American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the primary management approach for a primary spontaneous pneumothorax that measures less than 2 cm on a chest radiograph?

1. Observation alone

2. Needle aspiration

3. Emergent needle decompression

4. Thoracostomy tube insertion

The correct answer is: Observation alone

The primary management approach for a primary spontaneous pneumothorax (PSP) that measures less than 2 cm on a chest radiograph is observation alone. This recommendation is based on the understanding that small pneumothoraxes, particularly those measuring less than 2 cm, often resolve spontaneously without intervention. In cases of small pneumothoraces, the body can typically reabsorb the air in the pleural space over time, leading to resolution of the condition. The patient is usually advised to avoid high-risk activities, such as flying or scuba diving, which could exacerbate the situation. Follow-up care often includes monitoring the patient's symptoms and a follow-up chest radiograph to ensure that the pneumothorax is not enlarging. In contrast, more invasive interventions like needle aspiration or tube thoracostomy are generally reserved for larger or more symptomatic pneumothoraxes. Emergent needle decompression is specifically indicated in cases of tension pneumothorax, where immediate relief of pleural pressure is necessary, but this is not relevant for small, uncomplicated pneumothoraxes. Therefore, observation alone is an appropriate and effective management strategy for a primary spontaneous pneumothorax of this size.