American Board of Internal Medicine (ABIM) Certification Practice Exam

Which symptom indicates the need for immediate radiation therapy in superior vena cava syndrome?

1. Weight loss

2. Stridor

3. Persistent cough

4. Fatigue

The correct answer is: Stridor

The symptom that indicates the need for immediate radiation therapy in superior vena cava syndrome is stridor. Stridor is a high-pitched, wheezing sound caused by disrupted airflow, typically indicating that the airway is obstructed. In the context of superior vena cava syndrome, this obstruction can occur due to compression of the superior vena cava (SVC) by tumors or enlarged lymph nodes. When stridor is present, it signifies significant compromise of the airway and can lead to acute respiratory distress, making it a medical emergency. Immediate intervention, such as radiation therapy, may be warranted to reduce the tumor burden and alleviate the compressive effect on the SVC and potentially on the trachea as well. Other symptoms like weight loss, persistent cough, and fatigue can be associated with malignancies or chronic illnesses but do not typically signal the immediate need for intervention as strongly as stridor does. Weight loss may indicate a chronic process, persistent cough could suggest irritation or infection, and fatigue often results from a range of conditions. While they are important clinical features, they don’t reflect the acute and potentially life-threatening nature of stridor.