Prophylaxis for Venous Thromboembolism in patients undergoing THR and TKR

 THR and TKR

• Indications 

• PAST

• Present

Total hip replacement (THR) surgery,
as we know it, began in 1960.

Total knee replacement (TKR), as currently performed, was first described in 1971.

• While these operations are very successful,deep-vein thrombosis (DVT) and pulmonary embolism (PE) have been significant complications.

The reported prevalence of

• DVT in patients not receiving prophylaxis in clinical trials using mandatory venography has been 45%–57% after THR and 40%–84% after TKR.

• The reported prevalence of PE in other trials has been 0.7%–30% after THR (prevalence of fatal PE, 0.1%– 0.4%), and 1.8%–7% after TKR (prevalence of fatal PE, 0.2%–0.7%).

Patients with thrombophilic syndromes show even higher rate of venous thromboembolism as evident from the table above.

Based on AHA 

• VTE consists of 2 related conditions: deep vein thrombosis (DVT) and pulmonary embolism (PE).

• In 1884, Rudolph Virchow first proposed that thrombosis

        was the result of at least 1 of 3 underlying etiologic factors:

• Vascular endothelial damage, Stasis of blood flow, and Hypercoagulability of blood.

• In assessing whether prophylaxis is indicated, physicians should consider both the strength of individual risk factors and the cumulative weight of all risk factors.

Risk factors to consider for VTE , according to Canadian Orthopaedic association

Guidelines for Starting Pharmacologic Treatment in patients undergoing THR and TKR. 

Preventing Venous Thromboembolic Events in Patients undegoing THR/TKR

 

• A variety of strategies to prevent venous thromboembolism are available: 

• Pharmacological

• Oral antiplatelet agents

• Injectable low-molecular-weight heparins

• Injectable unfractionated heparin

• Injectable or oral factor Xa inhibitors

• Injectable or oral direct thrombin inhibitors

• Oral vitamin K antagonists 

• Mechanical modalities

• Graduated compression

• Intermittent pneumatic compression

• Venous foot pump 

• Combinations of these

Patients with a high risk of bleeding should be started on mechanical methods of prophylaxis (intermittent pneumatic compression and/or elastic stockings) at least until bleeding risk is reduced. In general, patients with one of the weak or moderate risk

• Whereas VTE prophylaxis has generally been recommended for 7 to 10 days, recent studies have found that extending preventive treatment through the 4 weeks after hospital discharge is beneficial in patients undergoing surgery for cancer or total hip replacement. Additional data are needed to define the optimal duration of VTE prophylaxis in other high-risk.

see the timing of anticoagulation required on the first box above , how long does medicine require . 

Thank You.