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Пульмонология, гематология (англ,рус)

·        Infection, particularly with gram-negative organisms.

·        Malignancy, particularly mucin-secreting adenocarcinomas of the pancreas and prostate and acute promyelocytic leukemia.

·        Shock from any cause.

·        severe tissue damage from head trauma, burns, frostbite, or gunshot wounds; complications of prostate surgery;

·        venomous snake bites in which enzymes enter the circulation that activate one or several coagulation factors and generate thrombin or directly convert fibrinogen to fibrin;

·        profound intravascular hemolysis;

·        aortic aneurysms or cavernous hemangiomas (Kasabach-Merritt syndrome) associated with vessel wall damage and areas of blood stasis.

 

Symptoms and Signs of DIC

·        In slowly evolving DIC, symptoms of venous thrombosis and pulmonary embolism may be present.

·        In severe, rapidly evolving DIC, skin puncture sites (eg, IV or arterial punctures) bleed persistently, ecchymoses form at sites of parenteral injections, and serious GI bleeding may occur. Delayed dissolution of fibrin polymers by fibrinolysis may result in the mechanical disruption of RBCs and mild intravascular hemolysis. Occasionally, microvascular thrombosis and hemorrhagic necrosis produce dysfunction and failure in multiple organs.

 

Diagnosis of DIC

·        decreasing plasma fibrinogen;

·        increased plasma d-dimer (an indication of in vivo fibrin deposition and degradation);

·        thrombocytopenia, a normal to minimally prolonged PT (results are typically reported as INR);

·        factor VIII is reduced in DIC because of the thrombin-induced generation of activated protein C, which proteolyses factor VIII.

 

Treatment of DIC

·        Immediate correction of the underlying cause is the priority (eg, broad-spectrum antibiotic treatment of suspected gram-negative sepsis, evacuation of the uterus in abruptio placentae).

·        If treatment is effective, DIC should subside quickly. If bleeding is severe, adjunctive eplacement therapy is indicated, consisting of platelet  oncentrates to correct thrombocytopenia;

·        cryoprecipitate to replace fibrinogen and factor VIII;

·        and fresh frozen plasma to increase levels of other clotting factors and natural anticoagulants (antithrombin, proteins C and S).

 

Hemophilia

·        Hemophilias are common hereditary bleeding disorders caused by deficiencies of either clotting factor VIII or IX.

·        Hemophilia A (factor VIII deficiency), which affects about 80% of hemophilic patients, and hemophilia B (factor IX deficiency) have identical clinical manifestations, screening test abnormalities, and X-linked genetic transmission.

·        Because these genes are located on the X chromosome, hemophilia affects males almost exclusively. Daughters of hemophilic males are obligate carriers, but sons are normal. Each son of a carrier has a 50% chance of having hemophilia, and each daughter has a 50% chance of being a carrier.

 

Diagnosis

·        Patients with hemophilia bleed into tissues (eg, hemarthroses, muscle hematomas, retroperitoneal hemorrhage), and the bleeding may be delayed after trauma. Hemarthroses can lead to synovitis and arthropathy

·        family history 

·        PTT is prolonged, but the PT and platelet count are normal.

·        Decrease of Factor VIII and IX.

 

Prevention and Treatment

·        should avoid aspirin and NSAIDs. The COX-2 inhibitors have little antiplatelet activity, may produce fewer GI erosions than aspirin or other NSAIDs, and can be used with caution in hemophilia.

·        To avoid surgical operations. Drugs should be given orally or IV.

·        In hemophilia A, factor VIII.

·        In hemophilia B, factor IX.

·        Desmopressin (SOME TRADE NAMES DDAVP, STIMATE) may temporarily raise factor VIII levels.

·        An antifibrinolytic agent (ε- aminocaproic acid SOME TRADE NAMES AMICAR 2.5 to 4 g po qid for 1 wk or tranexamic acid SOME TRADE NAMES CYKLOKAPRON 1.0 to 1.5 g po tid or qid for 1 wk) should be given to prevent late bleeding after dental extraction or other oropharyngeal mucosal trauma (tongue laceration).

 

BLEEDING DUE TO ABNORMAL BLOOD VESSELS

Bleeding may result from abnormalities in platelets, coagulation factors, or blood vessels. Vascular bleeding disorders are caused by defects in blood vessels, typically producing petechiae, purpura, and bruising but seldom leading to serious blood loss. Bleeding may result from deficiencies of vascular and perivascular collagen in Ehlers-Danlos syndrome and in other rare hereditary connective tissue disorders (pseudoxanthoma elasticum, osteogenesis imperfecta, Marfan syndrome). Hemorrhage may be a prominent feature of scurvy or of Henoch-Schönlein purpura, a hypersensitivity vasculitis common during childhood. In vascular bleeding disorders, tests of hemostasis are usually normal. Diagnosis is clinical.

Henoch-Schönlein Purpura (HSP)

·        Henoch-Schönlein purpura is vasculitis that affects primarily small vessels. It occurs most often in children.

·        Common manifestations include palpable purpura, arthralgias, GI symptoms and signs, and glomerulonephritis.

 

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