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?
What sort of immune response does asthma induce?
Name 3 key interleukins (and what they do) involved in asthma.
Th2 induces the release of:
1. IL-4 - induces class switching from IgG to IgE
2. IL-5 - recruits eosinophils
3. IL-10 - promotes the Th2 response and inhibits the Th1 response
How do we test for asthma?
What are the clinical findings in asthma?
Cough, wheezing, tachypnea, dyspnea, hypoxemia, pulsus paradoxus, mucus plugging, decreased I/E ratio
Describe the pathophysiology in bronchiectasis.
Chronic necrotizing infection of bronchi leads to permanently dilated airways which leads to loss of tone allowing for air to be trapped since it has trouble accelerating and be expelled
What are 5 things associated with bronchiectasis?
1. Bronchial obstruction
2. Poor ciliary motility (smoking)
3. Kartagener syndrome (defect in dynein arm of cilia)
4. Cystic fibrosis
5. Allergic bronchopulmonary aspergillosis
What are some clinical findings in bronchiectasis?
Purulent sputum, recurrent infections, hemoptysis
What is the main problem in restrictive lung disease?
Problem with filling the lung (restricted expansion)
What happens to FVC and TLC in restrictive lung disease?
What is the signature PFT's in restrictive lung disease?
FEV1/FVC ratio > 80%
What are the two types of restrictive lung disease and how do you characterize each?
1. Poor breathing mechanics - extrapulmonary, peripheral hypoventilation, normal A-a gradient
2. Interstitial lung diseases - decreased pulmonary diffusing capacity, increased A-a gradient
In terms of restrictive lung disease caused by poor breathing mechanics, what are two subcategories of deficits?
1. Problem with the muscles - e.g. polio, myasthenia gravis
2. Problem with the physical structure - e.g. scoliosis, morbid obesity
What are 10 interstitial lung diseases that can lead to restrictive lung disease?
2 respiratory distress syndromes:
1. Acute respiratory distress syndrome
2. Neonatal respiratory distress syndrome
2 from outside toxins
1. Drug toxicity (bleomycin, busulfan, amiodarone, methotrexate)
2 hypersensitivity reactions
1. Hypersensitivity pneumonitis
2. Goodpasture syndrome
3 that cause granulomas
2. Granulomatosis with polyangiitis (Wegener's)
3. Langerhans cell histiocytosis
1. Idiopathic pulmonary fibrosis
What is damaged in neonatal respiratory distress syndrome?
What is sarcoidosis?
Systemic disease involving non-caseating granulomas in multiple organs
What are some of the findings in sarcoidosis?
Bilateral hilar lymphadenopathy, increased ACE, hypercalcemia, dyspnea or cough
Why is there hypercalcemia in sarcoidosis?
Granulomas have 1 alpha hydroxylase so they upregulate vitamin D activity leading to increased serum calcium levels
Describe what happens in idiopathic pulmonary fibrosis.
Repeated cycles of lung injury and wound healing with increased collagen deposition - TGF beta from injured pneumocytes induces fibrosis
What are some of the drugs that can cause interstitial lung disease?
Bleomycin, busulfan, amiodarone, methotrexate
What is hypersensitivity pneumonitis?
Mixed type III/IV hypersensitivity reaction to organic environmental antigen
What are 5 clinical findings in hypersensitivity pneumonitis?
3. Chest tightness
What two groups of people is hypersensitivity pneumonitis often seen in?
2. Those exposed to birds
How do we treat hypersensitivity pneumonitis?
Remove the exposure