Predictors of rehospitalization for symptomatic venous thromboembolism after total hip arthroplasty

Surveillance for deep vein thrombosis and pulmonary embolism: recommendations from a national workshop

Deep vein thrombosis (DVT) and pulmonary embolism (PE), known collectively as venous thromboembolism (VTE), affect an estimated 900,000 people in the U.S. each year, resulting in several hundred thousand hospitalizations and about 300,000 deaths. Despite this substantial public health burden, no systematic collection of VTE-related morbidity and mortality data exists in the U.S. The available information about disease prevalence and incidence consists of estimates based mainly on population-based epidemiologic studies and analysis of hospital discharge or health insurance claims databases. The limited scope of the available data has raised the question of whether a systematic surveillance system for VTE should be established. To help answer this question and to make recommendations for the next steps toward better surveillance of VTE, the CDC asked the American Society of Hematology (ASH) to convene a national workshop of stakeholders representing relevant federal agencies, experts in VTE epidemiology and treatment, public health experts in VTE, and patient representatives. These groups were assembled by ASH for a 1-day meeting in Washington DC. The subspecialty experts included representatives from internal medicine, cardiovascular diseases, adult and pediatric hematology, surgery, obstetrics and gynecology, radiology, emergency medicine and trauma care, hospital practice and critical care, and geriatrics. Experts in epidemiology, healthcare quality, and health policy also participated. During the workshop, experts discussed their perspectives on the burden of disease from VTE and its diagnosis, treatment, and prevention. The workshop also focused on the advisability and feasibility of establishing systematic surveillance for VTE and included preliminary discussion of the advantages and disadvantages of various approaches. The workshop concluded that (1) improved utilization in clinical practice of existing, proven-effective preventive measures is critical to reducing the disease burden from VTE; (2) systematic surveillance of DVT and PE is needed to provide nationally representative data on the prevalence and annual incidence of DVT and PE in the U.S.; (3) tracking and documenting changes in the incidence of DVT and PE through systematic surveillance will be important to enhance prevention efforts; and (4) the CDC should convene a second group of experts to advise the agency in detail on the strengths, weaknesses, and feasibility of possible approaches to systematic surveillance for DVT and PE.

Risk factors for pulmonary complications, including pulmonary embolism, after total knee arthroplasty (TKA) in elderly Koreans

There has been a steady increase in elective TKA in elderly Koreans. However, there are few reports about the incidence of and risk factors for pulmonary complications, including pulmonary thromboembolism in these patients. We evaluated retrospectively 338 patients aged 60 years and over (290 females, median age 69 years) to assess the incidence and predictive factors for pulmonary complications, including pulmonary thromboembolism after TKA. Of these patients, 264 underwent simultaneous bilateral TKA (78%) by two surgeons and 56 (17%) had general anesthesia. No patient received thromboprophylaxis. There were 49 postoperative pulmonary complications in the 338 patients (14.2%, 49/338). Of the 49 patients, 27 developed atelectasis (27/49), six developed pneumonia (6/49), and four had pleural effusions (4/49) within 7 days of the surgery; 12 patients had a pulmonary thromboembolism (12/49) during their hospitalization. No pulmonary complication was fatal. Multivariate analysis revealed that pulmonary hypertension (right ventricular systolic pressure≥35 mmHg on transthoracic echocardiography; odds ratio (OR)=3.0, p=0.016) was independently associated with pulmonary complications. A resting PaCO(2)≥45 mmHg (OR=22.9, p=0.004) was the only independent predictor of the development of a pulmonary thromboembolism. Pulmonary hypertension may thus predict pulmonary complications and a PaCO(2) greater than 45 mmHg may be a risk factor for pulmonary thromboembolism following TKA. Preoperative blood gas analysis and transthoracic echocardiography can identify those patients at high risk for pulmonary complications, including pulmonary thromboembolism, after TKA in elderly Korean patients.

Risk factors for pulmonary embolism after hip and knee arthroplasty: a population-based study

Pulmonary embolism (PE) is a cause of death after total hip and knee arthroplasty (THA, TKA). We characterised the patient population suffering from in-hospital PE and identified perioperative risk factors associated with PE using nationally representative data. Data from the National Hospital Discharge Survey between 1990 and 2004 on patients who underwent primary or revision THA/TKA in the United States were analysed. Multivariate regression analysis was performed to determine if perioperative factors were associated with increased risk of in-hospital PE. An estimated 6,901,324 procedures were identified. The incidence of in-hospital PE was 0.36%. Factors associated with an increased risk for the diagnosis of PE included: revision THA, female gender, dementia, obesity, renal and cerebrovascular disease. An increased association with PE was found among patients with diagnosis of Adult Respiratory Distress Syndrome (ARDS), psychosis (confusion), and peripheral thrombotic events. Our findings may be useful in stratifying the individual patient's risk of PE after surgery.

Prevalence of thrombophilias in patients presenting for bariatric surgery

BACKGROUND

The rise in bariatric surgery has driven an increased number of complications from venous thromboembolism (VTE). Evidence supports obesity as an independent risk factor for VTE, but the specific derangements underlying the hypercoagulability of obesity are not well defined. To better characterize VTE risk for the purpose of tailoring prophylactic strategies, we developed a protocol for thrombophilia screening in patients presenting for bariatric surgery at our institution.

METHODS

Between April 2004 and April 2006, 180 bariatric surgery candidates underwent serologic screening for inherited thrombophilias (Factor V-Leiden mutation, low Protein C activity, low Protein S activity, Free Protein S deficiency) and acquired thrombophilias (D-Dimer elevation, Fibrinogen elevation, elevation of coagulation factors VIII, IX, and XI, elevation of Lupus anticoagulants and homocysteine level, and Antithrombin III deficiency). Prevalence rate of each thrombophilia in the subject group was compared to the actual prevalence rate of the general population.

RESULTS

Most plasma markers of both inherited and acquired thrombophilias were identified in higher than expected proportions, including D-Dimer elevation in 31%, Fibrinogen elevation in 40%, Factor VIII elevation in 50%, Factor IX elevation in 64%, Factor XI elevation in 50%, and Lupus anticoagulant in 13%.

CONCLUSIONS

Obesity is a well-described demographic risk factor for VTE. In bariatric surgery candidates routinely screened for serologic markers, both inherited and acquired thrombophilias occurred more frequently than in the general population, and may therefore prove to be useful for individualized VTE risk assessment and prophylaxis.

Risk assessment for hospital-acquired diseases: a risk-theory approach

We introduce a new approach to hospital-acquired disease risk assessment from public health databases. In a spirit similar to actuarial risk theory, we define an adjustment coefficient that can quantify the risk associated with a hospital department, allowing comparisons of similar departments. The adjustment coefficient characterizes the tail of the distribution of the total patient length of stay in a department before the first disease event occurs. We show that this coefficient is the solution of a Lundberg-like equation, and we provide a nonparametric estimation procedure for this measure, based on a Cramér-Lundberg approximation for the tail of the distribution. Using simulations, we provide evidence of the robustness of the approximation to various individual risk models. In addition, we illustrate the relevance of this approach by evaluating the risk associated with a standard patient safety indicator in 20 hospitals of southeastern France.

[Thromboembolic disease in orthopedic surgery]

Thromboembolic complications are frequent after orthopaedic surgery of the limbs. Strategies to minimize these complications go from recognize the risk factors of the patient to introduce new antithrombotic drugs, and including general medical care, regional anaesthesia and early mobilization. Based in epidemiological studies, prophylaxis must be extended 4-6 weeks in total hip and knee arthroplasty and in surgery of the hip fracture.

Weekend versus weekday admission and mortality after acute pulmonary embolism

BACKGROUND

Optimal management of acute pulmonary embolism (PE) requires medical expertise, diagnostic testing, and therapies that may not be available consistently throughout the entire week. We sought to assess whether associations exist between weekday or weekend admission and mortality and length of hospital stay for patients hospitalized with PE.

METHODS AND RESULTS

We evaluated patients discharged with a primary diagnosis of PE from 186 acute care hospitals in Pennsylvania (January 2000 to November 2002). We used random-effect logistic models to study the association between weekend admission and 30-day mortality and used discrete survival models to study the association between weekend admission and time to hospital discharge, adjusting for hospital (region, size, and teaching status) and patient factors (race, insurance, severity of illness, and use of thrombolytic therapy). Among 15 531 patient discharges with PE, 3286 patients (21.2%) had been admitted on a weekend. Patients admitted on weekends had a higher unadjusted 30-day mortality rate (11.1% versus 8.8%) than patients admitted on weekdays, with no difference in length of stay. Patients admitted on weekends had significantly greater adjusted odds of dying (odds ratio 1.17, 95% confidence interval 1.03 to 1.34) than patients admitted on weekdays. The higher mortality among patients hospitalized on weekends was driven by the increased mortality rate among the most severely ill patients.

CONCLUSIONS

Patients with PE who are admitted on weekends have a significantly higher short-term mortality than patients admitted on weekdays. Quality-improvement efforts should aim to ensure a consistent approach to the management of PE 7 days a week.

Guidelines for evaluation of new fever in critically ill adult patients: 2008 update from the American College of Critical Care Medicine and the Infectious Diseases Society of America

OBJECTIVE

To update the practice parameters for the evaluation of adult patients who develop a new fever in the intensive care unit, for the purpose of guiding clinical practice.

PARTICIPANTS

A task force of 11 experts in the disciplines related to critical care medicine and infectious diseases was convened from the membership of the Society of Critical Care Medicine and the Infectious Diseases Society of America. Specialties represented included critical care medicine, surgery, internal medicine, infectious diseases, neurology, and laboratory medicine/microbiology.

EVIDENCE

The task force members provided personal experience and determined the published literature (MEDLINE articles, textbooks, etc.) from which consensus was obtained. Published literature was reviewed and classified into one of four categories, according to study design and scientific value.

CONSENSUS PROCESS

The task force met twice in person, several times by teleconference, and held multiple e-mail discussions during a 2-yr period to identify the pertinent literature and arrive at consensus recommendations. Consideration was given to the relationship between the weight of scientific evidence and the strength of the recommendation. Draft documents were composed and debated by the task force until consensus was reached by nominal group process.

CONCLUSIONS

The panel concluded that, because fever can have many infectious and noninfectious etiologies, a new fever in a patient in the intensive care unit should trigger a careful clinical assessment rather than automatic orders for laboratory and radiologic tests. A cost-conscious approach to obtaining cultures and imaging studies should be undertaken if indicated after a clinical evaluation. The goal of such an approach is to determine, in a directed manner, whether infection is present so that additional testing can be avoided and therapeutic decisions can be made.

Targeting patients for anticoagulant prophylaxis trials in patients with cancer: who is at highest risk?

INTRODUCTION

It is not clear which cancer patients are at highest risk for developing venous thromboembolism (VTE).

MATERIALS AND METHODS

The epidemiology of VTE in cancer patients was investigated by linking the California Cancer Registry database to the discharge records of all patients hospitalized in California public hospitals between 1993-1999. Nineteen types of cancer were studied, four in detail.

RESULTS AND CONCLUSIONS

The incidence of VTE was highest in patients who presented with metastatic cancer, particularly clinically aggressive cancers associate with a high one-year mortality rate, such as pancreatic cancer. The incidence of VTE increased as the number of chronic medical co-morbid conditions increased. The incidence of VTE was highest in the first few months after diagnosis, and decreased over time, even when the death rate due to cancer remained constant. Patients with glioma had a very high incidence of VTE after invasive neurosurgery, whereas patients with solid cancers who underwent major surgery had a lower risk of developing VTE compared to patients who did not undergo major surgery. Development of VTE was associated with significantly shortened survival compared to cancer patients without VTE matched for age, race, sex, initial cancer stage and time after cancer diagnosis. This effect of VTE on survival was greatest in patients initially diagnosed with local or regional stage solid cancer as VTE was associated with emergence of metastatic disease. If primary thromboprophylaxis of cancer patients is considered, treatment should begin immediately after cancer diagnosis, and it should be targeted toward patients who have a biologically aggressive cancer that is initially metastatic and/or toward patients who have several chronic co-morbid conditions. Secondary thromboprophylaxis should be targeted toward patients who have evidence of an ongoing active malignancy. Glioma patients are at very high risk in the 3 month period immediately after invasive neurosurgery.

Risk of venous thrombosis: obesity and its joint effect with oral contraceptive use and prothrombotic mutations

In the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA study), body weight, height and body mass index (BMI) were evaluated as risk factors. Additionally, the joint effect of obesity together with oral contraceptive use and prothrombotic mutations on the risk of venous thrombosis were analysed. Three-thousand eight-hundred and thirty-four patients with a first venous thrombosis and 4683 control subjects were included, all non-pregnant and without active malignancies. Relative to those with a normal BMI (<25 kg/m(2)), overweight (BMI > or = 25 and BMI < 30 kg/m(2)) increased the risk of venous thrombosis 1.7-fold [odds ratio (OR)(adj(age and sex)) 1.70, 95% confidence interval (CI) 1.55-1.87] and obesity (BMI > or = 30 kg/m(2)) 2.4-fold (OR(adj) 2.44, 95% CI 2.15-2.78). An increase in body weight and body height also individually increased thrombotic risk. Obese women who used oral contraceptives had a 24-fold higher thrombotic risk (OR(adj) 23.78, 95% CI 13.35-42.34) than women with a normal BMI who did not use oral contraceptives. Relative to non-carriers of normal BMI, the joint effect of factor V Leiden and obesity led to a 7.9-fold increased risk (OR(adj) 7.86, 95% CI 4.70-13.15); for prothrombin 20210A this was a 6.6-fold increased risk (OR(adj) 6.58, 95% CI 2.31-18.69). Body height, weight and obesity increase the risk of venous thrombosis, especially obesity in women using oral contraceptives.

Hospital volume and patient outcomes in pulmonary embolism

BACKGROUND

In numerous high-risk medical and surgical conditions, a greater volume of patients undergoing treatment in a given setting or facility is associated with better survival. For patients with pulmonary embolism, the relation between the number of patients treated in a hospital (volume) and patient outcome is unknown.

METHODS

We studied discharge records from 186 acute care hospitals in Pennsylvania for a total of 15 531 patients for whom the primary diagnosis was pulmonary embolism. The study outcomes were all-cause mortality in hospital and within 30 days after presentation for pulmonary embolism and the length of hospital stay. We used logistic models to study the association between hospital volume and 30-day mortality and discrete survival models to study the association between in-hospital mortality and time to hospital discharge.

RESULTS

The median annual hospital volume for pulmonary embolism was 20 patients (interquartile range 10-42). Overall in-hospital mortality was 6.0%, whereas 30-day mortality was 9.3%. In multivariable analysis, very-high-volume hospitals (> or = 42 cases per year) had a significantly lower odds of in-hospital death (odds ratio [OR] 0.71, 95% confidence interval [CI] 0.51-0.99) and of 30-day death (OR 0.71, 95% CI 0.54-0.92) than very-low-volume hospitals (< 10 cases per year). Although patients in the very-high-volume hospitals had a slightly longer length of stay than those in the very-low-volume hospitals (mean difference 0.7 days), there was no association between volume and length of stay.

INTERPRETATION

In hospitals with a high volume of cases, pulmonary embolism was associated with lower short-term mortality. Further research is required to determine the causes of the relation between volume and outcome for patients with pulmonary embolism.

Epidemiology of venous thromboembolism after lower limb arthroplasty: the FOTO study

BACKGROUND

In view of recent substantial changes in the management of orthopedic surgery patients, a study was performed in order to update data on the epidemiology of venous thromboembolism (VTE) in patients undergoing lower limb arthroplasty according to contemporary practise.

METHODS

We performed a prospective observational study of a cohort of consecutive patients hospitalized for total hip or knee replacement in June 2003. The primary study outcome was the incidence of symptomatic VTE at 3 months. All events were adjudicated by an independent critical event committee.

RESULTS

Data from 1080 patients (mean age 68.0 years) were available; 63.2% were undergoing total hip replacement and 36.8% total knee replacement. Pharmacological thromboprophylaxis was administered for a mean time of 36 days. Injectable antithrombotics were used in more than 99% of patients, irrespective of the type of surgery. The incidence of the primary study outcome was 1.8% (20 events; 95% CI: 1.0-2.6%). The incidences were 1.3% and 2.8% in hip and knee surgery patients, respectively. There were two pulmonary embolisms, both in knee surgery patients; neither was fatal. Thirty-five per cent of VTEs occurred after hospital discharge. An age of at least 75 years and the absence of ambulation before hospital discharge were the only significant (P < 0.05) predictors of VTE. The rate of clinically significant bleeding was 1.0% and the rate of death was 0.9%.

CONCLUSIONS

The incidence of symptomatic VTE after lower limb arthroplasty is low, even if there is still a need to improve thromboprophylaxis, notably in patients undergoing knee arthroplasty.

Approaches to prevention of cardiovascular complications and events in diabetes mellitus

Diabetes mellitus affects about 8% of the adult population. The estimated number of patients with diabetes, presently about 170 million people, is expected to increase by 50-70% within the next 25 years. Diabetes is an important component of the complex of 'common' cardiovascular risk factors, and is responsible for acceleration and worsening of atherothrombosis. Major cardiovascular events cause about 80% of the total mortality in diabetic patients. Diabetes also induces peculiar microangiopathic changes leading to diabetic nephropathy conducive to end-stage renal failure, and to diabetic retinopathy that may progress to vision loss and blindness. In terms of major cardiovascular events, coronary heart disease and ischaemic stroke are the main causes of morbidity and mortality in diabetic patients. Peripheral arterial disease frequently occurs, and is more likely to be conducive to critical limb ischaemia and amputation than in the absence of diabetes. Although there are a number of differences in the pathogenesis and clinical features of diabetic macroangiopathy and microangiopathy, these two entities often coexist and induce mutually worsening effects. Endothelial injury, dysfunction and damage are common starting points for both conditions. Causes of endothelial injury can be distinguished into those 'common' to nondiabetic atherothrombosis, such as hypertension, dyslipidaemia, smoking, hypercoagulability and platelet activation; and those more specific and in some cases 'unique' to diabetes and directly related to the metabolic derangement of the disease, such as (i) desulfation of glycosaminoglycans (GAGs) of the vascular matrix; (ii) formation of advanced glycation end-products (AGE) and their endothelial receptors (RAGE); (iii) oxidative and reductive stress; (iv) decline in nitric oxide production; (v) activation of the renin-angiotensin aldosterone system (RAAS); and (vi) endothelial inflammation caused by glucose, insulin, insulin precursors and AGE/RAGE. Prevention of major cardiovascular events with the antithrombotic agent aspirin (acetylsalicylic acid) is widely recommended, but reportedly underutilised in patients with diabetes. However, some data suggest that aspirin may be less effective than expected in preventing cardiovascular events and especially mortality in patients with diabetes, as well as in slowing progression of retinopathy. In contrast, a recent study found picotamide, a direct thromboxane inhibitor, to be superior to aspirin in diabetic patients. Clopidogrel was either equivalent or less active in diabetic versus nondiabetic patients, depending upon different clinical settings.Recent studies have shown that some GAG compounds are able to reduce micro- and macroalbuminuria in diabetic nephropathy, and hard exudates in diabetic retinopathy, but it is as yet unknown whether these agents also influence the natural history of microvascular complications of diabetes. Lifestyle changes and physical exercise are also essential in preventing cardiovascular events in diabetic patients. Available data on the control of the metabolic state and the main risk factors show that careful adjustment of blood sugar and glycated haemoglobin is more effective in counteracting microvascular damage than in preventing major cardiovascular events. The latter objective requires a more comprehensive approach to the whole constellation of risk factors both specific for diabetes and common to atherothrombosis. This approach includes lifestyle modifications, such as dietary changes and smoking cessation and the use of HMG-CoA reductase inhibitors (statins), which are able to correct the lipid status and to prevent major cardiovascular events independently of the baseline lipidaemic or cardiovascular status. Tight control of hypertension is essential to reduce not only major cardiovascular events but also microvascular complications. Among antihypertensive measures, blockade of the RAAS by means of ACE inhibitors or angiotensin II receptor antagonists recently emerged as a potentially polyvalent approach, not only for treating hypertension and reducing cardiovascular events, but also to prevent or reduce albuminuria, counteract diabetic nephropathy and lower the occurrence of new type 2 diabetes in individuals at risk.

Validation of a clinical prognostic model to identify low-risk patients with pulmonary embolism

OBJECTIVE

To validate the Pulmonary Embolism Severity Index (PESI), a clinical prognostic model which identifies low-risk patients with pulmonary embolism (PE).

DESIGN

Validation study using prospectively collected data.

SETTING

A total of 119 European hospitals.

SUBJECTS

A total of 899 patients diagnosed with PE.

INTERVENTION

The PESI uses 11 clinical factors to stratify patients with PE into five classes (I-V) of increasing risk of mortality. We calculated the PESI risk class for each patient and the proportion of patients classified as low-risk (classes I and II). The outcomes were overall and PE-specific mortality for low-risk patients at 3 months after presentation. We calculated the sensitivity, specificity and predictive values to predict overall and PE-specific mortality and the discriminatory power using the area under the receiver operating characteristic curve.

RESULTS

Overall and PE-specific mortality was 6.5% (58/899) and 2.3% (21/899) respectively. Forty-seven per cent of patients (426/899) were classified as low-risk. Low-risk patients had an overall mortality of only 1.2% (5/426) and a PE-specific mortality of 0.7% (3/426). The sensitivity was 91 [95% confidence interval (CI): 81-97%] and the negative predictive value was 99% (95% CI: 97-100%) for overall mortality. The sensitivity was 86% (95% CI: 64-97%) and the negative predictive value was 99% (95% CI: 98-100%) for PE-specific mortality. The areas under the receiver operating characteristic curve for overall and PE-specific mortality were 0.80 (95% CI: 0.75-0.86) and 0.77 (95% CI: 0.68-0.86) respectively.

CONCLUSIONS

This validation study confirms that the PESI reliably identifies low-risk patients with PE who are potential candidates for less costly outpatient treatment.

Epidemiology of venous thromboembolism in 9489 patients with malignant glioma

OBJECT

The authors sought to define the incidence of symptomatic venous thromboembolism (VTE) in patients harboring malignant gliomas.

METHODS

The authors conducted a retrospective analysis of data obtained in all cases of malignant glioma diagnosed in California during a 6-year period; the occurrence of a VTE was identified using linked hospital discharge data. The Cox proportional hazard model was used to analyze the association of specific risk factors with the development of a VTE or death within 2 years of the cancer diagnosis. Among 9489 cases, the 2-year cumulative incidence of VTE was 7.5% (715 cases), with a rate of 16.1 events per 100 person-years during the first 6 months. Three hundred ninety-one (55%) of these 715 cases were diagnosed within 61 days of major neurosurgery. Risk factors for VTE included older age (hazard ratio [HR] 2.6, confidence interval [CI] 2.0-3.4 for age range 65-74 years compared with < or = 45 years), glioblastoma multiforme histology (HR 1.7, CI 1.4-2.1), three or more chronic comorbidities (HR 3.5, CI 2.8-4.3 [compared with no comorbidity]), and neurosurgery within 61 days (HR 1.7, CI 1.3-2.3). Patients in whom a VTE was present were at higher risk of dying within 2 years (HR 1.3, CI 1.2-1.4). In a nested case-control analysis of all VTE cases, there was no association between insertion of a vena cava filter and the risk of a recurrent VTE.

CONCLUSIONS

In patients harboring a glioma there was a very high incidence of symptomatic VTEs, particularly within 2 months of neurosurgery. The development of a VTE was associated with a 30% increase in the risk of death within 2 years. Further studies are needed to determine if risk stratification and the use of medical prophylaxis after neurosurgery improves outcomes.

Risk factors and clinical impact of postoperative symptomatic venous thromboembolism

BACKGROUND

Although common risk factors for venous thromboembolism (VTE) are well known, little data exist concerning the clinical impact of VTE in postoperative patients outside of controlled studies. This study evaluated prospective perioperative demographic and clinical variables associated with occurrence of postoperative symptomatic VTE.

METHODS

Demographic and clinical data were collected on surgical patients undergoing nine common general, vascular, and orthopedic operations presenting to the Veterans Health Administration Hospitals between 1996 and 2001 as part of the National Surgical Quality Improvement Program (NSQIP). The association between covariates and the incidence of postoperative symptomatic VTE (includes deep venous thrombosis and pulmonary embolism) was assessed using bivariable and multivariable regression.

RESULTS

Complete demographic and clinical information for analysis were available for 75,771 patients. The mean patient age was 65 years, and 96.6% were men. Major comorbidities included diabetes mellitus (DM), 25%; chronic obstructive pulmonary disease (COPD), 18.3%; and congestive heart failure (CHF), 3.9%. Symptomatic VTE was diagnosed in 805 patients (0.68%), varied significantly with procedure (0.14% for carotid endarterectomy vs 1.34% for total hip arthroplasty), and was associated with increased 30-day mortality (16.9% vs 4.4%, P < .0001). The incidence of VTE did not decline substantially between 1996 and 2001 (0.72% vs 0.68%). Preoperative factors associated with symptomatic VTE were older age, male gender, corticosteroid use, COPD, recent weight loss, disseminated cancer, low albumin, and low hematocrit (all P < .01) but not DM. Postoperative factors associated with VTE were myocardial infarction (MI), blood transfusion (>4 units), coma, pneumonia, and urinary tract infection (UTI), whereas those with hemodialysis-dependent renal failure were less likely to experience VTE (all P < .01). In multivariable analysis, adjusting for age and the variables significant by bivariable analysis, the strongest positive predictors of symptomatic VTE included UTI (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3 to 2.5), acute renal insufficiency (OR, 1.9; 95% CI, 1.1 to 3.2), postoperative transfusion (OR, 2.3; 95% CI, 1.4 to 3.7), perioperative MI (OR, 2.4; 95% CI, 1.5 to 3.9), and pneumonia (OR, 2.7; 95% CI, 2.1 to 3.5). In contrast, hemodialysis (OR, 0.3; 95% CI, 0.07 to 0.71), DM (OR, 0.75; 95% CI, 0.61 to 0.93), and higher preoperative albumin levels (OR, 0.8; 95% CI, 0.74 to 0.96, per mg/dL change) were protective from symptomatic VTE.

CONCLUSIONS

Although the overall incidence of symptomatic VTE is low in surgical patients, it is associated with significantly increased 30-day mortality. In addition to previously recognized risk factors, patients who have postoperative complications of an infectious nature, bleeding, or MI are at particular risk.

Incidence and short-term outcomes of primary and revision hip replacement in the United States

BACKGROUND

The purpose of this study was to use 2003 nationwide United States data to determine the incidences of primary total hip replacement, partial hip replacement, and revision hip replacement and to assess the short-term patient outcomes and factors associated with the outcomes.

METHODS

We screened more than eight million hospital discharge abstracts from the 2003 Healthcare Cost and Utilization Project Nationwide Inpatient Sample and approximately nine million discharge abstracts from five state inpatient databases. Patients who had undergone total, partial, or revision hip replacement were identified with use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes. In-hospital mortality, perioperative complications, readmissions, and the association between these outcomes and certain patient and hospital variables were analyzed.

RESULTS

Approximately 200,000 total hip replacements, 100,000 partial hip replacements, and 36,000 revision hip replacements were performed in the United States in 2003. Approximately 60% of the patients were sixty-five years of age or older and at least 75% had one or more comorbid diseases. The in-hospital mortality rates associated with these three procedures were 0.33%, 3.04%, and 0.84%, respectively. The perioperative complication rates associated with the three procedures were 0.68%, 1.36%, and 1.08%, respectively, for deep vein thrombosis or pulmonary embolism; 0.28%, 1.88%, and 1.27% for decubitus ulcer; and 0.05%, 0.06%, and 0.25% for postoperative infection. The rates of readmission, for any cause, within thirty days were 4.91%, 12.15%, and 8.48%, respectively, and the rates of readmissions, within thirty days, that resulted in a surgical procedure on the affected hip were 0.79%, 0.91%, and 1.53%. The rates of readmission, for any cause, within ninety days were 8.94%, 21.14%, and 15.72%, and the rates of readmissions, within ninety days, that resulted in a surgical procedure on the affected hip were 2.15%, 1.61%, and 3.99%. Advanced age and comorbid diseases were associated with worse outcomes, while private insurance coverage and planned admissions were associated with better outcomes. No consistent association between outcomes and hospital characteristics, such as hip procedure volume, was identified.

CONCLUSIONS

Total hip replacement, partial hip replacement, and revision hip replacement are associated with different rates of postoperative complications and readmissions. Advanced age, comorbidities, and nonelective admissions are associated with inferior outcomes.

The impact of venous thromboembolism on risk of death or hemorrhage in older cancer patients

BACKGROUND

Among older cancer patients, there is uncertainty about the degree to which venous thromboembolism (VTE) and its treatment increase the risk of death or major hemorrhage.

OBJECTIVE

To determine the prevalence of VTE in a cohort of older cancer patients, as well as the degree to which VTE increased the risk of death or major hemorrhage.

METHODS

We conducted a retrospective cohort study of linked Surveillance, Epidemiology, and End Results cancer registry and Medicare administrative claims data. Patients with any of ten invasive cancers diagnosed during 1995 through 1999 were included; the independent variable was VTE diagnosed concomitantly with cancer diagnosis. Outcomes included major hemorrhage during the first year after cancer diagnosis and all-cause mortality;

RESULTS

Overall, about 1% of patients who were diagnosed with cancer also had a VTE diagnosed concomitantly. After adjusting for sociodemographic factors and cancer stage and grade, concomitant VTE was associated with a relative increase in the risk of death for 8 of the 10 cancer types; the increase in risk tended to range 20-40% across most cancer types. Approximately 16.8% (95% confidence interval [CI] 14.9-18.8%) of patients with a concomitant VTE and 7.9% (95% CI 7.7-8.0%) of patients without a VTE experienced a major hemorrhage during the year after cancer diagnosis (P value <.001). The excess risk of hemorrhage associated with VTE varied substantially across cancer types, ranging from no significant excess (kidney and uterine cancer) to 11.5% (lymphoma).

CONCLUSION

Concomitant VTE is not only a marker and potential mediator of increased risk of death among older cancer patients, but patients with a VTE have a marked increased risk of major hemorrhage.

Thromboembolic disease after total hip arthroplasty: who is at risk?

The strong activation of the clotting cascade that occurs during total hip arthroplasty places patients at increased risk for venous thromboembolism. The risk is higher in those patients with the following predisposing factors, listed in approximate order of importance: hip fracture; malignancy, particularly if associated with chemotherapy; antiphospholipid syndrome; immobility; history of venous thromboemholism; administration of tamoxifen; raloxifene; oral contraceptives or estrogen; morbid obesity; stroke; atherosclerosis; and an American Society of Anesthesiologists physical status classification of 3 or greater. The following risk factors are weak or controversial: advanced age; diabetes mellitus; congestive heart disease; atrial fibrillation; varicose veins; and smoking. However, 50% of patients who develop thromboembolism after total hip arthroplasty have no clinical predisposing factors. In a matched, controlled study, we defined the major genetic predispositions that increase the risk of venous thromboembolism after total hip arthroplasty: deficiency of antithrombin III (< 75%) and protein C (< 70%), and prothrombin gene mutation. Preoperative genetic screening in conjunction with the recognized clinical risk factors can help categorize postoperative venous thromboembolism risk and differentiate patients who can be protected with milder and safer prophylaxis (eg, aspirin, intermittent pneumatic compression) compared with those at higher risk who need to be anticoagulated.

Hip and Knee Arthroplasty in the Geriatric Population

Osteoarthritis is the leading cause of hip and knee pathology in the geriatric population. Hip and knee arthroplasty are the definitive interventions to alleviate pain and restore physical functioning. Complications related to these procedures do occur: the most com-mon of these are infection, thromboembolism, dislocations, and periprosthetic fractures. New improvements related to minimally invasive and computer-assisted navigation surgery techniques are promising and already have shown excellent outcomes in patients exposed to joint arthroplasty.

The epidemiology of venous thromboembolism in the community: implications for prevention and management

The epidemiology of venous thromboembolism (VTE) in the community has important implications for VTE prevention and management. This review describes the incidence, survival, recurrence, complications and risk factors for deep vein thrombosis and pulmonary embolism occurring in the community. VTE incidence among whites of European origin exceeds 1 per 1000; the incidence among persons of African and Asian origin may be higher and lower, respectively. VTE incidence over recent time remains unchanged. Survival after VTE is worse than expected, especially for pulmonary embolism where one-quarter of patients present as sudden death. Of those patients who survive, 30% develop VTE recurrence and venous stasis syndrome within 10 and 20 years, respectively. Common independent VTE risk factors include surgery, hospitalization for acute medical illness, nursing home confinement, trauma, active cancer, neurologic disease with extremity paresis, superficial vein thrombosis, central venous catheter/transvenous pacemaker, and among women, oral contraceptives, pregnancy and the puerperium, and hormone and SERM therapy. Exposures can identify populations at risk but have a low predictive value for the individual person. An acquired or familial thrombophilia may predict the subset of exposed persons who actually develop symptomatic VTE. In conclusion, VTE is a common, lethal disease that recurs frequently and causes serious long-term complications. To improve survival and prevent complications, VTE occurrence must be reduced. Better individual risk stratification is needed in order to modify exposures and target primary and secondary prophylaxis to the person who would benefit most.

Venous thromboembolism in patients with colorectal cancer: incidence and effect on survival

PURPOSE

To describe the incidence and outcomes associated with venous thromboembolism (VTE) among patients with colorectal cancer.

METHODS

This was a retrospective analysis of all colorectal cancer patients diagnosed in California between 1993 and 1995 and 1997 to 1999. Principal outcomes were incident symptomatic VTE events and death. Associations between specific risk factors and principal outcomes were analyzed using Cox proportional hazards models.

RESULTS

Among 68,142 colorectal cancer patients, 50% were women, mean age was 70 +/- 15 years, and approximately 70% underwent a major operation. The 2-year cumulative incidence of VTE was 2,100 patients (3.1%), with an incidence rate that decreased significantly over time from 5.0% (events/100 patient-years) in months 0 to 6 to 1.4% during months 7 to 12 to 0.6% during the second year. Significant predictors of VTE included metastatic stage (hazard ratio [HR] = 3.2; 95% CI, 2.8 to 3.8) and three or more comorbid conditions (HR = 2.0; 95% CI, 1.7 to 2.3). The risk of VTE was significantly reduced among Asians/Pacific Islanders (HR = 0.4; 95% CI, 0.3 to 0.5.) and patients who underwent an abdominal operation (HR = 0.4; 95% CI, 0.3 to 0.4). In risk-adjusted models, VTE was a significant predictor of death within 1 year of cancer diagnosis among patients with local- (HR = 1.8; 95% CI, 1.4 to 2.3) or regional-stage disease (HR = 1.5; 95% CI, 1.3 to 1.8) but not among patients with metastatic disease (HR = 1.1; 95% CI, 1.0 to 1.2).

CONCLUSION

The incidence of VTE among colorectal cancer patients was highest in the first 6 months after diagnosis and decreased rapidly thereafter. Metastatic disease and the number of medical comorbidities were the strongest predictors of VTE. Incident VTE reduced survival among patients with local or regional disease, suggesting that, in these patients, VTE may reflect the presence of a biologically more aggressive cancer.

Incidence and risk factors for development of venous thromboembolism in Indian patients undergoing major orthopaedic surgery: results of a prospective study

INTRODUCTION

The incidence of venous thromboembolism (VTE) in Western populations undergoing major orthopaedic surgery without any thromboprophylaxis has been reported to range from 32% to 88%. There is however limited information on incidence of VTE in Indian patients and most of the Indian patients undergoing these surgeries do not receive any form of prophylaxis regardless of their risk profile.

METHODS

A prospective study was performed on 147 patients undergoing major orthopaedic surgery for total knee replacement (TKR), total hip replacement (THR), and proximal femur fracture fixation (PFF) without any prophylaxis. These patients were profiled for presence of the known risk factors responsible for development of VTE. A duplex ultrasound on both lower limbs was done 6 to 10 days after surgery. Twenty three patients underwent THR, 22 patients underwent TKR, and 102 underwent surgery for PFF. The patients were assessed clinically for any signs of deep venous thrombosis (DVT) and pulmonary embolism (PE). A helical CT scan was done in case of suspicion of PE and a duplex ultrasound was done in case of clinical suspicion of DVT irrespective of the stage of study.

RESULTS

The overall incidence of VTE was 6.12% and that of PE was 0.6%. The risk factors that were found to be significantly responsible for development of VTE (p < 0.05) were: immobility greater than 72 hours, malignancy, obesity, surgery lasting more than two hours.

CONCLUSION

The study reconfirms the belief that DVT has a lower incidence in Indian patients as compared with other ethnic groups.

The John Charnley Award: heritable thrombophilia and development of thromboembolic disease after total hip arthroplasty

We retrospectively assessed whether heritable thrombophilia-hypofibrinolysis was more common in patients developing venous thromboembolism after total hip replacement than among control patients who did not develop venous thromboembolism, as an approach to better identify causes of venous thromboembolism after total hip arthroplasty. Twenty patients with proximal deep venous thrombosis after THA and 23 patients with symptomatic pulmonary embolism were compared with 43 control patients who did not have postoperative venous thromboembolism. Five of 42 patients with venous thromboembolism (12%) and 0 of 43 control patients (0%) had antithrombin III deficiency (< 75%). Nine of 42 patients with venous thromboembolism (21%) and 2 of 43 control patients (4.7%) had protein C deficiency (< 70%). Ten of 43 patients with venous thromboembolism (9 heterozygous, 1 homozygous; 23%) and 1 of 43 control patients (heterozygous; 2%) had the prothrombin gene mutation. Patients who had venous thromboembolism after total hip arthroplasty were more likely than matched control patients to have heritable thrombophilia with antithrombin III or protein C deficiency, or homo-heterozygosity for the prothrombin gene mutation. Screening for these three tests of heritable thrombophilia before total hip arthroplasty should improve the identification of patients with a reduced risk of venous thromboembolism who may need only mild thromboprophylaxis, and of those patients with heritable thrombophilia in whom prophylaxis should be more aggressive.

LEVEL OF EVIDENCE

Prognostic study, Level II-1 (lesser-quality RCT). See the Guidelines for Authors for a complete description of levels of evidence.

Venous thromboembolism associated with hip and knee replacement over a ten-year period

This population-based study investigated the incidence and trends in venous thromboembolic disease after total hip and knee arthroplasty over a ten-year period. Death or readmission for venous thromboembolic disease up to two years after surgery for all patients in Scotland was the primary outcome. The incidence of venous thromboembolic disease, including fatal pulmonary embolism, three months after surgery was 2.27% for primary hip arthroplasty and 1.79% for total knee arthroplasty. The incidence of fatal pulmonary embolism within three months was 0.22% for total hip arthroplasty and 0.15% for total knee arthroplasty. The majority of events occurred after hospital discharge, with no apparent trend over the period. The data support current advice that prophylaxis should be continued for at least six weeks following surgery. Despite the increased use of policies for prophylaxis and earlier mobilisation, there has been no change in the incidence of venous thromboembolic disease.

Update on the diagnosis and management of pulmonary embolism

Pulmonary embolism (PE) is a common and often fatal disease. In the US, an estimated 40-53 people per 100,000 are diagnosed with PE annually and approximately 60,000 die from the disease. Diagnosis is difficult because symptoms are non-specific; however, a quick and accurate diagnosis is critical because, with appropriate therapy, the risk of recurrent (and potentially fatal) PE can be greatly reduced. Recent publication of prediction rules and improved non-invasive diagnostic tools have simplified diagnostic algorithms for PE. The efficacy of the standard treatment for PE, initial administration of continuous i.v. unfractionated heparin overlapped with long-term oral anticoagulation, is well established. However, newer treatment options such as low-molecular-weight heparins and the pentasaccharides may offer similar efficacy with improved convenience.

Age as a risk factor for venous thromboembolism after major surgery

PURPOSE OF REVIEW

Postoperative deep venous thrombosis and pulmonary embolism are serious and potentially life-threatening complications that frequently occur after major surgery. Most guidelines for thromboprophylaxis use advancing age as a key component to estimate thromboembolic risk. The reported effect of age on postoperative venous thromboembolism varies widely, making it unclear whether age alone is a significant risk factor. This article reviews the recent literature on the effect of age on the incidence of postoperative venous thromboembolism.

RECENT FINDINGS

Between 2003 and 2005, several cohort studies assessed the risk factors for postoperative venous thromboembolism, showing a variable effect of age on its incidence in the 2- to 3-month period after major surgery. Studies also revealed a significant difference in the effect of age on the incidence of venous thromboembolism depending on the type of surgery. Obesity, postoperative immobilization, the use of thromboprophylaxis, the nature of the surgery, and underlying comorbid conditions such as heart failure seem to have a greater influence on the risk of venous thromboembolism than does age.

SUMMARY

The variation in the effect of age on postoperative venous thromboembolism likely depends on whether or not other comorbid conditions or age-related changes in functional status are considered as risk factors. When these other risk factors are taken into account, the effect of advanced age decreases. More research is needed to develop validated venous thromboembolism risk-prediction tools for specific types of surgery. By use of this information, the intensity and duration of postoperative thromboprophylaxis can be tailored to the level of risk, not just age alone.

Pulmonary embolism prophylaxis: evidence for utility in thoracic surgery

Patients requiring thoracotomy for the treatment of malignancy are at risk for developing a pulmonary embolism. Few data exist on effective prophylaxis techniques in this specific patient population, yet effective strategies can be inferred from other major surgical procedures to reduce the risk of this potentially life-threatening complication.

Emerging Strategies in the Prevention of Venous Thromboembolism in Hospitalized Medical Patients

Venous thromboembolism (VTE) remains a significant cause of morbidity and mortality in hospitalized patients with acute medical illness. The high prevalence of VTE in this patient population, its clinically silent nature, and associated morbidity and mortality indicate that prophylactic therapy is appropriate in those determined to be at increased risk. Unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) have been shown to reduce the incidence of VTE and are the primary therapies used for prophylaxis in these patients. Although both UFH and LMWH have received grade 1A recommendations for the prevention of VTE in at-risk medical patients in the 2004 American College of Chest Physicians consensus conference statements, LMWH has advantages over UFH in its once-daily dosing scheme, reduced incidence of major and minor bleeding events, and reduced incidence of heparin-induced thrombocytopenia. Fondaparinux is a novel antithrombotic agent characterized by specificity for factor Xa and a lack of platelet interaction. A recent clinical trial in hospitalized patients with acute medical illness found that fondaparinux significantly reduced the incidence of both VTE and fatal pulmonary embolism compared with placebo, without increased major bleeding. Despite the availability of effective thromboprophylactic therapies, VTE prophylaxis continues to be underutilized in hospitalized medical patients.

Venous thromboembolism: disease burden, outcomes and risk factors

The epidemiology of venous thromboembolism (VTE) in the community has important implications for VTE prevention and management. This review describes the disease burden (incidence), outcomes (survival, recurrence and complications) and risk factors for deep vein thrombosis and pulmonary embolism occurring in the community. Recent comprehensive studies of the epidemiology of VTE that reported the racial demography and included the full spectrum of disease occurring within a well-defined geographic area over time, separated by event type, incident vs. recurrent event and level of diagnostic certainty, were reviewed. Studies of VTE outcomes had to include a relevant duration of follow-up. VTE incidence among whites of European origin exceeded 1 per 1000; the incidence among persons of African and Asian origin may be higher and lower, respectively. VTE incidence over recent time remains unchanged. Survival after VTE is worse than expected, especially for pulmonary embolism. Thirty percent of patients develop VTE recurrence and venous stasis syndrome. Exposures can identify populations at risk but have a low predictive value for the individual. An acquired or familial thrombophilia may predict the subset of exposed persons who actually develop symptomatic VTE. In conclusion, VTE is a common, lethal disease that recurs frequently and causes serious long-term complications. To improve survival and prevent complications, VTE occurrence must be reduced. Better individual risk stratification is needed in order to modify exposures and target primary and secondary prophylaxis to the person who would benefit most.

Derivation and validation of a prognostic model for pulmonary embolism

RATIONALE

An objective and simple prognostic model for patients with pulmonary embolism could be helpful in guiding initial intensity of treatment.

OBJECTIVES

To develop a clinical prediction rule that accurately classifies patients with pulmonary embolism into categories of increasing risk of mortality and other adverse medical outcomes.

METHODS

We randomly allocated 15,531 inpatient discharges with pulmonary embolism from 186 Pennsylvania hospitals to derivation (67%) and internal validation (33%) samples. We derived our prediction rule using logistic regression with 30-day mortality as the primary outcome, and patient demographic and clinical data routinely available at presentation as potential predictor variables. We externally validated the rule in 221 inpatients with pulmonary embolism from Switzerland and France.

MEASUREMENTS

We compared mortality and nonfatal adverse medical outcomes across the derivation and two validation samples.

MAIN RESULTS

The prediction rule is based on 11 simple patient characteristics that were independently associated with mortality and stratifies patients with pulmonary embolism into five severity classes, with 30-day mortality rates of 0-1.6% in class I, 1.7-3.5% in class II, 3.2-7.1% in class III, 4.0-11.4% in class IV, and 10.0-24.5% in class V across the derivation and validation samples. Inpatient death and nonfatal complications were <or= 1.1% among patients in class I and <or= 1.9% among patients in class II.

CONCLUSIONS

Our rule accurately classifies patients with pulmonary embolism into classes of increasing risk of mortality and other adverse medical outcomes. Further validation of the rule is important before its implementation as a decision aid to guide the initial management of patients with pulmonary embolism.

Deep vein thrombosis

Deep vein thrombosis and its sequelae pulmonary embolism and post-thrombotic syndrome are some of the most common disorders. A thrombus either arises spontaneously or is caused by clinical conditions including surgery, trauma, or prolonged bed rest. In these instances, prophylaxis with low-dose anticoagulation is effective. Diagnosis of deep vein thrombosis relies on imaging techniques such as ultrasonography or venography. Only about 25% of symptomatic patients have a thrombus. Thus, clinical risk assessment and D-dimer measurement are used to rule out deep vein thrombosis. Thrombus progression and embolisation can be prevented by low-molecular-weight heparin followed by vitamin K antagonists. Use of these antagonists for 3-6 months is sufficient for many patients. Those with antithrombin deficiency, the lupus anticoagulant, homozygous or combined defects, or with previous deep vein thrombosis can benefit from indefinite anticoagulation. In cancer patients, low-molecular-weight heparin is more effective than and is at least as safe as vitamin K antagonists. Women seem to have a lower thrombosis risk than men, but pregnancy or use of oral contraceptives or hormone replacement therapy represent important risk factors.

Perioperative management of the post-gastric-bypass patient presenting for body contour surgery

Bariatric surgery has evolved as an effective and relatively safe treatment for morbid obesity. With nearly every region of the body as a potential operative site and an unprecedented number of surgical procedures available, we must give attention to thoughtful perioperative management. Bariatric surgery is a life-changing event for the morbidly obese patient, and the body contouring that follows weight loss often has an equally profound effect. Plastic surgeons must strive to maintain the highest level of safety in this pursuit. The authors address issues surrounding preoperative evaluation and measures to minimize the risk of complications.

Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This article discusses the prevention of venous thromboembolism (VTE) and is part of the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following. We recommend against the use of aspirin alone as thromboprophylaxis for any patient group (Grade 1A). For moderate-risk general surgery patients, we recommend prophylaxis with low-dose unfractionated heparin (LDUH) (5,000 U bid) or low-molecular-weight heparin (LMWH) [< or = 3,400 U once daily] (both Grade 1A). For higher risk general surgery patients, we recommend thromboprophylaxis with LDUH (5,000 U tid) or LMWH (> 3,400 U daily) [both Grade 1A]. For high-risk general surgery patients with multiple risk factors, we recommend combining pharmacologic methods (LDUH three times daily or LMWH, > 3,400 U daily) with the use of graduated compression stockings and/or intermittent pneumatic compression devices (Grade 1C+). We recommend that thromboprophylaxis be used in all patients undergoing major gynecologic surgery (Grade 1A) or major, open urologic procedures, and we recommend prophylaxis with LDUH two times or three times daily (Grade 1A). For patients undergoing elective total hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or adjusted-dose vitamin K antagonist (VKA) [international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0] (all Grade 1A). For patients undergoing hip fracture surgery (HFS), we recommend the routine use of fondaparinux (Grade 1A), LMWH (Grade 1C+), VKA (target INR, 2.5; range, 2.0 to 3.0) [Grade 2B], or LDUH (Grade 1B). We recommend that patients undergoing hip or knee arthroplasty, or HFS receive thromboprophylaxis for at least 10 days (Grade 1A). We recommend that all trauma patients with at least one risk factor for VTE receive thromboprophylaxis (Grade 1A). In acutely ill medical patients who have been admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, we recommend prophylaxis with LDUH (Grade 1A) or LMWH (Grade 1A). We recommend, on admission to the intensive care unit, all patients be assessed for their risk of VTE. Accordingly, most patients should receive thromboprophylaxis (Grade 1A).

[Stationary thromboprophylaxis in casualty surgery. Relevance of postoperative mobility and preexisting risk factors]

The presented thromboprophylactic concept includes weight bearing and ankle motion as well as breathing therapy and drug prophylaxis (antiphlogistics, analgesic drugs, heparin). Routinely performed ultrasound screening of the deep veins (legs and pelvis) before release showed a low DVT incidence of 2.5% in a prospective clinical observation of 841 inpatients. Obesity, venous insufficiency, and a history of previous thromboembolic events were associated with a significantly increased risk of thrombosis (relative risk 4.1, 4,9, and 5.8, respectively) The duration of immobilization also had a relevant influence indicating that early postoperative physiotherapy in traumatology and orthopedic surgery has a widely underestimated thromboprophylactic effect.

Effect of age on the incidence of venous thromboembolism after major surgery

BACKGROUND

Most guidelines for administration of thromboprophylaxis after major surgery use age as a major predictor of postoperative venous thromboembolism (VTE). We sought to quantify the effect of age on the risk of symptomatic VTE after a spectrum of surgical procedures.

METHODS

Using the California Patient Discharge Data Set and specific ICD-9-CM surgical procedure codes, we retrospectively determined the incidence of VTE diagnosed within 91 days after 40 different urgent or elective surgeries performed in the hospital between 1992 and 1996. Logistic regression was used to quantify the effect of age on the incidence of postoperative VTE and to adjust for other risk factors.

RESULTS

1,464,452 cases underwent one of 40 different procedures (mean cases per procedure = 35,718, range 4500-145 500). There was a significant interaction between age and the type of surgery performed (P<0.0001). Qualitative analysis of the effect of age on the incidence of VTE stratified by the presence or absence of malignancy revealed three general patterns: a steady increase in the incidence of VTE with age, exemplified by appendectomy or cholecystectomy; an increase in VTE up to approximately age 65 with no increase thereafter, exemplified by total hip arthroplasty; and no effect of age on the incidence of VTE, exemplified by vascular surgery.

CONCLUSIONS

The relationship between age and the risk of VTE after surgery is complex and depends on the nature of the surgery and the underlying pathologic process. Advancing age was a significant predictor for VTE following surgeries performed for conditions not inherently associated with significant comorbidity. Conversely, advancing age was not associated with a higher incidence of VTE after surgeries performed for conditions strongly associated with serious underlying comorbidity, such as a malignancy or severe peripheral vascular disease.