A 35-year-old man of African descent presents with acute hemolytic crisis triggered by infection. Laboratory findings show hemoglobin 7.5 g/dL, reticulocyte count 18%, elevated indirect bilirubin, and positive osmotic fragility test. Peripheral blood smear shows spherocytes and polychromasia. What is the drug of choice for acute hemolytic episodes in hereditary spherocytosis?

Explanation

## Clinical Diagnosis The clinical presentation is consistent with **Hereditary Spherocytosis (HS)**: - Positive osmotic fragility test (hallmark finding) - Spherocytes on blood smear - Elevated reticulocyte count and indirect bilirubin - Acute hemolytic crisis triggered by infection ## Drug of Choice: Splenectomy **Key Point:** Splenectomy is the **definitive treatment** for symptomatic hereditary spherocytosis. It removes the primary site of extravascular hemolysis and is curative in ~80–90% of cases. **High-Yield:** HS is an **extravascular hemolytic anemia** — spherocytes are rigid and trapped in the spleen's red pulp. Removing the spleen eliminates the hemolytic mechanism. **Clinical Pearl:** Splenectomy is indicated in: 1. Moderate to severe hemolysis (Hb < 10 g/dL, reticulocyte count > 10%) 2. Recurrent hemolytic crises 3. Symptomatic patients (jaundice, gallstones, growth retardation in children) ## Pathophysiology of HS ```mermaid flowchart TD A[Defect in RBC membrane proteins<br/>Spectrin, ankyrin, band 3]:::outcome --> B[Loss of membrane stability] B --> C[RBC becomes spherical<br/>Less deformable] C --> D[Trapped in splenic red pulp] D --> E[Extravascular hemolysis]:::urgent F[Splenectomy]:::action --> G[Removes hemolytic organ] G --> H[Hemolysis resolves]:::outcome ``` ## Management Strategy in HS | Phase | Intervention | Rationale | |-------|-------------|----------| | **Acute crisis** | Transfusion, hydration, folic acid | Supportive; manage complications | | **Between crises** | Folic acid supplementation | Prevent folate depletion from chronic hemolysis | | **Definitive** | **Splenectomy** | **Removes site of hemolysis** | | **Post-splenectomy** | Pneumococcal, meningococcal, H. influenzae vaccination | Prevent overwhelming sepsis | **Mnemonic:** SHIV (Splenectomy, Hemolytic anemia, Infection prophylaxis, Vaccination) — remember to vaccinate before splenectomy. **Warning:** Do NOT confuse HS (extravascular) with PNH (intravascular). Splenectomy works in HS but not PNH.