Pneumo- is the Greek root for “air.” This chapter concerns the presence of air in two separate anatomic compartments in the chest. Pneumothorax is defined as air in the pleural space and is extremely common. Pneumomediastinum is defined as air in the mediastinum and is quite rare. Despite their differences, the principles used to treat these two conditions are similar. Successful management requires a thorough understanding of the thoracic anatomy and pathophysiologic mechanisms that cause these conditions. Pneumothorax may signal a life-threatening condition, and pneumomediastinum may be a sign of an innocuous problem that requires no treatment. This chapter provides an overview of the incidence, causes, pathophysiology, symptoms, radiologic signs, diagnostic evaluation, and most important, techniques for treatment of both pneumothorax and pneumomediastinum.
Pneumothorax is a collection of air or gas in the pleural space. It is classified into three subtypes: spontaneous, traumatic, and iatrogenic pneumothorax (Table 108-1). A spontaneous pneumothorax is a collection of air or gas in the chest that causes the lung to collapse. It can be further classified as primary (i.e., collapse of lung for no apparent reason) or secondary (i.e., collapse of the lung secondary to underlying pulmonary pathology), as detailed in Table 108-2. The incidence of all types of pneumothoraces is greater in men than in women. For primary pneumothorax, the incidence is 7.4 per 100,000 population per year in men and 1.2 per 100,000 in women. Similarly, the incidence of secondary pneumothorax is 6.3 per 100,000 population per year in men and 2.0 per 100,000 in women. More specifically, the incidence is greatest in tall, thin young males younger than the age of 30 years.1
Table 108-1. Types of Pneumothoraces |Favorite Table|Download (.pdf)
Table 108-1. Types of Pneumothoraces
Primary—no clinical lung disease
Secondary—complication of lung disease
Penetrating chest injury
Blunt chest injury
Transthoracic needle aspiration
Subclavian vein catheter placement
Table 108-2. Causes of Secondary Spontaneous Pneumothorax |Favorite Table|Download (.pdf)
Table 108-2. Causes of Secondary Spontaneous Pneumothorax
Disease of airway
Chronic obstructive pulmonary disease
Parenchymal lung infection
Pneumocystis carinii pneumonia
Interstitial lung diseases
Connective tissue disease
Idiopathic interstitial lung disease
A tension pneumothorax occurs as a result of a pulmonary parenchymal or bronchial injury that acts as a one-way valve, permitting air to enter the pleural space but not escape. This causes a decrease in venous return and leads to hemodynamic compromise owing to low preload. Iatrogenic pneumothorax occurs as a consequence of inadvertent puncture of the lung during an invasive procedure.
The lung has an inherent tendency to collapse and the chest wall to expand. Hence the pressure ...