Heparins pulmonary embolism

DVT, deep vein thrombosis HIT, heparin-induced thrombocytopenia PAI-I, plasminogen activator inhibitor PE, pulmonary embolism SERM, selective estrogen receptor modulator VTE, venous thromboembolism. 

FIGURE 7-11. Treatment of venous thromboembolism. LMWH, low-molecular-weight heparin PE, pulmonary embolism SBP, systolic blood pressure UFH, unfractionated heparin VTE, venous thromboembolism. (Reproduced from Haines ST, Zeolla M, Witt DM. Venous thromboembolism. In DiPiro JT, Talbert RL, Yee GC, et al, (eds.) Pharmacotherapy A Pathophysiologic Approach. 6th ed. New York McGraw-Hill 2005 398, with permission.)... 

Collins R., Scrimgeour A., Yusuf S Peto R. Reduction in fatal pulmonary embolism and venous thrombosis by perioperative administration of subcutaneous heparin Overview of results of randomized trials in general, orthopedic, and urologic surgery. N Engl J Med 1988 318, 1162-73. 

Eriksson B. I., Kalebo P Anthmyr B. A., et al. Prevention of deep-vein thrombosis and pulmonary embolism after total hip replacement. Comparison of low molecular weight heparin and unfractionated heparin. J Bone Joint Surg [Am] 1991 73A, 484-93. 

FIGURE 14-2. Treatment of venous thromboembolism (VTE). (LMWH, low-molecular-weight heparin PE, pulmonary embolism SBP, systolic blood pressure UFH, unfractionated heparin.)... 

Reviparin - low MW heparin Prevention of deep vein thrombosis and pulmonary embolism following surgery... 

Venous thrombi (red thrombi) are formed mainly from fibrin in simations where vascular stasis exists or in hypercoagulability states. Here the symptoms consist of deep vein thrombosis with the risks of pulmonary embolism and the mainstay of therapy is anti-coagulation with heparin and oral anticoagulants. 

Venous stasis resulting from prolonged bed rest, cardiac failure, or pelvic, abdominal, or hip surgery may precipitate thrombus formation in the deep veins of the leg or calf and may lead to fatal pulmonary embolism. Heparin may also be used prophylactically following surgery. 

Heparin is usually administered for a period ranging from 7 to 10 days. Frequently, during file last half of litis period of heparin liierapy, oral anticoagulation will be commenced with warfann. The time during which oral anticoagulation administration should be continued may be three months or longer after clinical evidence that file venous thrombosis has subsided and for one year after pulmonary embolism. 

In present times, because of early mobilization and shorter stays in hospital, venous thrombosis in the legs and resulting pulmonary embolism has declined to a large degree. In persons with acute myocardial infarction, prophylactic low-dose heparin has reduced the incidence of venous thrombosis in the legs. It is considered as a reasonable alternative to warfarin in selected patients. Preventive anlicoagulalion may be indicated in some cases to prevent strokes due to left ventricular mitral thrombi embolizing in tire brain. 

Simonneau G, Sors H, Charbonnier B, Page Y, Laaban J-P, Bosson J-L, Mottier D, Beau B A comparison of low-molecular-weight heparin with unfractionated heparin for acute pulmonary embolism. 

Fondaparinux is a chemically synthesized pentasaccharide that mimics the antithrombin-binding site of heparin and LMWH. Its molecular size (1728Da) is too small to bind to thrombin molecules while it is bound to antithrombin, Therefore, it is a pure anti-Xa inhibitor. It binds very little to platelets, proteins, or endothelium and is excreted in the urine, It does not form a complex with PF4 or other positively charged molecules. It is not neutralizable by protamine sulfate, Recent clinical trials have resulted in FDA approval for prophylaxis of deep vein thrombosis in orthopedic surgery, It has been shown to be effective and safe for the treatment of pulmonary embolism (20,21) and ACS (non-ST-elevation Ml) (OASIS 5—Michelangelo Trial) (17). 

The Matisse Investigators. Subcutaneous fondaparinux versus intravenous unfractionated heparin in the initial treatment of pulmonary embolism. N EnglJ Med 2003 349 1695-1702. 

Cade, J. F. Yung, W. L. "Heparin Kinetics in Venous Thrombosis and Pulmonary Embolism," Circulation, 1976, 53, 691-695. 

Q10 In high-risk patients scheduled to have general surgery, subcutaneous heparin can be given to reduce the risk of DVT and pulmonary embolism occurring after the operation. If DVT or pulmonary embolism has already occurred in hospital patients, the immediate treatment normally includes intravenous heparin. 

Mobilization may reduce complications, including pneumonia, deep vein thrombosis, pulmonary embolism and pressure ulcers. At present, there are no reUable data to recommend the use of compression stockings or low-dose heparin for deep vein thrombosis prohylaxis (Andre et al. 2007) but trials are ongoing (Dermis 2004). 

Of the many drugs used as prophylactic antithrombotic agents, heparin has a long history as therapy for both DVT and pulmonary embolism (PE). Many studies have shown that in moderate and high risk patients, heparin can prevent postoperative DVT and PE (4,19-21). Now, with the introduction of LMWHs, these benefits can be had together with easier dosing and potentially less risk of bleeding. 

Dose Treatment of established thrombosis. The traditional intravenous regimen of standard unfractionated heparin is a bolus i.v. injection of 5000 units (or 10 000 units in severe pulmonary embolism) followed by a constant rate i.v. infusion of 1000-2000 units per hour. Alternatively 15 000 units may be given s.c. every 12 h but control is less even. The APTT should be measured 6 h after starting therapy and the administration rate adjusted to keep it in the optimum therapeutic ratio of 1.5-2.5 this usually requires daily measurements of APTT preferably... 

The convenience (and cost-effectiveness) of LMW heparin therapy has resulted in widespread changes in practice. Patients with acute venous thromboembolism can be treated safely and effectively with LMW heparin as outpatients. Large-scale studies have demonstrated that outpatient treatment of acute deep vein thrombosis (DVT) with unmonitored body-weight adjusted LMW heparin is as safe and effective as inpatient treatment with adjusted dose intravenous standard heparin. Further trials have confirmed the safety and efficacy of LMW heparin therapy in acute pulmonary embolism and that 80% of imselected patients with acute thromboembolism can be safely treated as outpatients. ... 

Pulmonary embolism. Thrombolysis is superior to heparin at relieving obstructed veins demonstrated radiologically. While a reduction in mortality is thus implied, the numbers of cases reported in clinical trials of thrombolytics have been insufficient to... 

A third variety, so-called delayed-onset heparin-induced thrombocytopenia has also been described in several reports. In 12 patients, recruited from secondary and tertiary care hospitals, thrombocytopenia and associated thrombosis occurred at a mean of 9.2 (range 5-19) days after the withdrawal of heparin nine received additional heparin, with further falls in platelet counts (32). In a retrospective case series, 14 patients, seen over a 3-year period, developed thromboembolic complications a median of 14 days after treatment with heparin (33). The emboli were venous (n — 10), or arterial (n — 2), or both (n — 2) of the 12 patients with venous embolism, 7 had pulmonary embolism. Platelet counts were mildly reduced in all but two patients at the time of the second presentation. On readmission, 11 patients received therapeutic heparin, which worsened their clinical condition and further reduced the platelet count. 

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