Pneumothorax: Description
In a pneumothorax, air has entered the so-called pleural space – between the lung and the chest wall. In simple terms, the air is located next to a lung, so that it can no longer expand properly. The reasons for the pathological accumulation of air can vary.
There are about 10,000 cases of pneumothorax in Germany each year.
Negative pressure is lost
The lungs are surrounded from the outside by a smooth organ shell, the pleura. Another thin layer of tissue, the pleura, lines the chest wall from the inside. The lung and pleura together are called the pleura and are separated only by a narrow, fluid-filled space – the pleural space.
There is a certain negative pressure in the pleural space, which causes so-called adhesion forces to make the pleura and pleura literally stick to each other. This mechanism causes the lungs to follow the movements of the rib cage with every breath.
If air now enters the pleural space, the physical adhesion forces are neutralized. The lung cannot expand in the affected area during inhalation, but collapses (lung collapse). In some cases, however, so little air enters the pleural space that the affected person hardly notices it.
Forms of pneumothorax
- external pneumothorax: Here the air enters from the outside between the chest wall and the lungs – for example, in an accident in which something stabs the chest.
- internal pneumothorax: Here air enters the pleural space through the airways, for which there may be several reasons (see below). Internal pneumothorax is more common than external.
Pneumothorax can also be classified according to the extent of air entry: if there is very little air in the pleural space, physicians refer to it as a mantle pneumothorax. In this case, the lung is still largely denuded, so that the affected person may experience hardly any discomfort.
In pneumothorax with lung collapse, on the other hand, one lung has (partially) collapsed, causing severe discomfort.
A serious complication of pneumothorax is the so-called tension pneumothorax. It occurs in about three percent of pneumothorax cases. In a tension pneumothorax, more air is pumped into the pleural space with each breath, but it cannot escape. This causes the air to take up more and more space in the chest – it then also compresses the unaffected lung as well as additionally the large veins leading to the heart.
A tension pneumothorax is a life-threatening condition that must be treated immediately!
Pneumothorax: symptoms
In contrast, pneumothorax with lung collapse, with its greater air entry, is a dangerous condition that is usually accompanied by clear symptoms.
- shortness of breath (dyspnea), possibly accelerated (panting) breathing
- Irritable coughing @
- stabbing, breath-dependent pain in the affected side of the chest
- possible formation of an air bubble under the skin (skin emphysema)
- asymmetric movement of the chest during breathing (“lagging” of the affected side)
In the so-called catamenial pneumothorax, which occurs in young women around menstruation, the chest pain and shortness of breath are typically accompanied by coughing up of bloody secretions (hemoptysis).
In a tension pneumothorax, the shortness of breath continues to increase. If the lungs can no longer take in enough oxygen to supply the body, the skin and mucous membranes turn blue (cyanosis). The heartbeat is shallow and greatly accelerated. A tension pneumothorax must be treated by a doctor as soon as possible!
Pneumothorax: Causes and risk factors
Doctors distinguish between different forms of pneumothorax depending on the cause.
- secondary spontaneous pneumothorax: it develops from an existing lung disease. In most cases it is COPD (chronic obstructive pulmonary disease), less frequently other diseases such as pneumonia.
- Traumatic pneumothorax: It results from an injury to the chest. For example, the intense pressure of a collision during a car accident can break ribs and injure the lungs. Air can then enter the pleural space from the outside. Stab wounds to the chest can also cause a traumatic pneumothorax.
- iatrogenic pneumothorax: This is when the pneumothorax is the result of a medical procedure. For example, during chest compressions to resuscitate a cardiac arrest, ribs can break and injure the lung – with subsequent pneumothorax. Air can also inadvertently enter the pleural space during tissue removal from the lung (lung biopsy), bronchoscopy, or placement of a central venous catheter.
Important risk factor for primary spontaneous pneumothorax is smoking – about 90 percent of all pneumothorax patients are smokers!
Special cases of pneumothorax
Women are generally at lower risk for spontaneous pneumothorax than men. However, they are more prone to it in certain situations:
In childbearing age, a so-called catamenial pneumothorax can occur within 72 hours before or after menstruation. It usually develops on the right side. The cause of this special form of pneumothorax is not yet clear. Possibly endometriosis (with settlement of endometrium in the thoracic region) could be the trigger, or air could pass through the uterus into the abdominal cavity and from there into the chest. Catamenial pneumothorax is very rare but carries a high risk of recurrence.
Another special case is pneumothorax during pregnancy.
Pneumothorax: examinations and diagnosis
First, the doctor will take your medical history (anamnesis) in a conversation with you: He will inquire about the nature and extent of your symptoms, the time of their occurrence and any previous incidents and existing lung diseases. You should also inform the doctor about any medical interventions and injuries in the chest area.
If pneumothorax is suspected, an X-ray examination of the chest (chest X-ray) is performed as soon as possible. In most cases, some characteristic features can be made out on the X-ray: In addition to the accumulation of air in the pleural space, the collapsed lung can sometimes be seen on the X-ray.
If the X-ray examination does not produce clear findings, further examinations may be necessary, for example an ultrasound examination, a computer tomography or a puncture of the suspicious area (pleural puncture).
Pneumothorax: Treatment
The treatment of a pneumothorax initially depends on its exact severity.
Wait in mild cases
If there is only a small amount of air in the pleural space (mantle pneumothorax) and there are no severe symptoms, the pneumothorax can often recede completely without treatment. In this case, the affected person initially remains under medical observation to monitor the further course of the disease. Regular clinical examinations and X-ray checks help.
Pleural drainage and pleurodesis
In emergencies – especially in the case of a tension pneumothorax after an accident – the physician can puncture the pleural space with a cannula to initially relieve the lung so that the air that has entered can escape. This is followed later by pleural drainage.
If there is a risk of recurrent pneumothorax, physicians sometimes also perform a special operation called pleurodesis. This procedure is performed as part of a thoracoscopy, an examination of the chest cavity: the lung and pleura are “glued” together (i.e. the pleural space is removed) so that the lung cannot collapse again.
Pneumothorax: course of the disease and prognosis
The course of pneumothorax depends on its cause and the type and extent of any causative injury.
The prognosis for the most common form, spontaneous pneumothorax, is usually good. Not too extensive amounts of air in the pleural space (mantle pneumothorax) can often be absorbed by the body gradually, so that the pneumothorax resolves itself.
In addition, those affected should not engage in diving sports because of the pressure changes and should ideally stop smoking – both of which reduce the risk of a recurrence. Patients with large emphysema bubbles should also be cautious about air travel and, if necessary, consult with their physician in advance.
In traumatic pneumothorax, the prognosis depends on the injury to the lung and/or pleura. If there are major injuries after an accident, life may be at risk.
A tension pneumothorax must always be treated immediately, otherwise a severe course is likely.
In the case of an iatrogenic pneumothorax resulting from a lung puncture, the damage in the tissue leading to the entry of air into the pleural space is usually very small and heals on its own.
