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KEY POINTS
COPD is a leading cause of death worldwide and the lack of effective therapies and continued smoking prevalence indicate that this will be a major public health challenge confronting physicians for years to come.
COPD is a frequent cause of ICU admission and the diagnosis of COPD in ICU patients increases the risk of ICU delirium, ARDS, and in-hospital and postdischarge mortality.
Our limited understanding of the pathogenesis of COPD has hindered advancements in treatment of this disease highlighting the need for more basic and clinical research.
Animal models of COPD, particularly the cigarette smoke exposure model, reproduce key features of the disease providing the opportunity to gain key disease insights within a relatively short time frame.
Findings from animal models have identified the importance of inflammation, proteases, oxidants, and apoptosis in the pathophysiology of this disease. Furthermore, these studies have established key injury repair mechanisms that are activated in the lung in COPD.
The findings from these studies could lead to targeted strategies that block damaging injury responses and enhance protective lung repair responses in this disease.
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THE SIGNIFICANCE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE
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Chronic obstructive pulmonary disease (COPD) is defined as a disease state characterized by airflow limitation that is not fully reversible.1 The limitation in airflow is caused by airway inflammation,2 loss of lung elasticity,3 lung tissue destruction,4 and the closure of small airways.5,6 The airflow obstruction progresses over time and loss of lung function impairs the ability of individuals to carry out routine daily activities and greatly increases their risk of death. Indeed, COPD is now the third leading cause of death in the United States and is projected to become the third leading cause worldwide within the next 20 years.7,8 While the age-adjusted mortality for cardiovascular diseases had decreased significantly over the past 3 decades, the age-adjusted mortality for COPD has increased over this time period9 highlighting the need for better therapies10,11 and increased COPD research. It is well known that exposure to cigarette smoke, both first and second hand, is the primary etiologic factor associated with this disease. Although great strides have been made in reducing smoking prevalence in the United States, 43.8 millions people or 19.0% of the United States population (age 18 or older) continue to smoke.12 Moreover, smoking remains a major public health issue for adolescents with the latest surveys showing that 16% of all eighth graders had tried smoking and 17% of high school students continue smoking beyond graduation.13 Internationally, the picture is even bleaker with a smoking prevalence of 28% in China,14 27% in Germany, and 36% in Russia.15,16 These figures ensure that this disease will be a major public health issue for the foreseeable future.
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While cigarette consumption is the main risk factor for COPD, ...