From the Research
Pneumomediastinum is primarily caused by air leaking into the mediastinum due to alveolar rupture and subsequent air dissection along bronchovascular sheaths, with the most common causes including trauma, iatrogenic injuries, and conditions that increase intrathoracic pressure, as supported by the most recent study 1. The etiology of pneumomediastinum can be attributed to various factors, including:
- Trauma, such as blunt chest injury or penetrating wounds
- Iatrogenic injuries, such as those occurring during mechanical ventilation, endoscopic procedures, or surgery
- Excessive coughing or vomiting, which can lead to a Valsalva maneuver
- Asthma exacerbations and other conditions that increase intrathoracic pressure
- Recreational drug use, particularly cocaine and marijuana inhalation
- Esophageal perforation, also known as Boerhaave syndrome, often resulting from forceful vomiting In some cases, pneumomediastinum can occur spontaneously without an obvious trigger, especially in young, thin males, as noted in the study 2. The underlying mechanism involves pressure gradients between alveoli and surrounding tissues, leading to alveolar rupture when intrathoracic pressure suddenly increases, allowing air to escape and follow the path of least resistance along fascial planes into the mediastinum, as described in the study 3. Most cases of pneumomediastinum are self-limiting and resolve with conservative management, though identifying and treating the underlying cause is essential, as emphasized in the study 4. It is worth noting that while other studies, such as 5, discuss asthma and COPD, they are not directly relevant to the etiology of pneumomediastinum. Therefore, the focus should be on the most recent and highest quality study, which is 1, to guide the understanding of pneumomediastinum's etiology.