make recommendations based on findings in other patient populations rather than using the best available evidence in major trauma patients. Future studies must identify specific DVT risk factors in major trauma to allow accurate risk stratification, determine the time period patients remain at increased DVT risk and establish the role of combined thromboprophylaxis.

Unfractionated Heparin Three Times a Day versus Enoxaparin in the Prevention of Deep Vein Thrombosis in Trauma Patients

Venous thromboembolic disease is a significant source of morbidity and mortality in hospitalized trauma patients. Multiple drugs and dosing regimens have been suggested for pharmacoprophylaxis. In this study, we compared efficacy, complications, and cost of unfractionated heparin administered subcutaneously three times a day with standard-dosed enoxaparin for prophylaxis of deep venous thrombosis (DVT) in adult trauma patients over 1 year. Patients admitted for greater than 72 hours who received pharmacoprophylaxis as part of a comprehensive DVT protocol were included. A change was made in the protocol from enoxaparin (30 mg twice a day or 40 mg per day) to heparin (5000 U three times a day) at midyear. Surveillance lower extremity venous ultrasound was performed according to established institutional guidelines. Data, including demographics, associated injuries, complications, and cost, were collected and analyzed. Four hundred seventy-six patients met inclusion criteria. Two hundred thirty-seven (49.8%) patients received enoxaparin and 239 (50.2%) received heparin. Proximal lower extremity DVTs were detected in 16 (6.75%) patients in the enoxaparin group and 17 (7.11%) in the heparin group ( P = 0.999). Risk factors for DVT in these patients included spinal cord injury ( P = 0.001) and closed head injury ( P = 0.031). There was no difference between the incidence of pulmonary emboli and bleeding. There was an estimated yearly pharmacy cost savings of $135,606. In trauma patients, subcutaneous heparin dosed three times a day may be as effective as standard-dosed enoxaparin for prophylaxis of venous thromboembolism without increased complications. Heparin three times a day for venous thromboembolism prophylaxis was associated with significant pharmaceutical cost savings.

Mechanical compression versus subcutaneous heparin therapy in postoperative and posttrauma patients: a systematic review and meta-analysis

BACKGROUND

The risk of postoperative venous thromboembolic disease is as high as 30%, with an associated fatality risk of 1%. Therefore, prophylaxis is essential, but the optimal regimen remains controversial. This study was designed to systematically review and quantitatively summarize the impact of mechanical compression versus subcutaneous heparin on venous thromboembolic disease and posttreatment bleeding in postsurgical and posttrauma patients.

METHODS

Computerized searches of the MEDLINE and EMBASE databases through November 2008 were performed and supplemented with manual searches. We included studies that had: (1) a patient population undergoing surgery or admitted immediately posttrauma, (2) a randomized comparison of prophylaxis with mechanical compression versus subcutaneous heparin, (3) outcome measured in terms of deep vein thrombosis (DVT), pulmonary embolism (PE), or bleeding.

RESULTS

Two reviewers independently extracted data from the original articles, which represented 16 studies, including a total of 3,887 subjects. Meta-analysis was performed using a random effects model. The pooled relative risk for mechanical compression compared with subcutaneous heparin was 1.07 (95% confidence interval [CI] 0.72, 1.61) for DVT and 1.03 (95% CI 0.48, 2.22) for PE. Mechanical compression was associated with a significantly reduced risk of postoperative bleeding compared with subcutaneous heparin (risk ratio 0.47; 95% CI 0.31, 0.70). Subgroup analyses by heparin type suggested that low molecular weight heparin may reduce risk of DVT compared with compression (relative risk 1.80; 95% CI 1.16, 2.79) but remains similarly associated with an increased risk of bleeding.

CONCLUSIONS

These results suggest that the overall bleeding risk profile favors the use of compression over heparin, with the benefits in term of venous thromboembolic disease prophylaxis being similar between groups. Subgroup analyses suggest that low molecular weight heparin may have a differential effect; this observation should be further evaluated in future studies.

Thromboprophylaxis for trauma patients

This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the effects of thromboprophylaxis in trauma patients on mortality and incidence of DVT and PE. To compare the effects of different thromboprophylaxis interventions and their relative effects according to the type of trauma.

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

BACKGROUND

Although permanent prophylactic Greenfield filters (PPGF) are effective, their use in young trauma patients who may eventually return to active lifestyles is controversial due to concerns about the safety of the devices over a lifetime. This descriptive study was undertaken to provide follow-up on the long-term safety and durability of PPGF.

METHODS

All patients receiving a PPGF between April 1, 1992 and March 1, 2001 were sought for follow-up. Contacted patients were interviewed regarding known filter-related complications, venous thromboembolic events, and activity levels since the time of discharge from the hospital. Patients were also offered a physical examination focusing on venous thromboembolic sequelae, a plain film of the abdomen (KUB) to assess filter integrity and location, and an ultrasound to assess caval patency. As the original level of filter placement was usually not known, migration was defined as a filter above the first lumbar vertebra (L1).

RESULTS

The eligible cohort consisted of 188 patients. Ninety were unable to be located (47.8%), one refused enrollment (0.5%), and 97 patients or next of kin agreed to be interviewed by phone (51.6%) of whom 69 returned for evaluation (36.7%). No filter-related complications were self-reported. KUBs were performed in 68 patients; one filter strut fracture was found (1.5%), whereas no filter migrations above L1 were noted. No instances of caval thrombosis were found in 55 ultrasounds. Two patients suffered interim pulmonary emboli (2.1%), one of which was fatal. Of 15 interim deaths, autopsy or death certificates were available for four patients, nine had their causes of death related by next of kin, and two were unknown. Although 95.4% of nonspinal cord injury patients reported at least some ability to ambulate, only 64.6% could do so ad libitum. Of those patients ambulating without limitation, 28.6% reported a complete inability to run any distance and another 23.8% could run less than one block. Follow-up for patients completing interviews was 105.3 months +/- 18.0 months, and for patients undergoing imaging was 104.6 months +/- 16.4 months. Interim deaths occurred at 48.2 months +/- 26.0 months.

CONCLUSIONS

PPGF seem to be safe and effective at 105 months of follow-up; most patients report significant limitations in activity level at this same timeframe. PPGF should be the filter of choice for elderly patients in whom this time period can reasonably be expected to cover the patient's remaining life expectancy.

What are we missing: results of a 13-month active follow-up program at a level I trauma center

BACKGROUND

Poor follow-up by patients with trauma results in a lack of knowledge of postdischarge health-related issues. This study reports on postdischarge health-related issues discovered by a program of active postdischarge contact or follow-up.

METHODS

All patients discharged home from the trauma service were followed up in the following manner: within 4 weeks of discharge, telephonic follow-up was attempted three times followed by scanning of electronic records. Failing that, other physicians (specialists or primary care) were contacted. Once contact was established, the patient, family member, or physician was questioned about the general well-being, any specific health-related issue, and the resolution.

RESULTS

During the 13-month study period ending September 2007, a total of 1,353 patients met entry criteria. Contact was established with 692 (51%). Of these, 116 (17%) were found to have significant health issues: (1) severe uncontrolled pain, 45; (2) missed injury, 17 (spine fractures, 4; clavicle or hand or foot fractures, 6; facial bone fractures, 3; soft tissue, 3; hematuria, 1); (3) wound infections, 17; (4) other infections, 17 (urinary, 8; pulmonary, 7; blood stream, 2) (5) venous thromboembolism, 10; and (6) other, 9 (psychiatric, 6; nontraumatic, 3). One patient died at home within 24 hours of discharge. The issues were significant enough for the patients to seek medical care (outpatient, 39; emergency department visits, 52; hospitalization, 24).

CONCLUSION

A significant proportion of patients with trauma have moderate to severe health-related issues postdischarge that are often not found by the trauma team or the trauma registry. Active follow-up can identify the nature of the medical issues and help in designing system changes to reduce or eliminate them.