Risk factors associated with pulmonary embolism despite routine prophylaxis: implications for improved protection

Incidence, risk factors and potential timing of occurrence of pulmonary embolism in fatal trauma: An autopsy based case-control study on 2705 victims

BACKGROUND

Pulmonary embolism (PE) following trauma is a potentially preventable but highly lethal complication. We sought to investigate the incidence, risk factors and potential timing of occurrence of post-traumatic PE in a large cohort of trauma fatalities.

METHODS

A case-control study on 9266 consecutive trauma fatalities (between 1996 and 2005) from a regional autopsy-based trauma registry. Injuries were classified according to the Abbreviated Injury Scale-1990 edition (AIS-90) and the Injury Severity Score (ISS) was calculated. Hospitalized victims were categorized according to the presence or absence of PE on autopsy. Univariate comparisons and multivariate logistic regression analysis for probabilities of association (odds ratios-OR) were performed.

RESULTS

Out of 2705 subjects who met the inclusion criteria, 116 had autopsy findings of PE and constituted the PE group (incidence of 4,3%), while the remaining victims formed the control group. The survival time of the PE group ranged from 0.66 to 104.73 days. Victims in the PE group were older (median age 69.5 vs 59), had lower ISS values (median 16 vs 26) and longer post-injury survival times (median 13.6 vs 5.7 days). Positively associated risk factors were AIS2-5 pelvic ring injuries (OR:2.23) and secondary deaths following an uneventful hospital discharge (OR:3.97), while AIS2-5 head (OR:0.33) and abdominal injuries (OR:0.23) showed a reverse association.

CONCLUSIONS

Trauma fatalities with autopsy findings of PE were associated with less severe trauma indicating that PE was likely detrimental to the fatal outcome. Both the early and delayed occurrence of PE was reaffirmed. Prophylactic measures should be initiated promptly and extended post discharge for high risk patients to prevent secondary deaths.

Venous thromboembolism prophylaxis in the trauma intensive care unit: an American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document

Venous thromboembolism (VTE) is a potential sequela of injury, surgery, and critical illness. Patients in the Trauma Intensive Care Unit are at risk for this condition, prompting daily discussions during patient care rounds and routine use of mechanical and/or pharmacologic prophylaxis measures. While VTE rightfully garners much attention in clinical patient care and in the medical literature, optimal strategies for VTE prevention are still evolving. Furthermore, trauma and surgical patients often have real or perceived contraindications to prophylaxis that affect the timing of preventive measures and the consistency with which they can be applied. In this Clinical Consensus Document, the American Association for the Surgery of Trauma Critical Care Committee addresses several practical clinical questions pertaining to specific or unique aspects of VTE prophylaxis in critically ill and injured patients.

How to Safely Prevent Venous Thromboembolism in Severe Trauma Patients

Venous thromboembolism (VTE) is a life-threatening complication after trauma. Several studies have reported VTE prophylaxis using low-molecular-weight heparin; however, there is no consensus for prophylaxis after trauma. This study aimed to assess the efficacy and safety of our new anticoagulation therapy protocol using unfractionated heparin (UFH) plus intermittent pneumatic compression (IPC) to prevent post-traumatic VTE in high-risk trauma patients.This study enrolled 70 trauma patients who were admitted to the emergency medical center of Nagasaki University Hospital and had Risk Assessment Profile (RAP) scores ≥ 5. After stopping bleeding at the trauma site, all patients received intravenous UFH (10,000 U/day) plus IPC, which was continued for 14 days or until the patients could walk. On days 7 and 14, all patients underwent lower extremity sonography for deep-vein thrombosis screening. VTE incidences between patients with the above intervention and historical controls with IPC alone were compared.No significant differences in age, sex, and the RAP score were observed between the 105 controls and intervention patients. VTE occurrence was fewer in patients with the intervention (14.3%) than in the controls (28.6%; P = 0.029). No hemorrhagic complications occurred after UFH administration. Multivariable logistic analysis revealed a significant association between the intervention and low incidence of VTE (odds ratio: 0.390; 95% confidence interval: 0.163-0.913; P = 0.030).Routine UFH administration with IPC may prevent post-traumatic VTE without adverse events.

“Death Knell” for Prophylactic Vena Cava Filters? A 20-Year Experience with a Venous Thromboembolism Guideline

The role of prophylactic vena cava filters (pVCFs) in trauma patients remains controversial. After 20 years of data collection and experience, we reviewed our venous thromboembolism guideline for the efficacy of pVCFs in preventing pulmonary embolism (PE). A retrospective cohort study was performed using our Level I trauma center registry from January 1997 thru December 2016. This population was then divided by the presence of pVCFs. Univariate analysis was performed comparing the incidence of PEs, deep vein thrombosis, and mortality between those with and without a pVCF. There were 35,658 patients identified, of whom 2 per cent (n = 847) received pVCFs. The PE rate was 0.4 per cent in both groups. The deep vein thrombosis rate for pVCFs was 3.9 per cent compared with 0.6 per cent in the no-VCF group ( P < 0.0001). Given that there was no difference in the rates of PEs between the cohorts, the subset of patients with a PE were analyzed by their risk factors. Only ventilator days > 3 were associated with a higher risk in the no-pVCF group (0.2 vs 1.5%, P = 0.033). pVCFs did not confer benefit reducing PE rate. In addition, despite their intended purpose, pVCFs cannot eliminate PEs in high-risk trauma patients, suggesting a lack of utility for prophylaxis in this population.

WACEM Consensus Paper on Deep Venous Thrombosis after Traumatic Spinal Cord Injury

The risk and outcome of deep vein thrombosis (DVT) in patients who sustained spinal cord injury (SCI) remain a challenge. We aimed to assess the incidence, risk, burden, and prophylaxis of DVT after SCI. Thirty-nine studies were identified from among 250 relevant articles based on firstly, broad criterion of DVT among SCI cases. secondly, "risk factors" impacting DVT, thirdly, published reports from apex bodies of global importance such as World Health Organization, Centre for disease control, Atlanta USA, and others were given due weightage for their authenticity. SCI is characterized by loss of motor, sensory, and autonomic function with partial or total damage of the anatomical structure leading to increased risk of thrombogenesis. SCIs present a higher risk of venous DVT constituting 9.7% of deaths in the 1st year of follow-up. Currently, prophylaxis with mechanical methods, vena cava filters and antithrombotic chemoprophylaxis in SCI are interventions for the management of DVT. DVT in SCI patients is not uncommon and needs a high index of suspicion and implementation of institutional prophylaxis protocol.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

[Posttraumatic thromboembolic complications: Incidence, risk factors, pathophysiology and prevention]

Venous thromboembolism (VTE) remains a major challenge in critically ill patients. Subjects admitted in intensive care unit (ICU), in particular trauma patients, are at high-risk for both deep vein thrombosis (DVT) and pulmonary embolism (PE). The rate of symptomatic PE in injured patients has been reported previously ranging from 1 to 6%. The high incidence of posttraumatic venous thromboembolic events is well known. In fact, major trauma is a hypercoagulable state. Several factors placing the individual patient at a higher risk for the development of DVT and PE have been suggested: high ISS score, meningeal hemorrhage and spinal cord injuries have frequently been reported as a significant risk factor for VTEs after trauma. Posttraumatic pulmonary embolism traditionally occurs after a period of at least 5 days from trauma. The prevention can reduce the incidence and mortality associated with the pulmonary embolism if it is effective. There is no consensus is now available about the prevention of venous thromboembolism in trauma patients.

Lethal Trauma Pulmonary Embolism is a Black Swan Event in Patients at Risk for Deep Vein Thrombosis: An Evidence-Based Review

We delineated the incidence of trauma patient pulmonary embolism (PE) and risk conditions by performing a systematic literature review of those at risk for deep vein thrombosis (DVT). The PE proportion was 1.4 per cent (95% confidence interval = 1.2–1.6) in at-risk patients. Of 10 conditions, PE was only associated with increased age (P < 0.01) or leg injury (P < 0.01; risk ratio = 1.6). As lower extremity DVT (LEDVT) proportions increased, mortality proportions (P = 0.02) and hospital stay (P = 0.0002) increased, but PE proportions did not (P = 0.13). LEDVT was lower with chemoprophylaxis (CP) (4.9%) than without CP (19.1%; P < 0.01). PEwas lower withCP (1.0%) than without CP (2.2%; P = 0.0004). Mortality was lower with CP (6.6%) than without CP (11.6%; P = 0.002). PE was similar with (1.2%) and without (1.9%; P = 0.19) mechanical prophylaxis (MP). LEDVT was lower with MP (8.5%) than without MP (12.2%; P = 0.0005). PE proportions were similar with (1.3%) and without (1.5%; P = 0.24) LEDVTsurveillance. Mortality was higher with LEDVTsurveillance (7.9%) than without (4.8%; P < 0.01). A PE mortality of 19.7 per cent (95% confidence interval = 18–22) 3 a 1.4 per cent PE proportion yielded a 0.28 per cent lethal PE proportion. As PE proportions increased, mortality (P = 0.52) and hospital stay (P = 0.13) did not. Of 176 patients with PE, 76 per cent had no LEDVT. In trauma patients at risk for DVT, PE is infrequent, has a minimal impact on outcomes, and death is a black swan event. LEDVTsurveillance did not improve outcomes. Because PE was not associated with LEDVT and most patients with PE had no LEDVT, preventing, diagnosing, and treating LEDVT may be ineffective PE prophylaxis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Venous Thromboembolism Prophylaxis in Orthopaedic Trauma Patients: A Survey of OTA Member Practice Patterns and OTA Expert Panel Recommendations

OBJECTIVES

First, to provide the readership with a summation of the current practice patterns of North American orthopaedic surgeons for venous thromboembolism prophylaxis after musculoskeletal trauma. Second, to establish a set of guidelines and recommendations based on the most current and best available evidence for venous thromboembolism (VTE) prophylaxis after musculoskeletal trauma.

METHODS

A 24 item questionnaire titled "OTA VTE Prophylaxis Survey" was sent to active members of the Orthopaedic Trauma Association. PubMed and OVID/MEDLINE were used to search the current published literature regarding VTE prophylaxis in trauma patients using the following search terms: deep venous thrombosis, DVT, pulmonary embolism, PE, venous thromboembolism, VTE, prophylaxis, trauma, fracture, pneumatic compression device, PCD, sequential compression device, SCD, screening, ultrasound, duplex, ultrasonography, DUS, venography, magnetic resonance venography, MRV, inferior vena cava, IVC, filter, and IVCF. Each recommendation was graded using articles that were considered by the subcommittee as "the best available evidence" using the grading system adopted and endorsed by the American Academy of Orthopedic Surgeons' Evidenced Based Quality and Value committee.

RESULTS

Overall, 185 of 1545 members completed the online survey. The range and variety of prophylaxis and screening methods used among orthopaedic trauma surgeons in North America is large, with a number of agents or methods for which no literature exists to support their use in musculoskeletal trauma. A set of recommendations and guidelines were constructed based on the results of the literature analysis and graded according to guidelines mentioned above.

CONCLUSIONS

Due to the wide variability in practice patterns, poor scientific support for various therapeutic regimens and important medical-legal implications highlighted by the survey, a standardized set of guidelines and recommendations for VTE prophylaxis after musculoskeletal trauma will be critical in helping to improve patient care and minimize surgeons' exposure to potentially litigious activity.

LEVEL OF EVIDENCE

Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Caval filters in intensive care: a retrospective study

AIM

To evaluate the effectiveness of a caval vein filter (CVF) peri-implant monitoring protocol in order to reduce pulmonary embolism (PE) mortality and CVF-related morbidity.

BACKGROUND

The reduction in mortality from PE associated with the use of CVF is affected by the risk of increase in morbidity. Therefore, CVF implant is a challenging prophylactic or therapeutic option. Nowadays, we have many different devices whose rational use, by applying a strict peri-implant monitoring protocol, could be safe and effective.

MATERIALS AND METHODS

We retrospectively studied 62 patients of a general Intensive Care Unit (ICU) scheduled for definitive, temporary, or optional bedside CVF implant. A peri-implant monitoring protocol including a phlebocavography, an echo-Doppler examination, and coagulation tests was adopted.

RESULTS

In our study, no thromboembolic recurrence was registered. We implanted 48 retrievable and only 20 definitive CVFs. Endothelial adhesion (18%), residual clot (5%), cranial or caudal migration (6%), microbial colonization of the filter in the absence of clinical signs of infection (1%), caval thrombosis (1%), and pneumothorax (1%) were reported. Deep-vein thrombosis (DVT) was reported (8%) as early complication. All patients with DVT had a temporary or optional filter implanted. However, in our cohort, definitive CVFs were reserved only to 32% of patients and they were not associated with DVT as complication.

CONCLUSION

CVF significantly reduces iatrogenic PE without affecting mortality. Generally, ICU patients have a transitory thromboembolic risk, and so the temporary CVF has been proved to be a first-line option to our cohort. A careful monitoring may contribute to a satisfactory outcome in order to promote CVF implant as a safe prophylaxis option.

Computed tomography pulmonary angiography: more than a screening tool for pulmonary embolus

BACKGROUND

Traumatically injured patients have multiple causes for acute respiratory decompensation. We reviewed the use of computed tomography pulmonary angiography (CTPA) in critically injured patients to evaluate the results and impact on patient care.

METHODS

The charts of trauma patients (age >16 years) admitted to our intensive care unit for greater than 48 hours, who underwent CTPA for acute respiratory decompensation, were reviewed to determine the results of these studies and the effect on patient care.

RESULTS

We identified 188 patients who underwent CTPA for acute physiologic changes. Pertinent clinical finding were identified in 95% of studies and included atelectasis/collapse (56%), pleural effusion (18%), pneumonia (15%), and pulmonary embolus (18%). These results prompted interventions designed to improve patient outcome. The most frequent interventions were modifications of ventilator therapy (52%), antibiotic therapy (28%), mini-bronchoalveolar lavage (15%), or bronchoscopy (15%). Diagnostic agreement between chest x-ray and CTPA was poor to moderate (κ = 0.013-0.512).

CONCLUSIONS

Computed tomography pulmonary angiography is valuable in the evaluation of cardiopulmonary deterioration in critically ill traumatically injured patients. Computed tomography pulmonary angiography offers the ability to identify causes of acute physiologic changes not detected using standard chest x-ray. The results of these studies provide insight into the underlying pathophysiology and offer an opportunity to direct subsequent patient care.

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.

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.

Implante profilático e temporário de filtro de veia cava inferior no trauma

O tromboembolismo pulmonar (TEP) é importante causa de óbito no trauma e esse, na maioria das vezes, contraindica a principal farmacoterapia na prevenção e no tratamento do TEP: a anticoagulação. Relatamos um caso de paciente politraumatizado, com risco elevado de embolia pulmonar, submetido ao implante preventivo e temporário de filtro de veia cava inferior (FVC).

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.

Three thousand seven hundred thirty-eight posttraumatic pulmonary emboli: a new look at an old disease

OBJECTIVE

This study was undertaken to determine the current incidence of pulmonary embolism (PE) and its attributable mortality after injury.

BACKGROUND

Despite compliance with prophylactic measures, PE remains a threat to postinjury recovery. We hypothesized that the liberal use of chest computed tomography after injury has resulted in an increased rate of detection of PE but that the mortality attributable to PE has decreased over the past decade. We also postulated that the risk factors for posttraumatic PE might be different from those for deep venous thrombosis (DVT).

METHODS

We examined demographics, injury data, risk factors, and outcomes from patients with DVT and PE compiled in the recent years (2007-2009) in the National Trauma Data Bank (NTDB). For comparison, we used patient data entered into NTDB from 1994 to 2001. Statistical models were created to examine the predictors of DVT and PE and PE-related mortality.

RESULTS

Among 888,652 patients in the current NTDB cohort, there were 9398 episodes of DVT (1.06%) and 3738 of PE (0.42%). Although many risk factors overlapped, a severe chest injury (Abbreviated Injury Score ≥ 3) conferred a much higher risk of PE than DVT. When comparing results from centers that had contributed to both data sets, there was a more than 2-fold increase in PE occurrence in the current cohort (0.49% vs 0.21%, P < 0.01) but with a significant reduction in PE-adjusted mortality (odds ratio, 4.08 vs 2.42).

CONCLUSIONS

The reported incidence of PE after trauma has more than doubled in recent years, while the PE-associated mortality has significantly decreased, suggesting that we are identifying a different disease entity or stage. Chest injuries convey a substantial risk for PE, a risk not likely to be diminished by leg compression devices or vena cava filters.

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.

Cost-effectiveness of guidelines for insertion of inferior vena cava filters in high-risk trauma patients

BACKGROUND

Inferior vena cava filters (IVCFs) can prevent pulmonary embolism (PE); however, indications for use vary. The Eastern Association for the Surgery of Trauma (EAST) 2002 guidelines suggest prophylactic IVCF use in high-risk patients, but the American College of Chest Physicians (ACCP) 2008 guidelines do not. This analysis compares cost-effectiveness of prophylactic vs therapeutic retrievable IVCF placement in high-risk trauma patients.

METHODS

Markov modeling was used to determine incremental cost-effectiveness of these guidelines in dollars per quality-adjusted life-years (QALYs) during hospitalization and long-term follow-up. Our population was 46-year-old trauma patients at high risk for venous thromboembolism (VTE) by EAST criteria to whom either the EAST (prophylactic IVCF) or ACCP (no prophylactic IVCF) guidelines were applied. The analysis assumed the societal perspective over a lifetime. For base case and sensitivity analyses, probabilities and utilities were obtained from published literature and costs calculated from Centers for Medicare & Medicaid Services fee schedules, the Healthcare Cost & Utilization Project database, and Red Book wholesale drug prices for 2007. For data unavailable from the literature, similarities to other populations were used to make assumptions.

RESULTS

In base case analysis, prophylactic IVCFs were more costly ($37,700 vs $37,300) and less effective (by 0.139 QALYs) than therapeutic IVCFs. In sensitivity analysis, the EAST strategy of prophylactic filter placement would become the preferred strategy in individuals never having a filter, with either an annual probability of VTE of ≥ 9.6% (base case, 5.9%), or a very high annual probability of anticoagulation complications of ≥ 24.3% (base case, 2.5%). The EAST strategy would also be favored if the annual probability of venous insufficiency was <7.69% (base case, 13.9%) after filter removal or <1.90% with a retained filter (base case, 14.1%). In initial hospitalization only, EAST guidelines were more costly by $2988 and slightly more effective by .0008 QALY, resulting in an incremental cost-effectiveness ratio of $383,638/QALY.

CONCLUSIONS

Analysis suggests prophylactic IVC filters are not cost-effective in high-risk trauma patients. The magnitude of this result is primarily dependent on probabilities of long-term sequelae (venous thromboembolism, bleeding complications). Even in the initial hospitalization, however, prophylactic IVCF costs for the additional quality-adjusted life years gained did not justify use.

Thromboembolic Prophylaxis in Blunt Traumatic Intracranial Hemorrhage: A Retrospective Review

There are few data in the literature on venous thromboembolic (VTE) prophylaxis for the traumatic population with intracranial hemorrhage (ICH). We reviewed our institutional experience and compared the incidence of deep vein thrombosis and pulmonary embolism in patients with ICH receiving either early prophylaxis (<72 hours from admission) or late prophylaxis (>72 hours from admission), and the respective incidences in progression of intracranial hemorrhage. We identified 124 patients for this study. There were 29 patients (23%) who received early (<72 hours) pharmacological VTE prophylaxis and 53 patients (43%) received late (>72 hours) prophylaxis. In the study, 42 patients had intermittent pneumatic compression devices and received no pharmacological VTE prophylaxis. Among those with pharmacological VTE prophylaxis, 10 patients (8%) developed VTE (9 deep vein thrombosis and 1 pulmonary embolism). Three patients with pharmacological VTE prophylaxis developed ICH progression, with one being clinically significant. Our institutional review demonstrated that it seems safe to initiate early pharmacological VTE prophylaxis in blunt head trauma with stable ICH. Nevertheless, further prospective randomized studies are needed to fully elucidate the safety and efficacy in the timing of prophylaxis for blunt head trauma with ICH.

Venous thromboembolism in trauma: an update for the intensive care unit practitioner

Venous thromboembolism (VTE) in trauma patients is a capricious problem that continues to plague trauma surgeons and critical care physicians alike. Pharmacologic preventions of VTE with anticoagulants are often contraindicated in the trauma patient because of risk of bleeding diathesis. Mechanical prophylaxis in the form of venous compression boots often cannot be placed because of external fixators, swelling, and so forth. Providing effective VTE prophylaxis, while at the same time providing definitive care for the trauma patient, can be a nightmare. This review will first discuss the incidence and prevalence of VTE, as well as investigate the condition's diagnosis and treatment. Solutions to frequently encountered clinical dilemmas in managing VTE in trauma patients are considered in the form of frequently asked questions. Diagnostic techniques such as magnetic resonance venography, D-dimer, and various computed tomography methods are evaluated. Recent literature on preventive pharmacologic therapies is explored. The authors also consider whether vena cava filters prevent pulmonary embolism in trauma patients.

Safety and efficacy of vena cava filters in trauma patients

Pulmonary embolism (PE), due to its sudden onset, notoriously difficult diagnosis, unpredictable nature and often fatal outcome, remains one of the most feared complications in surgical practice. Trauma patients with multisystem injuries, extremity or pelvic fractures and head or spinal cord injuries often pose a significant dilemma for the surgeon because of the inability to use conventional measures such as anticoagulation therapy and compression devices. On the other hand, the incidence of deep vein thrombosis (DVT) is high among trauma patients and the attendant risk of PE is an important cause of morbidity and mortality. Inferior vena cava (IVC) interruption by placement of diverse filtering devices has evolved over the past three decades. With the use of these devices, the risk of PE has been reduced dramatically. However, variable rates of complications are reported from their use. In this study, we review all the available data on IVC filter placement in trauma patients and we discuss the potential complications of IVC filters in order to understand better the risk/benefit ratio of their use.

Posttraumatic thromboprophylaxis revisited: an argument against the current methods of DVT and PE prophylaxis after injury

BACKGROUND

Thromboprophylaxis after injury is a controversial issue. Practices and outcomes vary widely.

METHODS

Review of selected trauma literature on venous thromboprophylaxis after injury.

RESULTS

Multiple trauma articles suggest that the efficacy of different methods of thromboprophylaxis is unproven. Most of the practices on this issue are extrapolated from studies which were performed in non-trauma patients and therefore, may not be applicable in the unique trauma population.

CONCLUSIONS

In the absence of undisputable evidence, none of the current methods of venous thromboprophylaxis after injury should be considered as standard of care. There is a need to discover new methods of thromboprophylaxis for the Trauma patient.

The Current Status of Thromboprophylaxis after Trauma: A Story of Confusion and Uncertainty

It is difficult to support a standard of care for venous thromboprophylaxis after trauma when there is no convincing research that any of the currently used methods is consistently effective. Because many conclusions from the nontrauma literature have been misleadingly extrapolated to trauma patients, this review focuses exclusively on trauma articles. These articles present variable results. The rates of deep venous thrombosis and pulmonary embolism are widely different even among similar trauma populations. The heparin-unfractionated or low-molecular-weight and calf compression methods fail to show a reproducible effect in decreasing venous thromboembolic events. The current methods of venous thromboprophylaxis after trauma are inadequate and further research in this area is direly needed.

Prophylactic Inferior Vena Cava Filter Insertion for Trauma: Intensive Care Unit versus Operating Room

The frequency of insertion of prophylactic inferior vena cava filters (IVCF) among traumatized patients has increased nationally. That has placed a substantial operational and economic burden upon trauma centers. The purpose of this study was to compare and contrast successful implantation, morbidity, and cost-effectiveness of prophylactic IVCF insertion in a surgical-trauma intensive care unit (STICU) versus an operating room (OR). A retrospective chart review was conducted of all trauma patients who received a prophylactic IVCF at an urban Level I trauma center between January 1999 and December 2003. Data were collected to identify patient demographics, indications, anatomical site of insertion, hospital location of insertion, hospital days before insertion, and complications associated with insertion. One hundred thirty-four patients underwent prophylactic IVCF during the study period: seventy-eight (58%) in the OR and fifty-six (42%) in the STICU. The average age of patients for the OR and STICU groups were 38.6 years and 39.6 years, respectively. The average number of days to IVCF insertion was 6.5 days and 7.0 days in the OR and STICU groups, respectively. Indications for IVCF among patients who had placement in the OR were orthopedic injury (60%), spinal cord injury (25%), and head injury (15%). Indications for IVCF among patients who had placement in the STICU were head injury (38%), orthopedic injuries (34%), and spinal cord injury (25%). Three (3.8%) patients in the OR group and two (3.6%) patients in the STICU group required a change of anatomic insertion site from the femoral to the internal jugular vein. There were two (2.6%) complications associated with IVCF insertion in the OR and two (3.5%) complications associated with IVCF insertion in the STICU (P > 0.05). Insertion of IVCF in the STICU decreased patient-cost by an average of $1636 per patient. Prophylactic IVCF insertion in an STICU is cost-effective and can be performed with similar success and complication rates to IVCF insertion in an OR.

High Prevalence of Pulmonary Arterial Thrombi in Donor Lungs Rejected for Transplantation

BACKGROUND

Donor hypoxemia is a common reason for the rejection of lungs for transplantation. Organ donors are at high risk for venous thromboembolism. Pulmonary arterial thrombosis could contribute to donor hypoxemia. The primary objective of this study was to prospectively quantify the incidence of pulmonary arterial thrombosis in organ donors whose lungs were rejected for transplantation. The secondary objective was to better define the spectrum of histologic abnormalities in the same group of lungs.

METHODS

A complete gross pathologic and histologic analysis of whole lung specimens was done on lungs from 17 donors whose lungs were rejected for transplantation. Lungs had not been flushed with a pulmonary preservation solution.

RESULTS

Overall, 35% of the donors had gross or microscopic evidence of either pulmonary arterial thrombosis, pulmonary infarction, or both. Clinical characteristics, including oxygenation, were not significantly different between donors who had thrombi or infarction and donors who did not. Other pathologic findings included bronchopneumonia (focal or early in 4/17, moderate or severe in 8/17), respiratory bronchiolitis (7/17) and centriacinar emphysema (7/17).

CONCLUSIONS

Pulmonary arterial thrombosis and/or pulmonary infarction are very common in organ donors whose lungs are rejected for transplantation and might contribute to lung dysfunction both in lung donors and lung recipients. Further studies are needed to define the incidence of pulmonary arterial thrombosis in organ donors whose lungs are used for transplantation and to better assess the adverse clinical consequences of donor pulmonary arterial thrombosis in lung recipients.

Optimal Dose of Enoxaparin in Critically Ill Trauma and Surgical Patients

BACKGROUND

Low-molecular-weight heparin is effective for prevention of venous thromboembolism. The efficacy of daily dosing in critically ill patients is unknown.

METHODS

Seventeen critically ill patients on 40 mg of enoxaparin subcutaneously daily were studied. Anti-Xa activity was measured 4 hours after the third dose and before the fourth dose. Adverse events were recorded.

RESULTS

Mean peak anti-Xa activity was 0.19 +/- 0.09 International Units/mL and mean trough was 0.044 +/- 0.04 International Units/mL. The recommended target range is 0.1 to 0.2 International Units/mL. The trough was below therapeutic levels in all but two patients. One thrombosis occurred in a patient despite a therapeutic trough.

CONCLUSION

Daily dosing of enoxaparin is inadequate for critically ill patients and should be abandoned. Further studies using twice daily dosing are needed. Patients with renal insufficiency may require an increased interval of administration (daily dosing). Anti-Xa levels may not correlate with the risk of thromboembolic complications. Patients with renal insufficiency and morbid obesity may require alternative dosing and monitoring of anti-Xa levels.

Thromboprophylaxis Does Not Protect Severely Injured Patients against Pulmonary Embolism

The existing evidence on the effectiveness of thromboprophylaxis after trauma is conflicting. Although prophylaxis with heparin and/or sequential compression devices is practiced widely, many studies failed to document a clear benefit. A recent meta-analysis suggests that prophylaxis does not reduce posttraumatic deep venous thrombosis rates compared to no prophylaxis. The objective of this prospective study is to examine if the use of thromboprophylaxis prevents posttraumatic pulmonary embolism (PE). Sixty-four critically injured patients with clinical evidence of PE were studied by computed tomographic pulmonary angiography and/or conventional pulmonary angiography. PE was diagnosed in 24 (37.5%) patients. Patients with PE were similar to patients without PE with regard to demographics, injury type and severity, operations, and mortality. Thromboprophylaxis was used with equal frequency between PE and no-PE patients (71% vs 80%, P = 0.4). The type of prophylaxis used was similar between patients with PE (17% heparin, 71% sequential compression devices, 17% combination) and patients without PE (32%, 57%, and 10%, respectively; P = 0.16, 0.28, 0.69, respectively). Current methods of posttraumatic thromboprophylaxis may be inadequate. Practices from nontrauma populations have been erroneously extrapolated to the unique trauma population. To reduce the rate of PE after trauma, new methods of thromboprophylaxis should be considered.

Thromboembolism after trauma: an analysis of 1602 episodes from the American College of Surgeons National Trauma Data Bank

OBJECTIVE

Venous thromboembolic events (VTE) are potentially preventable causes of morbidity and mortality after injury. We hypothesized that the current clinical incidence of VTE is relatively low and that VTE risk factors could be identified.

METHODS

We queried the ACS National Trauma Data Bank for episodes of deep venous thrombosis (DVT) and/or pulmonary embolism (PE). We examined demographic data, VTE risk factors, outcomes, and VTE prophylaxis measures in patients admitted to the 131 contributing trauma centers.

RESULTS

From a total of 450,375 patients, 1602 (0.36%) had a VTE (998 DVT, 522 PE, 82 both), for an incidence of 0.36%. Ninety percent of patients with VTE had 1 of the 9 risk factors commonly associated with VTE. Six risk factors found to be independently significant in multivariate logistic regression for VTE were age > or = 40 years (odds ratio [OR] 2.01; 95% confidence interval [CI] 1.74 to 2.32), lower extremity fracture with AIS > or = 3 (OR 1.92; 95% CI 1.64 to 2.26), head injury with AIS > or = 3 (OR 1.24; 95% CI 1.05 to 1.46), ventilator days >3 (OR 8.08; 95% CI 6.86 to 9.52), venous injury (OR 3.56; 95% CI 2.22 to 5.72), and a major operative procedure (OR 1.53; 95% CI 1.30 to 1.80). Vena cava filters were placed in 3,883 patients, 86% as PE prophylaxis, including in 410 patients without an identifiable risk factor for VTE.

CONCLUSIONS

Patients who need VTE prophylaxis after trauma can be identified based on risk factors. The use of prophylactic vena cava filters should be re-examined.

Current Trends in Vena Caval Filtration with the Introduction of a Retrievable Filter at a Level I Trauma Center

OBJECTIVE

The purpose of this study was to document the initial experience, indications, technical success, and complications with an optional vena caval filter at a Level I trauma center.

METHODS

The trauma registry and interventional radiology database were reviewed for all venal caval filters placed during a 15-month period. Records were reviewed for age of patient, indication, type of filter, and duration between placement and removal of the filter.

RESULTS

One hundred thirty-six filters were placed into 130 patients (55 trauma patients), and the most frequently placed filter was the Günther Tulip (n = 58, 29 in trauma patients). Forty-five of 1,257 trauma patients received a prophylactic vena cava filter, for a rate of 4%. Twenty-two repositioning (n = 8) or removal procedures (n = 14, 9 in trauma patients) were performed in 15 patients, with a technical success rate of 93%. No minor complications and one major complication occurred. The average duration between placement and removal was 19 days (range, 11-41 days). The mean age of patients selected prospectively for filter removal (29 years; range, 18-71 years) was significantly lower than the mean age (49 years; range, 19-82 years) of trauma, surgical, and intracranial hemorrhage patients selected for placement of prophylactic permanent filters (p < 0.002; 95% confidence interval, 18.0-22.4).

CONCLUSION

The Günther Tulip filter is commonly used at this Level I trauma center as an optional filter that can be left in place as a permanent filter or removed up to 41 days after placement. Without an intervening repositioning procedure, the manufacturer suggests that the Günther Tulip filter can be safely removed within 14 days of implantation, or it can remain in place as a permanent filter.

Primary prevention of deep venous thrombosis and pulmonary embolism in acute spinal cord injured patients

STUDY DESIGN

Prospective clinical trial.

OBJECTIVES

To evaluate the efficacy of a specific protocol for prevention of thrombo-embolic disease occurring during the acute stage of spinal cord lesions, based on the simultaneous use of pharmacological plus mechanical procedures.

SETTING

Regional Spinal Unit of Florence, Italy.

INTRODUCTION

Deep venous thrombosis (DVT) is a dangerous pathology whose first clinical sign can be represented by unexpected pulmonary embolism (PE). Its incidence in acute spinal cord injured (SCI) patients is reported to range between 9% and 90%. Its prevention represents one of the major challenges for the clinicians involved in the care of such patients.

METHOD

Two hundred and seventy-five SCI patients consecutively admitted to our Centre were investigated by colour doppler ultrasonography of lower limbs and pelvis on admission, after 30-45 days and whenever clinically requested. Subcutaneous Nadroparine, a low molecular weight heparin (LMWH), plus early mobilisation, permanently dressed gradient elastic stockings (PGES), and external sequential pneumatic compression (ESPC) of the lower limbs, applied during the first 30 days after injury, were given to all of them. Colour doppler ultrasonography (CDUS) complete investigations of the lower limbs and pelvis were performed on admission, after 30-45 days and whenever clinically requested. The patients were divided into two groups according to their time interval from injury to the admission to our Centre.

RESULTS

The incidence of detected DVT was 2% in those patients (99) admitted early to our centre (within 72 h from the trauma), who immediately received our prophylactic protocol. No PE was reported. The other group of patients (176), all admitted between 8 and 28 days (mean 12 days) developed DVT in 26% of cases. None of these patients received ESPC before being admitted to our Centre. No patient had been admitted between 3 and 8 days interval time post injury.

CONCLUSION

Early application of pharmacological plus mechanical treatment for DVT prevention produces a marked reduction in such complications. It also reduces the risks of morbidity and mortality in our patients, and, not least, reduces the hospitalization costs during the early period of rehabilitation.

Compliance with Sequential Compression Device Prophylaxis in At-Risk Trauma Patients: A Prospective Analysis

The Sequential Compression Device (SCD) is frequently the sole measure used to prevent deep venous thrombosis (DVT) in trauma patients. The purpose of this study was to evaluate the compliance with physician orders for the application of SCD prophylaxis among nonambulatory trauma patients at risk for DVT. We conducted a prospective observational study at two Level I university-affiliated trauma centers. Nonambulatory trauma patients were observed during their early postadmission period in a non-critical care setting. Six observations were made as to proper SCD applications during a 24-hour period (two times in the morning shift, two in the evening shift, and two overnight). “Full compliance” was defined as SCD on and functioning properly in all six observations. In a total of 1343 observations in 227 patients only 42 patients (19%) were fully compliant. The devices were on and functioning in 712 (53%) observations. Among the 185 patients who were not fully compliant DVT risk factors were common (83%) and adjunctive heparin prophylaxis was infrequent (27%). The most common times for “noncompliant” observations were early afternoon and midmorning. On multivariate analysis only spinal column injury correlated with increased compliance. In nearly half of the observations trauma patients at risk for DVT were not receiving their SCD prophylaxis as per physician orders. Fewer than 20 per cent of patients had the devices on and functioning during each of the six observations during a 24-hour period. These data point to the need for education of hospital staff and for additional prophylactic measures in at-risk patients.

Prevention of venous thromboembolism in trauma and long bone fractures

Patients sustaining traumatic injuries are at high risk for the development of venous thromboembolism. The reported incidence of deep venous thrombosis in trauma patients ranges from 20 to 90%. The reported incidence of pulmonary embolism in trauma patients varies between 2.3 and 22%. The aging population and the survival of more severely injured patients may suggest an increasing risk of thromboembolism in the trauma patient population. There have been few randomized prospective studies assessing methods of thromboembolism prophylaxis in trauma patients. Controversy exists as to the optimal method of prophylaxis in this high-risk population. Contraindications arising from associated injuries often limit the potential options for prophylaxis in patients with trauma. Large prospective randomized studies are needed to determine the most effective means of prophylaxis in trauma patients, who have a wide range of both isolated and combined injuries. Future studies should also address the duration of prophylaxis because many trauma patients remain immobile for an extended time.