Bleeding Clotting Disorders BPT Class 15012013 9 a
Bleeding & Clotting Disorders. BPT Class 15/01/2013. 9 a. m. - 10 a. m. MBBS Combined 27 th April 2013 Prof C. V. Raghuveer. MBBS, MD, DCP, FICPath. Director of PG Studies & Research Yenepoya University.
Causes • Three major causes : • 1. Those due to Vascular Disorders. • 2. Those due to Platelet Disorders. • 3. Those due to Clotting Disorders.
1. Those due to Vascular Disorders. • • • They are again due to any of the following : 1. Damage to capillary endothelium. 2. Abnormalities in subendothelial matrix. 3. Abnormalities in extravascular supporting connective tissue. 4. Formation of abnormal blood vessels. • They can be Inherited or Acquired.
Inherited Vascular Bleeding Disorders • • 1. Hereditary hemorrhagic telengiectasia (Rendu-Weber Osler disease) Very rare, autosomal dominant. Abnormal dilated capillaries +, bleeding in skin nasal mucosa & even internal organs +. 2. Ehlers Danlos & Marfans Syndromes : Inherited defects in connective tissue. Blood vessels become fragile and bleed.
Acquired Vascular Bleeding Disorders. • 1. Henoch-Schonlein Purpura: • Hypersensitivity vasculitis. • Circulating immune complex deposits of • Ig. G, C 3, Fibrin in vessel wall causing vasculitis and • purpuric spots in skin • 2. H U S : Acute renal failure & bleeding • tendency. • 3. Other causes : infections, drug reactions, steroids, • senile purpura, scurvy.
2. Those due to Platelet Disorders • A) Those due to reduction in platelet count. • Thrombocytopenias. • B) Those due to defects in platelet function. • Thrombasthenias.
Thrombocytopenias. • 1. Impaired platelet production. • E. g, Bone marrow failure. • 2. Accelerated platelet destruction. • E. g, Immunologic destruction-ITP. • Increased platelet consumption- DIC. • 3. Splenic sequestration. • E. g, Splenomegaly. • 4. Dilutional loss. • E. g, Massive old whole blood transfusion.
ITP • • Acute in Children. Chronic in adults Self limiting. After infection with viral infections like viral hepatitis, infectious mononucleosis, CMV etc. Chronic associated with SLE, AIDS, Petechiae in acute ITP. Epistaxis, menorrhagia, Bleeding gums, hematuria etc in chronic ITP.
Lab findings in ITP • • • Platelet count < normal (10, 000 -50, 00 range). Platelet survival reduced. Bleeding time prolonged. Prothrombin time prolonged. Clotting time not prolonged. Anti-platelet antibodies +.
Disorders of Platelet Function 1. Defective adhesion. Bernard Soulier Syndr. V-W disease. 2. Defective aggregation. Glanzman, s Disease. 3. Disorders of platelet release reaction. 4. Aspirin therapy.
Coagulation/Clotting Disorders. 1. Classic Hemophilia. (Hemophilia-A) Deficiency or reduced activity of Factor VIII. Inherited as X-linked recessive. Manifests in Males, Females are carriers. Recurrent hemarthrosis is common presentation, muscle hematomas are common • Lab findings : Bleeding time prolonged. • PT- normal, APTT- prolonged. • • •
Clotting Disorders • • • Hemophilia-B (Christmas Disease) : Factor IX deficiency. Inheritance similar to Classic Hemophilia. Clinical features too arte similar. Factor assay helps in diagnosis.
Von Willebrand Disease. • Quantitative/qualitative deficiency of v. WF. • Incidence 1 in 1000 persons. • v. WF comprises larger fraction of Factor VIII- v. WF complex, which facilitates platelet adhesion to sub-endothelial collagen & clotting. • Gene for v. WF is on chr. 12, while gene for Factor VIII is on X-chr. • v. WD is inherited as autosomal dominant. • May occur in M or F. • Hemophilia is X-linked recessive. • v. WF is synthesised in endothelial cells. Factor VIII in hepatocytes. • v. WF facilitates platelet adhesion, while factor VIII activates Factor • X in intrinsic pathway of coagulation.
v. WD • • Clinically : v. WD – spontaneous bleeding in mucosa and wounds. Lab findings : Prolonged Bleeding Time. Normal platelets. Reduced v. WF in plasma. Defective platelet aggregation with ristocetin. Reduced Factor VIII activity.
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