… let’s say a bubble wrap. Many bubbles to increase the surface for contact. It’s not a flat surface but many short cylinders made of the same material. When a mini-cylinder is pressed with a the finger, the pressure increases and broke it out. What stays there is not useful as it was before. The surface is reduced after each small air-full cylinder is broken out.
When cigarette smoke enters into the airway, there’s a local reaction. Contraction of muscles around the airway (neck of a bubble) accompanied by irritation. When this reaction is repeated some air is trapped at the most internal levels of the lungs. There, many bubbles (alveoli) were available for gas exchange. The trapped air increases the pressure inside the bubbles and break them out one after another. The surface for getting most of the oxygen from the inspired air is progressively diminished.
Destroying a building: the lung
It is not only the increased pressure what breaks the bubbles out. If the plastic is weak the process is easier. The similarity implies a local response at cells of the alveoli as well as on the system of attachments. As in a building, many materials are involved in the stability of the whole structure. The system for stability of the alveoli inside the lungs is debilitated as part of the reaction to the components of smoke. Many cells come to help but the response is exaggerated and alveolar destruction also occurs.
When a combination of extreme local pressure and debilitation of the alveoli occurs, what comes is emphysema. Emphysema is more a histological concept, it is not based on clinical findings. For example we can say that chronic bronchitis is cough with sputum production for more than three months during two consecutive years. Emphysema is destruction of alveolar septa (divisions or walls of the bubbles), something that can be seen under microscopy.
Of course it’s not required to perform a biopsy to diagnose emphysema. Usually the diagnosis is an assumption based on changes at a macroscopic level: exaggerated chest size (particularly from back to front) or chest X-rays showing localized or generalized darkness due to lost of the tiny divisions in the pulmonary tissue. When those big findings are present in a patient with history of smoking and less phlegm during coughing but with increased breathlessness when performing some physical activity, the diagnosis of lung emphysema is obvious.
Reducing the impact of emphysema
Building back the bubbles in the lungs is as easy as trying to do that with the wrap: impossible. However some interventions may help to reduce the impact of the damage. The first measure is avoiding the injure: quit smoking to protect the healthy bubbles. The second is the administration of drugs to release some trapped air. The third intervention should be decreasing the inflammatory reaction when it happens like during repeated exacerbations. The fourth is learning to use the existing saved bubbles and, finally, sometimes it may be used surgery to eliminate extensive areas where alveoli are already destroyed (this as a last minute intervention with strict criteria). Oxygen may be required when the remaining healthy surface is really small.
Emphysema or Chronic Bronchitis
Some smokers develop more emphysema than chronic bronchitis. Others tend to do exactly the opposite but most of COPD patients have a combination of both disorders.
Emphysema sounds as a very disgusting word, but it needs to be taken into account when informing COPD patients about the reality of the disease. It may sound terrible but some times is a reality to be communicated to be sure of the understanding of COPD as a serious clinical condition.
Seriousness of emphysema
We physicians can deal with more of the disorders generated by smoking cigarettes. Although emphysema is irreversible, the condition that push toward a deterioration can be controlled. Emphysema could be consider as a word to help realize of the seriousness of COPD. It’s always there in a less or more extent, but it is there. It is not that Chronic Bronchitis is better than emphysema. Both are equally relevant to the quality of life as well as a prognostic factor for the survival of a patient.
Hopefully, many investigators are working to find the actions required to reduce the impact of emphysema. It is still in the mind and hands of a patient (literally) to take the first steps against emphysema advancement.