Most bleeding seen in the ED is a result of trauma—local wounds, lacerations, or other structural lesions—and the majority of traumatic bleeding occurs in patients with normal hemostatic mechanisms.1 In these patients, specific assessment of hemostasis is unnecessary. However, some ED patients have abnormal bleeding due to impaired hemostasis. Identifying these patients requires attention to the history and physical findings.2,3,4 Generally speaking, when patients have spontaneous bleeding from multiple sites, bleeding from untraumatized sites, delayed bleeding several hours after trauma, and bleeding into deep tissues or joints, the possibility of a bleeding disorder should be considered.
Important historical data that aid in identifying a congenital bleeding disorder include the presence of unusual or abnormal bleeding in the patient and other family members and any occurrence of excessive bleeding after dental extractions, surgical procedures, or trauma.5 Many patients with abnormal bleeding have an acquired disorder, such as liver disease, renal disease, or drug use (particularly ethanol, aspirin, nonsteroidal anti-inflammatory drugs, antiplatelet drugs, oral anticoagulants, antibiotics, and other salicylate-containing products).2,3,4 Many supplements and herbal preparations, including garlic, ginseng, ginkgo biloba, ginger, and vitamin E, can also increase bleeding tendencies.
The site of bleeding may provide an indication of the hemostatic abnormality. Mucocutaneous bleeding, including petechiae, ecchymoses, epistaxis, GI or GU bleeding, or heavy menstrual bleeding, is characteristic of qualitative or quantitative platelet disorders. Purpura is often associated with thrombocytopenia and commonly indicates a systemic illness. Bleeding into joints and potential spaces, such as between fascial planes and into the retroperitoneum, and delayed bleeding are most commonly associated with coagulation factor deficiencies. Patients who demonstrate both mucocutaneous bleeding and bleeding in deep spaces may have disorders such as disseminated intravascular coagulation, in which both platelet abnormalities and coagulation factor abnormalities are present (see chapters 233, "Acquired Bleeding Disorders," 234, "Clotting Disorders," and 235, "Hemophilias and von Willebrand's Disease").
Common laboratory tests for hemostasis have their limitations.6,7 They are generally useful and reliable for identifying disorders of coagulation factor function and quantitative platelet availability. However, tests of qualitative platelet function show a significant biologic variation, so that standardization has been difficult to achieve.8,9 In addition, liver disease and renal failure—two conditions that increase the potential for abnormal hemorrhage—may not give rise to consistent and measurable abnormal results on routine tests of hemostasis.10,11,12
THE PATIENT WITH A THROMBUS
Presentation of a patient to the ED with a disorder due to an intravascular thrombosis, such as a deep venous thrombosis or pulmonary embolus, suggests the potential for an underlying hypercoagulable state (see chapter 234). Premature coronary artery disease and acute coronary syndrome in individuals as young as teenagers have also been linked to hypercoagulable conditions. However, many, if not most, occurrences ...