COPD Flashcards
Define COPD
Preventable disease state that is characterized by airflow limitation that is not fully reversible.
Name two diseases included in COPD
Chronic Bronchitis
Emphysema
Why is asthma not included in definition of COPD?
Asthma is reversible
Define Emphysema
Pathologically defined as the presence of permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis.
Based on the pathology, or the “anatomic alterations of the lung,” associated with the disorder.
Define Chronic Bronchitis
Clinically defined as chronic productive cough for 3 months in each of 2 successive years in a patient in whom other causes of productive chronic cough have been excluded.
Based on the major “clinical manifestations” associated with the disease.
How many Americans currently suffer from COPD, chronic bronchitis, and emphysema?
appx. 24 million
Estimated 10 t0 15 million people
Two most common risk factors that cause the development of COPD
Tobacco smoke
Alpha 1-antitrypsin deficiency (AAT)
The evidence (list 4) linking cigarette smoking to the development of COPD.
Chronic cough, phlegm
Impaired lung function with evidence of obstructive pattern
Pathologic changes in airflow obstruction
So called susceptible smokers, who represent approximately 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
What is the treatment for Alpha one antitrypsin deficiency?
intravenous augmentation therapy
Describe the protease-antiprotease hypothesis of emphysema
When someone has ATT deficiency, neutrophil elastase may go “unchecked”, causing a breakdown of elastin and resulting in dissolution of alveolar walls
What is the protective threshold of Alpha one antitrypsin in the serum?
Protective threshold is 11µmol/L, or 57mg/dl
Mechanisms of airflow obstruction in COPD.
Inflammation and obstruction of the small airways (<2mm in diameter), loss of elasticity, which keeps small airways open when elastin is destroyed in emphysema and active bronchospasm.
Common symptoms and signs of COPD
Cough
Phlegm production
Wheezing
SOB, typicall with exertion
physical examination findings of a patient with COPD
Wheezing or diminished breath sounds (early on)
Hyperinflation (later)
Barrel chest
Diaphram flattening
Dimpling inward on the chest wall at the level of the diaphram on inspiration
PaCO2 to changes in FEV1 - “Rule of thumb”
In pt with COPD, PaCO2 is usually preserved until airflow obstruction is severe (i.e., FEV1 < 1L), when PaCO2 may increase
Four clinical goals for managing stable COPD
Establish the diagnosis of COPD Optimize lung function Maximize the pts functional status Simplify the medical regimen as much as possible Prolong survival whenever possible
Features that favor the diagnosis of COPD.
Chronic daily phlegm production
Diminished vascularity on chest x-rays
Decrease diffusing capacity
Features that favor the diagnosis of asthma.
If the diminished FEV1 obtained on spirometry can be normalized after use of an inhaled bronchodilator.
Is airflow obstruction resulting from emphysema considered to be reversible?
Airflow obstruction from emphysema itself is irreversible.
What fraction of patients with stable COPD demonstrate a reversible component to airflow obstruction defined as a 12% (200 ml) rise in the postbronchodilator FEV1
2/3 of the patients with stable COPD exhibit a reversible component of airflow obstruction
Why is bronchodilator therapy recommended for patients with COPD?
bronchodilators produce smooth muscle relaxation resulting in improved airflow obstruction, improved symptoms and exercise tolerance, and decrease in the frequency and severity of exacerbation.
Both __________________ and ___________________ bronchodilators can improve airflow in patients with COPD.
Anticholinergic
Adrenergic
Other treatment options to optimize lung function include administering ______________ and methylxanthines
Corticosteroids
Systemic corticosteroids can produce significant improvements in airflow in a minority (___________) of patients with stable COPD.
6 - 29%
Controlled trials do show lessened dyspnea in ___________________ recipients despite lack of measurable increases in airflow.
Methylxanthine
Side effects of methylxanthines use.
Anxiety Tremulousness Nausea Cardiac arrhythmias Seizures
To minimize the chance of toxicity, current recommendations suggest maintaining serum theophylline levels at _________________
8 to 10 mcg/ml
What does the phrase “acute exacerbation” mean?
Sudden worsening of COPD symptoms (SOB, color of phlegm)
List strategies used to improve lung function during an acute exacerbation of COPD.
inhaled bronchodilators (especially beta-2 agonist) antibiotics systemic corticosteroid
Criteria defining the candidacy for noninvasive ventilation
Acute respiratory acidosis (without frank respiratory arrest)
Hemodynamic stability
Ability to tolerate the interface needed for noninvasive ventilation.
Describe what can be done to maximize the ability of a stable COPD patient to perform the activities of of daily living.
Pharmacologic treatments to maximize functional status include administration of bronchodilators to enhance lung function as much as possible and consideration of methylxanthine therapy.
What therapy has been proven to prolong the survival of COPD patients?
Smoking cessation program
Indications for long-term oxygen therapy
Continuous CO2
resting PaO2 ≤ 55mmHg
resting PaO2 56-59 mmHg or SaO2 89% in the presence of any of the following:
1. Dependent edema, suggesting CHF
2. P. pulmonale on the electrocardiogram (P wave >3 mm in standard lead II, III, or aVf)
3. Erythrocytosis (hematocrit >56%)
Noncontinuous
O2 flow rate and # of hours per day must be specified
1. during exercise: PaO2 ≤55 mmHg or SaO2 ≤ 88% with low level of exertion
2. during sleep: PaO2 ≤ 55 mmHg or SaO2 ≤ 88% with associated complications, such as pulmonary hypertension, daytime somnolence, or cardiac arrhythmias
Why should patients receive optimal bronchodilator therapy before being assessed for supplemental long-term continuous oxygen?
1/3 of potential O2 candidates experience sufficient improvemetn with aggressive bronchodilation to avoid the need for long-term supplemental O2.
What can be done to prevent the progression of COPD?
Breath cleaner air
Quit smoking
