ABSTRACT
I. Introduction Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality globally and will continue to increase in importance as the world population continues to age (1,2). Exacerbations, characteristic of the course of COPD, are intermittent episodes of increased respiratory symptoms and worse pulmonary function that may be accompanied by fever and other constitutional symptoms. These episodes contribute significantly to the morbidity associated with COPD, and in advanced disease, they are also the most frequent cause of death (3-5). The clinical manifestations of exacerbations result from direct effects of virus and bacteria and from the host response to infection. However, not all exacerbations are infectious and air pollution and other environmental conditions that increase airway inflammation or bronchomotor tone likely account for 15% to 20% of exacerbations. Increased respiratory symptoms due to comorbid conditions such as congestive heart failure and pulmonary emboli should be clinically excluded in the evaluation of exacerbations. Several new clinical trials as well as observational studies have given us a base of evidence to refine our approach to treating exacerbations that should lead to improved outcomes for patients. A rational, stratified approach to the use of antibiotics for this condition based on these recent basic and clinical studies has been developed. Prevention of lower respiratory tract infections in COPD is possible; however, substantial research is required for such prevention to reach its full potential.
