Chronic Obstructive Disorders Flashcards
Chronic Obstructive Pulmonary Disease (COPD)
- what is it characterized by?
- what are the major disorders in this disease?
- characterized by decreased airflow rate during expiration, often accompanied by elevated functional residual capacity resulting from trapped air
- characterized by slow, progressive IRREVERSIBLE airway obstruction due to chronic bronchitis and/or emphysema
-Chronic bronchitis, emphysema, bronchiectasis
Define:
chronic bronchitis
emphysema
bronchiectasis
Chronic Bronchitis- a chronic productive cough for three months in each of two successive years in a pt in whom other causes of chronic cough have been excluded
Emphysema- abnormal and permanent enlargement of the airspaces that are distal to the terminal bronchioles, accompanied by destruction of the airspace walls WITHOUT obvious fibrosis
Bronchiectasis- shares many clinical features with COPD, including inflamed and easily collapsible airways and obstruction to airflow usually caused by infection
Is COPD a preventable disease?
Is it treatable?
Is it fully reversible?
preventable-YES!!
treatable- yes!
reversible- nooooo, airflow limitation is not fully reversible
COPD has periodic exacerbations with what sx?
- increased dyspnea
- increased sputum (usually colorless)
- occasionally respiratory failure
What is the most common cause of COPD? other causes?
cigarette smoking!
other causes include alpha 1 antitrypsan deficiency, environmental/occupational dusts and gases
COPD pathophysiology
how does COPD affect RV, FRC (functional residual capacity), TLC, and VC?
Airways become irritated or poisoned from cigarettes and cause airway obstruction in the smaller conducting airways. This results in peripheral airway resistance due to:
- destruction of alveolar support
- loss of elastic recoil
- structural narrowing due to inflammation
RV- increased
FRC- increased
TLC- may remain normal but is often increased
VC- reduced (due to air trapping and the decrease in lung elastic recoil)
Would you expect to see a V/Q mismatch in COPD? why or why not?
Yes, the loss of surface area along with bronchial obstruction and altered distribution of ventilated air results in V/Q mismatch
How does COPD create physiologic dead space?
COPD causes hyperinflation of the lungs (because of air trapping), in which alveolar pressure exceeds pulmonary artery pressure, stops perfusion and creates a physiologic dead space
Pathophysiology of Airflow Obstruction
- structural changes increase the work of breathing
- larger lung volumes put inspiratory muscles at a mechanical disadvantage
- diaphragm is flattened, decreasing its ability to change intrathoracic volume
- destruction of alveoli decreases surface area for gas exchange
How does Asthma differ from COPD?
asthma is reversible, COPD is not
Chronic bronchitis
aka and why
pathologic findings
classic sx
aka- Blue Bloaters, unable to maintain normal blood gases by increasing their breathing effort and therefore become hypoxic, hypercapic, cyanotic
findings-
- goblet cell hyperplasia
- mucous plugging, excess mucous secretion
- fibrosis (not interstitial fibrosis)
- narrowing of the airway lumen
- excessive bronchial secretions and airway obstruction cause a V/Q mismatch
classic sx
- dyspnea
- chronic cough (productive)
- mucous production (leading to frequent and recurrent pulmonary infections)
- weight gain (early on because they cant breathe so they become couch potatoes)
Emphysema
aka and why
what is it
most common cause
aka- pink puffers, pursed lip breathing is helpful because: 1. it increases resistance to the outflow of air and 2. helps prevent airway collapse by increasing airway pressure
what is it- abnormal enlargement of the airspaces distal to the terminal bronchioles, with destruction of the alveolar walls and capillary beds. The abnormal airspaces (Bullae) compress surrounding area of more normal lung
cause- cigarette smoking and alpha-1 antitrypsin deficiency
Emphysema patient presentation
- long history of progressive dyspnea with late onset of nonproductive cough
- initially, they are able to overventilate and maintain relatively normal blood gas levels until late in the disease
What are the two types of emphysema? Which one is most common? For each, what part of the lung is it most severe in?
Centrilobular emphysema (CLE) -most common type, most severe in upper lobes
Panlobular emphysema (PLE)- most severe in lower lung zones, generlly develops in pts with alpha-1 antitrypsin deficiency
What might you suspect in a 35 year old smoker patient with dyspnea?
alpha-1 antitrypsan deficiency