Clinical Concepts/Integration

Question 1

Hyaline Membrane Disease

Answer 1

• Premature infants have a lack of mature surfactant
• Alveoli are destabilized and collapse
• Increased elastance and recoil damage the alveoli and endothelium
• Protein leaks into the alveolus (noncardiogenic edema)
• Proteinaceous material creates ‘hyaline’ membranes on pathology

Question 2

Answer 2

Hyaline Membrane Disease

Question 3

Hyaline Membraen Disease Lung Volume

Answer 3

•decreases

Question 4

restrictive lung disease = […] elastance

Answer 4

increased

Question 5

HMD Treatment

Answer 5

• Surfactant replacement
• Oxygen
• Low pressure mechanical ventilation
• Low tidal volume
• High respiratory rate
• Nutrition

Question 6

Bronchopulmonary Dysplasia

Answer 6

Chronic lung disease due to

• Volutrauma/Barotrauma from ventilator
• Oxygen toxicity
• Inflammation

Question 7

Three Ways to Block an Airway

Answer 7

• in th elumen
• in the wall
• outside the wall

Question 8

BPD Physiology

Answer 8

• Mixed restrictive/obstructive disease
• Damaged airways
• No new airways after early second trimester
• Remodel airways to heal
• Damaged alveoli
• Millions of new alveoli and pulmonary capillaries heal gas exchange

Question 9

Answer 9

Question 10

Bronchioles depend on alveoli…

Answer 10

…to inflate, therfore pulling airways open.

Question 11

BPD Treatment

Answer 11

• Oxygen
• Nutrition
• Avoid Infection
• Avoid pulmonary hypertension
• Avoid aspiration
• Time

Question 12

Clues for CF

Answer 12

• Failure to thrive or ‘stunting’ 
• Chronic bronchiolitis’ and/or recurrent pneumonia
• Paroxysmal cough with cyanosis
• Abnormal stool history
• Hypochloremic alkalosis with dehydration

Question 13

CF Pathophysiology

Answer 13

• CFTR is a chloride channel
• CFTR regulates other channels; e.g. ENAC
• Reduced mucociliary clearance
• Chronic infection, especially P. aeruginosa
• Progressive damage to airway structure
• Bronchiectasis
• Thick sputum with high levels of DNA
• Progressive obstructive airway disease

Question 14

FEV1/FVC ratio is […] in obstructive airway disease.

Answer 14

decreased

Question 15

Answer 15

Endstage Bronchiectasis

Question 16

Cough

Answer 16

• Deep inspiration to load lung with gas
• Compression phase against closed vocal cords
• Rapid decompression phase
• Shake, rattle and roll
• Squeeze airways with dynamic compression

Question 17

Cough and CF

Answer 17

• Bronchiectasis commonly peripheral to equal pressure point at high lung volumes
• Mucus trapped behind airway compression

Question 18

Foreign Body Clues

Answer 18

• Age > 6-10 months and male
• ‘Helpful toddler sibling’ in home
• Sunflower seeds, peanuts, pinon nuts, etc….
• Coarse wheeze with monophonic component
• Heterophony (Differential air entry) with local hyperinflation or collapse
• 20-30% have a delayed diagnosis

Question 19

Intrathoracic Obstruction

Answer 19

•Intrathoracic airways 

• ncrease diameter with inspiration
• decrease diameter with expiration
• Intrathoracic obstruction causes expiratory wheeze
• Foreign body can be a ball-valve obstruction

Question 20

Croup

Answer 20

• subglottic narrowing
• Viral infection (parainfluenza, RSV)
• Onset with cold symptoms
• Development of sub-glottic (below the vocal cords) obstruction due to inflammation
• Barking cough and increased resistive work of breathing

Question 21

Extrathoracic Obstruction

Answer 21

Extrathoracic airways (pharynx, larynx, upper trachea)

• Increase diameter with expiration
• Decrease diameter with inspiration
• Extrathoracic airway obstruction causes inspiratory stridor
• Croup is a classic extrathoracic airway obstruction

Question 22

Croup and Helium

Answer 22

Sub-glottic space narrowest part of airway

• High velocities
• High Turbulence
• P = K2 x Flow2
• Helium is low density and reduces turbulence and work of breathing

Question 23

Intra - vs. Extrathoracic Obstruction

Answer 23

Inspiration:

• Pressure outside extrathoracic airway greater than in airway lumen
• Collapse on inspiration = inspiratory stridor

Expiration

• Pressure outside intrathoracic airway greater than in airway lumen
• Collapse on expiration = expiratory wheeze