A bulla in the lung is an air-filled sac or blister on the lung surface. These structures are typically larger than one centimeter in diameter, resulting from the destruction and enlargement of airspaces. While some bullae cause no issues, others can lead to significant health concerns, making it important to understand their potential danger.
Understanding Lung Bullae
Pulmonary bullae are gas-containing cystic structures within lung tissue. They have thin walls and form when tiny air sacs, called alveoli, are damaged and coalesce into larger, less efficient air pockets. This damage often occurs in emphysema, a type of chronic obstructive pulmonary disease (COPD), where air sac walls lose elasticity and break down. Over 80% of individuals with bullae also have emphysema.
Bullae vary considerably in size, ranging from one centimeter to as large as 20 centimeters in diameter. A bulla is considered “giant” if it occupies at least one-third of the volume of one side of the chest. Bullae are frequently associated with conditions like emphysema, pulmonary fibrosis, or certain genetic disorders such as Marfan syndrome and Ehlers-Danlos syndrome. They are often found in the upper lobes of the lungs, just beneath the outer lining.
Potential Health Complications
The presence of lung bullae can lead to several health complications, with danger often depending on their size, number, and location. One significant risk is a pneumothorax, commonly known as a collapsed lung. This occurs if a bulla ruptures, allowing air to leak into the space between the lung and chest wall, causing the lung to partially or fully collapse. A large or tension pneumothorax can be a medical emergency, as trapped air can put pressure on the heart and other organs.
Large bullae can also compress healthy lung tissue, leading to reduced lung function and difficulty breathing. As they expand, bullae take up space in the chest cavity, diminishing room for the healthy lung to expand properly during breathing. This can result in symptoms such as shortness of breath, chest pressure, and fatigue.
Another potential complication is infection within the bulla itself. As bullae are air-filled sacs, they can sometimes fill with fluid, creating an environment susceptible to bacterial growth. Bleeding (hemorrhage) into a bulla can also occur.
Diagnosis and Monitoring
Identifying lung bullae typically involves medical imaging. A chest X-ray can reveal large air pockets within the lungs. For a more detailed assessment, a computed tomography (CT) scan is often used. CT scans provide clearer images, allowing healthcare providers to determine the exact location, number, and size of the bullae.
Symptoms such as sudden chest pain or worsening shortness of breath may prompt a medical investigation. Pulmonary function tests, which measure how well the lungs exchange air, help assess the impact of bullae on lung function. For individuals diagnosed with bullae, especially those that are large or causing symptoms, regular monitoring is important. This helps track any changes in size or the development of complications.
Treatment Approaches
For many individuals, small bullae that do not cause symptoms may not require active treatment beyond watchful waiting. Managing underlying lung conditions, such as emphysema, remains important. Lifestyle adjustments, like smoking cessation, are important for preventing further lung damage.
When bullae lead to significant symptoms or complications, medical interventions become necessary. Oxygen therapy may be prescribed if blood oxygen levels are low to improve breathing. Medications such as bronchodilators can also be used to open airways and relieve shortness of breath.
In some cases, surgical intervention, known as a bullectomy, is considered. This procedure involves removing the bulla from the lung. A bullectomy is typically recommended for individuals experiencing severe breathing difficulties due to a giant bulla, recurrent pneumothorax, persistent lung infections, or significant pain. The surgery aims to improve airflow and allow the remaining healthy lung tissue to expand more effectively.