Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ INTRODUCTION ++ Venous thromboembolism (deep venous thrombosis and/or pulmonary embolism) is a common disorder, which is estimated to affect 900,000 patients each year in the United States. Pulmonary embolism may cause sudden or abrupt death, underscoring the importance of prevention as the critical strategy for reducing death from pulmonary embolism. Of the estimated 600,000 cases of nonfatal venous thromboembolism in the United States each year, approximately 60% present clinically as deep venous thrombosis and 40% present as pulmonary embolism. Most clinically important pulmonary emboli arise from proximal deep venous thrombosis (thrombosis involving the popliteal, femoral, or iliac veins). Upper extremity deep venous thrombosis also may lead to clinically important pulmonary embolism. Other less common sources of pulmonary embolism include the deep pelvic veins, renal veins, inferior vena cava, right side of the heart, and axillary veins. Acquired and inherited risk factors for venous thromboembolism have been identified (Table 90–1). (For inherited thrombophilia, see Chap. 89.) The risk of thromboembolism increases when more than one predisposing factor is present. ++Table Graphic Jump LocationTABLE 90–1RISK FACTORS FOR THROMBOEMBOLISMView Table||Download (.pdf) TABLE 90–1 RISK FACTORS FOR THROMBOEMBOLISM Acquired Hereditary Thrombophiliasa Advancing age (age >40 years) Activated protein C resistance History of prior thromboembolic event Prothrombin G20210A Recent surgery Antithrombin deficiency Recent trauma Protein C deficiency Prolonged immobilization Protein S deficiency Certain forms of cancer Dysfibrinogenemia Congestive heart failure Recent myocardial infarction Paralysis of legs Use of female hormones Pregnancy or postpartum period Varicose veins Obesity Antiphospholipid antibody syndromeb Hyperhomocysteinemia aSee also Chap. 89bSee also Chap. 85. +++ CLINICAL FEATURES ++ The clinical features of deep venous thrombosis and pulmonary embolism are nonspecific. +++ Venous Thrombosis ++ The clinical features of venous thrombosis include leg pain, tenderness, and asymmetrical swelling, a palpable cord representing a thrombosed vessel, discoloration, venous distention, prominence of the superficial veins, and cyanosis. In exceptional cases, patients may present with phlegmasia cerulea dolens (occlusion of the whole venous circulation, extreme swelling of the leg, and compromised arterial flow). In 50% to 85% of patients, the clinical suspicion of deep venous thrombosis is not confirmed by objective testing. Conversely, patients with florid pain and swelling, suggesting extensive deep venous thrombosis, may have negative results by objective testing. Patients with minor symptoms and signs may have extensive deep venous thrombi. Although the clinical diagnosis is nonspecific, prospective studies have established that patients can be categorized as low, moderate, or high probability for deep venous thrombosis using clinical prediction rules that incorporates signs, symptoms, and risk factors. +++ Pulmonary Embolism ++ The clinical features of acute pulmonary embolism include the following symptoms and signs that may overlap: — Transient dyspnea and tachypnea in the absence of other clinical features — Pleuritic chest ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.