Pathology Of Pulmonary Infection Flashcards
What causes lung infections
Microorganism Pathogenicity :
-Primary
-Facultative
-Opportunistic
Capacity to Resist Infection :
-State of Host Defence Mechanisms
-Age of Patient
Population at Risk
What is the cause of acute epiglottitus
H’influenza
Group A beta-haemolytic strep
What are the respiratory tract defense mechanisms
ALVEOLAR MACROPHAGES
MUCOCILIARY ESCALATOR
COUGH REFLEX
How does the lower respiratory tract stay sterile
What is the effect of infection on epithelium
Bronchial epithelium lost
Mucociliary escalator function lost
Predisposed pt to secondary bacterial infection
What are the anatomical classifications of pneumonia
Bronchopneumonia
Segmental
Lobar
Hypostatic
Aspiration
Obstructive, retention
Endogenous lipid
What does bronchopneumonia look like
Centre acinar region
Lower lung lobes
Bilateral
Patchy ossification
What does bronchopneumonia look like on xray
Bilateral patchy opacification
What does lobar pneumonia look like
Completely solid
Lacking in air
What does an xray of lobar pneumonia look like
What complications can Pneumonia cause
Pleurisy, Pleural Effusion and Empyema
Organisation:
- Mass lesion
- COP(cryptogenic organising pneumonia (BOOP))
- Constrictive bronchiolitis
Lung Abscess
Bronchiectasis
Pneumonia still potentially fatal
What does pleurisy look like
Fibrinous pleural exudate
What does chronic empyema look like
What does cryptogenic organising pneumonia look like
What can cause lung abscess
Obstructed bronchus
Aspiration
Some organisms
Metastatic in Pyaemia
Necrotic lung 2nd infection
What is bronchiactasis due to
Dilation of bronchi due to :
Infective episode
Recurrent infections
Proximal bronhcial obstruction
Lung parenchymal Destruction
What does bronchiactasis look like
What are some complications of bronchiectasis
Acute/Chronic Suppuration
Haemorrhage
What are the causes of recurrent infection
Local Bronchial Obstruction - Tumour, Foreign body
Local Pulmonary Damage - Bronchiectasis
Generalised Lung Disease - Cystic Fibrosis, COPD
Non-Respiratory Disease - Immunocompromised (HIV, other), Aspiration
What do opportunistic infections do
Infection by organisms not normally capable of producing disease in patients with intact lung defences - opportunistic pathogens
What is normal and abnormal pulmonary gas exchange
Normal PaO2 10.5 – 13.5 kPa
Normal PaCO2 4.8 – 6.0 kPa
Respiratory Failure:
Type I PaO2 <8 kPa (PaCO2 normal or low)
Type II PaCO2 >6.5 kPa (PaO2 usually low)
