BLOOD DISORDERS 1.3 (AB) Flashcards
What is hemostasis?
A phenomenon wherein the body maintains the fluidity of blood.
What are the classifications of hemostasis based on mechanism?
Blood vessels. platelets and clotting factors.
What are examples of congenital causes of hemostasis disorders?
Hemophilias. Von Willebrand disease. Afibrinogenemia. Anti-trypsin deficiency.
What are examples of acquired causes of hemostasis disorders?
Vitamin K deficiency. liver diseases. lupus anticoagulants. DIC.
What type of bleeding suggests a platelet or blood vessel disorder?
Mucous membrane/skin bleeding.
What type of bleeding suggests coagulopathy?
Deep-seated bleeding.
What does widespread bleeding suggest?
A systemic hemostatic defect.
What does localized bleeding suggest?
An anatomic lesion.
What does bleeding in the neonatal period suggest?
An inherited disorder.
What does acute onset of bleeding suggest?
An acquired disorder.
What inheritance pattern is associated with Hemophilia A or B?
X-linked recessive inheritance.
What inheritance pattern is associated with Von Willebrand disease?
Dominant pattern.
Which drugs may cause bleeding diathesis?
NSAIDs. phenytoin and warfarin.
What kind of lesions are seen in platelet disorders?
Petechiae and superficial ecchymoses.
What kind of lesions are seen in coagulation disorders?
Hematomas and hemarthrosis.
What does platelet count measure?
The number of platelets in the blood.
What clotting factors are measured by PT?
Factors I. II. V. VII and X.
What is PT useful for?
Monitoring anticoagulants
What clotting factors are measured by APTT?
Factors I. II. V. VIII. X. XI. XII. prekallikrein and kinogen.
What conditions prolong APTT?
Hemophilia and lupus anticoagulants.
What causes prolonged bleeding time?
Von Willebrand disease and connective tissue disorders.
When is bleeding time commonly tested?
Before dental procedures and circumcision
What is the most common platelet disorder in children?
Primary Immune Thrombocytopenia (PIT).
What age group is commonly affected by PIT?
2-6 years old.
What are common features of PIT?
Sudden petechiae and mucous membrane bleeding after a viral infection.
What causes PIT?
Autoantibodies against platelet membrane components.
What are the diagnostic criteria for PIT?
Isolated thrombocytopenia. normal peripheral smear. no splenomegaly or lymphadenopathy and response to ITP therapy.
What typically precedes PIT?
A viral infection 2-3 weeks before symptoms.
What is the treatment for PIT?
Corticosteroids. IVIG. Anti-D immunoglobulin.
When do you start treatment for PIT?
Platelets < 20 000 with bleeding or < 10 000 even without bleeding.
What is the response if platelet count is normal on CBC in suspected PIT?
Reassure the patient.
What is done in life-threatening PIT bleeding?
Platelet transfusion.
What clotting factor is deficient in Hemophilia A?
Factor VIII.
What is the inheritance of Hemophilia A?
X-linked.
What is the most common hemophilia?
Hemophilia A.
What are symptoms of mild Hemophilia A?
Often asymptomatic.
What are symptoms of moderate Hemophilia A?
Muscular and mucosal bleeding.
What are symptoms of severe Hemophilia A?
Joint bleeding and CNS bleeding.
What factor is deficient in Hemophilia B?
Factor IX.
What is another name for Hemophilia B?
Christmas disease.
How does Hemophilia B present?
Similar to Hemophilia A.
What are screening test results in Hemophilia B?
aPTT prolonged. PT normal.
How is hemophilia treated?
Replace deficient factor. FFP. cryoprecipitate.
What is cryoprecipitate used for?
Hemophilia A and Von Willebrand disease.
What factor is deficient in Hemophilia C?
Factor XI.
How does Hemophilia C present?
Asymptomatic until surgery or trauma.
What is Fletcher factor deficiency?
Factor XII or prekallikrein deficiency.
Does Fletcher factor deficiency cause bleeding?
No.
What vitamin is needed to activate clotting factors II. VII. IX. X?
Vitamin K.
What are the 3 forms of vitamin K?
K1 (phylloquinone). K2 (menaquinone). K3 (menadione).
Why is Vitamin K3 rarely used?
It can worsen congenital hemolytic disorders.
What are signs of vitamin K deficiency in infants?
Bleeding. coldness. bloody stools. history of no vitamin K at birth.
What are lab findings in vitamin K deficiency?
Prolonged PT. aPTT; check platelet count.
What is DIC?
A condition with simultaneous activation of clotting and fibrinolysis.
What causes DIC?
Infection. trauma. transfusion reactions. malignancy.
What are lab findings in acute DIC?
Prolonged PT and PTT. low platelets. fragmented RBCs. low fibrinogen. high fibrin degradation products.
What are lab findings in chronic DIC?
Normal PT and PTT. mildly reduced platelets. normal fibrinogen.
What is the treatment for DIC?
Treat underlying cause. antibiotics. blood component therapy (FFP. cryoprecipitate. platelets).
What are signs of hemorrhagic disease of the newborn?
Pallor. jaundice. umbilical stump bleeding. seizures.
What are labs in hemorrhagic disease of the newborn?
Anemia. leukocytosis. normal platelets. prolonged PT. normal aPTT.
What is the treatment for hemorrhagic disease of the newborn?
Vitamin K (oral or parenteral).
What is whole blood used for?
Restore tissue oxygenation and blood volume.
Why is whole blood use limited?
Storage leads to platelet and plasma deterioration.
What is packed RBC used for?
Restore oxygenation and volume.
What is the dose of packed RBC in pediatrics?
10-15 ml/kg.
What blood components can be separated from plasma?
Cryoprecipitate and cryosupernatant.
What should be done before transfusion?
Cross-matching and retyping.
What is a febrile non-hemolytic transfusion reaction?
Fever due to chemical incompatibility; stop transfusion and monitor temperature.
What are signs of allergic transfusion reactions?
Itching and wheals.
What are signs of acute hemolytic transfusion reaction?
Pallor during transfusion.
What is transfusion-related sepsis?
Fever and hypothermia during transfusion.
What is transfusion-related respiratory dysfunction?
Difficulty breathing during or after transfusion.
What are metabolic complications of transfusion?
Hyperkalemia
What causes dilutional coagulopathy?
Large volume transfusion dilutes clotting factors.
What are delayed transfusion reactions?
Delayed hemolytic reaction. GVHD. post-transfusion purpura.
What are late complications of transfusion?
Iron overload. alloimmunization. transfusion-transmitted infections.
What are treatments for iron overload?
Deferoxamine. deferiprone. deferasirox.
What is alloimmunization?
Immune response causing febrile reactions. TRALI and platelet refractoriness.
What infections can be transmitted via transfusion?
Hepatitis B. Hepatitis C. CMV. HIV. malaria.
