Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thromboembolism in high-risk patients

VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The use of anticoagulant therapy during pregnancy is challenging because of the potential for both fetal and maternal complications. This guideline focuses on the management of VTE and thrombophilia as well as the use of antithrombotic agents during pregnancy.

METHODS

The methods of this guideline follow the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

We recommend low-molecular-weight heparin for the prevention and treatment of VTE in pregnant women instead of unfractionated heparin (Grade 1B). For pregnant women with acute VTE, we suggest that anticoagulants be continued for at least 6 weeks postpartum (for a minimum duration of therapy of 3 months) compared with shorter durations of treatment (Grade 2C). For women who fulfill the laboratory criteria for antiphospholipid antibody (APLA) syndrome and meet the clinical APLA criteria based on a history of three or more pregnancy losses, we recommend antepartum administration of prophylactic or intermediate-dose unfractionated heparin or prophylactic low-molecular-weight heparin combined with low-dose aspirin (75-100 mg/d) over no treatment (Grade 1B). For women with inherited thrombophilia and a history of pregnancy complications, we suggest not to use antithrombotic prophylaxis (Grade 2C). For women with two or more miscarriages but without APLA or thrombophilia, we recommend against antithrombotic prophylaxis (Grade 1B).

CONCLUSIONS

Most recommendations in this guideline are based on observational studies and extrapolation from other populations. There is an urgent need for appropriately designed studies in this population.

Preventing deep vein thrombosis after stroke: strategies and recommendations

OPINION STATEMENT

The risk of deep vein thrombosis (DVT) after stroke is increased in patients with restricted mobility, a previous history of DVT, dehydration, or comorbidities such as malignant diseases or clotting disorders. Patients with an increased risk of DVT should receive prophylactic treatment. To reduce the chance of DVT, patients should be mobilized as soon as possible and should be kept well hydrated. Anti-embolism stockings cannot be recommended, because they have been demonstrated not useful for preventing DVT or pulmonary embolism in patients with stroke, and they are associated with a significantly increased risk of skin breaks. The usefulness of intermittent pneumatic compression is currently under study in a randomized clinical trial. Treatment with subcutaneously administered low-dose unfractionated heparin is preferred to unfractionated heparin and may be considered in patients with ischemic stroke if the risk of DVT is estimated to be higher than the risk of hemorrhagic complications. Aspirin may also be effective for patients with ischemic stroke who have contraindications to anticoagulants, although direct comparisons with anticoagulants are not available. In patients with intracerebral hemorrhage, low-dose subcutaneous low-molecular-weight heparin is probably safe after documentation of cessation of active bleeding, and may be considered on an individual basis after 3 to 4 days from stroke onset.

Perioperative care for patients with rheumatic diseases

The perioperative care of patients with rheumatic diseases is hampered by a lack of evidence-based recommendations. Rheumatologists are called upon to 'clear' their patients for surgery, yet the evidence upon which to base decisions is fractionated and inconsistent. We have systematically reviewed the current literature and developed suggestions for three key areas that require particular deliberations in patients with rheumatic diseases scheduled for surgery: the management of cardiovascular risk, use of immunosuppressive drugs, and states of altered coagulation. For patients with rheumatic diseases associated with increased cardiovascular risk, such as rheumatoid arthritis and systemic lupus erythematosus, we suggest following the American College of Cardiology-American Heart Association guidelines using the underlying disease as a risk modifier. Most evidence suggests a neutral effect of conventional DMARDs in the perioperative period, with no need to discontinue them prior to surgery. Conversely, we suggest minimizing perioperative steroid use and unnecessary 'steroid preps'. The potential benefits of discontinuing biologic drugs in the perioperative setting needs to be carefully balanced with the risks associated with a disease flare. We discuss the American College of Chest Physicians guidelines, which classify individuals with antiphospholipid antibody syndrome as high-risk patients for perioperative thrombosis who are likely to require bridging therapy in most perioperative settings.

Bleeding risk secondary to deep vein thrombosis prophylaxis in patients with lower gastrointestinal bleeding

INTRODUCTION

Deep vein thrombosis (DVT) and pulmonary embolism (PE) continue to pose a major burden on the health care system in the United States. The precise timing of anticoagulation initiation in critically ill patients with recent or active lower gastrointestinal bleeding (LGIB) is not well defined. We set out to study the safety and efficacy of early heparin administration for DVT prophylaxis in these patients.

METHODS

A review of all patients admitted to the ICU with a diagnosis of LGIB over a 13-year period was performed. A total of 60 patients received subcutaneous heparin along with mechanical prophylaxis, whereas 59 patients had intermittent pneumatic compression devices alone.

RESULTS

There was no difference in morbidity or mortality between the groups who received heparin and the nonheparin cohort. Neither of the groups developed a DVT or PE during the study period. Patients who received heparin had a median ICU LOS of 3 days, when compared with 2 days for patients who did not receive heparin (P < .0118). There was a significant association between units of blood received during the first 24 hours in the ICU and heparin usage (P < .0229). Those administered heparin received more units (median 3) than those who did not receive heparin (median 2).

CONCLUSIONS

Administration of subcutaneous heparin increases the transfusion requirements and LOS in ICU patients with LGIB. After 24 hours, however, the blood transfusion requirements are equivalent. DVT prophylaxis in patients with a diagnosis of LGIB should be initiated after 24 hours of ICU admission.

Micro-mobile foot compression device compared with pneumatic compression device

BACKGROUND

A combination mechanical-pharmacologic regimen is an accepted prophylactic treatment against symptomatic venous thromboembolism for patients undergoing total hip and knee arthroplasties. Foot pumps have been recognized as effective mechanical devices. Research suggests pharmacologic prophylaxis for venous thromboembolism is associated with complications and foot pumps offer an adjunct or alternative approach. Presumably the effectiveness of foot pumps relate to enhancement of venous flow.

QUESTIONS/PURPOSES

We compared an established foot pump system with a new mobile foot pump for their ability to influence mean peak venous velocity in the common femoral, popliteal, and posterior tibial veins.

METHODS

We evaluated 60 healthy subjects with the established and the novel foot-pump systems. Ultrasonography was used to measure baseline and peak venous velocity with mechanical compression. We constructed 95% confidence intervals (CI) on the mean differences between the two devices to establish equivalence limits. We compared ratios of peak velocity to resting velocity. Subjects subjectively rated the two foot pumps with respect to size, fit, and comfort.

RESULTS

The 95% CI test for equivalence of the mean differences between the two devices was inconclusive. The novel device augmented the venous velocity 11 times greater than the resting velocity in the posterior tibial vein and three times greater than the resting velocity in the popliteal vein. The established foot pump augmented the venous velocity 15 times greater than the resting velocity in the posterior tibial vein and four times greater than the resting velocity in the popliteal vein. The novel device rated better for size, fit, and comfort when compared with the established device.

CONCLUSIONS

The established foot pump tended to be associated with greater peak velocities; the novel device produced more consistent mean peak venous velocities and may be more acceptable to patients and caregivers.

Deep vein thrombosis: a clinical review

Background:

Deep vein thrombosis (DVT) is the formation of blood clots (thrombi) in the deep veins. It commonly affects the deep leg veins (such as the calf veins, femoral vein, or popliteal vein) or the deep veins of the pelvis. It is a potentially dangerous condition that can lead to preventable morbidity and mortality.

Aim:

To present an update on the causes and management of DVT.

Methods:

A review of publications obtained from Medline search, medical libraries, and Google.

Results:

DVT affects 0.1% of persons per year. It is predominantly a disease of the elderly and has a slight male preponderance. The approach to making a diagnosis currently involves an algorithm combining pretest probability, D-dimer testing, and compression ultrasonography. This will guide further investigations if necessary. Prophylaxis is both mechanical and pharmacological. The goals of treatment are to prevent extension of thrombi, pulmonary embolism, recurrence of thrombi, and the development of complications such as pulmonary hypertension and post-thrombotic syndrome.

Conclusion:

DVT is a potentially dangerous condition with a myriad of risk factors. Prophylaxis is very important and can be mechanical and pharmacological. The mainstay of treatment is anticoagulant therapy. Low-molecular-weight heparin, unfractionated heparin, and vitamin K antagonists have been the treatment of choice. Currently anticoagulants specifically targeting components of the common pathway have been recommended for prophylaxis. These include fondaparinux, a selective indirect factor Xa inhibitor and the new oral selective direct thrombin inhibitors (dabigatran) and selective factor Xa inhibitors (rivaroxaban and apixaban). Others are currently undergoing trials. Thrombolytics and vena caval filters are very rarely indicated in special circumstances.

Venous thromboembolic disease in trauma and surveillance ultrasonography

BACKGROUND

The literature reports a wide variation in the incidence of venous thromboembolic (VTE) disease in trauma patients. The performance of routine surveillance venous duplex ultrasound of bilateral lower extremities is controversial. Furthermore, recent examinations of the national trauma databank registry have suggested that routine duplex surveillance is associated with higher deep venous thrombosis (DVT) detection rates.

MATERIALS AND METHODS

We examined the incidence and risk factors for VTE disease in 2827 trauma patients admitted over a 2-y period to a state-verified level I trauma center. Detailed chart review was carried out for patients with VTE disease. We then evaluated the effects of a routine bilateral lower extremity duplex surveillance guideline on VTE detection in the subset of injury patients admitted to the trauma service.

RESULTS

We found an approximately 2% incidence of venous thromboembolic disease in a mostly blunt trauma population. Amongst patients with VTE disease, the most common risk factors were obesity and significant head injury. We then evaluated the 998 patients with injury who were admitted to the trauma service 1 y before and after surveillance guideline implementation. Despite a nearly 5-fold increase in the number of duplex scans, with a substantial increase in cost, we found no significant difference in the incidence of DVT.

CONCLUSIONS

Our preliminary data argue against the use of routine duplex surveillance of lower extremities for DVT in trauma patients. A larger, prospective analysis is necessary to confirm these findings.

Prophylaxis for venous thromboembolic disease in pregnancy and the early postnatal period

BACKGROUND

Venous thromboembolic disease (TED), although rare, is a major cause of maternal mortality and morbidity, hence methods of prophylaxis are often used for women at risk. This may include women delivered by caesarean section, those with a personal or family history of TED and women with inherited or acquired thrombophilias (conditions that predispose people to thrombosis). Many methods of prophylaxis carry a risk of side effects, and as the risk of TED is low, it is possible that the benefits of thromboprophylaxis may be outweighed by harm. Current guidelines for clinical practice are based on expert opinion only, rather than high quality evidence from randomised trials.

OBJECTIVES

To determine the effects of thromboprophylaxis in women who are pregnant or have recently delivered and are at increased risk of TED on the incidence of venous TED and side effects of treatment.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009).

SELECTION CRITERIA

Randomised trials comparing one method of thromboprophylaxis with placebo or no treatment, and randomised trials comparing two (or more) methods of thromboprophylaxis.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently and resolved any discrepancies by discussion.

MAIN RESULTS

Sixteen trials met the inclusion criteria but only 13 trials, involving 1774 women, examining a range of methods of thromboprophylaxis, contributed data for the outcomes of interest. Four of them compared methods of antenatal prophylaxis: low molecular weight heparin (LMWH) versus unfractionated heparin (UFH) (two studies), and heparin versus no treatment (two studies). Eight studies assessed postnatal prophylaxis after caesarean section; one compared hydroxyethyl starch with unfractionated heparin; four compared heparin with placebo; and the other three compared UFH with LMWH. One study examined prophylaxis in the postnatal period.The small number of statistically significant findings in this review are largely derived from trials which are not of high methodological quality. It was not possible to assess the effects of any of these interventions on most outcomes, and especially on rare outcomes such as death, TED and osteoporosis, because of small sample sizes and the small number of trials making the same comparisons.There was some evidence of side effects associated with thromboprophylaxis.

AUTHORS' CONCLUSIONS

There is insufficient evidence on which to base recommendations for thromboprophylaxis during pregnancy and the early postnatal period. Large scale randomised trials of currently-used interventions should be conducted.

Thromboprophylaxis for trauma patients

This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the effects of thromboprophylaxis in trauma patients on mortality and incidence of DVT and PE. To compare the effects of different thromboprophylaxis interventions and their relative effects according to the type of trauma.

[Prevention of venous thromboembolic disease in general surgery]

Postoperative venous thromboembolic disease (VTED) affects approximately one in four general surgery patients who do not receive preventive measures. In addition to the risk of pulmonary embolism, which is often fatal, patients with VTED may develop long-term complications such as post-thrombotic syndrome or chronic pulmonary hypertension. In addition, postoperative VTED is usually asymptomatic or produces clinical manifestations that are attributed to other processes and consequently this complication is often unnoticed by the surgeon who performed the procedure. Thus, the most effective strategy consists of effective prevention of VTED using the most appropriate prophylactic measures against the patient's thromboembolic risk. There is sufficient evidence that VTED can be prevented by pharmacological methods, especially heparin and its derivatives and with mechanical methods such as support tights or intermittent pneumatic compression of the lower extremities. To reduce the incidence of VTED as far as possible, strategies have been proposed that include a combination of drugs and mechanical methods, new antithrombotic drugs, or prolonging the duration of prophylaxis in patients at very high risk, such as those who have undergone surgery for cancer. Another important aspect is the optimal moment to initiate prophylaxis with anticoagulant drugs with the aim of achieving an adequate equilibrium between antithrombotic efficacy and the risk of hemorrhagic complications. The present article reviews the available evidence to attempt to optimize prevention of VTED in general surgery and in some special groups, such as laparoscopic surgery, short-stay surgery and obesity.

Evaluation and management of stroke

In contrast to myocardial infarction, stroke is a heterogeneous disease with multiple different causes. Determination of stroke mechanism is critical to choosing optimal therapy to prevent recurrence. This article reviews the diagnostic approach to stroke and prognostic and treatment implications of specific stroke mechanisms. Data on the role of antiplatelet and anticoagulant therapy in secondary stroke prevention, as well as the role of these agents and thrombolytic therapy in acute stroke treatment are reviewed. Situations of particular relevance to the practicing hematologist—stroke in the young, patients with multiple recurrent strokes, patients with abnormal hypercoagulable laboratory testing, and treatment of intracerebral hemorrhage following thrombolytic therapy—are discussed.