The basic events in the development of COPD's symptoms
Posted Sep 16 2008 6:03am
Starting the offense and defense
When COPD starts to develop in a susceptible smoker, the progression of events is led by airflow reduction. Patients may undergo a long process of decrease in airflow that leads to retention of some air inside the lungs. The retention of air is the resultant of an extended expiratory phase that needs to be interrupted to take oxygen again. Year after year, the smoker restricts their normal balance between expiration and inspiration. The loss of equilibrium between the respiratory phases intensifies during physical activities when the oxygen requirements increases. Of course, the pulmonary system suffers due to the air trapping and the whole body will feel that the oxygen requirement is not completely satisfied.
More oxygen to work
The body requirements of oxygen during physical activity puts the smoker in disadvantage. The smoker will require more rest intervals than a non-smoker during active motion. The issue is that everybody needs to move and if the insult to the lungs continue, some normal activities start to look like exercise to the smoker.
During physical activity a smoker, now with an continuously irritated airway have a persistent reduction in airway caliber. The easiness of expiration disappears and the oxygen requirement makes of immediate inspiration a solution. Air with CO2 that needed to leave lungs gets trapped during breathing but the lung elasticity allows the adaptation of the gas until the pressure inside the lungs at the end of expiration start to increase.
Do I look powerful?
When pressure at the end of expiration increases there are additional changes or adaptations at the respiratory system. Muscles that used not to work as intense as they could, now begin to work and when more muscles are working more energy is required. The excess energy requested by the body translates into excess oxygen requirement and the chronic smoker will not be able to satisfy this demand. At this point, the positive lung internal pressure results in an exaggerated inflation that will be visible externally by any good observer. The smoker, already a patient, has hyperinflation and the adapted diafragm, intercostals, and some cervical and shoulder muscles are working during activities that weren’t strenuous before.
Forgetting to move
The whole situation makes the patient to do less. Doing less leads to reduced fitness and with more physical movement the hyperinflation gets worse manifested with breathlessness. Then with less physical activity the breathlessness is more apparent. The patient becomes sedentary and the quality of life is reduced.
When did it start?
And all this, just because the subject needed some tranquilizer, some garbo, or some powerful look or was anxious and started lighting cigarettes. This started a chain of airway irritation, airflow reduction, gas retention, excess lung inflation, breathlessness during exercise, exercise restriction, breathlessness during activities, activities restriction, sedentary lifestyle, lost good quality of life.