Medicine (Hematologic) Flashcards
What is anemia?
-Decrease in red blood cells leading to less oxygen carrying capacity and delivery to end organs. Can be classified as macrocytic, nomocytic, microcytic
What are examples of microcytic, normocytic and macocytic anemias?
-Microcytic: Iron deficiency, thalassemia, lead poisoning
-Normocytic: Acute blood loss, myelodysplastic syndroms, anemia of chronic disease, hemolytic anemias
-Macrocytic: Folate deficiency, vitamin B12 deficiency, alcoholism, drug toxicity
What is alpha-thalassemia?
-Autosomal recessive disease: Decrease in alpha-globin chain of Hemoglobin
-Varying degrees based on how many chains are affected
-1-2 deletions mild anemia with no treatment or symptoms
-3 deletions cause severe hemolytic anemia
-4 deletions not compatible with life
What is beta thalassemia?
Autosomal recessive disease: Decrease in beta-globin chain of hemaglobin. Common in Greeks
-Mild form: No treatment
-Severe form: Hemolytic anemia. No HbA. Need for transfusion
What is pernicious anemia?
-Decrease in intrinsic factor due to autoimmune destruction of gastric parietal cells. Causes vitamin B12 deficiency and macrocytic anemia
-Macrocytic anemia
What is sickle cell anemia?
-Autosomal recessive disorder: Intrinsic defect causing extravascular hemolysis of sickled cells. Structural change of hemaglobin due to mutation.
-Severe hemolytic anemia, vaso-occlusive crises (acute chest pain, autosplenectomy, increased risk of infection from encapsulated organisms)
-Treat with hydroxyurea (increases HbF which prevents sickling and bone marrow transplant
What is leukemia?
-Disease of the mesenchymal cells of the blood with abnormality in proliferation and increased life span of myeloid or lymphoid cells. Can be classified as acute vs chronic, myeloid vs lymphoid.
What are important characteristics of AML?
-Acute myelogenous leukemia
-Most common leukemia in adults
-Gingival infiltrates
-Thrombocytopenia
What are important characteristics of CML?
-Chronic myelogenous leukemia
-Less common
-Philadelphia chromosome: Chromosome 22,9 BCR gene
-More indolent
What are important characteristics of ALL?
-Acute lymphocytic leukemia
-Most common childhood leukemia
-Cure rate 2/3, even higher in children
What are important characteristics of CML?
-Most common overall
-No cure, goal is to prolong life. Stage with Rai system
What is hemophilia?
-X-linked recessive bleeding disorder. Type A and B
What is hemophilia A?
-Congenital deficiency in clotting factor VIII on X chromosome
What is hemophilia B?
-Congenital deficiency in clotting factor IX
How is hemophilia A and B classified?
-Severe: Factor levels below 1%, spontaneous bleeds occur
-Moderate: Factor levels between 1-5%. Prolonged bleeding
-Mild: Factor levels above 5%. Prolonged bleeding
How is hemophilia A and B managed for outpatient dental procedures?
-Recombinant factor concentrates of VIII or XI. Raise levels to 80-100% and maintain above 50%
-Factors with short half life, should be administered 20 minutes post-op
-TXA (antifibrinolytic agent)
-DDAVP (for Hemophilia A, raises factor VIII and vWF)
What is von Willebrand disease?
-Congenital platelet bleeding disorder due to a deficiency or dysfunction of von Willebrand factor. Typically autosomal dominant
-Classified based on quantitative (type I and most common) or qualitative type II
How is von willebrand’s disease managed for surgical procedures?
Depends on type:
-Type I: DDAVP (Desmopressin)
-IV: 0.3 micrograms/kg over 20 minutes
-IN: 150 microgram spray
-Need to monitor free water
-Type 2-3: Cryoprecipitate, factor VIII, amicar
What is factor V Leiden?
-Autosomal dominant mutation resulting in resistance to activated protein C
-Hypercoagulable state
-Need DVT prophylaxis
What is lymphoma?
-Malignancy of lymphocytes that arises in lymph nodes.
-Types are Hogkin and non- hodgkin lymphoma)
What is multiple myeloma?
-A malignancy characterized by neoplastic transformation of plasma cells
-Pt may be on anti-resorptive agents
How does a transfusion of PRBCs affect CBC labs?
-Each unit increases hemoglobin by 1 g/dL and hematocrit by 3%
How does a transfusion of platelets affect labs?
-Increases platelet count by 5-10k (50k minimum for surgery)
