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Underlying Systemic Diseases that Cause or Exacerbate a Bleeding Tendency Acquired bleeding disorders are commonly secondary to, or associated with, systemic disease. The clinical evaluation of a patient with a bleeding tendency must therefore include a thorough assessment for evidence of underlying disease. Bruising or mucosal bleeding may be the presenting complaint in liver disease, severe renal impairment, hypothyroidism, paraproteinemias or amyloidosis, and conditions causing bone marrow failure. All coagulation factors are synthesized in the liver and hepatic failure results in combined factor deficiencies. This is often compounded by thrombocytopenia from splenomegaly due to portal hypertension. Coagulation factors II, VII,. | Chapter 059. Bleeding and Thrombosis Part 6 Underlying Systemic Diseases that Cause or Exacerbate a Bleeding Tendency Acquired bleeding disorders are commonly secondary to or associated with systemic disease. The clinical evaluation of a patient with a bleeding tendency must therefore include a thorough assessment for evidence of underlying disease. Bruising or mucosal bleeding may be the presenting complaint in liver disease severe renal impairment hypothyroidism paraproteinemias or amyloidosis and conditions causing bone marrow failure. All coagulation factors are synthesized in the liver and hepatic failure results in combined factor deficiencies. This is often compounded by thrombocytopenia from splenomegaly due to portal hypertension. Coagulation factors II VII IX X and proteins C S and Z are dependent on vitamin K for posttranslational modification. Although Vitamin K is required in both procoagulant and anticoagulant processes the phenotype of vitamin K deficiency or the warfarin effect on coagulation is bleeding. The normal blood platelet count is 150 000-450 000 pL. Thrombocytopenia results from decreased production increased destruction and or sequestration. Although the bleeding risk varies somewhat by the reason for the thrombocytopenia bleeding rarely occurs in isolated thrombocytopenia at counts 50 000 pL and usually not until 10 000-20 000 pL. Coexisting coagulopathies as seen in liver failure or disseminated coagulation infection platelet-inhibitory drugs and underlying medical conditions can all increase the risk of bleeding in the thrombocytopenic patient. Most procedures can be performed in patients with a platelet count of 50 000 pL. The level needed for major surgery will depend on the type of surgery and the patients underlying medical state although a count of approximately 80 000 pL is likely sufficient. History of Thrombosis The risk of thrombosis like that of bleeding is influenced by both genetic and environmental influences. The major .
