Atelectasis (Compressive)

Atelectasis (Compressive) is a condition where part of the lung collapses due to pressure from outside the lung tissue. This pressure can come from fluid, air, or a mass in the chest cavity pressing on the lung. It affects the respiratory system by reducing the amount of air that can enter the affected lung area, leading to difficulty breathing and decreased oxygen delivery to the body. The collapse prevents normal lung expansion, which can cause shortness of breath, chest discomfort, and sometimes coughing. This condition can occur after surgery, trauma, or due to diseases that cause fluid buildup in the chest. The severity depends on how much lung tissue is compressed and how quickly the pressure develops.

Atelectasis (Compressive) is defined as the collapse of lung tissue resulting from external pressure on the lung parenchyma, leading to alveolar collapse and impaired gas exchange. The core pathology involves mechanical compression by pleural effusion, pneumothorax, tumor, or enlarged lymph nodes, which prevents alveolar expansion. This form of atelectasis differs from obstructive atelectasis, where airway blockage causes collapse. It is clinically significant because it reduces effective lung volume, causing hypoxemia and increased work of breathing. Common causes include pleural effusion, pneumothorax, and mediastinal masses. The condition can lead to complications such as infection or respiratory failure if untreated. Recognition and differentiation from other types of atelectasis are essential for appropriate management.