1. 1.

    Dilutional anemia of pregnancy

    1. (a)

      Plasma volume increases by ~50% and red blood cell (RBC) mass increases by ~30%

    2. (b)

      Average Hgb at term gestation is 11.6 g/dL

    3. (c)

      If Hgb is <10.5 g/dL, the cause is something other than dilutional anemia

    4. (d)

      Hgb ≥ 14.5 g/dL may reflect inadequate volume expansion

  2. 2.

    Thalassemia

    1. (a)

      Microcytic, hemolytic anemia due to a reduced synthesis of one of the polypeptide globin chains

    2. (b)

      Leads to: imbalance in globin chain synthesis; defective hemoglobin synthesis; and erythrocyte damage resulting from excess globin subunits

    3. (c)

      Alpha-thalassemia  – decreased alpha-chain production. Four types because there are four alpha chain genes:

      1. (i)

        Silent carrier (three functioning genes) – seen in 30% of African Americans

      2. (ii)

        α-thalassemia trait (two functioning genes) – 3% of African Americans. Consider in black women with microcytic anemia that does not respond to iron therapy

      3. (iii)

        Hemoglobin H disease (one functioning gene) – moderately severe anemia, splenomegaly, fatigue, and generalized discomfort

      4. (iv)

        α0-thalassemia or Bart’s hydrops (no functioning genes) – beta chains form tetramers without alpha chains. Generally incompatible with life. Individuals die in utero or shortly after birth of hydrops fetalis

    4. (d)

      Beta-thalassemia  – decreased beta-chain production. Two genes for beta chains, thus types of thalassemia:

      1. (i)

        Β0-thalassemia (AKA β-thalassemia major or Cooley’s anemia) – no beta chain formation

        1. 1.

          Severe anemia develops in the first few months of extra-uterine life

        2. 2.

          Expansion of marrow cavities due to increased erythropoietin production causes skeletal abnormalities and pathologic fractures

        3. 3.

          Splenomegaly leads to leukopenia and thrombocytopenia

        4. 4.

          Transfusions are required to maintain life, leading to iron accumulation, which may lead to DM, adrenal insufficiency, infertility, and heart failure

        5. 5.

          Treatment: transfusion to maintain Hgb > 10 g/dL, splenectomy, and iron chelation therapy

          1. (a)

            Normal Hgb 2 g/dL at age <2

          2. (b)

            Typical Hgb 4–10 g/dL age 2–12

        6. 6.

          Rare for these patients to conceive. If they do, higher incidence of spontaneous abortion, intrauterine fetal demise (IUFD), and IUGR

      2. (ii)

        β+-thalassemia (AKA β-thalassemia minor) – some beta-chain production exists. Mild anemia (Hgb 9–11) and benign clinical course.

        1. 1.

          Tolerate pregnancy well

      3. (iii)

        Excess α chains precipitate and form inclusion bodies in RBC precursors

  3. 3.

    Sickle cell disease  – RBC undergo sickling when they are deoxygenated, causing clinical signs/symptoms

    1. (a)

      Homozygous for abnormal Hgb (hemoglobin SS or sickle cell anemia)

      1. (i)

        Valine is substituted for glutamic acid as the sixth amino acid in the beta chains

      2. (ii)

        Oxygen tension is the most important determinant of sickling; Hgb S begins to aggregate at a PO2 of less than 50 mmHg

      3. (iii)

        Other factors that increase sickling:

        1. 1.

          Hgb S concentration >50% of the total Hgb

        2. 2.

          Dehydration (due to increased blood viscosity)

        3. 3.

          Hypotension, which causes vascular stasis

        4. 4.

          Hypothermia

        5. 5.

          Acidosis

      4. (iv)

        Sickled cells can form aggregates and cause vaso-occlusive disease, which may lead to infarctive crises (most often occurring in chest, abdomen, back, and long bones), CVA, and, rarely, peripheral neuropathy

      5. (v)

        Increased risk of pneumonia and pyelonephritis in pregnant patients with sickle cell disease than in other pregnant patients

      6. (vi)

        Pregnancy exacerbates complications of sickle cell anemia

        1. 1.

          Pulmonary embolism (PE) and infection are the leading cause of death

        2. 2.

          Fetal mortality is elevated (~20%)

        3. 3.

          Increased incidence of preterm labor, placental abruption, placenta previa, and hypertensive disorders of pregnancy

      7. (vii)

        Principles of anesthetic management:

        1. 1.

          Use crystalloid to maintain intravascular volume

        2. 2.

          Transfuse RBCs to maintain O2-carrying capacity

        3. 3.

          Supplemental O2 and use pulse oximetry

        4. 4.

          Maintain normothermia

        5. 5.

          Prevent peripheral venous stasis

    2. (b)

      Heterozygous for abnormal Hgb (hemoglobin SA or sickle cell trait)

      1. (i)

        Pregnant women with sickle cell trait are at increased risk for asymptomatic bacteriuria, pyelonephritis, and preeclampsia

    3. (c)

      Double heterozygous for abnormal Hgb (hemoglobin SC or sickle cell hemoglobin C disease)

      1. (i)

        Hgb SC disease have increased tendency to develop marrow necrosis, which predisposes to fat emboli

  4. 4.

    Autoimmune hemolytic anemia

    1. (a)

      Four main types:

      1. (i)

        Incomplete warm autoantibodies

        1. 1.

          Usually IgG

        2. 2.

          RBC destruction in the spleen

        3. 3.

          Treatment: corticosteroids, splenectomy, gamma-globulin

      2. (ii)

        Complete warm autoantibodies (type I and II)

        1. 1.

          IgM antibodies

        2. 2.

          RBC destruction in the liver or intracellular

        3. 3.

          Treatment: corticosteroids, splenectomy, plasma exchange, corticosteroids

      3. (iii)

        Cold autoagglutinins and hemolysis

        1. 1.

          IgM antibodies

        2. 2.

          RBC destruction intracellular

        3. 3.

          Treatment: corticosteroids and keeping the patient warm

      4. (iv)

        Biphasic hemolysins (acute and chronic)

        1. 1.

          IgG antibodies

        2. 2.

          RBC destruction intracellular

        3. 3.

          Treatment: treat underlying infection, plasmapheresis, chlorambucil

    2. (b)

      Etiologies:

      1. (i)

        Primary or idiopathic

      2. (ii)

        Secondary

        1. 1.

          Neoplasms

        2. 2.

          Drug-related

        3. 3.

          Infections

        4. 4.

          Connective tissue diseases

        5. 5.

          Other diseases

        6. 6.

          Pregnancy