Valvular pneumothorax is the ingress and increasing increase in the volume of air in the pleural cavity due to the development of a valve mechanism that passes air from the environment or lung into the pleural cavity and prevents its exit in the opposite direction. Disease is characterized by sharp pain in the chest, subcutaneous emphysema, rapid shallow breathing, pallor of the skin with a cyanotic tinge, severe general condition. Diagnosis includes assessment of physical changes, lung radiography data, pleural puncture with measurement of intrapleural pressure. Emergency care consists in draining the pleural cavity for constant air aspiration. In the future, an operation is carried out aimed at eliminating the valve mechanism.
ICD 10
S27.0 J93
Meaning
Taking into account the presence of communication of the pleural cavity with the environment, it is customary to distinguish between open, closed and valvular (valve) pneumothorax. In pulmonology and thoracic surgery, valvular pneumothorax is regarded as the most formidable type of pathology, leading to a significant violation of external respiration and gas exchange in the lungs. With valvular pneumothorax, as a result of the formation of a valve mechanism in the wound canal, air enters the pleural cavity at the time of inhalation, and does not leave it at the time of exhalation, because the fistula opening closes. This leads to an increasing increase in the volume of gas in the pleural cavity with each subsequent inhalation, which is accompanied by a progressive deterioration of the patient’s condition.
Types of valvular pneumothorax
Depending on the mechanism of formation, there are internal and external valvular pneumothorax.
With internal valvular pneumothorax, as a rule, there is simultaneous damage to the large bronchus and a flap wound of the lung. Air enters the pleural cavity through a defect in the visceral pleura. The role of the valve is performed by a flap of lung tissue: on inhalation, it passes air into the pleural cavity, and on exhalation it blocks the way for gas to escape back into the lung.
The extreme degree of manifestation of a closed valvular pneumothorax is a tense pneumothorax. It is characterized by high air pressure in the pleural cavity, a sharp shift of the mediastinal organs to the healthy side, lung collapse, a rapid increase in subcutaneous emphysema, respiratory and cardiovascular complications.
An external valvular pneumothorax is spoken of if the wound canal through which air enters the lung communicates with the environment through a defect of the parietal pleura. In this case, the soft tissues of the damaged chest wall serve as a valve. At the moment of inhalation, the edges of the wound expand, air freely penetrates into the pleural cavity, and during exhalation, the wound opening subsides without releasing air back.
With valvular pneumothorax, a pathological symptom complex develops, causing the severity of the patient’s condition. As a result of an increase in intrapleural pressure (it becomes sharply positive), the damaged lung is squeezed and turned off from breathing; irritation of the nerve endings of the pleura joins this, which together ensures the development of pleuropulmonary shock. The displacement of the mediastinum in the opposite direction causes a violation of central hemodynamics, and lung collapse leads to acute respiratory failure.
Causes
Taking into account the etiological mechanisms, we can talk about wound (traumatic) and spontaneous valvular pneumothorax.
The causes of wound valvular pneumothorax, as a rule, are closed chest injuries with rupture of lung tissue or penetrating chest wounds, in which there is a rapid “gluing” of the wound opening on the chest wall with the continued gaping of the bronchial wound. Such injuries include rib fractures, knife and gunshot wounds to the chest, ruptures of the bronchi, perforation of the esophagus or bronchus by a foreign body, damage to the trachea during intubation, falling from a height, an accident, etc. Valvular pneumothorax of a traumatic nature is often combined with intrapleural bleeding – hemothorax.
With spontaneous valvular pneumothorax, there is a rupture of the altered portion of the lung tissue. Pathological processes contributing to the development of valvular pneumothorax may include tuberculosis, lung abscess, pulmonary bullous emphysema, pneumoconiosis, cystic fibrosis, spontaneous rupture of the esophagus, etc. Cough, physical exertion, diving, playing wind instruments, etc. predispose to the development of spontaneous valvular pneumothorax.
Symptoms
The causes and complex of functional disorders determine the nature and severity of the manifestation of valvular pneumothorax. Usually, the patient’s condition with valvular pneumothorax is assessed as extremely severe. There is an excitement of the patient; pronounced pain in the chest of a dagger or stabbing nature, which radiates into the shoulder, shoulder blade, abdominal cavity. Shortness of breath, cyanosis, weakness are rapidly progressing, loss of consciousness may occur.
With a strained valvular pneumothorax, swelling of the cervical veins and veins of the upper extremities, expansion of intercostal spaces, an increase in the affected side of the chest in volume is noted. Tachycardia, arterial hypotension, rapid shallow breathing are characteristic.
Through interstitial spaces, through the fiber of the lung root, air enters the mediastinum, exits into the subcutaneous tissue of the face, neck, intermuscular spaces of the abdomen, extremities – pneumomediastinum and subcutaneous emphysema develop. The typical appearance of a patient with subcutaneous emphysema is characterized by a moon-shaped face, an increase in the volume of parts of the trunk, subcutaneous crepitation, nasal speech.
Rapid and significant accumulation of air in the pleural cavity can cause pulmonary or heart failure and death. Late complications of valvular pneumothorax include reactive pleurisy and pleural empyema.
Diagnostics
For valvular pneumothorax, a triad of physical symptoms is pathognomonic: weakening of breathing, tympanic sound and absence of vocal tremor. Examination reveals a lag of the affected side of the chest during breathing, smoothness of intercostal spaces, subcutaneous emphysema. Lung x-ray with valvular pneumothorax indicates a decline of the lung, a shift of the mediastinal shadow to the healthy side. With pleurisy, the horizontal level of fluid in the pleural cavity is determined.
The diagnostic pleural puncture with manometry allows differentiating between closed, open and valvular pneumothorax. With a closed pneumothorax, the value of intrapleural pressure is stable, slightly negative (-3-1 cm of water). With an open pneumothorax, there is a fluctuation in the indicators of intrapleural pressure in the region of zero (-1 to +1 cm of water). The valvular pneumothorax is indicated by a sharply positive pressure in the pleural cavity with a tendency to increase.
In the presence of fluid, aspiration and subsequent examination of pleural effusion for microflora and cellular composition are performed. The study of arterial blood gases, KOS is shown. In order to determine the localization and size of the pleural fistula, diagnostic thoracoscopy and pleuroscopy are performed.
Treatment
The first task in valvular pneumothorax is urgent decompression of the lung and mediastinum. For this purpose, discharge puncture or transthoracic drainage of the pleural cavity is performed with the imposition of passive drainage by Bulau. Only then can the patient be transported to the hospital for further treatment. In order to stabilize the patient’s condition, narcotic and non-narcotic analgesics, cardiovascular agents are administered, oxygen inhalation is adjusted, antitussive drugs and antibiotics are prescribed.
The most important task of treatment is the transfer of the valvular pneumothorax to the closed one. For this purpose, constant drainage of the pleural cavity is carried out. The cessation of air intake through the drainage indicates the sealing of the pleural cavity. Drainage removal from the pleural cavity is performed 1-2 days after the complete expansion of the lung, confirmed radiologically.
If the expansion of the lung cannot be achieved by means of minor surgery, surgical treatment of valvular pneumothorax is performed. If the chest wall is damaged, thoracotomy and suturing of the wound defect are performed. With the threat of recurrence of spontaneous valvular pneumothorax, surgical treatment of the underlying disease is required. At the same time, depending on the pathology, marginal lung resection, segmentectomy, lobectomy, bilobectomy, pleurectomy with lung decortication, bull electrocoagulation, pleurodesis, and other interventions can be performed.
Prognosis and prevention
Complications of valvular pneumothorax affecting the outcome of the disease may include shock lung syndrome, the development of bronchopleural fistulas, pyopneumothorax, cardiopulmonary insufficiency. With timely provision of qualified assistance, it is possible to achieve recovery.
Prevention of the occurrence of valvular pneumothorax requires efforts to prevent injuries, as well as preventive detection and planned treatment of patients with pulmonary pathology by a pulmonologist, thoracic surgeon, phthisiologist.
Literature
- Prehospital diagnostic errors and therapeutic policy in spontaneous pneumothorax. Bulynin VI, Red’kin AN, Solod NV. Klin Med (Mosk). 1997;75(10):41-3. link
- Emergency therapy of pneumothorax using a Tiegel-valve. Sefrin P. Fortschr Med. 1982 Jul 22;100(27-28):1323-5. link
- A model for diagnosis and initial therapy of pneumothorax in the neonate. Sexson WR, McCollum LL. J Perinatol. 1989 Dec;9(4):420-2. link
- Diagnostic criteria and treatment of pneumothorax. Grupo de Trabajo de la SEPAR. Arch Bronconeumol. 2002 Dec;38(12):589-95. link
- Thoracoscopy in the diagnosis and treatment of spontaneous pneumothorax. Boutin C, Astoul P, Rey F, Mathur PN. Clin Chest Med. 1995 Sep;16(3):497-503. link