COPD Flashcards
What is COPD?
a preventable and treatable disease state characterized by airflow limitation that is not fully reversible; it is progressive and associated with an abnormal inflammatory response of lungs to noxious gases like cigarette smoke
What are two diseases included with COPD?
chronic bronchitis and emphysema
Why is asthma not technically included in the new definition of COPD?
because asthma can be reversible until you reach a certain point and airflow limitation becomes chronic
What is emphysema?
defined as the presence of permanent enlargement of the airspaces distal to the terminal bronchioles accompanied by destruction of the walls of the airspaces without fibrosis
What is chronic bronchitis?
an inflammatory disease of the peripheral airways and clinically defined as chronic, productive cough for more than 3 months in each of 2 consecutive years
How many Americans currently suffer from COPD, chronic bronchitis and emphysema?
10-15 million (Gary) 24 million (Egan)
What are two of the most common risk factors that cause the development of COPD?
cigarette smoking and alpha antritrypism deficiency
What are the 4 pieces of evidence that link cigarette smoking to the development of COPD?
- symptoms of COPD are more common in smokers than nonsmokers
- impaired lung function with evidence of an obstructive pattern of lung dysfunction is more common in smokers than nonsmokers
- pathologic changes of airflow obstruction and chronic bronchitis are evident in lungs of smokers
- so called susceptible smokers, who represent 15% of all cigarette smokers, experience more rapid rates of decline of lung function than nonsmokers
What is the other name for alpha one antitrypsin deficiency?
genetic emphysema
Describe the protease-antiprotease hypothesis of emphysema
it explains the pathogenesis of emphysema in AAT deficiency but there is also evidence that suggests there are individuals with COPD who have normal amounts of AAT (which is conflicting)
What is the protective threshold of alpha one antitrypsin in the serum?
11 micromol/L or 57 mg/dl
What are the mechanisms of airflow obstruction in COPD?
- inflammation and obstruction of small airways
- loss of elasticity
- active bronchospasm
What are the common symptoms and signs of COPD?
- cough
- phlegm production
- wheezing
- shortness of breath
What are the physical examination findings of a patient with COPD?
- wheezing
- diminished breath sounds
- barrel chest
- hoover sign
_____ is usually preserved until airflow obstruction is severe (i.e. FEV1 < 1L) when it may increase
PaCO2
What are the four clinical goals for managing stable COPD?
- establish the diagnosis of COPD
- optimize lung function
- maximize patient’s functional status
- simplify medical regimen
- prolong survival whenever possible
List the features that favor the diagnosis of COPD
chronic daily phlegm production
List the features that favor the diagnosis of asthma
diminished FEV1 on spirometry can be normalized after use of an inhaled bronchodilator
What is stage I of COPD?
mild; FEV1/FVC <70% and FEV1 80% predicted
What is stage II of COPD?
moderate; FEV1/FVC <70% and FEV1 50-79% predicted
What is stage III COPD?
severe; FEV1/FVC <70% and FEV1 30-49% predicted
What is stage IV COPD?
very severe; FEV1/FVC <50% predicted plus chronic respiratory failure
Is airflow obstruction resulting from emphysema considered to be reversible?
no
What fraction of patients with stable COPD demonstrate a reversible component to airflow obstruction defined as 12% rise in the postbronchodilator FEV1?
up to 2/3