When Air Becomes Breath
The Pentagon (restricted airspace)
Gen Chem 2
11th most expensive clinical condition (to medicare)
Schedule VI Drugs
100
What is FEV1, and what does it measure?
Forced Expiratory Volume in 1 second. It's a marker of airway obstruction.
100
Name one example of obstructive and one example of restrictive lung diseases.
Obstructive: COPD, asthma.
Restrictive: Pulmonary fibrosis, sarcoidosis, obesity hypoventilation.
100
What is the normal pH range for arterial blood?
Normal arterial pH: 7.35–7.45.
100
What are two risk factors for developing COPD?
Major risk factors: Smoking, air pollution, occupational exposure, alpha-1 antitrypsin deficiency.
100
What class of drug is albuterol, and how does it help in COPD or asthma?
Albuterol is a short-acting β₂-agonist. It relaxes bronchial smooth muscle → rapid relief in bronchospasm (asthma, COPD exacerbations).
200
Define residual volume (RV) and total lung capacity (TLC).
Residual Volume (RV): Volume of air left in lungs after maximal exhalation. Total Lung Capacity (TLC): The total volume of air in lungs after maximal inspiration (includes RV).
200
Describe how lung volumes (RV, TLC) are altered in obstructive vs restrictive disease.
Obstructive: ↑RV, ↑TLC (due to air trapping). Restrictive: ↓RV, ↓TLC (due to limited expansion).
200
What is the bicarb buffer system and how does respiration affect it?
Inspiring/holding breath retains CO2, driving towards acidosis, and hyperventilating expels CO2, driving towards alkalosis
200
Describe the pathway by which smoking leads to emphysematous changes in alveoli.
Smoking → chronic inflammation → ↑elastase activity → alveolar wall destruction → ↓surface area for gas exchange (emphysema).
200
What is the MOA of tiotropium? When is it indicated?
Tiotropium is a long-acting muscarinic antagonist. It blocks M3 receptors → bronchodilation. Indicated in maintenance therapy of COPD.
300
What happens to the FEV1/FVC ratio in obstructive vs restrictive diseases?
In obstructive disease, FEV1 decreases significantly, so FEV1/FVC is <70%. In restrictive disease, both FEV1 and FVC are reduced proportionally, so the ratio is normal or increased.
300
What is the pathophysiologic difference between emphysema and chronic bronchitis?
Emphysema: Alveolar wall destruction, ↓elastic recoil, air trapping.
Chronic bronchitis: Mucus gland hyperplasia → productive cough.
Both under COPD umbrella but with different pathology.
300
How does the body compensate for respiratory acidosis vs metabolic acidosis?
Respiratory acidosis: Kidneys retain HCO₃⁻.
Metabolic acidosis: Lungs increase ventilation to blow off CO₂.
300
How does alpha-1 antitrypsin deficiency cause disease?
Alpha-1 antitrypsin inhibits elastase. Deficiency → unopposed elastase → alveolar wall destruction → panacinar emphysema, especially in lower lobes.
300
Why is salmeterol often paired with fluticasone?
Salmeterol = long acting β₂-agonist; Fluticasone = inhaled corticosteroid. Combo improves symptoms and reduces exacerbations.
400
Describe ventilation and how it relates to lung compliance.
Ventilation (volume of air entering the lungs per min) depends on lung compliance (ΔV/ΔP) and airway resistance. High compliance (as in emphysema) = easier to expand; low compliance (as in fibrosis) = stiff lungs, harder to expand.
400
What would a flow-volume loop look like in restrictive lung disease?
400
Define the alveolar-arterial (A–a) O₂ gradient.
Double or nothing: What does an elevated gradient mean?
Elevated gradient indicated decreased diffusion of O2 from alveoli to pulmonary capillaries
400
What are common systemic complications of severe COPD? (Name at least 2)
Systemic complications: Weight loss/cachexia, cor pulmonale, polycythemia, osteoporosis, depression.
400
What is the short acting form of tiotropium?
Ipratropium
500
Explain how changes in airway resistance affect ventilation using Poiseuille’s law.
Poiseuille’s Law: Resistance ∝ 1/r⁴. Small changes in airway radius greatly increase resistance, decreasing airflow. This explains wheezing and dyspnea during bronchoconstriction.
500
Why does air trapping occur in emphysema, and how does this contribute to a barrel chest?
In emphysema, destruction of alveolar walls reduces elastic recoil → air is not fully exhaled → air trapping → increased AP diameter → barrel chest (↑TLC, ↑RV).
500
A patient with COPD has impaired CO2 clearance. What would be seen in blood and how is it compensated?
COPD → hypoventilation → ↑PaCO₂ → kidneys retain HCO₃⁻ → ↑HCO₃⁻
500
Explain cor pulmonale and how it results from chronic hypoxia in COPD.
Chronic hypoxia → pulmonary vasoconstriction → ↑pulmonary artery pressure → RV hypertrophy/failure → cor pulmonale. Seen in late-stage COPD.
500
Diskus is a trademark brand name, all praise to pharm companies. What is the actual route of administration of the glorious brand Diskus?
Dry powder inhalation