Lung atelectasis: what is it, causes, symptoms, treatment, prognosis

What is atelectasis?

Atelectasis - This is a collapse or collapse of the lung, leading to a decrease in gas exchange or its absence. It is usually a unilateral disease that affects part or all of one lung. Atelectasis is a condition in which the alveoli are deflated to little or no volume, as opposed to pulmonary compaction, in which they are filled with fluid. He is often called collapse of the lungalthough this term can also refer to pneumothorax.

The condition is very often found on chest x-rays and other radiological examinations and can be caused by a variety of common conditions and diseases. Although atelectasis is often described as a collapse of the lung tissue, it is not synonymous with pneumothorax, which is a more specific condition characterized by atelectasis. Acute atelectasis can occur as a postoperative complication or as a result of surfactant deficiency. Have premature babies this leads to respiratory distress syndrome.

The term uses a combination of forms atel– + ectaz from Greek: ἀτελής, "incomplete" + ἔκτασις, "stretching".

Signs and symptoms

Signs and symptoms may be absent or include:

• cough, but not noticeable;
• chest pain (infrequently);
• labored breathing (frequent and superficial);
• low oxygen saturation;
• pleural effusion (transudative type);
• cyanosis (late sign);
• increased heart rate.

It is a common misconception and pure assumption that atelectasis causes fever. Study of 100 postoperative patients followed by serial chest x-rays cells and temperature measurements showed that the incidence of fever decreased as the incidence atelectasis. In a recent review article summarizing the available published data on the association between atelectasis and postoperative fever, it was concluded that there is no clinical data to support this assumption.

Causes and risk factors

The most common cause is postoperative atelectasis, characterized by splinting, that is, breathing restriction after abdominal surgery.

Another common reason is pulmonary tuberculosis. Smokers and the elderly are also at increased risk. Outside of this context, atelectasis implies some blockage of the bronchiole or bronchus that may be inside the airways. (foreign body, mucous plug), from the wall (tumor, usually squamous cell carcinoma) or external compression (tumor, lymph node, tubercle). Another reason is poor distribution of surfactant (surfactant) during inhalation, causing surface tension that tends to collapse of the smaller alveoli. Atelectasis can also occur during airway debridement, as air is removed from the lungs along with sputum. There are several types of atelectasis, depending on the underlying mechanisms or the spread of alveolar collapse; resorption (obstructive), compression, microatelectasis and contraction atelectasis. Relaxing atelectasis (also known as passive atelectasis) is when pleural effusion or pneumothorax disrupts contact between the parietal and visceral pleura.

Risk factors associated with an increased likelihood of developing the disorder include:

• type of surgery (thoracic, cardiopulmonary surgery);
• the use of muscle relaxants;
• obesity;
• high oxygen levels.

Factors not associated with the development of atelectasis include:

• age;
• the presence of chronic obstructive pulmonary disease (COPD) or asthma;
• type of anesthetic.

Diagnostics

Clinically significant atelectasis is usually seen on a chest x-ray; results may include lung opacity and / or loss of lung volume. Postoperative atelectasis will be bibasal. If the cause of atelectasis is not clinically apparent, a chest CT scan or bronchoscopy may be required. Direct signs of atelectasis include displacement of interlobar fissures and movable structures within the chest, excessive swelling of the unaffected ipsilateral lobe or contralateral lung and clouding of the collapsed share.

Classification

Atelectasis can be acute or chronic. In acute atelectasis, the lung has recently collapsed and is primarily characterized by the lack of air. In chronic atelectasis, the affected area is often characterized by a complex mixture of lack of air, infection, bronchodilation (bronchiectasis), destruction and scarring (fibrosis of the lung).

Absorption (resorption) atelectasis.

The Earth's atmosphere is mainly composed of 78 vol. % nitrogen and 21 vol. % oxygen (+ 1 vol.% argon and traces of other gases). Since oxygen is exchanged at the alveolocapillary membrane, nitrogen is the main component of the inflated state of the alveoli. If a large volume of nitrogen in the lungs is replaced by oxygen, the oxygen can subsequently be absorbed into blood, reducing the volume of the alveoli, leading to a form of alveolar collapse known as absorption atelectasis.

- Compression (relaxing) atelectasis.

Usually the condition is associated with the accumulation of blood, fluid or air in the pleural cavity, as a result of which the lung is mechanically destroyed. This is common in pleural effusion due to congestive heart failure (ZSN). Air leakage into the pleural cavity (pneumothorax) also leads to compression atelectasis.

- Cicatricial (contraction) atelectasis.

It occurs when localized or generalized fibrotic changes in the lungs or pleura prevent expansion and increase the elastic response during exhalation. Causes include granulomatous disease, necrotizing pneumonia, and radiation fibrosis.

Chronic atelectasis.

Chronic atelectasis can take one of two forms - middle lobe syndrome or rounded atelectasis.

- Syndrome of the right middle lobe.

In right middle lobe syndrome, the middle lobe of the right lung is compressed, usually due to pressure on the bronchus from enlarged lymph nodes and sometimes a tumor. A blocked, compressed lung may develop pneumoniawhich does not go away completely and leads to chronic inflammation, scarring and bronchiectasis.

- Spotted atelectasis.

It occurs due to a lack of a surfactant, as occurs with a disease of the hyaline membrane in newborns or with acute (adult) respiratory distress syndrome (ARDS).

- Rounded atelectasis.

In rounded atelectasis (folded lung syndrome or Blesovsky syndrome), the outer part of the lung slowly collapses as a result scarring and compression of the membrane layers covering the lungs (pleura), which manifests itself in the form of thickening of the visceral pleura and entrapment of the pulmonary fabrics. This gives a rounded look on the X-ray that doctors might mistake for a tumor. Rounded atelectasis is usually a complication of asbestosis(asbestos-related pleural disease), but it can also result from other types of chronic scarring and thickening of the pleura.

Treatment

Treatment is aimed at addressing the underlying cause. Postoperative atelectasis is treated with physiotherapy aimed at breathing deeply and encouraging coughing. A stimulus spirometer is often used as part of breathing exercises. Walking is also highly recommended to improve lung inflation. Patients with chest deformities or neurological conditions causing superficial breathing for a long time, mechanical devices may be helpful to help breathe. One method is continuous positive airway pressure, which is delivered with compressed air or oxygen through the nose or face mask to ensure that the alveoli do not collapse even at the end inhalation. The procedure is useful because partially swollen alveoli can expand more easily than collapsed alveoli. Sometimes additional respiratory support with a ventilator is required.

The primary treatment for acute massive atelectasis is to eliminate the underlying cause. A blockage that cannot be cleared by coughing or suctioning from the airways can often be removed with bronchoscopy. In case of infection, antibacterial drugs are prescribed. Chronic atelectasis is often treated with antibiotics because infection is almost inevitable. In some cases, the affected portion of the lung can be surgically removed when recurrent or chronic infections become disabling or cause significant bleeding. If the tumor is blocking the airway, removing the obstruction with surgery, radiation therapy, chemotherapy or laser therapy can prevent the progression of the disease and the development of recurrent obstructive pneumonia.

Forecast

After the cause of atelectasis is eliminated, most patients recover quickly and do not have serious long-term consequences. Patients with long-term (chronic) disease causing atelectasis may require further treatment if the condition returns.

Prophylaxis

Smokers can reduce the risk of postoperative atelectasis by stopping smoking if possible 6-8 weeks before surgery. After surgery, patients are encouraged to breathe deeply, cough regularly, and start moving as early as possible. In the prevention of atelectasis, the use of devices that stimulate voluntary deep breathing (stimulating spirometry), and performing certain exercises, including changing the position of the body to increase the evacuation of mucus and other discharge.

The prevention of atelectasis is also achieved by deep breathing. If possible, conditions that cause shallow breathing for a long time should be treated.