tailieunhanh - Chapter 110. Coagulation Disorders (Part 3)

Clinically, hemophilia A and hemophilia B are indistinguishable. The disease phenotype correlates with the residual activity of FVIII or FIX and can be classified as severe (25% of normal, the disease is discovered only by bleeding after major trauma or during routine presurgery laboratory tests. Typically, the global tests of coagulation show only an isolated prolongation of the aPTT assay. | Chapter 110. Coagulation Disorders Part 3 Clinically hemophilia A and hemophilia B are indistinguishable. The disease phenotype correlates with the residual activity of FVIII or FIX and can be classified as severe 1 moderate 1-5 or mild 6-30 . In the severe and moderate forms the disease is characterized by bleeding episodes into the joints hemarthroses soft tissues and muscles after minor trauma or even spontaneously. Patients with mild disease experience infrequent bleeding that is usually secondary to trauma. Among those with residual FVIII or FIX activity 25 of normal the disease is discovered only by bleeding after major trauma or during routine presurgery laboratory tests. Typically the global tests of coagulation show only an isolated prolongation of the aPTT assay. Patients with hemophilia have normal bleeding times and platelet counts. The diagnosis is made after specific determination of FVIII or FIX clotting activity. Early in life bleeding may present after circumcision or rarely as intracranial hemorrhages. The disease is more evident when children begin to walk or crawl. In the severe form the most common bleeding manifestations are the recurrent hemarthroses which can affect every joint but mainly affect knees elbows ankles shoulders and hips. Acute hemarthroses are painful and clinical signs are local swelling and erythema. To avoid pain the patient may adopt a fixed position which leads eventually to muscle contractures. Very young children unable to communicate verbally show irritability and a lack of movement of the affected joint. Chronic hemarthroses are debilitating with synovial thickening and synovitis in response to the intraarticular blood. After a joint has been damaged recurrent bleeding episodes result in the clinically recognized target joint which then establishes a vicious cycle of bleeding resulting in progressive joint deformity that in critical cases requires surgery as the only therapeutic option. Hematomas into the muscle of .