Pneumothorax

Pneumothorax - the presence of air in the pleural cavity, which leads to partial or complete collapse of the lung. It can develop spontaneously or against the background of existing lung diseases, injuries or medical procedures. It is a sign of violation of lung hermetism, which can occur when bulls and cysts are ruptured with bullous emphysema, tearing with adhesive pleurodesis, stump failure after resection, chest trauma due to rupture (with closed chest trauma) or injury (with penetrating chest injuries), damage or detachment of the bronchus.

Pneumothorax can be in pure form, when there is only accumulation of air, and in combination with exudates, for example, hemopneumothorax. Diagnosis of pneumothorax is based on data from physical examination and radiography of chest organs. Most pneumothorax requires aspiration or drainage of the pleural cavity.

Intrapleural pressure is normally negative (less than atmospheric pressure); this provides an independent expansion of the lung with the expansion of the thorax. In pneumothorax, air enters the pleural cavity through a damaged thoracic wall or lumen of the mediastinal organs. As a result, intrapleural pressure rises, which leads to a restriction of lung dilatation.

[1], [2]

Causes of pneumothorax

By the volume of collapse of the lung, pneumothorax can be small (up to 25%), medium (50-75%), total (100%) and tight, when there is a displacement of the mediastinum. According to the type of air flow into the pleural cavity and its movement in it are distinguished:

• closed pneumothorax with the entry of air from the bronchus into the pleural cavity during inspiration (most favorable, but in the presence of bronchial inflammation the pleural cavity can become infected);
• open pneumothorax, when there is a sufficient communication of the pleural cavity with the surface of the thorax and air entering it through the wound during exhalation (it is dangerous only for infection);
• Valve pneumothorax, when air from the bronchus enters the pleural cavity during inspiration, and during exhalation a piece of lung or scraps of bulla cover the hole in the bronchus and prevent air from exiting the bronchial tree, with more inhalation collapsing (the most dangerous form, since rapidly compresses the lung with a shift in the mediastinum and the development of pulmonary heart failure). More often pneumothorax one-sided, but can be and bilateral.

Hemopneumothorax and pyopneumothorax should be classified as pneumothorax, which is accompanied by the development of severe cardio-pulmonary syndrome, a clinic resembling myocardial infarction, and respiratory failure. Piopnevmotorax develops when the abscess breaks out of the mild insufficiency of the bronchus stump after resection of the lung, the formation of a bronchopleural fistula. With it, in addition to accumulation of pus, the collapse of the lung is provided by the intake of air. Piopneumomotorax, especially in young children, must be differentiated from diaphragmatic hernia (the phenomenon of signs of intestinal obstruction), lobar emphysema (there is a displacement of the mediastinum with it). Adults should be aware of the possibility of a huge lung cyst, but with it there is no intoxication.

Primary spontaneous pneumothorax occurs in persons who do not suffer from lung disease, especially in tall, lean young people under the age of 20 years. This is believed to be due to the immediate rupture of subpleural apical vesicles or bulls due to smoking or hereditary factors. Usually pneumothorax develops at rest, although some cases develop with a load associated with trying to get or stretch various objects. Primary spontaneous pneumothorax can also develop during diving and flight at high altitudes due to uneven pressure changes in the lung.

Secondary spontaneous pneumothorax occurs in persons with lung diseases and is most often due to rupture of vesicles or bulls in patients with severe COPD (with a forced exhalation volume of 1 second <1 L), infection of Pneumocystis jiroveci (formerly called P. Carinii) in patients with HIV infection , with cystic fibrosis or any other parenchymal lung diseases. Secondary spontaneous pneumothorax is usually more serious than primary spontaneous, as it occurs in older patients with a smaller compensatory reserve of lung and heart function.

Menstrual pneumothorax is a rare form of secondary spontaneous pneumothorax that develops within 48 hours of the onset of menstrual bleeding in premenopausal women and sometimes in postmenopausal women taking estrogen. The cause is intrathoracic endometriosis, possibly due to migration of the endometrium of the abdominal cavity through diaphragmatic defects or as a result of embolization of pelvic veins. When menstruation in the pleura, a defect is formed, as the endometrium is rejected.

Traumatic pneumothorax is a frequent complication of blunt and penetrating chest injuries.

[3], [4], [5], [6],

Causes of spontaneous pneumothorax

Primary

The rupture of subpleural bulls due to smoking

Secondary

More often

• Bronchial asthma
• COPD
• Cystic Fibrosis
• Necrotizing pneumonia
• The infection of Pneumocystis jiroveci (formerly called P. Carinii)
• Tuberculosis

Less often

• Diseases of the lungs
  • Idiopathic pulmonary fibrosis
  • Granulomatosis from Langerhans cells
  • Lung cancer
  • Lymphangioleiomyomatosis
  • Sarcoidosis
• Diseases of connective tissue
  • Ankylosing spondylitis
  • Ehlers-Danlos Syndrome
  • Marfan syndrome
  • Poliomyositis / dermatomyositis
  • Rematoitic arthritis
  • Sarcoma
  • Systemic sclerosis
  • Endometriosis of the thoracic cavity
  • Tuberous sclerosis

Tense pneumothorax is a pneumothorax that causes a progressive increase in intrapleural pressure to exceed atmospheric pressure throughout the entire respiratory cycle, leading to lung collapsing, displacement of the mediastinum, and deterioration of the venous influx to the heart. The air continues to flow into the pleural cavity, but can not exit from there. Without adequate treatment, a reduced venous influx can cause systemic hypotension and respiratory and cardiac arrest for several minutes. This condition usually occurs in patients who are on artificial ventilation with positive exhalation pressure (especially during resuscitation). In rare cases, it is a complication of traumatic pneumothorax, where the wound of the chest wall acts as a one-way valve that allows more and more air to flow into the pleural cavity when inhaled, which can not then go back.

Iatrogenic pneumothorax is caused by medical interventions, including transthoracic needle aspiration, pleurocentesis, central venous catheter installation, artificial lung ventilation and cardiopulmonary resuscitation.

[7], [8]

Symptoms of pneumothorax

The clinical picture depends on the degree of collapse of the lung, but rather pronounced: chest pain is moderate, constant, the connection with breathing and coughing is not very pronounced. Rapid breathing develops, when there is more than 25% of the collapse, dyspnea, cyanosis of the face, lips.

The thorax lags behind in the act of breathing on the side of the pneumothorax, the intercostal spaces swell, especially with deep inspiration and coughing; with intense pneumothorax - swollen.

Percutaneously: when a collapse of up to 25% of the volume - bright tympanitis; at large volumes - boxed sound. Auscultatory: when there is a collapse of up to 25% of the volume, sharply reduced breathing; at large volumes - "mute" lung. With intense pneumothorax, pronounced pulmonary heart failure with changes on the ECG, like myocardial infarction.

Non-traumatic pneumothorax are sometimes asymptomatic. In other cases, such symptoms of pneumothorax develop as: dyspnea, pleural pain in the chest and anxiety. Dyspnea may develop suddenly or gradually, depending on the rate of development and the volume of pneumothorax. Pain can simulate myocardial ischemia, lesion of the musculoskeletal system (with irradiation in the shoulder) or abdominal cavity pathology (with irradiation in the abdomen).

Classical physical changes are the absence of vocal tremor, increased percussion sounds and weakening of respiration on the side of pneumothorax. With significant pneumothorax, the affected side can be enlarged, the trachea - markedly shifted in the opposite direction.

Complications of pneumothorax

The three main problems encountered in the treatment of pneumothorax are air sucking into the pleural cavity, inability to achieve lung expansion and recurrent pulmonary edema.

The air is sucked into the pleural cavity, usually through a primary defect, but can be carried out through the place of installation of pleural drainage, if this wound is not properly sealed and not sealed. It is more common in secondary than in primary spontaneous pneumothorax. Most cases are resolved spontaneously within less than 1 week.

The impossibility of re-spreading the lung usually occurs due to persistent airflow into the pleural cavity, endobronchial obstruction, carapaceous lung, or improper placement of pleural drainage. If the flow of air into the pleural cavity or incomplete expansion is maintained for more than 1 week, thoracoscopy or thoracotomy is necessary.

Lung edema occurs as a result of its overstretch and rapid expansion after trying to create a negative pressure in the pleural cavity after a lung stay in the collapsed state for more than 2 days. Effective oxygen therapy, use of diuretics, supportive therapy of lung and heart functions.

[9], [10], [11], [12], [13], [14], [15],

Diagnosis of pneumothorax

The diagnosis of "pneumothorax" is established on the basis of radiography of chest organs on inhalation in the vertical position of the patient, when an accumulation of X-ray air and the absence of lung tissue in the space between the collapsed whole lung or its lobe and parietal pleura is revealed. With large pneumothorax, displacement of the trachea and mediastinum is also visualized.

The size of pneumothorax is defined as the percentage of the volume of half of the chest occupied by air, and is calculated as 1 - the ratio of the width of the lung, raised to the third degree, and the width of the affected half of the chest, also raised to the third power. For example, if the width of one half of the chest is 10 cm and the width of the lung is 5 cm, the ratio of the cubes of these dimensions is 5/10 = 0.125. Thus, the size of pneumothorax corresponds to: 1 - 0,125 = 0,875 or 87,5%. The presence of adhesions between the lung and chest wall prevents symmetrical lung collapsing, as a result of pneumothorax may seem atypical or fragmented, which prevents calculations.

From instrumental studies, the most informative radiography of chest organs (establishing the presence of a condition such as pneumothorax and the degree of collapse of the lung); thoracoscopy to identify the cause (in the presence of technical means, a one-stage sealing of the lung is possible). To identify the sealing of the lung and the syndrome of lung compression, puncture of the pleural cavity is performed. Stressed pneumothorax is characterized by the fact that the air comes under pressure. If the fistula in the lung was sealed on its own - the air is removed with difficulty and the lung is straightened, which confirms the control radiograph.

Hemotorax and hemopneumothorax are accompanied by a clinic of exudative non-pleural pleurisy. Damage to the thoracic lymphatic duct is accompanied by the development of chylothorax, which manifests itself clinically as pleurisy, but when a pleural cavity is punctured, a fluid (similar to fat emulsion) is obtained.

The initial differential diagnosis of lesions is performed by chest radiographs. Pleural puncture with the laboratory examination of exudate is mandatory, a condition for differential diagnosis of the pathological process. The highest diagnostic effect is given by thoracoscopy.

The detection of small pneumothorax is sometimes difficult with chest radiography. To conditions that have identical radiographic signs, include emphysematous bullae, skin folds and the imposition of shadows of the stomach or intestine on the pulmonary fields.

[16], [17], [18], [19], [20], [21],

Treatment of pneumothorax

Dry pleurisy and non-exudative exudative small volumes are treated on an outpatient basis or in a therapeutic hospital. Exudative pleurisy of large volumes and purulent pleurisy, hemoplethritis and hemothorax, pneumothorax, including traumatic injuries, are the competence of thoracic surgeons, and the patient should be hospitalized in a specialized department.

Before carrying out chest X-ray, oxygen therapy is necessary; oxygen accelerates pleural air reabsorption. Treatment of pneumothorax depends on the type, size and clinical manifestations of pneumothorax. Primary spontaneous pneumothorax, having a size of less than 20% and not causing clinical manifestations on the part of the respiratory or cardiovascular system, can be safely resolved without treatment, if subsequent chest radiographs performed at approximately 6 and 48 hours show no progression. Significant or symptomatic primary spontaneous pneumothorax should be evacuated when draining the pleural cavity.

Drainage is done by inserting a needle for intravenous small-diameter injections or a ponytail catheter in the 2nd intercostal space along the mid-incision line. The catheter is connected to a three-way adapter and a syringe. The air is taken from the pleural cavity through the adapter into the syringe and removed. The process is repeated until the lung expands or until 4 liters of air are removed. If the lung is straightened, the catheter can be removed, but it is also possible to leave it after attaching a one-way Heimlich valve (which allows the patient to move). If the lung does not expand, drainage of the pleural cavity is necessary; in any case, patients are usually hospitalized for follow-up. With the primary spontaneous pneumothorax, the initial installation of pleural drainage connected to a container filled with water and possibly an aspirator device is possible. Patients who develop primary spontaneous pneumothorax should be informed of the need to stop smoking, since smoking is a major risk factor for this condition.

In secondary and traumatic pneumothoraxes, drainage of the pleural cavity is usually performed, although some cases of a small pneumothorax can be treated out-patient. With iatrogenic pneumothorax with the presence of clinical manifestations, aspiration is most optimal.

Tense pneumothorax is an emergency. Treatment of pneumothorax should begin immediately, by inserting a needle with a diameter of 14 or 16 gauge in the II intercostal space along the mid-incision line, which then connects to the catheter. The sound of the pressurized air confirms the diagnosis. The catheter can be left open or attached to the Heimlich valve. Emergency decompression should be completed by installing a thoracostomy tube, after which the catheter is removed.

How to prevent pneumothorax?

Relapses are observed within 3 years after the first spontaneous pneumothorax in about 50% of cases; pneumothorax is best prevented by the use of videothoracoscopic surgical intervention, during which suturing bullae, pleurodesis, parietal pleurectomy or the introduction of talc; in some medical centers, thoracotomy is still performed. These procedures are recommended in the absence of the effect of drainage of the pleural cavity with spontaneous pneumothorax, with recurrent pneumothorax or in patients with secondary spontaneous pneumothorax. The frequency of relapse after these procedures is less than 5%. If it is impossible to perform thoracoscopy, chemical pleurodesis is possible through the pleural drainage tube. This procedure, although significantly less invasive, reduces the relapse rate by only about 25%.