Are smokers with COPD predisposed to developing pneumonia?
Posted Oct 19 2009 10:03pm
The answer is yes. As previously mentioned, smoking increases mucus production and impairs the clearing action of the cilia in the airway. Also, the addition of bacteria, inflammatory cells, and damaged lung cells to the secretions in the airway and lung make the secretions especially thick, tenacious, and difficult to clear. Therefore, in such a stagnant and nutritious (the mucus) environment, bacteria can flourish and cause infection of the lung (pneumonia). Furthermore, even the inflammatory cells are damaged by tobacco smoke so that their ability to fight infection is diminished.
For all of these reasons, pneumonia is not only more common, but it is often also more severe in smokers with COPD (chronic obstructive pulmonary disease, that is, emphysema and/or chronic bronchitis) than in non-smokers without COPD. Moreover, the inflammatory cells that accumulate in the lung to fight off the infection can fill the alveolar spaces and thereby further limit diffusion of oxygen and carbon dioxide. Therefore, smokers with COPD, who already have impaired breathing (pulmonary function), often become much worse when there is a superimposed infection of the lung (pneumonia). Figure 7 is a microscopic section of a lung with pneumonia in a patient with COPD.