Haematology Overview Quiz

Haematology Overview

• Haematology is the study of blood and blood-forming tissues
• This presentation focuses on learning objectives, blood cell disorders, haematological indices, and anemia

Learning Objectives

• Knowledge: Understand the pathophysiology, etiology, epidemiology, manifestations, complications, and management of hematological disorders
• Skills: Interpret clinical presentations and investigations, apply evidence-based management plans, distinguish emergency situations, and ensure patient homeostasis

Blood Cell Disorders

• The presentation introduces blood cell disorders as a specific topic for study

Hematological Indices

• Red Blood Cells (RBCs)
  • Source: Yolk sac (early development), liver and spleen, bone marrow (adult)
  • Stages of development: Totipotent stem cells→pluripotent stem cells → committed stem cells→proerythroblasts→erythroblasts→normoblasts→reticulocytes→RBCs
  • Shape: Biconcave
  • Count: Male: 4.5-6 million/mm³, Female: 3.8-4.8 million/mm³
  • Diameter: 7.2 microns
  • Abnormal shapes: Spherocytes, Sickle cells, Target cells, Microcytes, Macrocytes, Megalocytes, Anisocytosis
  • Hematocrit (PCV or HCT): Volume of packed RBCs in 100ml blood, Normal = 45%, ↑ PCV=dehydration/polycythemia, ↓ PCV=hypervolemia/anemia
  • Mean corpuscular volume (MCV): Volume of RBCs, ↑MCV=macrocytic, ↓MCV=microcytic
  • Mean corpuscular hemoglobin (MCH): Amount of Hb/100ml blood, ↓MCH=hypochromic
  • Mean corpuscular hemoglobin concentration (MCHC): Concentration of Hb/100ml blood, ↓MCHC=hypochromic
  • Erythrocyte sedimentation rate (ESR): Vertical distance of RBCs in blood column, Increased ESR = inflammation, infections, cancer, autoimmune diseases
  • Reticulocytes: Immature RBCs, indicator of bone marrow activity, Increased reticulocytosis = hemolysis, acute hemorrhage, anemia with treatment, absent reticulocytosis = bone marrow failure
• Blood Film Analysis
  • Identifies abnormal RBC shapes, associated with various diseases (e.g., sickle cell anemia, spherocytosis).
• Other important parameters: Hemoglobin (Hb) normal values (Male :13.5-16 gms%, Female: 11.5-13.5 gms%), low Hb levels=anemia or hypervolemia

Anemia

• Reduced oxygen-carrying capacity of the blood
• Identified as Hb < 11.5 gm% in females and Hb < 13 gm% in males
• Etiology: Diminished intake, diminished absorption, increased loss, and increased requirements

Polycythemia

• High red blood cell count (RBCs > 6 million/mm³), elevated hematocrit (PCV > 55%), and increased red blood cell volume (>36 mL/kg in males, 32 mL/kg in females).
• Types: primary polycythemia vera and secondary polycythemia

Hemostasis

• Maintaining blood inside blood vessels (keeps blood in the lumen of blood vessels)
• Balance between clotting and anti-clotting systems
• Components: Blood vessels, platelets, coagulation system

White Blood Cell Disorders

• Leukemia : Uncontrolled proliferation, abnormal white blood cells in blood
• Classification: Acute and chronic, from myelocytic or lymphocytic origin.
• Etiology: Radiation, chemicals, drugs, genetic factors, and infections
• Lymphoma: Malignant proliferation of lymphoreticular system. Types: Hodgkin and non-Hodgkin lymphomas