Flashcards in RESPIRATORY: 604 - 605 Deck (53)
What is the main problem in obstructive lung disease?
Obstruction of air flow - can't get air out of the lungs
What happens to the residual volume and forced vital capacity in obstructive lung disease?
RV increases and FVC decreases
What is forced vital capacity (FVC)?
What are the significant PFT's in obstructive lung disease?
Extremely decreased FEV1
Decreased FEV1/FVC ratio (hallmark)
Name the major complication in obstructive lung disease.
Chronic, hypoxic pulmonary vasoconstriction can lead to cor pulmonale
What is cor pulmonale?
Enlargement and failure of the right ventricle of the heart as a response to pulmonary hypertension
What are the 4 types of obstructive lung disease?
1. Chronic bronchitis
Describe the pathophysiology of chronic bronchitis.
Hyperplasia of mucus-secreting glands in the bronchi leads to mucus plugs obstructing the airway
What is the classic description of a patient with chronic bronchitis?
What clinical findings are associated with chronic bronchitis?
1. Productive cough
5. Late-onset dyspnea
6. CO2 retention
What type of cough is diagnostic for chronic bronchitis?
Productive cough for > 3 months per year (not necessarily consecutive) for > 2 years
Which airways are primarily affected in chronic bronchitis?
What is the Reid index?
Thickness of gland layer/total thickness of bronchial wall
What complications are patients with chronic bronchitis at risk for?
Infection and cor pulmonale
What is the Reid index in patients with chronic bronchitis?
Describe the pathologic changes in emphysema.
Destruction of alveolar walls leads to enlargement of air spaces, decreased recoil, and increased compliance
Why do emphysema patients exhale through pursed lips?
To increase airway pressure and prevent airway collapse during respiration
What are the two types of emphysema and what are they associated with?
1. Centriacinar - smoking
2. Panacinar - alpha1-antitrypsin deficiency
What is chronic bronchitis usually linked to?
What are two mechanisms by which emphysema leads to air trapping?
1. Loss of elastic recoil and subsequent collapse of small airways
2. Imbalance of proteases and antiproteases
Is emphysema more a physical or physiologic obstruction?
What is the most important antiprotease in the lung?
Why does the lung need antiproteases?
To protect the lung tissue from proteases from inflammation stimulated by alveolar macrophages
Why does smoking lead to emphysema?
Lots of toxic debris --> increased activity of alveolar macrophages --> increased inflammation --> increased protease activity
Is asthma reversible or irreversible?
What is asthma?
Bronchial hyperresponsiveness causing reversible bronchoconstriction
Describe three histologic findings in asthma.
1. Smooth muscle hypertrophy
2. Curschmann spirals (shed epithelium forms mucus plugs)
3. Charcot-Leyden crystals (formed from breakdown of eosinophils in sputum)
List 5 causes of asthma.
2. Viral URI's
What type of hypersensitivity reaction is asthma?