34 - Obstructive Pulmonary Disorders

Question 1

1) Know the main categories of obstructive lung diseases (↑ in resistance to flow)

Answer 1

o Obstruction from conditions in the wall of the airway
 Asthma, acute/chronic bronchitis
o Obstruction related to loss of lung parenchyma
 Emphysema
o Obstruction of the airway lumen
 Bronchiectasis, bronchiolitis, cystic fibrosis, acute tracheobroncial obstruction, epiglottitis, croup syndrome

Question 2

2) Know the main differences between the three most prevalent obstructive lung disorders: asthma, chronic bronchitis, and emphysema

Answer 2

Asthma - high reversibility
Chronic bronch - high sputum
Emphysema - high alveolar damage

Question 3

3) Describe the main pathophysiological features of chronic asthma

Answer 3

• Allergen comes into contact with airway
• Inflammatory cells are recruited and are activated (releasing inflammatory mediators)
• Bronchoconstrcition, plasma exudation, and edema, vasodilation, mucus hypersecretion, activation of sensory nerves.
• Chronic inflammation
o Leads to structural changes
o Basement membrane thickening, angiogenesis, hyperplasia and hypertrophy
• MAIN FEATURE:
o Contraction of airway smooth muscle, airway wall thickening, accumulation of airway secretions/mucus/debris

Question 4

Asthma treatment

Answer 4

• Treatment
o Beta adrenergic agents
 Stimulate Beta-2 receptors on bronchial smooth muscle
o Anticholinergics
 Block M3 receptors
o Controller treatments
 Modify asthmatic environment
 Many of these block inflammatory mediators
• Inhaled corticosteroids, antilekotrienes, long-acting Beta agonist, theophylline, systemic corticosteroids, Anti-IgE treatment

Question 5

4) Recognize key pulmonary function test abnormalities in obstructive lung disorders

Answer 5

• Cardinal pulmonary function abnormality: Decrease in airflow rates throughout vital capacity
• Peak expiratory flow rate, forced expiratory volume in the first second and maximal mid-expiratory flow rate are all decreased
• The PERF and FEV1 will get better as attack diminishes, but MMERF might have some residual depression
• Lung volume measurements demonstrate and increase in total lung capacity and residual volume.
• V/Q relationship decreases?