Atelectasis Clinical Presentation
- Author: Tarun Madappa, MD, MPH; Chief Editor: Zab Mosenifar, MD more...
History
Atelectasis may occur postoperatively following thoracic or upper abdominal procedures.
Although atelectasis is considered to be the most common cause of early postoperative fever, the existing evidence is contradictory; in a study by Mavros et al, they found no clinical evidence supporting the concept that atelectasis is associated with early postoperative fever.[5]
Most symptoms and signs are determined by the rapidity with which the bronchial occlusion occurs, the size of the lung area affected, and the presence or absence of complicating infection.
Rapid bronchial occlusion with a large area of lung collapse causes pain on the affected side, sudden onset of dyspnea, and cyanosis. Hypotension, tachycardia, fever, and shock may also occur.
Slowly developing atelectasis may be asymptomatic or may cause only minor symptoms. Middle lobe syndrome often is asymptomatic, although irritation in the right middle and right lower lobe bronchi may cause a severe, hacking, nonproductive cough.
Physical
The physical examination findings show dullness to percussion over the involved area and diminished or absent breath sounds. Chest excursion in the area is reduced or absent. The trachea and the heart are deviated toward the affected side.
Causes
The primary cause of acute or chronic atelectasis is bronchial obstruction by the following:
- Plugs of tenacious sputum
- Foreign bodies
- Endobronchial tumors
- Tumors, a lymph node, or an aneurysm compressing the bronchi and bronchial distortion
External pulmonary compression by pleural fluid or air (ie, pleural effusion, pneumothorax) may also cause atelectasis.
Abnormalities of surfactant production contribute to alveolar instability and may result in atelectasis. These abnormalities commonly occur with oxygen toxicity and ARDS.
Resorptive atelectasis is caused by the following:
- Bronchogenic carcinoma
- Bronchial obstruction from metastatic neoplasm (eg, adenocarcinoma of breast or thyroid, hypernephroma, melanoma)
- Inflammatory etiology (eg, tuberculosis, fungal infection)
- Aspirated foreign body
- Mucous plug
- Malpositioned endotracheal tube
- Extrinsic compression of an airway by neoplasm, lymphadenopathy, aortic aneurysm, or cardiac enlargement
Relaxation atelectasis is caused by the following:
- Pleural effusion
- Pneumothorax
- A large emphysematous bulla
Compression atelectasis is caused by the following:
- Chest wall, pleural, or intraparenchymal masses
- Loculated collections of pleural fluid
Adhesive atelectasis is caused by the following:
- Acute respiratory distress syndrome
- Smoke inhalation
- Cardiac bypass surgery
- Prolonged shallow breathing
Cicatrization atelectasis is caused by the following:
- Chronic tuberculosis
- Fungal infections
- Radiation fibrosis
Replacement atelectasis is caused by alveoli filled by tumor or fluid.
Right middle lobe syndrome (also known as Brock syndrome) refers to recurrent right middle lobe collapse secondary to airway disease, infection, or a combination of the two. The right middle lobe airway is long and thin and has the poorest drainage or clearance of all the lobes of the lung, resulting in trapped mucus. Individuals with middle lobe syndrome are often asymptomatic, although some present with recurrent productive cough and history of right-sided pneumonias.
Rounded atelectasis is caused by asbestos pleural plaques.
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