Certified Pediatric Emergency Nurse (CPEN) Practice Exam 2025 – All-in-One Guide to Master Your Certification!

A pneumothorax is defined as the presence of air in the pleural space, which is the area between the lung and the chest wall. This condition can lead to lung collapse because the air in the pleural space disrupts the negative pressure that is essential for lung expansion during breathing. When air accumulates in this space, it can compress the lung and impede normal respiratory function.

This definition differentiates pneumothorax from other conditions such as hemothorax, where blood collects in the pleural space, or pleural effusion, which is characterized by fluid accumulation, typically due to infection or other underlying issues. Inflammation of lung tissue does not pertain directly to the concept of pneumothorax either, as it refers to conditions like pneumonia rather than the presence of air in the pleural space. Understanding these distinctions is critical in pediatric care and emergency situations where rapid assessment of respiratory issues is vital.