Pathology of respiratory tract infection Flashcards
(31 cards)
3 types of microorganism pathogens
- Primary
- Facultative
- Opportunistic
Upper Respiratory Tract Infection examples
- Coryza, common cold
- Sore throat syndrome
- Acute Laryngotracheobronchitis (Croup)
- Laryngitis
- Sinusitis
- Acute Epiglottitis
Acute Epiglottitis
Bacterial infection of the epiglottis
- Group A beta-haemolytic Streptococci
- Haemophilus influenzae (type b- Hib)
Lower Respiratory Tract infections
- Bronchitis
- Bronchiolitis
- Pneumonia
What are the respiratory tract defence mechanisms?
- Macrophage-mucociliary escalator system!
- General immune system
- Respiratory tract secretions
- Upper respiratory tract as a ‘filter’
Composition of the macrophage-mucociliary escalator system
- Alveolar macrophages
- Mucociliary escalator
- Cough reflex
Action of the macrophage-mucociliary escalator system
They contact deposited particles either by chance or by oriented motion in response to chemical agents in particles
3 classifications of Pneumonia
- Anatomical
- Aetiological (circumstances)
- Microbiological
Aetiological classifications of Pneumonia
- Community acquired pneumonia
- Hospital acquired (nosocomial) pneumonia
- Pneumonia in the immunocompromised
- Atypical pneumonia
- Aspiration pneumonia
- Recurrent pneumonia
Patterns of Pneumonia
- Bronchopneumonia
- Segmental
- Lobar
What is bronchopneumonia?
inflammation of the lungs, arising in the bronchi or bronchioles
What is lobar pneumonia?
a form of pneumonia characterised by inflammatory exudate within the intra-alveolar space resulting in consolidation that affects a large and continuous area of the lobe of a lung.
- A whole lobe is affected.
Complications of Pneumonia
- Pleurisy, Pleural Effusion and Empyema
- Lung Abscess
- Bronchiectasis
What is Cryptogenic Organising Pneumonia (COP)?
COP is a swelling of the small airways in your lung. It has symptoms that can closely mimic a pneumonia infection.
-It is also known as bronchiolitis obliterans organising pneumonia (BOOP).
What is a lung abcess?
Abscesses occur most commonly when microbial infection causes necrosis of the lung parenchyma, forming 1 or more cavities.
- Forms necrotic lung
How does Bronchiectasis occur?
Pathological dilatation of Bronchi due to:
- Severe infective episode
- Recurrent infections, many causes
- Proximal bronchial obstruction
- Lung parenchymal destruction
complications of aspiration pneumonia
- Vomiting
- Oesophageal lesion
- Obstetric anaesthesia
- neuromuscular disorders
- Sedation
What are opportunistic infections?
- Infection by organism not normally capable of producing disease in patients with intact lung defences
- Increased chance of “ordinary “ infections
What PaO2 and PaCO2 is in Type I respiratory failure?
PaO2 < 8kPa
PaCO2 normal or low
What PaO2 and PaCO2 is in Type I respiratory failure?
PaCO2 > 6.5kPa
PaO2 usually low
What 4 abnormal states are associated with Hypoxaemia?
- Ventilation/Perfusion imbalance
- Diffusion impairment
- Alveolar hypoventilation
- Shunt
What occurs during physiological pulmonary arteriolar vasoconstriction?
- Alveolar oxygen tension falls
- Can be localised effect
- All vessels constrict if there is arterial hypoxaemia!!!
What is a protective mechanism for pulmonary vascular changes in Hypoxia?
Do not send blood to alveoli short of oxygen.
What does a shunt cause?
- Severe bronchopneumonia
- Lobar pattern with areas of consolidation
