THE DIAGNOSTIC APPROACH TO DEEP VENOUS THROMBOSIS

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.

Pulmonary embolism as a cause of death in patients with heart disease: an autopsy study

STUDY OBJECTIVE

To establish the prevalence of pulmonary embolism (PE) in autopsy material at a tertiary cardiac referral center and its importance as a cause of death in patients with heart disease (HD).

DESIGN

Case series.

SETTING

National Heart Institute, Mexico City.

PATIENTS

One thousand thirty-two patients who died at our institution from 1985 to 1994 in whom an autopsy study was performed.

MEASUREMENTS AND RESULTS

Of the 1,032 autopsies reviewed, 231 cases (24.4%) of PE were found; 100 of these patients had a diagnosis of massive PE. Massive PE (obstruction of either of the main pulmonary arteries or more than two lobar arteries) was found to be the third cause of death in this HD population. By age-group distribution, the global prevalence of massive events was higher in patients < 10 years old. Clinical suspicion (premortem) was raised in only 18% of the cases.

CONCLUSIONS

PE was a frequent cause of morbidity and mortality in patients with HD who underwent autopsies. The incidence of massive PE was high in children.

Acute pulmonary embolism

Deep vein thrombosis (DVT) and, therefore, pulmonary embolism (PE) are often preventable. Because of the lack of specificity of symptoms and signs, DVT and PE are frequently clinically unsuspected, leading to substantial diagnostic and therapeutic delays and resulting in considerable morbidity and mortality. Furthermore, prophylaxis continues to be dramatically underused. The incidence of venous thromboembolism is high in hospitalized patients, and both surgical as well as medical patients are at risk.

Ultrasound diagnosis of deep venous thrombosis

The ultrasound diagnosis of deep venous thrombosis by an emergency physician is occurring with increased frequency. The examination is simple to perform and, when combined with a clinical pretest probability or D-dimer, can aid in the rapid disposition ofa patient with lower extremity pain and swelling. The technique and findings of the limited lower extremity ultrasound and the data to support its use in the emergency department are discussed.

The Impact of Pelvic and Lower Extremity Fractures on the Incidence of Lower Extremity Deep Vein Thrombosis in High-Risk Trauma Patients

Lower extremity fractures (LEFx) and pelvic fractures (PFx) are believed to increase the risk of lower extremity deep vein thrombosis (LEDVT). We studied trauma patients at high risk for LEDVT to determine whether an increased incidence of LEDVT was associated with LEFx and/or PFx. From January 1995 through December 1997 4163 trauma patients were admitted to our Level I trauma center. One thousand ninety-three patients at high risk for LEDVT were screened with serial lower extremity venous duplex ultrasound. Their medical records were retrospectively reviewed for demographics, mechanism of injury, and fracture data. The occurrence of LEDVT, pulmonary embolus, and LEDVT prophylaxis and treatment were noted. The incidence of LEDVT in the fracture group (Fx) was compared with that in the nonfracture group (NFx) using chi-square analysis and logistic regression. Statistical significance was set at ≤0.05. Complete data were available for 1059 of 1093 patients. Five hundred sixty-nine (53.73%) patients had PFx and/or LEFx, 151 (14.26%) patients had PFx only, 317 (29.3%) patients had LEFx only, and 101 (9.54%) patients had both PFx and LEFx. Four hundred ninety (46.27%) patients had NFx. In 1059 patients LEDVT was detected in 125 (11.8%). Sixty-three patients in the Fx groups developed LEDVT (50.4%): 19 (15.2%) PFx patients, 15 (12.0%) PFx/LEFx patients, and 29 (23.2%) LEFx patients. Sixty-two (49.6%) NFx patients developed LEDVT. LEDVT incidence was not significantly different between the Fx and NFx groups or among the PFx, LEFx, and PFx/LEFx groups ( P = 0.317). Nine patients developed pulmonary embolism: four NFx patients, two LEFx patients, two PFx patients, and one PFx/LEFx patient. Significant predictors of LEDVT were age and hospital length of stay. Mean age in patients with LEDVT was 47.58 years and in patients without LEDVT it was 40.89 years ( P < 0.001). Mean hospital length of stay in patients with LEDVT was 29.81 days and in patients without LEDVT it was 16.84 days. The power of this study to detect differences representing medium effect sizes was greater than 90 per cent. We conclude that LEFx and/or PFx was not associated with an increased incidence of LEDVT in trauma patients at high risk for LEDVT. Lower extremity venous duplex ultrasound needs to be performed in both Fx and NFx groups to detect LEDVTs.

The diagnosis of lower extremity deep venous thrombosis

The diagnosis of lower extremity deep venous thrombosis (DVT) is critical to emergency physicians because of the risk of pulmonary embolism. This article reviews the diagnostic modalities available for patients with suspected lower extremity DVT. The use of compression ultrasonography and the recent advances in the D-dimer assays are emphasized. A clinical algorithm that utilizes a non invasive approach to this potentially life threatening disease is presented.

Diagnosis of pulmonary embolism with use of computed tomographic angiography

Pulmonary embolism (PE) is a common diagnostic problem, particularly in hospitalized patients. It remains a frequent cause of unexpected deaths. Traditionally, the diagnostic work-up for suspected PE has centered on the use of ventilation-perfusion (V-P) radionuclide lung scanning. However, V-P scanning does not provide adequate confirmation or exclusion of the diagnosis in the majority of patients who undergo this test. Although published guidelines advise further diagnostic testing after nondiagnostic V-P scans, clinicians infrequently perform such testing, and management decisions are commonly based on clinical judgment. In recent years, there has been an increasing interest in the use of computed tomographic (CT) angiography in the diagnostic evaluation of patients with suspected PE. Although there are unresolved issues regarding its sensitivity in detecting small peripheral emboli, CT angiography is more accurate than V-P scanning in the diagnosis of PE and yields other intrathoracic diagnoses. Herein we summarize the problems with the traditional approach centered on the use of V-P scanning in the diagnosis of PE and propose an alternative diagnostic strategy based primarily on the use of CT angiography.

Thromboembolism after hip and knee arthroplasty: diagnosis and treatment

Postoperative thromboembolism is a potentially lethal complication. Its diagnosis may be difficult, as the classic clinical signs and symptoms are often absent, making a high index of suspicion imperative for diagnosis. Anticoagulant therapy is effective in reducing morbidity and mortality due to thromboembolism, but is associated with a substantial rate of bleeding complications in the immediate postoperative period. Inferior vena cava filters constitute an alternative to anticoagulant therapy, but are also associated with a substantial complication rate. The appropriate use of diagnostic tests combined with clinical suspicion can guide the orthopaedic surgeon in deciding which patients require treatment for thromboembolism.

Sonographic estimates of vein size in the lower extremities: subjective assessment compared with direct measurement

PURPOSE

We studied whether subjective impression of vein size is a valid means of assessment during sonographic evaluation for deep vein thrombosis.

METHODS

Diameter was assessed at 5 predetermined venous segments on 975 legs of 721 patients referred for evaluation for lower extremity deep vein thrombosis. The sonographer recorded a subjective assessment of whether the venous segment was enlarged, normal, or narrowed based on a visual impression of sonographic images obtained without compression. This subjective impression was then compared with the absolute measurements of vein diameter and vein diameter:artery diameter ratio at each segment.

RESULTS

A significant correlation was found between the subjective characterization of vein size as enlarged, normal, and narrowed and both the absolute vein diameter and the vein:artery ratio at all 5 segments.

CONCLUSIONS

Vein size can be reliably categorized by the subjective impression of experienced sonographers. Therefore, actual measurement of the vein diameter is not necessary in the evaluation for deep vein thrombosis in the majority of patients.

Vascular ultrasonography

Although vascular ultrasonography has been established as an essential diagnostic tool in many clinical settings, its role in the emergency department patient population is uncertain. Preliminary reports of emergency physician--directed ultrasonography are promising. Further studies are needed to establish its reliability and suitability in the emergency department setting.