Episode Details

Core Clinical Concepts Blood disorders disrupt homeostasis. Key pathological threads include:

• Fatigue: Secondary to tissue hypoxia (anemia, cancer).
• Infection Risk: Compromised immunity and risk for infection is a major concern in hematologic cancers and a common side effect of therapy.
• Pain: Common and classic in sickle cell disease (SCD) and oncology.
• Perfusion & Clotting: Excessive clotting impairs perfusion; inadequate clotting causes blood loss and fluid volume deficit.

Anemia: Definition & Pathophysiology Anemia is not a disease but a manifestation of an underlying pathologic process. It is defined as a deficit in red blood cell (RBC) count, hemoglobin (Hgb) quantity/quality, and/or volume of packed red blood cells (hematocrit). Tissue hypoxia drives all clinical findings. The body compensates via cardiopulmonary escalation, increasing heart rate (HR) and stroke volume to maintain cardiac output (CO). Low blood viscosity contributes to systolic murmurs and bruits. If O2 demand exceeds supply, angina or MI occurs. Chronic overwork leads to heart failure (HF), cardiomegaly, congestion, and peripheral edema.

Diagnostics & Classification Diagnostics rely on CBC, reticulocyte count, and peripheral smear. Anemia is classified by:

1. Morphology (RBC size/color): Most accurate framework.
   • Normocytic, Normochromic (MCV 80–95 fL, MCH 27–31 pg): Caused by acute blood loss, hemolysis, CKD, cancers, or SCD.
   • Microcytic, Hypochromic (MCV <80 fL, MCH <27 pg): Caused by iron deficiency, thalassemia, lead poisoning, B6/copper deficiency.
   • Macrocytic, Normochromic (MCV >95 fL, MCH >31 pg): Caused by B12 (cobalamin) deficiency, folic acid deficiency, or liver disease.
2. Etiology (Cause): Best for structuring care. Divided into decreased RBC production, blood loss, or increased RBC destruction (hereditary like SCD/G6PD vs. acquired like DIC, HELLP, prosthetic valves, or bypass).

Severity & Clinical Manifestations Symptoms depend on onset speed, severity, and Hgb level:

• Mild (Hgb 10–12 g/dL): Often asymptomatic. Heavy exercise triggers compensatory palpitations, mild fatigue, and dyspnea.
• Moderate (Hgb 6–10 g/dL): Cardiopulmonary symptoms (dyspnea, palpitations) occur both during activity and at rest.
• Severe (Hgb <6 g/dL): Multi-system decompensation occurs.
  • Integumentary: Pallor (shunted blood flow), jaundice (bilirubin from RBC hemolysis), and severe itching (accumulation of skin bile).
  • Cardiopulmonary: Marked tachycardia, angina, murmurs, and congestive failure.