Prevention of Venous Thromboembolism

Abstract

Patients with clinical conditions such as surgery, trauma, and acute medical illness have a transiently increased risk of venous thromboembolism and merit consideration for adequate thromboprophylaxis. The choice of an appropriate pharmacologic or physical means of prophylaxis should be made taking into account both the thrombotic and bleeding risk associated with patient-related factors and the type of surgery or other disease state involved. A large number of randomized clinical trials, meta-analyses, and guidelines developed by scientific societies worldwide have addressed this issue and have provided information and recommendations that should be considered carefully. The aim of this review is to provide the practicing physician with a brief updated summary of the subject, stratifying those patients at low thrombotic risk who do not require specific thromboprophylaxis apart from early ambulation, from those at moderate or higher thrombotic risk. Patients at moderate thrombotic risk face a 10 to 20% risk of deep vein thrombosis (DVT) and require prophylaxis with low-dose unfractionated heparin or low molecular weight heparins (LMWHs) at a dosage < 3400 U once daily, or with graduated elastic stockings if their bleeding risk is high. Patients with an expected 20 to 40% DVT rate without prophylaxis are considered at high thrombotic risk and should be treated preferentially with LMWHs at high prophylactic dosage (> 3400 U). Patients undergoing major orthopedic surgery face a DVT rate > 40%, are considered at very high risk of venous thromboembolism, and should be given either LMWHs at high prophylactic dosage, fondaparinux, or vitamin K antagonists--either alone or in association with intermittent pneumatic compression devices.

Epidemiology and Risk Factors for Venous Thrombosis

“…This is probably due to the rarity of trauma compared to the other triggers. These findings, and those of others, point out the tremendous potential that thromboprophylaxis might have if it were effective and administered optimally in patients at risk of venous thrombosis (23). For example, if thromboprophylaxis were perfectly effective among hospitalized patients, up to 25% of all venous thromboembolisms could be avoided.…”

Prevention of thromboembolic events in surgical patients through the creation and implementation of a computerized risk assessment program

“…The list of common DVT risk factors was compiled based on a survey of multiple DVT prevention guidelines (Table II). [3][4][5][6][7][8] Our algorithm and DVT risk factor list was incorporated into the CPRS electronic medical record at the Jesse Brown VAMC as part of the Pre-Admission Testing order set that must be completed for every surgical patient before a procedure. The DVT assessment portion of this order set included the complete list of risk factors and a risk stratification algorithm (Fig 1).…”

“…2 Fortunately, DVT can be largely prevented with mechanical and pharmacological prophylaxis, and multiple guidelines have been established to stratify patients based on DVT risk and have recommended appropriate prevention measures. [3][4][5][6][7] While these guidelines provide refined strategies for DVT risk assessment and prophylaxis, they are difficult to implement in the clinical setting and compliance is poor. Thus, DVT leading to PE remains the number one preventable cause of hospital death.…”

Venous thrombosis in the elderly: more questions than answers

“…49 These include mechanical lower extremity compression devices and/or anticoagulant drugs such as unfractionated or low-molecular-weight heparin or fondaparinux. Most regimens call for lower doses than are typically used to treat established VTE and use fixed administration schedules without monitoring blood tests.…”