Resp Pathologies

Question 1

What is emphysema

Answer 1

Destruction of alveolar walls and permanent enlargement of air spaces distal to terminal bronchioles

Question 2

How is emphysema caused

Answer 2

Cigarette smoke/inhaled pollutants - cause inflammatory cells to accumulate and release elastases and oxidants which destroy alveolar walls and elastin

Alpha-1 antitrypsin deficiency - without this antiproteinase there is an imbalance between proteinases and antiproteinases which results in destruction of elastin

Question 3

What happens to small airways as a result of emphysema

Answer 3

Small airways collapse as loss of elastin from alveolar walls causes radial traction to be lost ->bronchioles collapse as no longer held open by alveoli

Question 4

What effects does a loss of elastin have on the lung

Answer 4

Increases lung compliance

Decreases elastic recoil - results in air trapping

Lungs become hyperinflated due to loss of elastic recoil

Question 5

Why is airway obstruction worse in expiration than inspiration

Answer 5

Because the postivie intrapulmonary pressure during expiration exacerbates the narrowing of intra-thoracic airways

Question 6

What are the signs and symptoms of emphysema

Answer 6

Symptoms:

• Shortness of breath
• Reduced exercise tolerance

Signs:

• Barrel chest
• Obstructive pattern on spirometry

Question 7

What is interstitial lung disease

Answer 7

Group of diseases where there is tissue destruction and fibrosis

Interstitium of lung becomes filled with fibrous tissue, cells or fluid

Question 8

What does deposition of fibrous tissue in the interstitium result in

Answer 8

Lung becomes stiffer and harder to expand

Decreased lung compliance

Increased elastic recoil - lungs become smaller as a result

Restrictive type of ventilatory defect

Decreased chest expansion

Decreased lung volume

Lengthened diffusion time for gases - thick alveolar walls

Question 9

Do airways narrow in interstitial lung disease

Answer 9

No airways do not narrow as fibrous tissue exerts an outward radial traction on small bronchioles to keep airways open

Question 10

What are the signs and symptoms of interstitial lung disease

Answer 10

Signs:

• tachypnoea
• tachycardia
• reduced chest movement
• course crackles

Symptoms:

• shortness of breath
• reduced exercise tolerance
• dry cough

Question 11

What is pneumothorax and what happens to the lungs in a patient with pneumothorax

Answer 11

Pneumothorax - air in pleural space

If pneumothorax occurs, the lung on the side where it occurs will become squashed by the air inside the pleural space so lung collapses

Question 12

What is atelectasis

Answer 12

Lung collapse - either incomplete expansion of lungs or collapse of previously inflated lung

Question 13

What is respiratory distress syndrome

Answer 13

Condition that can occur in premature babies when surfactant is not produced resulting in high surface tension in fluid lining alveoli -> lungs harder to expand

Surfactant not produced until 26 weeks

Question 14

What are the signs and symptoms of RDS

Answer 14

Cyanosis

Grunting

Intercostal and subcostal recession

Nasal flaring

Tachypnoea

Question 15

Name some causes of hypoventilation

Answer 15

Trauma to brain stem or spinal cord

Opiates

Phrenic and intercostal nerve injury

Mysathenia gravis

Inherited muscle diseases

Severe obesity affecting chest wall

Kyphoscoliosis affecting chest wall

Pneumothorax

Large pleural effusion

Poor lung compliance due to RDS or lung fibrosis

Upper airway obstruction due to laryngeal oedema or foreign body

High airway resistance due to very severe acute asthma or late stage COPD