Respiratory System

Question 1

Describe the pathophysiology of a pneumothorax

Answer 1

air enters the pleural cavity, separating the visceral and parietal pleura and destroys the negative pressure

• disrupts the equilibirum between the elastic recoil forces of the lung and chest wall
• lung tends to recoil by collapsing towards the hilum

Question 2

Identify the causes of pneumothorax

Answer 2

• can occur spontaneously or secondary to trauma e.g. shooting, rib fracture, stabbing

Question 3

Identify the signs/symptoms of a pneumothorax

Answer 3

• plural pain
• tachypnoea
• dyspnoea
• fatigue

Question 4

Identify possible complications of pneumothorax

Answer 4

• severe hypoxaemia
• tracheal deviation from the affected lung
• hypotension

Question 5

Describe the pathophysiology of emphysema

Answer 5

abnormal enlargement of gas-exchange airways accompanied by destruction of alveolar walls

• inhaled oxidants in tobacco smoke and air pollution stimulate inflammation, which over time causes alveolar destruction and loss of the normal elastic recoil of the bronchi

Question 6

Identify the signs/symptoms of emphysema

Answer 6

• dyspnoea
• cough
• wheezing
• prolonged expiration
• barrel chest

Question 7

Identify the complications of emphysema

Answer 7

• pneumothorax

- pulmonary hypotension

Question 8

Describe the pathophysiology of chronic bronchitis

Answer 8

Chronic inflammation of the bronchi
- hyper secretion of mucus and chronic productive cough for at least 3 months of the year for at least 2 consecutive years

Question 9

Describe the effect of continuous bronchial irritation and inflammation (chronic bronchitis)

Answer 9

Causes bronchial oedema and increases the size and number of mucous glands in the airway epithelium

• thick mucus cannot be cleared because of impaired ciliary function

Question 10

Identify the signs/symptoms chronic bronchitis

Answer 10

• productive cough
• intermittent wheezing
• prolonged expiration
• cyanosis

Question 11

Identify possible complications of chronic bronchitis

Answer 11

• respiratory failure: inadequate intake of oxygen and exhalation of co2
• Cor pulmonale
• pneumothorax

Question 12

Describe the pathophysiology of a pulmonary embolism

Answer 12

Occlusion of a portion of the pulmonary vascular bed by an embolus (may be a thrombus), tissue fragment, lipids, foreign body or air bubble

Question 13

Define the 3 different types of pulmonary emboli

Answer 13

• massive occlusion: occludes a major portion of the pulmonary circulation
• embolus with infarction: an embolus that is large enough to cause infarction of a portion of lung tissue
• embolus without infarction: an embolus that is not severe enough to cause permanent lung injury

Question 14

Identify the signs/symptoms of a pulmonary embolism

Answer 14

Non-specific and often asymptomatic

• sudden onset of chest pain
• dyspnoea
• tachypnoea
• tachycardia

Question 15

Define the pathophysiology of asthma

Answer 15

Chronic inflammatory disease which is characterised by reversible airway obstruction and bronchospasm

• after exposure to trigger, mast cells release variety of inflammatory mediators

Question 16

What triggers asthma?

Answer 16

Allergens, irritants, exercise or infection

Question 17

Identify complications of asthma

Answer 17

• respiratory failure

Question 18

Discuss the pathophysiology of Acute Respiratory Distress Syndrome

Answer 18

characterised by lung inflammation through activation of the inflammatory response

• all disorders causing ARDS cause massive pulmonary inflammation that injures the alveolar-capillary membrane and produces severe pulmonary oedema and hypoxaemia

Question 19

Provide examples of direct and indirect ARDS

Answer 19

Direct: aspiration of highly acidic gastric contents or inhalation of toxic gases

Indirect: chemical mediators released in response to systemic disorders such as sepsis

Question 20

Identify the role of neutrophils in the development of ARDS

Answer 20

activated neutrophils release inflammatory mediators

• mediators extensively damage the alveolar-capillary membrane and greatly increase capillary membrane permeability
• allows fluids, proteins and various blood cells to leak from capillary bed into pulmonary interstitium and alveoli

Question 21

Identify signs/symptoms of ARDS

Answer 21

• dyspnoea
• rapid shallow breathing
• inspiratory crackles
• decreased lung compliance

Question 22

Identify complications of ARDS

Answer 22

mediators responsible for alveolar capillary damage often causes widespread inflammation, endothelial damage and capillary permeability throughout the body

• results in systemic inflammatory response syndrome
• leads to multiple organ dysfunction syndrome
• can result in death

Question 23

Describe what is meant by the term lung compliance and which conditions can decrease/increase it

Answer 23

Refers to the ease with which the lungs can be inflated
- Measure of the change in lung volume that occurs with the change in intrapulmonary pressure

Decrease: pulmonary fibrosis, pneumonia, pulmonary oedema

Increase: pulmonary emphysema, asthma