Respiratory System Flashcards
Describe the pathophysiology of a pneumothorax
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
Identify the causes of pneumothorax
- can occur spontaneously or secondary to trauma e.g. shooting, rib fracture, stabbing
Identify the signs/symptoms of a pneumothorax
- plural pain
- tachypnoea
- dyspnoea
- fatigue
Identify possible complications of pneumothorax
- severe hypoxaemia
- tracheal deviation from the affected lung
- hypotension
Describe the pathophysiology of emphysema
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
Identify the signs/symptoms of emphysema
- dyspnoea
- cough
- wheezing
- prolonged expiration
- barrel chest
Identify the complications of emphysema
- pneumothorax
- pulmonary hypotension
Describe the pathophysiology of chronic bronchitis
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
Describe the effect of continuous bronchial irritation and inflammation (chronic bronchitis)
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
Identify the signs/symptoms chronic bronchitis
- productive cough
- intermittent wheezing
- prolonged expiration
- cyanosis
Identify possible complications of chronic bronchitis
- respiratory failure: inadequate intake of oxygen and exhalation of co2
- Cor pulmonale
- pneumothorax
Describe the pathophysiology of a pulmonary embolism
Occlusion of a portion of the pulmonary vascular bed by an embolus (may be a thrombus), tissue fragment, lipids, foreign body or air bubble
Define the 3 different types of pulmonary emboli
- 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
Identify the signs/symptoms of a pulmonary embolism
Non-specific and often asymptomatic
- sudden onset of chest pain
- dyspnoea
- tachypnoea
- tachycardia
Define the pathophysiology of asthma
Chronic inflammatory disease which is characterised by reversible airway obstruction and bronchospasm
- after exposure to trigger, mast cells release variety of inflammatory mediators
What triggers asthma?
Allergens, irritants, exercise or infection
Identify complications of asthma
- respiratory failure
Discuss the pathophysiology of Acute Respiratory Distress Syndrome
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
Provide examples of direct and indirect ARDS
Direct: aspiration of highly acidic gastric contents or inhalation of toxic gases
Indirect: chemical mediators released in response to systemic disorders such as sepsis
Identify the role of neutrophils in the development of ARDS
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
Identify signs/symptoms of ARDS
- dyspnoea
- rapid shallow breathing
- inspiratory crackles
- decreased lung compliance
Identify complications of ARDS
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
Describe what is meant by the term lung compliance and which conditions can decrease/increase it
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
