- Abnormal permanent enlargement of distal air spaces with destruction of alveolar walls _ lung fibrosis. Overlaps with chronic bronchitis to form a disease spectrum known as chronic obstructive pulmonary disease.
- Due to an imbalance between lung proteases and anti-proteases.
- A bulla is an avascular low attenuation area that is larger than 1 cm and has a thin but perceptible wall.
- Associated with smoking but other chemicals and genetic disorders predispose to the condition (e.g. alpha-1 antitrypsin deficiency).
- Three types of emphysema
- Panacinar, centrilobular and paraseptal.
- The different types of emphysema may coexist.
- May be asymptomatic, early in the disease.
- Exacerbations commonly precipitated by infection.
- Cough, wheeze and exertional dyspnoea.
- Tachypnoea, wheeze, lip pursing (a form of PEEP), use of accessory muscles (patients are referred to as pink puffers).
- Signs of hypercarbia include coarse tremor, bounding pulse, peripheral vasodilatation, drowsiness, confusion or an obtunded patient.
- CXR – focal area of well-defined lucency outlined with a thin wall. A fluid level may indicate infection within the bulla.
- Other CXR features include hyperexpanded lungs with associated flattening of both hemi-diaphragms, ‘barrel-shaped chest’, coarse irregular lung markings (thickened dilated bronchi – chronic bronchitisoverlaps) and enlargement of the central pulmonary arteries in keeping with pulmonary arterial hypertension.
- REMEMBER to look for lung malignancy/nodules; a common association.
- CT quantifies the extent, type and location of emphysema. It may also identify occult malignancy.
- Post-infective pneumatoceles.
- Loculated pneumothorax.
- Oligaemia secondary to pulmonary emboli or hilar vascular compression.
- Emphysematous bullae form part of a spectrum of chronic obstructive pulmonary disease.
- Bullae in their own right usually need no active treatment. However, if severe disease, lung reduction surgery should be considered.