Pneumothorax is an excessive accumulation of air between the pleural leaves, leading to a short-term or long-term disorder of respiratory function of the lungs and cardiovascular insufficiency. All cases of pneumothorax can be attributed to one of the three main forms: iatrogenic (complication of diagnostic and therapeutic manipulations), traumatic (there is a direct connection with traumatism of the chest apparatus of the thoracic cavity) or spontaneous pneumothorax of the lung (sudden disruption of the integrity of the visceral pleural leaf).
In a situation where the pleural cavity has no direct communication with the air of the environment, the volume of air that has fallen at the time of injury into one or both of the peristal cavities remains at the same level, and therefore a closed pneumothorax arises.
Open pneumothorax develops in the case when a defect between the pleural cavity and the surrounding environment is preserved, as a result of which air is unobstructed as it accumulates between the pleura sheets and is removed from the pleural cavity during respiratory movements.
Valve pneumothorax is similar to the open pathogenetic mechanisms of origin, but its main difference is that during the act of breathing, the soft-tissue structures of the chest move, so that air accumulates more in the pleural cavity rather than is removed from it. At the initial stage, compensatory mechanisms cope with increasing intrapleural pressure, but in a situation where the level of intrapleural pressure exceeds the indices of atmospheric pressure, a strained pneumothorax arises, which greatly complicates the patient's condition and requires immediate surgical intervention.
In establishing an accurate diagnosis, it is necessary to evaluate not only the volume of air in the pleural cavity, but also the degree of collapse of the lung, which largely affects the violation of respiratory function. In addition to lung collapse on the side of the lesion, there may be signs of accumulation of fluid or blood in the pleural cavity. In this situation, we are talking about hemopneumothorax, and the amount of treatment depends on the severity of the disease. Another type of pneumothorax is pyopneumotorax, that is, a combined accumulation of purulent contents and air in one or both of the pleural cavities.
Causes of pneumothorax
Each of the three main forms of pneumothorax can develop when exposed to a particular etiopathogenetic factor or when combined.
Pneumothorax traumatic genesis is provoked by a traumatic effect on the thoracic cavity organs: gunshot and stabbed-cut penetrating lesions of the chest cavity, exposure to the organs of the chest cavity of blunt objects, causing fractures of the ribs with displacement of fragments or rupture of the pulmonary parenchyma.
The iatrogenic nature of pneumothorax involves a one-sided or two-sided accumulation of air in the pleural cavity, triggered by improperly performed diagnostic or therapeutic manipulation (pleural puncture with pulmonary injury, pleural biopsy, catheterization through central venous access, endoscopic transbronchial biopsy with perforation of the bronchus wall, barotrauma as a complication of the artificial ventilation).
The emergence of spontaneous pneumothorax can not be tied to any specific etiologic factor, since it occurs against a background of complete well-being, but there are pathological conditions that are at risk and can act as a provocateur of pneumothorax: the pathology of the bronchopulmonary system of the lungs (chronic obstructive pulmonary disease, asthma , cystic fibrosis , emphysematous bulla), lung diseases of infectious nature ( tuberculosis , Pneumocystis pneumonia, lung abscess o) interstitial pulmonary pathology (Wegener's granulomatosis, sarcoidosis , idiopathic pulmonary fibrosis), systemic connective tissue disease ( scleroderma , dermatomyositis , rheumatoid arthritis), cancer in the lung ( sarcoma , central lung cancer ).
There is a separate nosological form of "menstrual pneumothorax", the manifestations of which have a clear dependence on the timing of menstruation and women suffering from endometriosis. This pathology is extremely rare and in most cases does not need a specific diagnosis.
The manifestation of clinical symptoms in a patient and the degree of their severity depends on the type of pneumothorax, the volume of air in the pleural cavity and the compensatory capabilities of the body. The presence or absence of signs of cardiovascular and respiratory failure depends on the degree of collapsing of the lung and compression of the mediastinal organs.
In the classical form, pneumothorax is a sudden emergency condition, which is characterized by a sudden debut of the clinical symptom complex and a rapid increase in symptoms. The first sign of pneumothorax is a sharp stitching pain in the chest, often without a clear localization and radiating to the shoulder girdle, neck and upper half of the abdominal cavity. Some patients do not feel a pronounced pain syndrome, but complain about acute shortage of air and shortness of breath, in connection with which, the frequency and depth of respiratory movements increase.
In order to reduce the pain syndrome and the severity of dyspnea, the patient is forced to take the position of "lying on the sore side" and limit the depth of the respiratory movements, which is a pathognomonic symptom of pneumothorax. If there is an open type of pneumothorax, then through the wound in the chest there is a discharge of foamy blood, which comes out with noise.
The degree of manifestation of pneumothorax symptoms directly depends on the severity of lung sagging, so the classic symptom complex develops with lung collapse (in 40%). With a small amount of free gas in the pleural cavity, there is a sluggish latent flow with an unexpressed pain syndrome, which to a large extent negatively affects the timely diagnosis of the disease.
At primary objective inspection of the patient the expressed paleness of mucous membranes and integuments, cyanosis of an upper half of a trunk and a head is revealed. The affected half of the thorax visually lags behind in the act of breathing compared to the other half, and also the swelling of the intercostal space on the side of the alleged pneumothorax is noted.
Traumatic pneumothorax is often accompanied by the spread of air into the intermuscular and subcutaneous spaces of the chest and neck, which leads to signs of subcutaneous emphysema (an increase in the volume of soft tissues, a sensation of a crunch during palpation).
Carefully performed percussion and auscultation of the lungs in 100% of cases allows to establish reliably the diagnosis of "pneumothorax". Thus, during percussion, an empty boxed sound is detected over the affected half of the chest, as the conductivity of sound over the air is very good, while auscultatory vesicular breathing is completely absent or sharply weakened.
Suspicion of pneumothorax is an absolute justification for the appointment of a chest X-ray of the thoracic cavity, as this method of examination is considered the best in diagnosing the presence of air in the pleural cavities. Mandatory is the performance of the roentgenogram in the standing position and lateroposition. The signs of pneumothorax are the presence of free gas in the pleural cavity, a decrease in the volume of the lung on the side of the lesion, and in the case of intense pneumothorax, displacement of the mediastinal structures is determined in a healthy way.
With a limited volume of air in the pleural cavity, it is necessary to perform computed tomography, which allows to diagnose not only limited pneumothorax, but also the cause of its occurrence (tuberculous cavity, emphysematous bullae, pulmonary diseases accompanied by interstitium pathology).
It should be borne in mind that within a day after the development of pneumothorax, it is possible to attach the pleural pleura reaction, which manifests itself in the form of an increase in body temperature, soreness in the chest during breathing and movements. Subsequently, the phenomenon of respiratory failure increases, due to the development of the adhesion process in the pleural cavities, which hampers the spreading of the lung tissue.
The incidence of spontaneous pneumothorax is 3-15 cases per 100,000 population. The risk group for this disease is young men with asthenic constitution, who have bad habits in the form of smoking and alcohol abuse.
It is believed that the primary spontaneous pneumothorax develops in the case of complete absence of pathological changes in the lungs, but numerous randomized studies using videotouracoscopy and computed tomography prove the presence of subpleurally located emphysematous bullae in 90% of cases.
The mechanism of the penetration of free gas into the pleural cavity in the primary pneumothorax is that inflammatory changes in the small airways primarily arise, as a result of which the air present in the bullae penetrates the pulmonary interstitial tissue. Due to the increase in pressure, air rapidly rushes to the root of the lung and through the mediastinal parietal pleura breaks into the pleural cavity.
The clinical symptomatology of primary spontaneous pneumothorax arises against the background of complete well-being and consists in the onset of an acute pain syndrome that persists in the first day of the disease, after which only the dyspnea remains. The appearance of tachycardia , expressed by cyanosis of the upper half of the chest, is evidence in favor of the development of intense pneumothorax.
In most cases, a limited pneumothorax develops, which does not require specific treatment and is resolved independently. The recurring primary spontaneous pneumothorax accounts for 30% of cases, and usually between the first episode and a relapse it does not take six months.
Secondary spontaneous pneumothorax is characterized by a more aggressive and severe course, as it occurs against a background of any pulmonary or cardiovascular disease. The incidence of secondary spontaneous pneumothorax is 2-5 cases per 100,000 population and the risk group is elderly people suffering from chronic lung diseases.
The main diagnostic feature in this situation is the presence of chest pain and dyspnea, although in some cases the clinical manifestations are rather meager. Relapses of this disease are observed in 40% of cases. Symptoms of pneumothorax arise after excessive physical activity or psychoemotional stress. There is a sharp daggerache in one or both halves of the chest, accompanied by difficulty breathing and dry nauseated cough.
In a situation where valvular pneumothorax takes place, dyspnea progressively increases until apnea , there is an asymmetry of the chest due to an increase in the side of the lesion, often a loss of consciousness, due to increasing hypoxia and hypercapnia. If air flows slowly into the pleural cavity and there are no signs of respiratory and cardiovascular failure, the pain syndrome is not very pronounced and pneumothorax sometimes occurs absolutely asymptomatic.
Features of an objective examination of the patient with valve pneumothorax is the presence of tympanic sound during percussion and a decrease in vocal jitter on the side of the lesion. The percussion boundaries of cardiac dullness are reduced, and when the tight pneumothorax is closed, the boundaries of cardiac dullness are shifted in the opposite direction.
An additional method of investigation necessary for the diagnosis of spontaneous pneumothorax is X-ray in standard projections, as well as lateroscopy, which allows to diagnose even a small amount of free gas. In a situation where there is a large amount of air accumulation in the left pleural cavity, the diagnosis is difficult, since clinical manifestations and changes in ECG recording can simulate acute myocardial infarction . In this case, the patient is recommended the determination of specific troponins, the level of which increases with acute coronary insufficiency .
For the purpose of clarifying the type of spontaneous pneumothorax, pleural puncture with manometry is recommended. For a closed type of pneumothorax, both low-negative and weakly positive levels of intrapleural pressure (from -3 cm.vod.st up to +4 cm.v.st.) are characteristic. An open spontaneous pneumothorax is accompanied by an intrapleural pressure close to the zero value. With valve spontaneous pneumothorax there is a sharply positive intrapleural pressure with progressive increase.
In the case of hydropneumothorax, pleural punctate must necessarily be examined for the presence of specific pathogens, as well as for determining the cellular composition. In the case of valvular pneumothorax, videotoracoscopy is recommended, which allows reliable determination of the size and location of pleural fistula.
Separately, the appearance of spontaneous pneumothorax in a newborn child should be considered, as a consequence of an increase in intrabronchial pressure at the time of the first inspiration, accompanied by uneven stretching of the lung tissue. In children of the older age group, the appearance of signs of spontaneous pneumothorax is most often associated with an increase in pressure in the lumen of the bronchi in diseases such as pertussis , bronchial asthma and aspiration of a foreign body. It should be borne in mind that the occurrence of spontaneous pneumothorax in children can be triggered by the rupture of congenital retention cysts or bulls.
The clinical symptom complex of pneumothorax in childhood is practically the same as that of adulthood, but it is characterized by a rapid increase in symptoms and a pronounced seizure syndrome, often hampering the timely diagnosis of the underlying disease.
Operative allowances in childhood are extremely rare, provided a reliably diagnosed malformation of the lungs or disruption of the integrity of the wall of the bronchi and esophagus.
Pneumothorax first aid
The first emergency aid for any type of pneumothorax is not only the use of drug therapy, but also the observance of a certain regimen. The patient first of all needs to provide complete mental and physical rest in the orthostatic position and in this position it is necessary to urgently hospitalize an ambulance in a surgical hospital.
The beginning of resuscitation should be carried out in the ambulance. If pneumothorax develops as a result of a chest injury and is accompanied by bleeding, it is necessary to apply a sealing bandage to the wound surface and urgently begin cardiovascular drug therapy: Cordiamin in a dose of 2 ml or 1% Mesaton 1 ml subcutaneously; intravenous administration of Korglikona 0,06% 1 ml in 10 ml isotonic sodium chloride solution; 10% Sulphocamphocaine 3 ml subcutaneously.
For the purpose of analgesia, the use of Baralgina 5 ml intravenously, and if necessary 2% Promedol solution 1 ml with 1% solution of Diphenhydramine 2 ml intravenously.
In a situation where there is pronounced hypoxia and hypercapnia, the use of oxygen therapy with a mixture of "laughing gas" and oxygen is recommended.
After providing the first emergency care, the patient is hospitalized in a surgical hospital. The volume of therapeutic measures performed with suspicion of pneumothorax directly depends on the type of pneumothorax and the presence of concomitant pathology.
In the case of limited pneumothorax without signs of compression of the mediastinal organs, it is advisable to engage in expectant conservative therapy with complete physical and psycho-emotional rest and adequate analgesia (2% solution of Omnepona 2 ml subcutaneously).
Absolutely all patients with diagnosed pneumothorax, regardless of the gas composition of the blood, recommended adequate oxygen therapy, as numerous randomized studies prove the beneficial effect of this method of treatment on the resolution of pneumothorax. It should be borne in mind that when performing oxygen therapy for patients suffering from chronic lung disease, it is recommended to monitor the gas composition of the blood, in order to avoid the increase in signs of hypercapnia.
Indications for the production of urgent pleural puncture at the prehospital stage are: an increase in dyspnea and severe hypotension , caused by compression of mediastinal structures in the air available in the pleural cavity. Passive aspiration, which occurs with pleural puncture, in 50-70% leads to complete spreading of the collapsed lung and improving the patient's condition.
Patients aged after 50 years with a recurrent course of pneumothorax prefer not to use simple pleural puncture, but to establish a drainage tube and conduct active aspiration of air.
A small defect in the visceral pleura (up to 2 mm) can be sealed with laser and diathermic coagulation. In a situation where the defect of the pleural leaf is large, there is a possibility of its self-closure during installation of the drainage tube during the first 2 days.
As a preventive treatment measure, the method of pleurodesis is widely used, in which tetracycline powder is insufflated into the pleural cavity, which contributes to the adhesion of pleural sheets.
In a situation where there is a large amount of air in the pleural cavity, the patient is shown a small surgical intervention - the establishment of drainage in the pleural cavity with the use of Bobrov's apparatus for performing passive aspiration. This operational manual does not require specific training of the patient and can be performed even at the pre-hospital stage by an ambulance doctor for medical reasons.
This manipulation is carried out in the "sitting" position under local anesthesia with a 0.5% solution of Novocain in the amount of 20 ml subcutaneously in the projection of the second intercostal space along the mid-incision line. After adequate anesthesia, the surgeon performs an incision of the superficial soft tissues and introduces a special medical instrument called "trocar", by means of which drainage with fixation to the skin is inserted into the pleural cavity. The quality of air aspiration is greatly influenced by the diameter of the selected drainage pipe. So, in a situation where there is a traumatic pneumothorax, a drainage tube of a larger diameter should be preferred. The end of the drainage tube is lowered into the Bobrov's can, thereby ensuring passive aspiration. In a situation where passive aspiration is ineffective, it is advisable to use a vacuum aspirator to suck air out of the pleural cavity.
When carrying out drainage of the pleural cavity, it is necessary to strictly observe all the rules for its implementation, since this manipulation has a wide range of possible complications (subcutaneous and intermuscular emphysema, penetration into the heart and lungs, and infection of the pleural cavity). Intrapleural administration of anesthetics is used as a sanation of the pleural cavity. Indication for the removal of pleural drainage is the complete expansion of the lung tissue and the absence of signs of the presence of free gas in the pleural cavity, confirmed by radiography.
If the patient has signs of traumatic pneumothorax accompanied by extensive damage to the lung tissue, he is shown urgent surgical intervention, which involves suturing the defect of the lung tissue, stopping bleeding, layer-wise suturing the soft tissues of the chest and the mandatory installation of a drainage tube.
Recurrent spontaneous pneumothorax is the rationale for conducting a diagnostic and therapeutic video inspection for a patient, during which a thoracoscope is introduced through endoscopic access, allowing visualization of the presence of pulmonary bulls and their subsequent removal.
The main tasks of the operative method of treatment of pneumothorax are: resection of existing bullous changes in the lungs, performance of pleurodesis. A surgical intervention must be clearly justified. So, absolute indications for the use of extensive thoracotomy are: the lack of the effect of conservative treatment and the use of pleural cavity drainage for seven days, the signs of bilateral spontaneous pneumothorax, the emergence of spontaneous hemopneumothorax, the recurrent course of pneumothorax even after the application of chemical pleurodesis, the occurrence of pneumothorax, as an occupational disease divers.
In the rehabilitation period after surgical treatment the patient should adhere strictly to the regime for quitting smoking, avoiding excessive physical activity and refusal to fly on the plane for 1 month.
In most cases, pneumothorax has a favorable prognosis for restoring health and working capacity, provided timely adequate medical care and sufficient rehabilitation measures are provided.
The lethal outcome of the disease occurs only with extensive valve tension pneumothorax, accompanied by a disorder of central hemodynamics and severe form of hypoxia, and also with the complication of pneumothorax.
After pneumothorax, the development of exudative pleurisy, that is, the accumulation of fluid in the pleural cavity, and with the attachment of infectious inflammation, empyema of the pleura. An empyema of the pleura is a dangerous disease, since if there is a risk of developing a septic condition.
Traumatic pneumothorax in 50% of cases is accompanied by the accumulation of blood clots in the pleural sinuses and the development of hemopneumothorax, which carries a danger to the life of the patient, as it is accompanied by the development of cardiovascular insufficiency and severe anemic syndrome.
The prolonged collapse of the lung, which occurs with a strained pneumothorax, is accompanied by a violation of pulmonary pneumotization and the development of pneumonia of a stagnant nature. This condition needs not only immediate air aspiration, but also the appointment of massive antibacterial therapy.
Another frequent complication of pneumothorax is the development of a febrile pulmonary edema caused by an intensive overgrowth of the lung after a prolonged collapse. This condition is quickly stopped by the appointment of diuretics in an adequate dose provided that cardiovascular maintenance therapy is maintained.