Hematology

Hematology Overview

  • Discussion on hematology focusing on:

    • Anemias (4 types)

    • Clotting disorders (3 types)

    • Immune disorders (3 types)

Complete Blood Count (CBC)

  • Importance of CBC: Most common test for hematologic function.

  • Key Components:

    • Red Blood Cell Count (RBC), Hemoglobin, and Hematocrit

    • Reticulocytes: Show bone marrow function

      • Low reticulocyte count: Bone marrow suppression.

      • High reticulocyte count: Bone marrow responding to stimuli like anemia.

    • White Blood Cell Differential: Important for infections.

      • Neutrophils: Primary defense against bacteria.

      • Bands: Immature neutrophils, increased with infection (indicates bandemia).

      • Eosinophils: Response to allergens.

      • Basophils: Prevent excessive clotting and increase blood flow to injured tissues.

Anemias

Definition

  • Anemia: Decreased RBCs or hemoglobin concentration leading to decreased oxygen capacity of blood.

Classification of Anemia Causes

  • Decreased Production: Nutritional deficiency, chronic GI blood loss, bone marrow failure.

  • Increased Loss: Acute hemorrhage, sickling, sequestration in the spleen.

  • Increased Destruction: Structural problems in RBC or external factors like medication or infection.

Common Clinical Manifestations

  • Symptoms: Pallor, fatigue, headache, tachycardia (as compensatory response to reduced oxygen delivery).

Types of Anemia

1. Iron Deficiency Anemia

  • Most common, often due to nutritional deficiency.

  • Iron transferred from mother to baby lasts 5-6 months.

  • Prevention: Iron supplements when transitioning to solids.

  • Key Point: No cow's milk before age 1.

  • Important education: Stools may become dark due to iron supplementation, not a cause for concern.

2. Sickle Cell Anemia

  • Normal hemoglobin (A) replaced with sickle hemoglobin (S).

  • Symptoms: Pain, swelling, higher risk of strokes, acute chest syndrome, sequestration crises.

  • Management: Stay hydrated, pain relief (with NSAIDs and opioids), blood transfusions, prophylactic antibiotics due to functional asplenia.

  • Treatment: Hydroxyurea to increase fetal hemoglobin and promote healthier RBCs.

3. Beta Thalassemia

  • Deficiency in beta polypeptide chain formation, leading to RBC damage and marrow expansion.

  • Symptoms: Similar to anemia but with physical changes (bone remodeling, frontal bossing).

  • Treatment: Blood transfusions, iron chelation therapy to prevent hemosiderosis from excess iron.

4. Aplastic Anemia

  • Complete bone marrow failure (pancytopenia).

  • Treatment: Bone marrow transplant, immunosuppression if immune-mediated.

Clotting Disorders

Overview

  • Disruption in hemostasis resulting in excessive bleeding or clotting.

Key Components of Clotting

  • Vascular influence, platelets, and clotting factors are crucial for proper clotting response.

1. Hemophilia

  • Congenital deficiency of coagulation factors (Factor VIII - Hemophilia A and Factor IX - Hemophilia B).

  • Treatment: Replace missing factors, corticosteroids for inflammation, and careful activity management (prevention strategy).

2. Immune Thrombocytopenia (ITP)

  • Immune-mediated thrombocytopenia with easy bruising, and mucosal bleeding.

  • Treatment: Activity restriction, medications (prednisone or IVIG), splenectomy if chronic.

3. Disseminated Intravascular Coagulation (DIC)

  • Consumptive coagulopathy due to conditions that damage blood vessels.

  • Treatment: Address underlying cause, platelet replacement, and may consider heparin for thrombin inhibition.

Immunologic Deficiency Disorders

Overview

  • Disorders leading to impaired or misdirected immune responses.

1. HIV/AIDS

  • Transmission risks and management similar to adults (antiretroviral therapy, immunizations).

2. Severe Combined Immunodeficiency (SCID)

  • Absence of humoral and cell-mediated immunity leading to severe susceptibility to infections.

  • Treatment: IVIG and ultimately bone marrow transplant.

3. Wiskott-Aldrich Syndrome

  • Characterized by thrombocytopenia, eczema, and immunodeficiency.

  • Treatment: Similar to SCID (platelets, IVIG, prophylactic antibiotics, and bone marrow transplant).

Blood Transfusion Therapy

Important Considerations

  • Know the risks and management strategies for blood transfusions, including monitoring vital signs, rules for administration, and managing complications.