COPD Flashcards
COPD
Chronic obstructive pulmonary disease - characterized by chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible - preventable and treatable.
COPD is an umbrella term for emphysema and chronic bronchitis.
Emphysema
Damage or destruction of the alveoli resulting in alveolar enlargment.
How are the alveoli affected in emphysema?
The alveoli enlarge, and lose their elasticity.
What aspect of breathing people with emphysema have difficulty with?
Exhaling
What is the difference between emphysema and chronic bronchitis?
Chronic bronchitis has clinical features such as a productive cough where as emphysema is based on structural changes to the lung.
What is FEV1/FEV ratio is a sign of COPD?
0.7
How does smoking cause COPD?
When the alveoli is exposed chemical irritants in cigarettes it cause inflammation of the alveolar wall.
The inflammatory reaction attracts immune cells which release inflammatory mediators such as leukotrienes, IL and TNF and proteases such as ELASTASES and COLLAGENASES.
What is the significance of the elastases and collagenases being released?
The cause break down of the collagen and elastin in the alveolar wall. This causes the alveoli to lose their elasticity and collapse.
How does lose of elastin affect septa?
Septa are the thin alveolar walls, breakdown of the septa causes alveoli to merge to form much larger air spaces, this decreases the surface area available for gas exchange. Affecting Co2 and O2 levels.
Acinus
Endings of the lung airway where the clusters of alveoli are located.
Centriacinar emphysema affects where?
The proximal alveolar of the acinus - typically in the upper lobes of the lungs.
Panacinar emphysema affect where?
Where the entire acinus is affected, specifically in the lower half of the lungs
What genetic condition is panacinar emphysema often associated with?
Alpha 1 antitrypsin deficiency (A1AT deficiency)
What is alpha 1 antitrypsin?
A protease inhibitor of elastase
How does cigarette smoke affect AIAT?
Cigarette smoke decreases Alpha 1 antitrypsin activity.
Paraseptal emphysema affects where?
The distal alveoli of the acinus, classicly affects the periphery of the lobes of the lungs, near the interlobular septa.
What is the big clinical risk with paraseptal emphysema?
The lung wall can rupture leading to a pneumothorax.
What are the symptoms of emphysema?
Dyspnea Slow exhalation through pursed lips Hypoxemia Cough with small amount of sputum Barrel shaped chest
Dyspnea
Shortness of breath
What blood pressure complication occurs as a result of emphysema?
Pulmonary hypertension
Cor pulmonale
Enlargement of the right side of the heart due to pulmonary hypertension, leads to right sided heart failure.
Treatment of COPD?
Reduce risk factors - stopping smoking
Supplemental oxygen
Medication: Bronchodilators, ICS, antibiotics
Overview of emphysema
Irritants in cigarette smoke lead to break down of elastin in alveolar walls. This leads to air trapping and poor gas exchange - which eventually leads to hypoxemia.
Chronic bronchitis
Inflammation of the bronchial tubes, said to be chronic because it results in a productive cough present for 3 months a year for 2 years.
What are the risk factors of chronic bronchitis?
Smoking
Air pollutants (S2 and NO2)
Family history
Exposure to dust and silica
What type of epithelium lines the airways?
Ciliated pseudostratified columnar epithelium.
How does smoking cause chronic bronchitis?
Smoke causes hypertrophy and hyperplasia of the mucinous glands of the main bronchi and the goblet cells in the bronchioles.
> this increases mucus production
Smoking also makes the cilia shorter and less mobile making it hard to move mucus out of the lungs.
Why is the increased production in bronchioles such a problem?
As the bronchioles are smaller, it is easy for an increase in mucus production to lead to airway obstruction.
How are chronic bronchitis and emphysema diagnosed differently?
Emphysema has a pathlogical diagnosis (CT scan).
Chronic bronchitis has a clinical diagnosis - history productive cough (3 months a year for 2 years).
Why do people with chronic bronchitis cough so much?
Due to the increased mucus production and decreased functioning of cilia, patients relying on coughing to get rid of their mucus plugs.
What are the symptoms of bronchitis?
Wheezing due to airway obstruction
Crackles
Hypoxemia
Hypercapnia