Pathology of pulmonary infection Flashcards
List some upper respiratory tract infections
Coryza - common cold Sore throat syndrome Acute laryngotracheobronchitis (croup) Laryngitis Sinusitis Acute epiglottitis
What infections usually cause acute epiglottis?
Group A beta-haemolytic streptococci
Haemophilus influenza type B
Parainfluenza type 4
List some lower respiratory tract infections
Bronchitis
Bronchiolitis
Pneumonia
Describe some respiratory tract defence mechanisms
Macrophage-mucociliary escalator system
Immune system
Respiratory tract secretions
What are the 7 different types of pneumonia
Community acquired pneumonia Hospital acquired/nosocomial pneumonia Pneumonia in the immunocompromised Atypical pneumonia Aspiration pneumonia Recurrent pneumonia Cryptogenic organising pneumonia/bronchiolitis obliterates organising pneumonia (COP/BOOP)
What are some complications of pneumonia?
Pleurisy Pleural effusion Empyema Fibrosis from chronic inflammation Lung abscess Bronchioectasis
Describe COP/BOOP
Non-infectious pneumonia, inflammation of bronchioles and surrounding tissue, which is often complicated with an existing chronic inflammatory disease or induced by certain drugs (amiodarone)
What drug can cause COP/BOOP?
Amiodarone
What can cause a lung abscess?
Obstructed bronchus Aspiration Certain organisms e.g. SA, pneumococci Pyaemia Necrotic lung
What can cause bronchiectasis?
Severe infective episodes recurrent infections proximal bronchial obstruction lung parenchymal destruction Damage to epithelium/cilia e.g. viral infections
Describe bronchioectasis
Bronchi dilates, making the MCE not as effective. Debris collects and infections develop
What are the common symptoms of bronchiectasis?
Cough Abundant purulent foul smelling sputum Haemoptysis Signs of chronic infection Coarse crackles Clubbing
How do you treat bronchiectasis?
Postural drainage
Antibiotics
Surgery in severe cases
What can cause recurrent lung infections?
Bronchial obstruction - tumour, foreign body
Pulmonary damage - bronchiectasis
Lung disease - CF, COPD
Non-resp disease - immunocompromised
What can cause aspiration pneumonia?
Vomiting Oesophageal lesion Obstetric anaesthesia Neuromuscular disorders Sedation
List some opportunistic pathogens which can cause pneumonia
Low grade bacterial pathogens
CMV
Pneumocystis jirovecii
Fungi/yeasts
Describe type I respiratory failure
Low PaO2 and normal/low PaCO2
Lung damage
V-P mismatch or R to L shunts
Describe type II respiratory failure
Low PaO2 and high PaCO2
Alveolar hypoventilation
What can cause type I respiratory failure?
Low ambient oxygen V-P mismatch Alveolar hypoventilation Diffusion problems Shunt
What causes type II respiratory failure?
Increased airways resistance Reduced breathing effort Decrease in lung area available for GE Neuromuscular problems Deformed/rigid/flail chest
What 4 abnormal states are associated with hypoxaemia (can think of these for each specific lung disease)?
V-P mismatch
Diffusion impairment
Alveolar hypoventilation
Shunt
How can pulmonary vascular changes in hypoxaemia affect the heart?
In long standing hypoxia, if all the vessels to the heart are constricted in response to poor ventilation, the right ventricle adapts and hypertrophies to try and compensate by increasing blood flow to the lungs = right sided heart failure
Describe pulmonary shunt
Blood passes from right to left side of the heart without contacting ventilated alveoli
What is hypoxic cor pulmonale?
Hypertrophy of the right ventricle resulting from disease affecting the function and/or structure of the lung
