Respiratory Tract Infections Flashcards
Micro-organism pathogenicity
Primary>facultative>opportunistic
Coryza
Common cold, URTI
Sore throat syndrome
URTI
Acute laryngotracheobronchitis
Croup, URTI
Laryngitis, sinusitis, acute epiglottitis
URTI
LRTI
Bronchitis, bronchiolitis, pneumonia
Respiratory Tract defence mechanisms
MQ mucociliary escalator system
general, secretions, filter in nose hairs
Macrophage-mucociliary escalator system
Clears depositions in alveoli which have been engulfed by alveolar macrophages. cough reflex to clear mucous. Mostly we swallow it. Keeps lower respiratory tract sterile
Pneumonia
Affects alveoli (parenchyma).
Aetiological classification of pneumonia
Community acquired Hospital acquired Immunocompromised Atypical Aspiration Recurrent
Patterns of pneumonia
Broncho - bilateral basal Segmental Local Hypostatic (fluid build up) Aspiration
Bad outcomes of pneumonia
Pleurisy, pleural effusion, empyema, organisation, abscess, bronchiectasis (saggy)
Causes of lung abscess
Tumour, Aspiration, organisms, necrotic lung, metastasis
Bronchiectasis
75% starts in childhood, cough with foul sputum, coarse crackles, clubbing. Can cause heammhorage
Causes of aspiration pnuemonia
Vomiting, oesophageal lesion, obstetric anaesthesia, neuromuscular disorders, sedation
FIO2
21%
Type 1 respiratory failure
PaO2<8kPa
Type 2 respiratory failure
PaCO2>6.5kPa (usually low O2)
4 causes of hypoxaemia
Ventilation/perfusion imbalance
Diffusion impairment
Alveolar hypoventilation
Shunt
Pulmonary vascular changes in hypoxia
Vessels constrict to protect body
Treatment for hypoxaemia due to low V/Q (pneumonia)
Increased oxygen
Shunt
Usually 2-4%, does not respond to increased FIO2
