Which organ complication is most commonly responsible for mortality in adult patients with sickle cell disease?

Explanation

## Organ Complications and Mortality in Sickle Cell Disease ### Leading Cause of Death in Adults with SCD **Key Point:** **Acute chest syndrome (ACS)** and its progression to pulmonary hypertension and cor pulmonale is the leading cause of mortality in adult patients with sickle cell disease. ### Acute Chest Syndrome: Pathophysiology 1. **Pulmonary infarction** from vaso-occlusion 2. **Fat embolism** from bone marrow necrosis 3. **Infection** (bacterial pneumonia, atypical organisms) 4. **In situ thrombosis** in pulmonary vessels 5. **Acute lung injury** from inflammatory cascade ### Pulmonary Complications Timeline ```mermaid flowchart TD A[Sickle Cell Disease]:::outcome --> B[Recurrent ACS episodes]:::action B --> C[Chronic pulmonary damage]:::action C --> D[Pulmonary hypertension]:::outcome D --> E[Right ventricular dysfunction]:::action E --> F[Cor pulmonale]:::urgent F --> G[Cardiogenic shock & death]:::urgent ``` ### Comparison of Major SCD Complications | Complication | Age of Onset | Mortality Impact | Reversibility | |--------------|--------------|------------------|---------------| | Splenic sequestration | Childhood | High in children | Potentially reversible | | Acute chest syndrome | Adolescence/Adult | **Highest in adults** | Reversible if early | | Pulmonary hypertension | Adult | Very high | Irreversible | | Stroke | Childhood/Adult | High | Irreversible | | Osteonecrosis | Adult | Low | Irreversible but not fatal | **High-Yield:** Pulmonary hypertension develops in 30–40% of adults with SCD and is associated with a 4-fold increase in mortality risk. It is the single most important predictor of poor prognosis in adult SCD. **Clinical Pearl:** Elevated tricuspid regurgitant jet velocity (TRV) on echocardiography is used to screen for pulmonary hypertension in SCD patients; those with TRV >2.8 m/s have significantly reduced survival.