Pulmonary Embolism In Trauma Patients Research Articles

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.

Retrievable Vena Cava Filters for Preventing Pulmonary Embolism in Trauma Patients: A Cautionary Tale

Retrievable vena cava filters (RFs) offer the appeal of short-term prophylaxis for trauma patients temporarily at risk for pulmonary embolism (PE) without the long-term risks of permanent vena cava filters (PFs). However, the evidence that RFs and PFs reduce the risks of PE and death in trauma patients is not conclusive. RFs were introduced at our trauma center in August 2002. The purpose of this study was to evaluate the effects of RFs on our strategy to prevent PE in trauma patients. We reviewed our trauma registry to compare rates of filter placement, filter-related complications (FRCs), and PE before (Group I: January 2000 to August 15, 2002) and after (Group II: August 16, 2002 through December 2004) RF introduction. Indication for filter placement, filter retrieval, FRCs, and incidence of PE were compared. There were 5,042 patients in Group I and 5,038 patients in Group II. There was a threefold increase in filter placement in Group II compared with Group I (55 [1.1%] versus 161 [3.2%]; p < 0.001). There were no significant differences between the rates of PE (0.2% versus 0.2%, p = 0.636) or major FRCs (1.8% versus 2.5%, p = 0.777). Major FRCs included two filter infections with sepsis, one vena cava thrombotic occlusion, one filter lodged in the jugular vein during retrieval, and one PE after filter placement. RF removal was attempted in 43 (27%) patients and successful in 33 (21%). The advent of RFs was associated with a threefold increase in vena cava filter placement in our trauma center. Major FRCs were encountered and a very low incidence of PE was not altered by their use. Successful removal could be verified in only 21% of RFs. The results of this study lead us to question the rationale for a more liberal use of vena cava filters in trauma patients.

Deep Venous Thrombosis and Pulmonary Embolism in Trauma Patients: An Overstatement of the Problem?

Deep Venous Thrombosis and Pulmonary Embolism in Trauma Patients: An Overstatement of the Problem?

Deep Venous Thrombosis and Pulmonary Embolism in Trauma Patients: An Overstatement of the Problem?

Deep Venous Thrombosis and Pulmonary Embolism in Trauma Patients: An Overstatement of the Problem?

Deep Venous Thrombosis and Pulmonary Embolism in Trauma Patients: An Overstatement of the Problem?

Deep venous thrombosis (DVT) and pulmonary embolism (PE) affect high-risk trauma patients (HRTP). Accurate incidence and clinical importance of DVT and PE in HRPT may be overstated. We performed a ten-year retrospective analysis of HRTP of the Pennsylvania Trauma Outcome Study. High-risk factors (HRF) included pelvic fracture (PFx), lower extremity fracture (LEFx), severe head injury (CHI) (AIS - head > or =3), and spinal cord injury. HRF alone or in combination, age, Injury Severity Score (ISS), and Glasgow Coma Score (GCS) were examined for association with DVT/PE. A total of 73,419 HRTP were included: 1377 (1.9%) had DVT, 365 (0.5%) had PE. The incidence of DVT in level I trauma centers was 2.2 per cent and was 1.5 per cent in level II centers. The lowest incidence of DVT was 1.3 per cent for isolated LEFx; highest was 5.4% for combined PFx, LEFx, and CHI. Variables associated with DVT included age, ISS, and GCS (all P < 0.001). In logistic regression analysis, only ISS was consistently predictive for DVT and PE. Though increased during the past decade, the overall incidence of DVT in HRTP remains below 3 per cent. Only the combination of multiple injuries or an ISS >30 result in DVT incidence of > or =5 per cent. We believe that current guidelines for screening for DVT may need to be reevaluated.

Diagnosis of posttraumatic pulmonary embolism: is chest computed tomographic angiography acceptable?

Pulmonary angiography (PA-gram) has long been the accepted criterion standard for diagnosing pulmonary embolism (PE). Computed tomographic angiography has recently been advocated as an equivalent alternative to PA-gram. CT angiography is known to be insensitive for peripheral (segmental and subsegmental) emboli. We have previously found that a significant number of posttraumatic PEs occur early. We therefore hypothesized that because of the fragmentation of these early (soft) clots, posttraumatic PEs would be found disproportionately in the lung periphery. Trauma patients with PE confirmed by PA-gram were identified from our trauma database and medical records. PA-grams and reports were re-reviewed and the location of all emboli was documented. We identified 45 patients, with an average age of 46 +/- 19 years; two thirds of the patients were men and 82% had a blunt mechanism of injury. Patients had PE diagnosed between days 0 and 57. Overall, PE was confined to segmental or smaller vessels in 27 (60%) patients and to subsegmental vessels in 7 (16%) patients. Twelve patients (27%) had a PE within the first 4 days. Furthermore, 32 patients (71%) had unilateral clot and 22 patients (48.9%) had clot confined to one region. PE frequently occurs soon after injury. The majority of PEs after trauma are found peripherally (in segmental or subsegmental vessels). Right/left pulmonary artery embolisms are likely to be found only later in a trauma patient's course. Any diagnostic study used to diagnose pulmonary embolism in trauma patients must have sufficient resolution capacity to reliably detect segmental and subsegmental clot. A diagnostic modality such as CT scanning that is insensitive to peripheral embolisms may miss a significant number of posttraumatic PEs.

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.

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

Trauma surgeons use a variety of methods to prevent venous thromboembolism (VT). The rationale for their use frequently is based on conclusions from research on nontrauma populations. Existing recommendations are based on expert opinion and consensus statements rather than systematic analysis of the existing literature and synthesis of available data. The objective is to produce an evidence-based report on the methods of prevention of VT after injury. A panel of 17 national authorities from the academic, private, and managed care sectors helped design and review the project. We searched three electronic databases (MEDLINE, EM-BASE, and Cochrane Controlled Trial Register) to identify articles relevant to four key questions: methods of prophylaxis, methods of screening, risk factors for VT, and the role of vena caval filters. The initial 4,093 titles yielded 73 articles for meta-analysis. A random-effects model was used for all pooled results. Study quality was evaluated by previously published quality scores. In this article (part I), we report on the question ranked by the experts as the most important, i.e., Which is the best method to prevent VT?, and also on the incidence of deep venous thrombosis and pulmonary embolism in trauma patients. The incidence of deep venous thrombosis and pulmonary embolism reported in different studies varies widely. The pooled rates are 11.8% for deep venous thrombosis and 1.5% for pulmonary embolism. Only a few randomized controlled trials have evaluated the methods of VT prophylaxis among trauma patients, and combining their data is difficult because of different designs and preventive methods used. The quality of most studies is low. Meta-analysis shows no evidence that low-dose heparin, mechanical prophylaxis, or low-molecular-weight heparin are more effective than no prophylaxis or each other. However, the 95% confidence intervals of many of the comparisons are wide; therefore, a clinically important difference may exist. The trauma literature on VT prophylaxis provides inconsistent data. There is no evidence that any existing method of VT prophylaxis is clearly superior to the other methods or even to no prophylaxis. Our results cast serious doubt on the existing policies on VT prophylaxis, and we call for a large, high-quality, multicenter trial that can provide definitive answers.

Timing of the Occurrence of Pulmonary Embolism in Trauma Patients

To determine how soon after trauma pulmonary embolism (PE) occurs and if there is an association between the duration of this interval and mortality. Retrospective case series. All patients admitted to our trauma service with established PE based on high probability findings on ventilation perfusion scan, positive results on a pulmonary arteriogram, or autopsy from July 1, 1990, to September 30, 1995. Time interval between injury and PE. Level I university trauma center. Of 18,255 trauma patients identified, 63 met our criteria for PE (30 using a pulmonary arteriogram; 26, a ventilation perfusion scan; and 7, autopsy). Four patients (6%) had a documented PE on day 1 following injury. Mortality was not correlated with the interval between injury and PE. Of the 63 patients, 58 (92%) had 1 or more established risk factors for thromboembolism. The ratio of PaO2 to fraction of inspired oxygen was the only factor predictive of mortality (P = .02, logistic regression analysis). Pulmonary embolism occurs in the immediate period following injury. Aggressive workup in patients with signs consistent with PE should be instituted promptly. Trauma patients who have at least 1 risk factor for thromboembolism should receive prophylaxis as soon after injury as possible.

Pulmonary Emboli in Trauma Patients at Robert Packer Hospital Trauma Center

Pulmonary emboli are a source of significant morbidity and mortality in the trauma population. The incidence at Robert Packer Hospital is 0.23% with a mortality rate of 50%. A retrospective analysis over the last six years found eight out of 3450 trauma patients with documented pulmonary emboli. The purpose of this study was to identify those risk factors associated with the development of pulmonary embolism in trauma patients.

Prevention of Deep Vein Thrombosis and Pulmonary Embolism in Acetabular and Pelvic Fracture Surgery

In a prospective nonrandomized study, a protocol was examined for prophylaxis of deep venous thrombosis and pulmonary embolism in patients with operative treatment of acetabular and pelvic fractures. There were 197 patients in the study with 203 fractures, including 148 acetabular and 55 pelvic fractures. There were 2 cases of bilateral acetabular fractures and 4 cases with both acetabular and pelvic fractures. The protocol involved preoperative noninvasive screening of the lower extremities, intraoperative and postoperative use of mechanical antithrombotic devices, and chemical prophylaxis with warfarin for 3 weeks following removal of surgical drains. There were 11 cases (6%) of preoperative deep venous thrombosis detected. There were 6 cases of postoperative deep venous thrombosis and 2 cases of pulmonary embolism. The incidence of postoperative venous thrombosis and pulmonary embolism was 3% and 1%, respectively. The protocol was found to be effective for preoperative detection of venous thrombosis and prevention of deep venous thrombosis and pulmonary embolism in trauma patients with minimal bleeding complications and no morbidity from embolic disease.

Deep Venous Thrombosis and Pulmonary Embolism in Trauma Patients

Trauma patients are at exceedingly high risk for the development of deep venous thrombosis and pulmo nary embolism. The incidence, pathophysiology, diag nosis, prophylaxis, and therapy of deep venous throm bosis and pulmonary embolism in the trauma patient are reviewed. The type of injury, systemic pertubations, and enforced immobility are important factors in pathogenesis. Patients with lower extremity injuries and spine fractures with paraplegia appear to be at highest risk. Orthopedic devices used to treat these injuries of ten preclude the conventional noninvasive diagnostic modalities. Further, hemorrhagic risk often impacts the judgment regarding the use of prophylactic measures as well as the therapy once deep venous thrombosis is diagnosed. Better data regarding the incidence of ve nous thromboembolism and the applicability of existing diagnostic, prophylactic, and treatment approaches in this population are needed. Accidents are responsible for over 140,000 deaths and approximately 70 million nonfatal injuries an nually in the United States [1]. Most of the fatalities occur within hours of injury as a result of exsangui nation or a lethal head injury, but approximately 20% survive for days or weeks [2], usually in the intensive care unit. The primary causes of late death are sepsis and multiple-organ failure [2]. Increasing evidence, however, suggests that pulmonary embo lism (PE) is now becoming a leading cause of late death, especially in some high-risk groups [3-5]. The increase in the incidence of PE is due in part to improvements in trauma care, which have lowered the early mortality rate [6-8], leaving more patients at risk for late death. In addition, autopsy examina tions, used more frequently to audit trauma care systems [6,9], have documented an increase in clini cally unsuspected deep venous thrombosis (DVT) and PE. This review was prompted because of the appar ent increase in DVT and PE in the trauma popula tion, and because the trauma patient presents very difficult and unique problems compared with the nontrauma patient with regard to the diagnosis, prophylaxis, and treatment of these disorders. In this review, we address the incidence, pathophys iology, diagnosis, treatment, and prophylaxis of DVT and PE in the trauma patient. We do not con sider the entities of fat embolism or pulmonary microemboli as a cause of late pulmonary failure.