COPD is a condition that presents in different ways or forms. In one presentation, the individual has a constant cough and cannot control his bronchial secretions. This is diagnosed as** chronic bronchitis**. The disease process takes place in the inner lining of the airways and the mucus cells secrete excess mucus. Cilia, the hairy structures in the lining of the airways which are supposed to mobilize and limit and clear the mucus, do not work properly. This process is commonly caused by exposure to excessive tobacco smoke. The net result is excess mucus production and inability to clear these secretions effectively.
What happens in emphysema?** Emphysema**, another form of COPD, presents quite differently. In emphysema, the normal elasticity of the lungs, which should allow for inhalation and exhalation “without thought,” is compromised and reduced. Individuals diagnosed with emphysema have to actively focus to engage the muscles that assist with breathing and work to push the air out of the lungs. There is then space for new air to enter the lungs with the next breath.
Loss of the elasticity results in two consequences. First, the person has to harness and use great effort and energy to simply inhale and exhale, compared with healthy individuals who do this unconsciously with little effort. The second consequence is that air may enter the lungs with each new breath before air from the previous breath has been exhaled completely. This results in stretching the lungs even more and even greater loss of elasticity. We call this phenomenon “trapped air.” When a radiologist observes hyper-inflated lungs on a chest x-ray, he is observing permanent changes in the lungs caused by this process. A patient is often alerted to the possibility of COPD (emphysema), even if asymptomatic.
Chronic bronchitis versus emphysema: Which is more easily treatable?It’s fair to say that it’s easier to treat chronic bronchitis when comparing it to emphysema. This is because emphysema results in a permanent anatomical change in the lungs. Unlike the symptoms of the smoker, the damage is not reversible or significantly relieved by taking medications.
Current treatment of emphysema
Until recently, the only viable option to treat emphysema was to offer guidance to the patient to limit energy use so breathing is less taxing. Patients with emphysema become quite fearful of any exertion so they become more and more sedentary, and less fit. The other alternative is to adjust the activities-of-daily-living, making all physical efforts more efficient, to reduce the demand on the impaired lungs. This is the basis of Pulmonary Rehabilitation.** A new valve treatment for emphysema**
There’s a new procedure that may offer help to patients diagnosed with emphysema without interlobar collateral ventilation experience. The special valve is introduced in the bronchus of a hyper-inflated lobe of the lung, geographically where the movement of air is most compromised. This valve allows the air during exhalation to be expelled, preventing air from coming in to that compartment during that phase of breathing. The rationale behind the treatment is that when these portions of the lung are allowed to deflate completely, that allows other healthier portions of the lung to have more room in the chest cavity to inhale and exhale. In addition, the diaphragm (the primary respiratory muscle), pushed into a flat position by the hyper-inflated lung in emphysema, is allowed to return to its more normal dome position. This allows the diaphragm to contract more effectively.
The placement of the new valve mimics the objectives of a current surgical procedure where portions of the lung are removed to reduce the stagnant air that does not escape when emphysema-type breathing occurs. A big plus is that placement of the bronchial valve can be done without invasive surgery. Valve placement can be accomplished using a fiber-optic tube called a bronchoscope.
The valve study and challenges
The study done at the Mayo Clinic and at the University of Groningen in the Netherlands, was recently published in the New England Journal of Medicine. The promising results showed that individuals who had this procedure had improvements in spirometry readings, and six minute walk distance testing, when compared with subjects who received standard treatment.
Currently there are two valve devices on the market - the Zephyr and the** IBV**. These valves can also be removed safely after the lung has readjusted. Challenges remain primarily in selecting the right candidates for this valve treatment. It can also be difficult to identify and select the lobes that do not have communication with other sections of the lung (a requirement for the valve to work), and to prevent infections associated with placement of a foreign object in the body.
Nevertheless, it’s encouraging news and a first step in improving the outcome of what has been termed a “hopeless disease.”
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