What is lung consolidation?
Consolidation of the lung is simply a “solidification” of the lung tissue due to accumulation of solid and liquid material in the air spaces that would have normally been filled by gas. It is also known as pulmonary consolidation. The most common cause of consolidation is pneumonia – inflammation of the lung – as cellular debris, blood cells and exudate collects in the alveoli (air sacs) of the lung.
Consolidation may be patchy in distribution and involve only certain lobules of the lung although it can be widespread and affect entire lobes of the lung. It may be complete or incomplete. Although the term ‘consolidation’ is often used loosely and associated with pneumonia, it can also occur for various other reasons. Accumulation of pus, edema and even collapse of the lung (atelectasis) may also result in consolidation. The collection of solids and fluid is not isolated to the air spaces and the surrounding lung parenchyma may also be edematous. This affects the lung’s capacity to expand and allow for gas exchange between the air spaces and blood vessels in the lung tissue.
Signs and Symptoms of Consolidation
Some of the more prominent symptoms may be due to the disease process itself. Patients will also report shortness of breath/difficulty breathing (dyspnea) which is dependent on the extent of consolidation, noisy breathing and other abnormal breathing sounds. Pallor or cyanosis may also be present as well as coughing.
Physical examination :
- Percussion : dull note
- Palpation : tactile fremitus
- Vocal resonance (‘ninety nine’, ‘one one one’) : numbers clearly audible, whispering pectoriloquy
- Abnormal breathing sounds : bronchial breathing and egophony
- Pleural friction rub
- Unilateral reduction in chest expansion
Radiological features (x-ray) :
- Opacity of the affected area, lobule or lobe
- Loss of clarity of the heart border, diaphragm and or verterbal bodies (thoracic vertebrae)
- Patchy consolidation may be seen with bronchopenumonia while confluent consolidation seen in lobar pneumonia.
- Cavitation, bulging interlobular fissures and pleural effusion may also be evident.
Causes of Lung Consolidation
Pneumonia (lobar pneumonia and bronchopnemonia) is the most common cause of pulmonary consolidation. Although pneumonia may be due to a host of causes, consolidation is often seen with infectious pneumonia in the middle to late stages. The radiographic features may vary depending on the type of pathogen responsible for the infection. Read more on pneumonia types and causes.
Pulmonary consolidation may also be seen with non-infectious pneumonia, like aspiration pneumonia, where foreign material (solid, liquid or gas) enters the lung spaces and damages the parenchyma. Most other causes of consolidation may first lead to pneumonia which then results in consolidation.
Other cause of lung consolidation may include :
- Atelectasis (collapsed lung)
- Infections (lung)
- Aspergillosis (invasive/infection or allergic)
- Hydatid cyst
- Pulmonary edema (fluid in lungs)
- Tumors of the lung