Pneumothorax - Collapsed Lung
In order for the respiratory system to operate properly, certain conditions must be maintained inside the chest cavity.
The lungs are like two sacs of air - they have no musculature of their own and cannot inflate by themselves. It is the action of the diaphragm moving downwards that expands the chest cavity and allows air to enter the lungs.
This works because the pressure in the pleural space - which is the area around the lungs - is lower than the pressure inside the lungs. When the diaphragm pulls downward and expands the chest cavity, this pressure becomes even lower. This is what draw air into the lungs.
If, due to an injury or pathological condition the pressure inside the chest becomes higher than the pressure inside the lungs - or conversely, lung pressure drops below that of the surrounding pleural cavity - the result is a collapsed lung, or pneumothorax.
In the early days of medicine (when application of leeches and opening a person's veins were standard treatments and mercury was considered a cure for syphilis), physician/barbers were known to induce lung collapse as a way of treating tuberculosis; it was believed that "resting the lung" by allowing it to collapse would allow the lesion to heal.
Jean Marc Itard, a French medical pioneer of the Enlightenment Period, first identified pneumothorax in 1803. One of his students, Rene Lannaec, who would eventually invent the modern stethoscope, provided the medical profession with the first detailed clinical report on the condition in 1819.
Types of Pneumothorax
The "average" victim of what is known as simple spontaneous pneumothorax - a collapsed lung without an apparent cause - is a tall, underweight male under the age of 40. Even in these cases however, the victim is likely to have a history of respiratory problems, even if symptoms are not present at the time. Spontaneous pneumothorax can also be caused by change in outer pressure, as when scuba diving or flying. Generally, however, spontaneous pneumothorax is due to a weakness on the lung tissue itself. These weak spots are cysts called bullas or blebs; they resemble bladders and contain fluid. When one breaks or ruptures, simple pneumothorax can result. One study, undertaken a few years ago and published in 2004, demonstrated that loud music could also cause spontaneous pneumothorax.
In any event, this is usually a partial collapse of the lung, and readily treated. If small enough, it may correct itself without any treatment at all as the lung gradually reinflates.
Tension pneumothorax is far more serious. When this happens, the lung collapses completely, pushing the heart and arteries and the trachea to one side, seriously compromising its ability to pump blood and blocking the airway.
As with the simple variety, tension pneumothorax can happen at any time. It is more likely to occur in patients with other respiratory problems, however, including chronic bronchitis or asthma, or emphysema. Pneumothorax can develop when anything punctures the chest wall such as biopsy needles, bullets or knives.
Unfortunately, pneumothorax symptoms are not always distinguishable from other respiratory or cardiac conditions. Shortness of breath, chest pains, elevated respiration rate with little chest movement are signs of pneumothorax, but may also indicate a heart attack, asthma, stroke, or may even be the symptoms of an asbestos
cancer such as lung cancer or mesothelioma. One symptom particular to pneumothorax is enlarged neck veins, as the collapsed lung puts pressure on the trachea. Pulse will be weak; there may be dry coughing as well.
The physician will first do a standard exam by listening through a stethoscope, then order an x-ray, which will indicate whether or not an abnormal space in the chest cavity. If the x-ray suggests pneumothorax, s/he will confirm this with an electrocardiogram, which provides a clearer picture of the chest interior and heart action. Finally, the physician will analyze a blood sample for oxygen and CO2 levels.
Pneumothorax and Malignant Pleural Mesothelioma
The main connection here is that the outward symptoms are similar. Plueral mesothelioma patients experience the same type of chest pains and shortness of breath; in some cases, those suffering from malignant mesothelioma have been misdiagnosed with pneumothorax, as the latter condition has been known to be recurrent in certain patients with a weak respiratory system and/or a history of respiratory disorders.
In a 2000 study published in the American Journal of Industrial Medicine, four individuals known to have been exposed to asbestos had experienced the symptoms outlined above. Two of the subjects were initially misdiagnosed with pneumothorax, then remained without symptoms for the next 1 - 2 years. None of the four subjects died from pneumothorax, although all were ultimately diagnosed with mesothelioma.
The lesson drawn from the study is that when it comes to symptoms such as chest pains and shortness of breath and there is a history of asbestos exposure, the chances are far greater that the problem is mesothelioma or other asbestos-related disease than it is pneumothorax.
This, incidentally is not to say that mesothelioma victims do not suffer from pneumothorax. Any condition that weakens the lung, including lung cancer, can cause the lung to collapse. It is only to say that the early symptoms of mesothelioma can be mistaken for pneumothorax. Since mesothelioma is difficult to detect and diagnose in any event, it is best to get a second opinion when it comes to symptoms such as those outlined above.
In the case of tension pneumothorax, aspiration of the chest may be necessary.
This involves cutting an incision and inserting a tube into the pleural cavity in order to release any trapped air and reduce air pressure. This can be a painful process; in addition, patients run the risk of secondary infection, hemorrhage, and fluid accumulation in the lung; the procedure may also cause a drop in blood pressure to dangerous levels.
Pleurectomy (removal of part of the pleural lining) and pleurodesis (causing abrasions on the chest wall in order to cause the lung to attach to this surface with scar tissue as it heals, may also prevent pneumothorax from occurring. Both of these procedures are common treatments for mesothelioma.
'Pneumothorax (Collapsed Lung)' Resources:Notes
- Penn State College of Medicine. "Pneumothorax."
- Wikipedia. "Pneumothorax."
- Penn State, op. cit.
- Noppen, et. al. "Music: a New Cause of Primary Spontaneous Pneumothorax"
- Penn State, op. cit.
- Alkhuja, Samer, et. al. "Malignant Pleural Mesothelioma Presenting as Spontaneous Pneumothorax."
- Schiffman and Stöppler. "Pneumothorax."
- Wikipedia, op. cit.