Risk factors for venous thromboembolism

Unraveling disparities: Probing gender, race, and geographic inequities in pulmonary heart disease mortality in the United States: An extensive longitudinal examination (1999-2020) leveraging CDC WONDER data

This comprehensive study delves into the epidemiological landscape of Pulmonary Heart Disease (PHD) mortality in the United States from 1999 to 2020, leveraging the extensive CDC WONDER database. PHD encompasses conditions affecting the right side of the heart due to lung disorders or elevated pressure in the pulmonary arteries, including pulmonary hypertension, pulmonary embolism, and chronic thromboembolic pulmonary hypertension (CTEPH). Analyzing data from death certificates, demographic characteristics, and geographical segmentation, significant trends emerge. The age-adjusted mortality rates (AAMRs) for PHD-related deaths show a fluctuating pattern, initially decreasing from 1999 to 2006, followed by a steady increase until 2020. Male patients consistently exhibit higher AAMRs than females, with notable disparities observed among racial/ethnic groups and geographic regions. Non-hispanic (NH) Black or African American individuals, residents of specific states like Colorado and the District of Columbia, and those in the Midwest region demonstrate elevated AAMRs. Furthermore, nonmetropolitan areas consistently manifest higher AAMRs than metropolitan areas. These findings underscore the urgent need for intensified prevention and treatment strategies to address the rising mortality associated with PHD, particularly among vulnerable populations. Insights from this study offer valuable guidance for public health initiatives aimed at reducing PHD-related mortality and improving outcomes nationwide.

Efficacy and safety of pre-operative insertion of inferior vena cava filter in patients undergoing bariatric surgery: a systematic review

Prophylactic placement of inferior vena cava (IVC) filters prior to performing bariatric surgery is an intervention of unclear safety and efficacy with disagreement between current practice guidelines. To better characterize the risk and benefit of IVC filter insertion prior to bariatric surgery based on the current evidence. A systematic review of the literature of patients with prophylactic IVC filter insertion prior to bariatric surgery was performed and 32 studies were identified for inclusion into the review, of which none were randomized controlled trials. Meta-analysis was performed including the high-quality included studies. Seven high quality studies reported thrombotic events in patients undergoing bariatric surgery who had an IVCF and a control group which allowed for meta-analysis. The pooled odds ratio of venous thrombotic events in the IVC filter population versus the group without IVC filters was 1.57 (95%CI 0.89, 2.76). Among high quality studies 5 reported major bleeding with a rate of 0.76% and 6 reported on IVC filter complications with a rate of 0.67%. Overall no significant reduction in the rate of venous thrombosis was found with prophylactic IVC filter insertion. Use of IVC filters for prophylaxis remains a concern given the lack of clear efficacy in this setting and a small but present complication risk.

Incidence and Risk Factors of Venous Thromboembolism Following Hepatectomy for Colorectal Metastases: A Population-Based Retrospective Cohort Study

BACKGROUND

Incidence of venous thromboembolism (VTE) following hepatectomy for colorectal cancer (CRC) metastases is unclear. These patients may represent a vulnerable population due to increased tumour burden. We aim to identify the risk of VTE development in routine clinical practice among patients with resected CRC liver metastases, the associated risk factors, and its impact on survival.

METHODS

We conducted a population-based retrospective cohort study of Ontario patients undergoing hepatectomy for CRC metastases between 2002 and 2009 using linked universal healthcare databases. Multivariable logistic regression was used to estimate the association between patient characteristics and VTE risk at 30 and 90-days after surgery. Cox proportional-hazards regression was used to estimate the association between VTE and adjusted cancer specific (CSS) and overall survival (OS).

RESULTS

1310 patients were included with a mean age of 63 ± 11. 62% were male. 51% had one metastatic deposit. Major hepatectomy occurred in 64%. VTE occurred in 4% within 90 days of liver resection. Only longer length of stay was associated with VTE development (OR 6.88 (2.57-18.43), p <0.001 for 15-21 days versus 0-7 days). 38% of VTEs were diagnosed after discharge, comprising 1.52% of the total cohort. VTE was not associated with inferior CSS or OS.

CONCLUSIONS

Risk of VTE development in this population is similar to those undergoing hepatectomy for other indications, and to the risk following other cancer site resections where post-operative extended VTE prophylaxis is currently recommended. The number of VTEs occurring after discharge suggests there may be a role for extended VTE prophylaxis.

Incidence and locations of preoperative deep venous thrombosis (DVT) of lower extremity following tibial plateau fractures: a prospective cohort study

Background

There is still lack of data on deep vein thrombosis (DVT) following bone trauma. This study aimed to determine the epidemiologic characteristics of deep venous thrombosis (DVT) of lower extremities following tibial plateau fractures.

Methods

Retrospective analysis of prospectively collected data on patients presenting with tibial plateau fractures between October 2014 and December 2018 was conducted. Duplex ultrasonography (DUS) was routinely used to screen for preoperative DVT of bilateral lower extremities. Data on demographics, comorbidities, injury-related data, and laboratory biomarkers at admission were collected. Univariate analyses and multivariate logistic regression analyses were used to identify the independent risk factors associated with DVT.

Results

A total of 1179 patients were included, among whom 192 (16.3%) had a preoperative DVT, with incidence rate of 1.0% for proximal and 15.3% for distal DVT. The average interval between fracture occurrence and diagnosis of DVT was 3.5 days (median, 2 days), ranging from 0 to 19 days. DVT involved the injured extremity in 166 (86.4%) patients, both the injured and uninjured extremities in 14 patients (7.3%) and only the uninjured extremity in 12 patients (6.3%). Six risk factors were identified to be associated with DVT, including gender (male vs female), hypertension, open fracture, alkaline phosphatase > 100 u/L, sodium concentration < 135 mmol/L, and D-dimer > 0.5 mg/L.

Conclusion

These epidemiologic data are conducive to the individualized assessment, risk stratification, and development of targeted prevention programs.

Risk Factor and Mortality in Patients with Pulmonary Embolism Combined with Infectious Disease

BACKGROUND

Infectious conditions may increase the risk of venous thromboembolism. The purpose of this study was to evaluate the risk factor for combined infectious disease and its influence on mortality in patients with pulmonary embolism (PE).

METHODS

Patients with PE diagnosed based on spiral computed tomography findings of the chest were retrospectively analyzed. They were classified into two groups: patients who developed PE in the setting of infectious disease or those with PE without infection based on review of their medical charts.

RESULTS

Of 258 patients with PE, 67 (25.9%) were considered as having PE combined with infectious disease. The sites of infections were the respiratory tract in 52 patients (77.6%), genitourinary tract in three patients (4.5%), and hepatobiliary tract in three patients (4.5%). Underlying lung disease (odds ratio [OR], 3.69; 95% confidence interval [CI], 1.926-7.081; p<0.001), bed-ridden state (OR, 2.84; 95% CI, 1.390-5.811; p=0.004), and malignant disease (OR, 1.867; 95% CI, 1.017-3.425; p=0.044) were associated with combined infectious disease in patients with PE. In-hospital mortality was higher in patients with PE combined with infectious disease than in those with PE without infection (24.6% vs. 11.0%, p=0.006). In the multivariate analysis, combined infectious disease (OR, 4.189; 95% CI, 1.692-10.372; p=0.002) were associated with non-survivors in patients with PE.

CONCLUSION

A substantial portion of patients with PE has concomitant infectious disease and it may contribute a mortality in patients with PE.

Venous thromboembolism prophylaxis in inflammatory bowel disease flare-ups

Background:

Inflammatory bowel disease (IBD) is a set of chronic inflammatory diseases associated with significant morbidity. Generally, IBD patients have twice the risk of venous thromboembolism (VTE) compared to healthy controls. VTE in IBD is associated with greater morbidity and mortality. This is compounded by the underutilization of pharmacological anticoagulation in hospitalized patients with IBD. One study showed that half the IBD patients who developed VTE were not receiving any thrombotic prophylaxis.

Method:

We carried out a retrospective chart review of VTE prophylaxis use and safety in patients admitted with IBD flare-up between 2014 and 2017.

Results:

We evaluated 233 patients (mean age 36.7 years; 53.6% male). Of these patients, 55.2% were Caucasian and 40.5% were African American; 72.5% had Crohn’s disease and 21% ulcerative colitis. About one-third of our patients were on chronic steroids. Pharmacological prophylaxis was used in 39.7% of the patients. This significantly correlated with male sex, recent surgery, history of VTE, smoking, and chronic steroid use. Meanwhile, hematochezia, aspirin use, and a history of gastrointestinal bleeding were correlated with less use of pharmacological prophylaxis. Patients receiving pharmacological prophylaxis showed no difference in the incidence of bleeding events.

Conclusions:

Multiple factors were associated with the use of pharmacological prophylaxis in hospitalized patients, including sex, steroid use, history of VTE events or gastrointestinal bleeding, and hematochezia. The incidence of major bleeding was not significantly greater in IBD patients receiving pharmacological prophylaxis.

A haemodynamic concept in the management of superficial non-saphenous vein thrombosis

Objective

Through the analysis of the haemodynamic model in the development of superficial non-saphenous vein thrombosis, the authors propose a therapeutic approach which is based on an ultrasound study of the superficial and perforating venous system of the lower limbs.

Methods

The authors propose the development of a haemodynamic model in the evolution of superficial non-saphenous vein thrombosis. They analyse three cases to highlight the importance of venous haemodynamics in the development of this condition and its possible complications, such as the progression of thrombosis in the deep vein system through the perforating veins.

Results

The evolution of a thrombosis in the venous network of the lower limbs from the peripheral collateral veins to the deep vein can be haemodynamically explained through this model involving the perforating vein system.

Conclusions

In the management and treatment of superficial non-saphenous vein thrombosis, it is essential to perform an accurate ultrasound evaluation of the superficial venous system, the deep venous system and the perforator system, according to venous haemodynamic principles. This study proposes a new model to be used in the ultrasonic management and treatment of superficial non-saphenous vein thrombosis.

[Analysis of prophylactic effect of extended-duration anticoagulant drugs in elderly patients undergoing hip fracture]

OBJECTIVE

To evaluate the prophylactic effect of extended-duration anticoagulant drugs on venous thromboembolism, and to explore the time of drug prevention for venous thromboembolism after hip fracture.

METHODS

A retrospective analysis of 143 patients undergoing hip fractures from November 2017 to October 2018 in Peking University People's Hospital was conducted to investigate the relationship between the extended-duration anticoagulant drug and the morbidity of venous thromboembolism and bleeding during the treatment. All the drug prevention programs for the patients included in the study were implemented in accordance with the 2016 edition of the Guidelines for Prevention of Venous Thrombosis in Orthopaedic Surgery by Orthopaedic Society of Chinese Medical Association. The patients in the two groups were followed up for venous thromboembolism and bleeding during the medication within 5 weeks after the fracture. Venous thromboembolism included symptomatic and asymptomatic deep venous thrombosis of the lower extremities, pulmonary thromboembolism, and all the patients with deep venous thrombosis of the lower extremities required vascular ultrasound results to obtain clear evidence. The results of vascular ultrasound were the basis for determining deep venous thrombosis. Bleeding conditions were included, but not limited to gastrointestinal bleeding, wound bleeding, intracranial hemorrhage, intraspinal hematoma, and fundus hemorrhage.

RESULTS

There were no pulmonary thromboembolism in both groups after surgery. The morbidity of deep venous thrombosis was 22.09% and 8.77% in the 2-week and 4-week groups (P=0.037), the time to deep venous thrombosis in the two groups was (17.32±7.75) days and (29.20±0.17) days after surgery. One case of bleeding occurred during the use of anticoagulant drugs in both groups, the morbidity of bleeding during the treatment was 1.16% and 1.75% (P=0.769), respectively.

CONCLUSION

Extended-duration anticoagulant drugs to 4 weeks after surgery can significantly reduce the morbidity of postoperative venous thromboembolism, and does not increase the risk of bleeding. Patients with a risk of bleeding should carefully assess the risks and benefits of drug prevention and choose the best treatment.

Pulmonary Embolism during Stuporous Episodes of Catatonia Was Found to Be the Most Frequent Cause of Preventable Death According to a State Mortality Review: 6 Deaths in 15 Years

Case reports have indicated that pulmonary embolism (PE) can be associated with deaths during episodes of catatonia. A 15-year death registry in Kentucky state psychiatric hospitals was reviewed for deaths during episodes of catatonia. From 2002 to May of 2016, reports of 96 deaths at these state psychiatric hospitals were found and reviewed by the state mortality committee. The charts of the identified catatonic patients were thoroughly reviewed. All 6 deaths occurred during episodes of what Fink and Taylor would call retarded catatonia and Ungvari would call acute stuporous catatonia. The deaths were sudden and appeared to be explained by PE. They accounted for 6% (6/96) of the state hospital deaths. Moreover, they explained 32% (6/19) of the deaths that the committee considered preventable at some level, making pulmonary embolism by far the most important cause of preventable deaths. Catatonia diagnosis and treatment were far from optimal. The stupor in these 6 patients lasted many weeks with a median duration of catatonic symptoms while hospitalized of 45 days in the total sample and 75 days in four patients who died suddenly. If replicated in other mortality databases from other states or countries, two lessons in prevention of these PE deaths in catatonia would be the urgent needs to: 1) improve the skills of clinicians (psychiatrists and internists) for diagnosing and treating stuporous episodes of catatonia and 2) quickly and aggressively treat stuporous episodes of catatonia.

Incidence and risk factors of deep venous thrombosis following arthroscopic posterior cruciate ligament reconstruction

The objective of this study was to identify the incidence and associated risk factors for deep venous thrombosis (DVT) after arthroscopic posterior cruciate ligament (PCL) reconstruction.This study included 128 patients who underwent arthroscopic PCL reconstruction. Venography was performed on the operated leg 3 days postoperatively. The patients were divided into 2 groups based on whether they had DVT. A correlation analysis was performed to determine the factors associated with DVT.Of all the 128 patients, 28 patients (21.9%) developed DVT, with 4 (3.1%) in a proximal location. Significant differences were found in the mean age, time of application of tourniquet, mean VAS scores, mean D-dimer level, mean cholesterol level, and various surgical procedures in patients with DVT compared with those without DVT. DVT is difficult to diagnose solely based on clinical symptoms.The incidence of DVT was 21.9% in patients who underwent arthroscopic PCL reconstruction. The rate of asymptomatic clots in the calf region was rather high after PCL reconstruction, and the rate of proximal clots was 4%. Older age, longer durations of tourniquet application, higher VAS scores and D-dimer levels, and complex surgical procedures were all substantial risk factors for DVT after PCL reconstruction. The treatment of DVT with batroxobin and anticoagulants was effective and safe.

Optional Vena Cava Filters: What, Why, and When

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

Retrievable Inferior Vena Cava Filters in Patients with Cancer: Complications and Retrieval Success Rate

Active cancer (ACa) is strongly associated with venous thromboembolism and bleeding. Retrievable inferior vena cava filters (RIVCF) are frequently placed in these patients when anticoagulation cannot be continued. Objectives. To describe the complications and retrieval rate of inferior vena cava filters in patients with ACa. Methods. Retrospective review of 251 consecutive patients with RIVCF in a single institution. Results. We included 251 patients with RIVCF with a mean age of 58.1 years and a median follow-up of 5.4 months (164 days, IQR: 34-385). Of these patients 32% had ACa. There were no differences in recurrence rate of DVT between patients with ACa and those without ACa (13% versus 17%, p = ns). Also, there were no differences in major filter complications (11% ACa versus 7% no ACa, p = ns). The filter retrieval was not different between groups (log-rank = 0.16). Retrieval rate at 6 months was 49% in ACa patients versus 64% in patients without ACa (p = ns). Filter retrieval was less frequent in ACa patients with metastatic disease (p < 0.01) or a nonsurgical indication for filter placement (p = 0.04). Conclusions. No differences were noted in retrieval rate, recurrent DVT, or filter complications between the two groups. ACa should not preclude the use of RIVCF.

Warfarin treatment and antifungal agent caspofungin for severe fungal infection in a patient previously treated with radiotherapy for oropharyngeal cancer

Drug–Drug interactions is important when caring for warfarin‐treated patients. We examined the impact on INR with coadministration of warfarin and caspofungin and showed no affect on the INR. Coadministrations of fluconazole lead to a marked increase in INR. We concluded that administration of caspofungin and warfarin was safe.

Venous Thromboembolism in Patients Diagnosed With Lung Cancer

PURPOSE

Considering the high prevalence of lung cancer, our purpose was to summarize the existing literature to identify the several factors that contribute to the increased risk of venous thromboembolism (VTE) in patients with lung cancer and to analyze the current recommendations for thromboprophylaxis and treatment of VTE in those patients.

METHODS

We searched the Medline and EMBASE databases from February 1985 to February 2014 to identify retrospective and prospective randomized controlled studies that investigate one or more risk factors for VTEs in patients with lung cancer.

RESULTS

A VTE is a major complication for patients diagnosed with lung cancer. The risk factors for VTE events in patients with lung cancer consist of cancer-related (histological type and stage of cancer), treatment-related (surgery, chemotherapy, angiogenic agents, and supportive care agents), and patient-related factors (comorbidities, immobility, performance status, and prior thrombosis). Low-molecular-weight heparins are recommended for long-term treatment of cancer-associated thrombosis. Duration of anticoagulant therapy beyond 6 months should be based on individual clinical evaluation. Thromboprophylaxis for patients with lung cancer during hospitalization and immediate postoperative period is well established.

CONCLUSIONS

Efforts to assess thrombotic risk in patients with lung cancer may improve therapeutic and preventive strategies in the future, with final goal to minimize the burden and consequences of thrombotic events in patients with lung cancer.

Venous thromboembolism and lung cancer: a review

Venous thromboembolism (VTE) is a common complication of malignancies and epidemiological studies suggest that lung cancer belonged to the group of malignancies with the highest incidence rates of VTE. Risk factors for VTE in lung cancer patients are adenocarcinoma, NSCLC in comparison with SCLC, advanced disease, pneumonectomy, chemotherapy including antiangiogenic therapy. Other risk factors are pretreatment platelet counts and increased release of TF-positive microparticles. Elevated D-dimer levels do not necessarily indicate an increased risk of VTE but have been shown to be predictive for a worse clinical outcome in lung cancer patients. Mechanisms responsible for the increase in venous thrombosis in patients with lung cancer are not understood.

Currently no biomarker is recognized as a predictor for VTE in lung cancer patients.

Although several clinical trials have reported the efficacy of antithrombotic prophylaxis in patients with lung cancer who are receiving chemotherapy, further trials are needed to assess the clinical benefit since these patients are at an increased risk of developing a thromboembolism.

Periprocedural management of patients on anticoagulants

Every year, new studies are undertaken to address the complex issue of periprocedural management of patients on anticoagulants and antiplatelet medications. In addition, newer drugs add to the confusion among clinicians about how to best manage patients taking these agents. Using the most recent data, guidelines, and personal experience, this article discusses recommendations and presents simplified algorithms to assist clinicians in the periprocedural management of patients on anticoagulants.

[Risk factors and features of critically ill patients with deep vein thrombosis in lower extremities]

PURPOSE

The purpose of this study was to identify the features, risk scores and risk factors for deep vein thrombosis in critically ill patients who developed deep vein thrombosis in their lower extremities.

METHODS

The participants in this prospective descriptive study were 175 adult patients who did not receive any prophylactic medication or mechanical therapy during their admission in the intensive care unit.

RESULTS

The mean age was 62.24 (±17.28) years. Men made up 54.9% of the participating patients. There were significant differences in age, body mass index, and leg swelling between patients who developed deep vein thrombosis and those who did not have deep vein thrombosis. The mean risk score was 6.71(±2.94) and they had on average 4.01(±1.35) risk factors. In the multiple logistic regression, body mass index (odds ratio=1.14) and leg swelling (odds ratio=6.05) were significant predictors of deep vein thrombosis.

CONCLUSION

Most critically ill patients are in the potentially high risk group for deep vein thrombosis. However, patients who are elderly, obese or have leg edema should be closely assessed and more than one type of active prophylactic intervention should be provided.

Insertion of central venous catheters induces a hypercoagulable state

BACKGROUND

Central venous catheters (CVCs) increase the risk of venous thromboembolism. We have previously demonstrated that pulmonary artery catheters are associated with a hypercoagulable state in an animal model and in patients. The purpose of this study is to determine whether the insertion of a CVC is associated with a similar response.

METHODS

ANIMAL

7F femoral artery catheters were placed in healthy anesthetized swine (N = 16). Serial arterial blood samples were drawn immediately before and after an 8.5F jugular vein CVC and then for 3 hours after CVC removal. Samples were analyzed using kaolin-activated thromboelastography (TEG) at precisely 2 minutes. Human: An institutional review board-approved prospective observational trial was conducted, with informed consent, in patients with critical illness (N = 8) at a Level I trauma center. Blood was drawn from indwelling arterial catheters immediately before and 60 minutes after CVC insertion. Samples were stored in sodium citrate for 15 minutes before TEG. Routine and special coagulation tests were performed on stored samples in the hospital pathology laboratory.

RESULTS

Insertion of a CVC decreased TEG clotting time (R) by 55% in swine and by 29% in humans (p < 0.001 and 0.019, respectively). Initial clot formation time (K) was reduced by 41% in swine and by 36% in humans (p = 0.003 and 0.019). Fibrin cross-linking (α) was accelerated by 28% in swine and by 17% in humans (p = 0.007 and 0.896), but overall clot strength (maximum amplitude) was not affected. There was no change in routine or special coagulation factors, including von Willebrand factor, antithrombin III, prothrombin time, international normalized ratio, or activated partial thromboplastin time. In animals, the hypercoagulable TEG response was persistent for 3 hours after CVC removal and was prevented by pretreatment with enoxaparin (n = 4) but not heparin (n = 2).

CONCLUSION

In healthy swine and patients with critical illness, a systemic hypercoagulable state occurred after CVC insertion, and this may partially account for an increased risk of venous thromboembolism. However, because the sample size was small and not powered to detect changes in coagulation proteins, no inferences can be made about the mechanism for the hypercoagulable response.

Whole blood viscosity assessment issues V: Prevalence in hypercreatinaemia, hyperglycaemia and hyperlipidaemia

Background:

Diabetes and kidney failure are chronic diseases that are associated with cardiovascular complications, while dyslipidaemia is a strong risk factor. Hyperviscosity is believed to be associated and managed with antiplatelet, but not routinely assessed.

Aims:

This work investigates the prevalence of hyperviscosity in diabetes, dyslipidaemia and renal failure with a view to determine the proportion of patients who may not require antiplatelet therapy.

Materials and Methods:

Archived clinical pathology data for the period of 1999 to 2008 were utilized. 50,162-cases concomitantly tested for blood sugar, creatinine and lipid profile, as well as haematocrit and total proteins in five alternate years were extracted. The prevalence of different viscosity ranges associated with positive results was evaluated.

Results:

Hyperviscosity is about 4% prevalent in hyperglycemia and hyperlipidaemia, less in hypercreatinaemia. Hypoviscosity has statistically significantly the least <2.5% prevalent, while normoviscosity is most prevalent. Reverse analyses affirm that higher levels of hyperglycemia and hyperlipidaemia are statistically significant more associated with fourth compared to first quartile viscosity (p < 0.01).

Conclusion:

Previous report demonstrated that hypoviscosity is synonymous to high international normalized ratio where anticoagulant/antiplatelet is not recommended. This study demonstrates that up to 97.5% of cases investigated for chronic diseases could benefit from antiplatelet medication. This report corroborates with previous reports that hyperviscosity may not be very frequent. However, the level of stasis associated with laboratory evidence-based chronic disease affirms that the subclinical vasculopathy should be managed, and laboratory monitoring will provide clinical evidence base.

Risk factors and incidence of deep vein thrombosis in lower extremities among critically ill patients

AIMS AND OBJECTIVES

To investigate how many critically ill patients developed deep vein thrombosis (DVT) during their admission to intensive care units (ICU) and to compare the characteristics of patients with and without deep vein thrombosis.

BACKGROUND

Critically ill patients are a high-risk group for deep vein thrombosis because they typically have multiple risk factors, such as prolonged immobility, mechanical ventilation and old age.

DESIGN

A prospective observational study was employed.

METHODS

The subjects were 90 patients who were older than 18 years of age, who were admitted to an intensive care unit for more than five days and were not provided any prophylactic measures. Data were collected at a university hospital for five months. A duplex scan was performed on day 2.4 on average and repeated between days 5-7 to diagnose deep vein thrombosis. The iliac, femoral, popliteal and tibial veins were examined by compression and colour Doppler methods of the duplex scan by one technician.

RESULTS

Age, gender and body mass index were significant factors for deep vein thrombosis development (p < 0.05). Ten patients (11.1%) developed deep vein thrombosis during their stay in the intensive care units.

CONCLUSIONS

The incidence was lower than in Western studies in which patients were not provided prophylaxis, but may increase with an extended observation period as in previous studies.

RELEVANCE TO CLINICAL PRACTICE

The results of this study could allow ICU nurses to recognise the DVT incidence in critically ill patients. This result could lead to more active prevention and monitoring of DVT by ICU nurses, especially for high-risk patients, such as older or obese patients.

Pulmonary embolism: predicting disease severity

Pulmonary embolism (PE) is the most common cause of acute pulmonary hypertension, yet it is commonly undiagnosed, with risk of death if not recognized promptly and managed accordingly. Patients typically present with hypoxemia and hypomania, although the presentation varies greatly, being confounded by co-morbidities such as pre-existing cardio-respiratory disease. Previous studies have demonstrated variable patient outcomes in spite of similar extent and distribution of pulmonary vascular occlusion, but the path physiological determinants of outcome remain unclear. Computational models enable exact control over many of the compounding factors leading to functional outcomes and therefore provide a useful tool to understand and assess these mechanisms. We review the current state of pulmonary blood flow models. We present a pilot study within 10 patients presenting with acute PE, where patient-derived vascular occlusions are imposed onto an existing model of the pulmonary circulation enabling predictions of resultant haemodynamic after embolus occlusion. Results show that mechanical obstruction alone is not sufficient to cause pulmonary arterial hypertension, even when up to 65 per cent of lung tissue is occluded. Blood flow is found to preferentially redistribute to the gravitationally non-dependent regions. The presence of an additional downstream occlusion is found to significantly increase pressures.

Breast cancer chemotherapy induces the release of cell-free DNA, a novel procoagulant stimulus

BACKGROUND

Thrombosis is a common complication for breast cancer patients receiving chemotherapy. However, the mechanisms by which breast cancer chemotherapeutic agents increase this risk are largely uncharacterized. Nucleic acids released by injured cells may enhance coagulation via the activation of the contact pathway.

OBJECTIVES

In this study, we examined the effects of breast cancer chemotherapy agents on the release of cell-free DNA (CFDNA) and its relationship to thrombin generation using in vitro and in vivo methods.

METHODS

CFDNA release and thrombin-antithrombin (TAT) levels were measured in plasma of breast cancer patients and healthy mice receiving chemotherapy. Venous whole blood and cultured cells were exposed to chemotherapy and CFDNA release and levels of DNA-histone complexes were measured. The procoagulant activity of isolated CFDNA was measured with calibrated, automated thrombin generation.

RESULTS

Breast cancer patients receiving chemotherapy had elevated levels of CFDNA 24 h post-chemotherapy, a time-point at which elevated thrombin-antithrombin levels have been previously reported. Treatment of healthy mice with doxorubicin, epirubicin and 5-fluorouracil increased CFDNA release, with a corresponding elevation in TAT complex formation. Venous whole blood and neutrophils incubated with chemotherapeutic agents had elevated CFDNA in plasma or cell supernatants. In addition, incubation of venous whole blood with chemotherapy decreased histone-DNA complex levels. CFDNA released from epirubicin-treated whole blood significantly elevated thrombin generation in a dose-dependent manner, and involved activation of the contact pathway.

CONCLUSIONS

Release of CFDNA from chemotherapy-injured cells may represent a novel mechanism by which thrombosis is triggered in cancer patients.

Physical inactivity and idiopathic pulmonary embolism in women: prospective study

OBJECTIVES

To determine the association between physical inactivity (that is, a sedentary lifestyle) and incident idiopathic pulmonary embolism.

DESIGN

Prospective cohort study.

SETTING

Nurses' Health Study.

PARTICIPANTS

69 950 female nurses who completed biennial questionnaires from 1990 to 2008. Main outcome measures The primary outcome was idiopathic pulmonary embolism confirmed in medical records. Multivariable Cox proportional hazards models controlled for age, body mass index (BMI), energy intake, smoking, pack years, race, spouse's educational attainment, parity, menopause, non-aspirin non-steroidal anti-inflammatory drugs, warfarin, multivitamin supplements, hypertension, coronary heart disease, rheumatological disease, and dietary patterns. The primary exposure was physical inactivity, measured in hours of sitting each day. The secondary exposure was physical activity, measured in metabolic equivalents a day.

RESULTS

Over the 18 year study period, there were 268 cases of incident idiopathic pulmonary embolism. There was an association between time of sitting and risk of idiopathic pulmonary embolism (41/104 720 v 16/14 565 cases in most inactive v least inactive in combined data; P<0.001 for trend). The risk of pulmonary embolism was more than twofold in women who spent the most time sitting compared with those who spent the least time sitting (multivariable hazard ratio 2.34, 95% confidence interval 1.30 to 4.20). There was no association between physical activity and pulmonary embolism (P=0.53 for trend).

CONCLUSIONS

Physical inactivity is associated with incident pulmonary embolism in women. Interventions that decrease time sitting could lower the risk of pulmonary embolism.

The association of active cancer with venous thromboembolism location: a population-based study

OBJECTIVE

To test active cancer for an association with venous thromboembolism (VTE) location.

PATIENTS AND METHODS

Using the resources of the Rochester Epidemiology Project, we identified all Olmsted County, MN, residents with incident VTE during the 35-year period 1966-2000 (N = 3385). We restricted analyses to residents with objectively diagnosed VTE during the 17-year period from January 1, 1984, to December 31, 2000 (N = 1599). For each patient, we reviewed the complete medical records in the community for patient age, gender, and most recent body mass index at VTE onset; VTE event type and location; and previously identified independent VTE risk factors (ie, surgery, hospitalization for acute medical illness, active cancer, leg paresis, superficial venous thrombosis, and varicose veins). Using logistic regression we tested active cancer for an association with each of 4 symptomatic VTE locations (arm or intra-abdominal deep venous thrombosis [DVT], intra-abdominal DVT, pulmonary embolism, and bilateral leg DVT), adjusted for age, gender, body mass index, and other VTE risk factors.

RESULTS

In multivariate analyses, active cancer was independently associated with arm or intra-abdominal DVT (odds ratio [OR], 1.76; P = .01), intra-abdominal DVT (OR, 2.22; P = .004), and bilateral leg DVT (OR, 2.09; P = .02), but not pulmonary embolism (OR, 0.93).

CONCLUSION

Active cancer is associated with VTE location. Location of VTE may be useful in decision making regarding cancer screening.

[Effects on changes in femoral vein blood flow velocity with the use of lower extremity compression for critical patients with brain injury]

PURPOSE

This study was done to evaluate the mean venous velocity (MVV) response with knee and thigh length compression stockings (CS) versus intermittent pneumatic compression (IPC) devices in immobile patients with brain injuries.

METHODS

We carried out a randomized controlled study. We analyzed both legs of a randomly chosen sample of 43 patients assigned to one of 4 groups (86 legs). The patients were sequentially hospitalized in the intensive care unit (ICU) in "S hospital" from November 2005 to December 2006. The base line and augmented venous velocity was measured at the level of the common femoral vein. We applied leg compression 42 times over 7 days (for 2 hours at a time at 2 hour intervals).

RESULTS

There was a statistical difference among the 4 groups. The difference for the "IPC" group was more significant than the "CS" group.

CONCLUSION

These results indicate that the application of IPC can be considered as an effective method to prevent deep vein thrombosis for immobile patients with brain injury.

An evaluation of practice pattern for venous thromboembolism prevention in Lebanese hospitals

BACKGROUND

Venous thromboembolism (VTE) is a major cause of death among hospitalized patients. Many VTE prophylaxis guidelines have been developed, including the American College of Chest Physicians (ACCP). VTE prophylaxis is required in specific patients; however, its practice is not always optimal, and often depends on the hospitals' protocols. In Lebanon, information about the appropriateness of VTE prophylaxis in health care centers is lacking.

OBJECTIVE

The primary objective of this study was to evaluate the pattern of VTE prophylaxis application, including agents, doses, duration of treatment, and route of administration, in Lebanese health care centers.

METHODS

A Lebanese multi-center, prospective, chart review study was conducted over 4 months. Data on demographics, VTE prophylaxis medication, dose, route, duration, and associated risk factors were collected by pharmacy students. The appropriateness of VTE prophylaxis was determined as per ACCP guidelines. Patients receiving VTE treatment were excluded from the study. Institutional review board (IRB) approval was obtained from each hospital center.

RESULTS

A total of 840 patients were included. Both gender groups were equally represented in the sample and the mean age was 59 +/- 19.53 years. The majority (639/840, 76.1%) of the sample were at high risk for deep venous thrombosis (DVT), and inappropriate VTE prophylaxis was reported in 35% of the low-risk group, in 70% of the moderate-risk group, and in 39% of the high-risk group (P < 0.0001). Comparing proper VTE prophylaxis practice between intensive care unit (ICU) and non-ICU patients, there was no statistical difference observed in teaching hospitals (67.2% vs. 65.5%, P = 0.312). However, in non-teaching hospitals, appropriate VTE prophylaxis practice was more prevalent in ICU than non-ICU patients (65.9% vs. 51.2%, P = 0.004). The average duration of VTE prophylaxis was less than 10 days. Missing data was a major limitation for this study, where, for instance, the duration of prophylaxis could not be accurately abstracted in half of the sample. Another limitation was the absence of laboratory results needed for clinical assessment of the regimen used.

CONCLUSION

This study reflected the importance of assessing VTE prophylaxis in Lebanese hospitals, thus, the need for implementing established guidelines to improve the overall patient safety.

A critical review of thromboembolic complications associated with central venous catheters

PURPOSE

Central venous catheters (CVC) are commonly used in critical care. While thrombosis is a well-recognized and frequent complication associated with their use, CVC-related thromboembolic complications, including pulmonary embolism (PE) and right heart thromboembolism (RHTE), occur less frequently and often evade diagnosis. Little information exists to guide clinicians in the diagnosis and management of CVC-related thromboembolic complications.

SOURCE

We critically review and synthesize the literature highlighting the incidence of CVC-related thrombosis. We highlight the risk for developing thromboembolic complications and provide approaches to diagnosing and managing RHTE.

PRINCIPLE FINDINGS

The incidence of CVC-related thrombosis varies depending on patient, site, instrument, and infusate-related factors. Central venous catheters-related thrombosis represents an important source of morbidity and mortality for affected patients. Pulmonary embolism occurs in approximately 15% of patients with CVC-related upper extremity deep venous thrombosis (UEDVT). More frequent use of transesophageal echocardiography, in patients with suspected and confirmed PE, has resulted in increased detection of RHTE. While it is recognized that the occurrence of RHTE, in association with PE, increases mortality, the optimal strategy for their management has not been established in a clinical trial.

CONCLUSION

Central venous catheter-related thrombosis occurs frequently and represents an important source of morbidity and mortality for affected patients. Our review supports that surgery and thrombolysis have both been demonstrated to enhance survival in patients with RHTE and PE. However, important patient, clot, and institutional considerations mandate that treatment for patients with RHTE and PE be individualized.

Incidental Pulmonary Embolism Identified on Chest CT during Initial Trauma Evaluation

Deep venous thrombosis and pulmonary embolism frequently occur after trauma and continue to account for significant morbidity and mortality in this population. Asymptomatic pulmonary emboli are also believed to be quite common, but the incidence as well as the implications of these events is unknown. This case report describes two patients whose pulmonary emboli were found incidentally on the initial trauma workup. Very little has been written concerning this issue and in this case report we review the risk factors and clinical significance of these “incidentally discovered” pulmonary emboli.

Avaliação da utilização de profilaxia da trombose venosa profunda em um hospital escola

CONTEXTO: A trombose venosa profunda (TVP) é uma doença freqüente e grave. A profilaxia é o melhor meio para reduzir a sua incidência, diminuindo a morbimortalidade gerada por suas complicações. Na relação custo x efetividade, é melhor manter uma rotina profilática do que tratar a doença já instalada. OBJETIVO: Verificar se a profilaxia da TVP está sendo utilizada de maneira adequada e rotineira no Hospital Escola Doutor José Carneiro (HEJC), de Maceió (AL). MÉTODOS: Foi realizado um estudo transversal descritivo no HEJC durante o período de 6 meses. A amostra foi de 298 pacientes, de diferentes especialidades. Os dados foram coletados nos prontuários, divididos em clínicos (68,5%) e cirúrgicos (31,5%). Analisou-se, em cada paciente, como se procedeu a utilização da profilaxia para a TVP. Foram pesquisados fatores clínicos, medicamentosos e cirúrgicos para todos os pacientes e, com base nesses dados, foi realizada estratificação do risco conforme a classificação recomendada pela Sociedade Brasileira de Angiologia e Cirurgia Vascular (SBACV). O estudo estatístico foi realizado através do software SPSS, utilizando os testes qui-quadrado e de correção bivariada, considerando o valor de p < 0,05. RESULTADOS: Dos 298 pacientes analisados, 204 eram da clínica médica, onde 28,9% eram de baixo risco, 60,3% médio risco e 10,8% alto risco para TVP; e 94 pacientes eram da clínica cirúrgica, onde 43,6% apresentaram baixo risco, 52,1% médio risco e 4,3% alto risco. Apenas 23% dos pacientes do grupo clínico e 2,1% para o grupo cirúrgico receberam a profilaxia de forma adequada. CONCLUSÃO: Apesar da eficácia da profilaxia para a TVP já ter sido comprovada e difundida, em nosso meio ainda não atinge os níveis desejados de utilização.

A case control study of deep venous thrombosis in relation to factor V G1691A (Leiden) and A4070G (HR2 Haplotype) polymorphisms

Activated protein C resistance (APCR) is a significant risk factor for venous thromboembolism (VTE), with the factor V (FV) G1691A (Leiden) mutation accounting for the majority of inherited APCR cases. An additional FV polymorphism, A4074G (FV-HR2), reportedly increased VTE risk by some, but not all groups. We determined the prevalence of FV-Leiden and FV-HR2 SNPs in 126 patients with deep venous thrombosis (DVT), and 197 control subjects. Frequencies of FV-Leiden A and HR2 G alleles, together with FV-Leiden G/A and A/A (but not HR2 A/G) genotypes were significantly higher among patients. While no significant linkage disequilibrium was noted between FV 1691A and 4070G or A alleles, significantly higher prevalence of single-mutant 1691G/4070G and 1691A/4070A haplotypes were seen in patients. FV Leiden and FV HR2 haplotype are independent risk factors for DVT, and their coinheritance does not seem to increase significantly DVT risk imparted by either.

Failure of the American College of Chest Physicians-1A protocol for lovenox in clinical outcomes for thromboembolic prophylaxis

A total of 290 consecutive patients who underwent total hip and total knee arthroplasty were prospectively entered into a clinical anticoagulation trial using a 10-day course of Lovenox with the American College of Chest Physicians-1A guidelines. Major complications occurred in 9% of patients; symptomatic deep vein thrombosis occurred in 9 (3.8%) patients, and nonfatal pulmonary embolism in 3 (1.3%) patients. Complications included 4.7% readmissions, 3.4% return to the operating room for wound incision and drainage, 5.1% prolonged hospitalization (wound drainage), and 3.4% injection site complications. Wound drainage of more than 7 days was predictive of readmission and wound reoperation. A body mass index of more than 35 was predictive of prolonged wound drainage. Return to the operating room for wound complications occurred 3x more frequently with the use of Lovenox than in our previous study using warfarin. Surgical site complications requiring readmission or reoperation should be considered "major" complications.

Efficacy of deep venous thrombosis prophylaxis in the medical intensive care unit

The purpose of this study was to determine the incidence of deep venous thrombosis in medical intensive care unit patients receiving deep venous thrombosis prophylaxis. This was a prospective cohort study of 141 consecutive adult patients anticipated to remain in the medical intensive care unit for >48 hours. Deep venous thrombosis prophylaxis was provided using subcutaneous unfractionated heparin or a sequential compression device according to risk-stratified protocol. Compression ultrasound was performed. Fourteen patients (9.9%) developed deep venous thrombosis on follow-up studies. Incidence of deep venous thrombosis was 7.9% per person year (95% confidence interval, 4.8-12.8). Two of 14 developed pulmonary embolism. Eight patients required full anticoagulation with intravenous heparin or coumadin. In-hospital mortality was similar in both groups. Patients with deep venous thrombosis had a statistically higher risk of pulmonary embolism: 14.2% (95% confidence interval, 2.0-43.0) versus 0.0% (95% confidence interval, 0-3; P = .009). Incidence of deep venous thrombosis is high in medical intensive care unit patients receiving standard prophylaxis. Adherence to strict deep venous thrombosis prophylaxis protocol and exploration of other prophylaxis regimens should be pursued.

Hyperhomocysteinemia is associated with deep venous thrombosis of the lower extremities in Tunisian patients

OBJECTIVES

To test the association between hyperhomocysteinemia (HHC) and deep venous thrombosis (DVT) of lower extremities in Tunisians.

DESIGN AND METHODS

This case-control study included 90 patients with DVT of the lower extremities and 160 healthy controls. Plasma homocysteine, vitamin B(12) and folate were determined using immunoenzymatic methods. Logistic regression models were performed to test whether the association between HHC and DVT is independent and to precise determinants of HHC in DVT patients.

RESULTS

Plasma total homocysteine concentrations were significantly higher in patients with DVT (17.4+/-11.5 micromol/L) and in patients with idiopathic DVT (15.2+/-6.4 micromol/L) as compared to controls (11.5+/-3.3 micromol/L). HHC was significantly associated (p<0.001) with all DVT (OR, 8.82; 95% CI, 3.96-19.6) as well as idiopathic DVT (OR, 7.40; 95% CI, 3.01-10.8). These associations persisted after adjustment for several thrombosis risk factors. In patients with DVT, HHC was related to folate and vitamin B(12) concentrations, but neither to the type of occurrence nor to the recurrence of DVT.

CONCLUSION

HHC is independently associated with first DVT of lower extremities in Tunisians. Homocysteine should be assessed in patients with DVT and the effect of vitamin B supplementation should be tested among them.

Differences in clinical presentation of pulmonary embolism in older vs younger patients

BACKGROUND

In order to better define the clinical characterization of pulmonary embolism (PE) in the elderly, the clinical and laboratory findings were compared in older (> or = 65 years old) and younger (< 65 years old) patients.

METHODS AND RESULTS

The study group comprised 149 patients (58 older and 91 younger) who received a final diagnosis of PE and were retrospectively evaluated. The severity of PE was assessed by calculating the pulmonary vascular obstruction scores (PVOs) scintigraphically: PVOs > or = 50% was defined as severe disease. Dyspnea was the most frequent symptom in both groups. Chest pain and hemoptysis were less frequent in older patients (48.3% vs 79.1%, p = 0.001; 6.9% vs 20.9%, p = 0.021, respectively) whereas syncope occurred more often in the older group (27.6% vs 9.9%, p = 0.005). PVOs > or = 50% occurred in 55.1% of older and 32.9% of younger patients (odds ratio: 1.67, 95%confidence interval: 1.118-2.507, p = 0.013).

CONCLUSIONS

The clinical presentation of PE can be subtle or atypical in elderly patients and hence they may have more severe disease. Therefore, a high clinical suspicion is required in order to prevent delays in diagnostic work-up and initiation of appropriate treatment.

Epidemiology of acute deep vein thrombosis

Although the factors leading to venous thrombosis have been known for over a century, Virchow's initial model of thrombosis has been extensively refined. Activated coagulation is now recognized to be of primary importance in venous thrombogenesis; the concept of venous injury has been expanded to include molecular changes in the endothelium; and stasis has been redefined as a largely permissive factor. Furthermore, it is now clear that venous thrombi undergo a dynamic evolution beginning early after their formation. The natural history of acute deep venous thrombosis (DVT) is a balance between recurrent thrombotic events and processes that restore the venous lumen, both of which have important implications for the development of complications. Although pulmonary embolism (PE) is clearly the most life threatening complication of acute DVT, the long term socio-economic consequences of the post thrombotic syndrome (PTS) have perhaps been underemphasized in clinical trials. The development of post-thrombotic manifestations is related to both residual venous obstruction and valvular incompetence. Recognition of the factors contributing to a poor outcome, including recurrent thrombotic events, the rate of recanalization, the global extent of venous reflux, and the anatomic distribution of reflux and obstruction is important, as there may be therapeutic alternatives to alter the natural history of acute DVT. The treatment alternatives will continue to expand with the introduction of new therapeutic drugs, for both systemic and catheter-directed therapy, and mechanical thrombectomy devices. The primary care physician is challenged with the task of correctly evaluating deep vein thrombosis and providing his patient with access to the most clinically appropriate, and cost-effective, diagnostic and management options available. This article will review the epidemiology of DVT, its risk factors and major complications.

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.