From the Guidelines
Atelectasis is a condition where part of the lung collapses or becomes airless due to blockage of the airways or pressure on the lung, and it is a significant cause of morbidity and mortality, particularly in patients undergoing surgery or with underlying respiratory disease. It occurs when the tiny air sacs (alveoli) in the lungs deflate or fill with fluid, preventing normal oxygen exchange. Common causes include mucus plugs, foreign objects, tumors blocking airways, chest injuries, or prolonged bed rest, especially after surgery. Symptoms may include shortness of breath, cough, chest pain, and low oxygen levels, though some cases produce no symptoms.
Causes and Risk Factors
The causes of atelectasis can be categorized into obstructive and non-obstructive types. Obstructive atelectasis occurs when there is a blockage in the airways, such as a mucus plug or a foreign object, while non-obstructive atelectasis is caused by factors such as chest injuries, prolonged bed rest, or underlying lung disease.
Treatment and Prevention
Treatment depends on the cause and severity but typically includes addressing the underlying issue, deep breathing exercises, incentive spirometry, chest physiotherapy, bronchoscopy to remove blockages, or supplemental oxygen. The use of noninvasive positive pressure ventilation (NIPPV) or continuous positive airway pressure (CPAP) has been shown to be effective in preventing postoperative pulmonary complications, including atelectasis, in high-risk patients 1. Prevention strategies include early mobilization after surgery, deep breathing exercises, avoiding smoking, and proper treatment of respiratory infections.
Clinical Significance
Atelectasis can lead to pneumonia or respiratory failure if left untreated, and it is a significant contributor to morbidity, mortality, and length of stay in hospitalized patients. The condition occurs because without regular inflation, the surfactant that keeps air sacs open breaks down, causing collapse and potentially creating a cycle of worsening atelectasis. Therefore, early recognition and treatment of atelectasis are crucial to prevent long-term complications and improve patient outcomes.
Some key points to consider in the management of atelectasis include:
- Early mobilization and deep breathing exercises to prevent atelectasis
- Use of NIPPV or CPAP in high-risk patients to prevent postoperative pulmonary complications
- Bronchoscopy to remove blockages or secretions
- Supplemental oxygen to improve oxygenation
- Chest physiotherapy to help clear secretions and improve lung expansion
- Avoiding smoking and proper treatment of respiratory infections to prevent atelectasis.
From the Research
Definition of Atelectasis
- Atelectasis is a state of collapsed and non-aerated region of the lung parenchyma, which is otherwise normal 2.
- This pathological condition is usually associated with several pulmonary and chest disorders and represents a manifestation of the underlying disease, not a disease per se.
Causes of Atelectasis
- Atelectasis may occur in three ways:
- airway obstruction
- compression of parenchyma by extrathoracic, intrathoracic, chest wall processes
- increased surface tension in alveoli and bronchioli 2.
- Atelectasis can also be caused by resorption of alveolar air distal to obstructing lesions of the airways, surfactant deficiency, simple pneumothorax, diaphragmatic dysfunction, or hypoventilation 3.
Diagnosis of Atelectasis
- Chest radiographs using both the anterior-posterior and lateral projections are mandatory to document the presence of atelectasis 2.
- Lung sonography (LUS) can be used to assess lung recruitment maneuvers and detect lung collapse 4.
- Direct signs of atelectasis include crowded pulmonary vessels, crowded air bronchograms, and displacement of the interlobar fissures 3.
- Indirect signs of atelectasis include pulmonary opacification, elevation of the diaphragm, shift of the trachea, heart, and mediastinum, displacement of the hilus, compensatory hyperexpansion of the surrounding lung, approximation of the ribs, and shifting granulomas 3.
Treatment of Atelectasis
- The treatment of atelectasis varies depending on duration and severity of the causal disease from chest physiotherapy to postural drainage, bronchodilator and anti-inflammatory therapy 2.
- Persistent mucous plugs should be removed by bronchoscopy 2.
- Avoiding high fractions of oxygen in inspired gas during induction and maintenance of anaesthesia may prevent formation of atelectasis 5.
- Intermittent "vital capacity"-manoeuvres together with PEEP reduces the amount of atelectasis and pulmonary shunt 5.