W5

Question 1

What is the main pathophysiological difference between an obstructive and restrictive lung condition?

Answer 1

Obstructive ==> Limitation of expiratory airflow due to abnormal airways
Restrictive ==> Limitation of inspiratory airflow due to abnormal lung tissue

Question 2

What is COPD?

Answer 2

Chronic obstruction of expiratory airflow due to abnormalities in the airways and/or loss of alveoli tissue

Question 3

What are the typical clinical findings in a COPD pt?

Answer 3

• SOB
• Incr. RR and WOB
• Wheeze
• Cough
• Abnormal ausc. findings
• Fatigue
• Hyperinflation on CXR
• FEV1 / FVC < 0.7
• Hypoxemia +/- hypercapnia

Question 4

What are the risk factors for COPD?

Answer 4

• Smoking
• Secondary exposure to smoke or other environmental toxins
• Age
• Hx of childhood respiratory infections
• Genetics

Question 5

What is pathophysiology for COPD?

Answer 5

Airway inflammation (from chronic exposure to risk factors) ⇒ mucus hypersecretion + alveoli tissue destruction ⇒ Decr. elastic recoil and radial traction (decr. lung compliance) + expiratory airflow obstruction ⇒ Air trapping ⇒ Hyperinflation

Question 6

Chronic hypoxemia can lead to R sided heart failure. What is the term and pathophysiological process for this?

Answer 6

Cor pulmonale
Chronic hypoxia → Hypoxia pulmonary vasoconstriction → Pulmonary artery HT → R ventricle pathological hypertrophy → R sided diastolic dysfunction (cor pulmonale)

Question 7

What are the complications from hyperinflated lungs

Answer 7

⇑ Alveolar dead space
V/Q mismatch
Hypoxemia
Dyspnoea
⇑ Use of accessory respiratory muscle
⇓ Use of diaphgram during ventilation

Question 8

What is the pathophysiology of asthma?

Answer 8

Incr. airway sensitivity to stimulus ⇒ bronchial hyperactivity ⇒ mucus hypersecretion (goblet cell hypertrophy) + bronchial smooth muscle hypertrophy ⇒ Incr. airway obstruction and constriction ⇒ Decr. expir. airflow + premature airway collapse

Question 9

Describe bronchiectasis.

Answer 9

Permanent dilation of airways

Question 10

What is the pathophysiology of bronchiectasis?

Answer 10

Initial infection ⇒ Inflammatory and mucociliary response ⇒ Mucus hypersecretion + cilia dysfunction (impaired mucociliary clearance) ⇒ mucus plug formation ⇒ microbial colonisation ⇒ further inflammation and infection ⇒ destruction of airway elasticity and muscular components⇒ ⇓ bronchial elastic recoil ⇒ further ⇓ mucociliary clearance ⇒ cycle of chronic inflammation

Question 11

What is the pathophysiology of cystic fibrosis?

Answer 11

CF transmembrane conductance regulator gene defect ⇒ ⇑ chloride and sodium ion uptake in epithelial cells of respiratory tract ⇒ ⇑ water reuptake into cells ⇒ ⇓ Aqueous sole layer height ⇒ ⇑ mucus viscosity and tenacity ⇒ ⇓ mucociliary clearance ⇒ Mucus plug formation ⇒ Microbial colonisation ⇒ Recurrent respiratory infection

Question 12

What the non-respiratory complications of cystic fibrosis?

Answer 12

• Fat malabsorption
• Poor weight gain
• Anemia
• Osteopenia
• Malnutrition
• Cystic fibrosis diabetes

Question 13

What is the pathophysiology of pulmonary fibrosis?

Answer 13

Irreversible accumulation of scar tissue within the lung interstitium ⇒ Thickening and rigidity of interstitium ⇒ ⇓ lung compliance + ⇑ elastic recoil ⇒ ⇓ lung expansion/capacity

Question 14

Clubbing is a common clinical sign in chronic pulmonary diseases due to ____

Answer 14

Chronic hypoxemia

Question 15

List 4 respiratory disease questionnaires

Answer 15

• Chronic respiratory disease questionnaire
• St George’s respiratory disease questionnaire
• Nijmegen Questionnaire
• Modified medical research council dyspnea score

Question 16

What is dynamic hyperinflation and pathophysiology underlying it?

Answer 16

Dynamic hyperinflation ⇒ Incr. hyperinflation during physical activity
Hyperinflation ⇒ Diaphragm in a shortened position ⇒ ⇓ Contribution to ventilation ⇒ ⇑ ventilation requirements (during physical exertion) ⇒ ⇑ Expir. Flow rate demands + ⇓ time for expir. ⇒ Inability to meet demands (due expir. Flow limitations) ⇒ ⇑ hyperinflation during physical activity (dynamic hyperinflation) ⇒ ⇑ Dyspnea