A mechanical method of DVT prophylaxis is indicated in patients at high risk of bleeding with anticoagulation prophylaxis.These includes patients with active or recent gastrointestinal bleeding, patients with hemorrhagic stroke, and those with hemostatic defects such as severe thrombocytopenia.69 It is contraindicated in patients with evidence of leg ischemia due to peripheral vascular disease.There is a theoretical risk of fibrinolysis and clot dislodgement.70 Leg wrappings and stockings with no pressure gradient are ineffective in the prevention of DVT.71 Hilleren-Listerud demonstrated that knee-length GCS and IPC devices are as effective as thigh-length GCS and IPC devices.They are also more comfortable, cheaper and more user-friendly for the patient.
72 Tivozanib selleck Chin et al compared the efficacy and safety of different modes of thromboembolic prophylaxis for elective total knee arthroplasty in Asian patient and recommended IPC as the preferred method of thromboprophylaxis for TKA.73 However no meaningful difference in performance between GCS and IPC was demonstrated by Morris and Woodcock.74 Daily use of elastic compression stockings after proximal DVT reduced the incidence of postphlebitis syndrome by 50%.20 Other mechanical means in both medical and surgical patients include ambulation and exercises involving foot extension.They improve venous flow and should be encouraged.Pharmacological Unfractionated heparin , low-molecular-weight heparins , fondaparinux, and the new oral direct selective thrombin inhibitors and factor Xa inhibitors are effective pharmacological agents for prophylaxis of DVT.
Studies have shown that the incidence of all DVTs, proximal DVT, and all PE including fatal PE has been reduced by low-dose UFH.75,76 LMWH has additional advantages Biochanin A over unfractionated heparin.It can be given once or twice daily without laboratory monitoring.Other advantages are predictability, dose-dependent plasma levels, a long half-life, less bleeding for a given antithrombotic effect, and a lower incidence of heparin-induced thrombocytopenia than with UFH.77 The risk of heparin-induced osteoporosis is lower with LMWH than with UFH as it does not increase osteoclast number and activity.78 It has a far greater effect on inhibition of factor Xa and a lesser effect on antithrombin III by inhibiting thrombin to a lesser extent than UFH.
79 Current contraindications to the early initiation of LMWH thromboprophylaxis include the presence of intracranial bleeding, ongoing and uncontrolled bleeding elsewhere, and incomplete spinal cord injury associated with suspected or proven spinal hematoma.Fondaparinux, a synthetic pentasaccharide, has been approved for prophylaxis of DVT.It is an indirect selective inhibitor of factor Xa which binds to antithrombin with high affinity in a reversible manner.Heparin-induced thrombocytopenia has not been reported with fondaparinux as it does not interact with platelet function and aggregation, and has a predictable response.