8.1 Lower Respiratory Tract Infections Flashcards
Give examples of lower respiratory tract infections
Acute Bronchitis (not the same as Chronic Bronchitis!) Bronchiectasis Bronchiolitis Empyema Lung Abscess Pneumonia
What is acute bronchitis
inflammation of the large airways of the lung – bronchi.
What is bronchiectasis?
Bronchiectasis is a permanent dilatation and thickening of the airways associated with chronic cough, sputum production, bacterial colonization, and recurrent infection
What is broncholitis?
Bronchiolitis is a viral infection of the bronchioles, the smallest air passages in the lungs.
What causes bronchiolitis?
Respiratory Syncytial virus - commonly occurs in children under 1 years of age.
What is empyema?
Empyema is a collection of pus in the pleural cavity, usually associated with pneumonia but may also develop after thoracic surgery or trauma
What is a lung abscess?
localised collection of pus within the lung that leads to cavity formation usually with a thick wall.
How would a lung abscess appear on an x ray?
Radiological imaging typically demonstrates the presence of air-fluid levels in the cavity.
What commonly causes lung abscesses?
Abscesses occur most commonly when microbial infection causes necrosis of the lung parenchyma.
When might a lung abscess cause a purple tissue cough?
If necrosis of lung parenchyma is communicating with an airway
What is pneumonia?
Pneumonia is a general term denoting inflammation of the lung parenchyma due to infection. Cellular exudate accumulates in alveolar spaces
What is Pneumonitis?
Inflammation of the lung parenchyma due to non-infective causes such as physical or chemical damage
What is lobar pneumonia?
Pneumonia localised to particular lobe/s of the lung
What is bronchopneumonia?
Diffuse patchier spread of pneumonia across lung tissue
How are pneumonia’s classified?
- Source of infection - where it was acquired and other aetiological factors
- Infecting organism
What are common causative organisms of community acquired pneumonia?
Streptococcus Pneumoniae
It is less commonly caused by Haemophilus influenzae, Moraxella catarrhalis, Klebsiella pneumoniae and Staphylococcus aureus.
What is the most common cause of pneumonia in smokers?
Streptococcus Pneumoniae
Smoking associated with COPD increased risk of infection with haemophilus influenza and mortadella catarrhalis
What are atypical organisms that may cause community acquired pneumonia?
Atypical organisms = lack a cell wall
Mycoplasma Pneumoniae
Chlamydia Pneumoniae
Legionella Pneumoniae
What is nosocomial pneumonia?
A nosocomial or hospital acquired pneumonia is defined as an infection of the lower respiratory tract in hospitalised patients, occurring > 48 hours after admission and was not incubating at the time of admission
What are important causative organisms of nosocomial pneumonia?
Gram negative bacteria and Staphylococcus aureus, including MRSA
What is aspiration pneumonia?
Aspiration of food, drink, saliva or vomitus can lead to pneumonia.
What individuals are prone to aspiration pneumonia?
individuals whose level of consciousness is altered, due to anaesthesia, alcohol or drug abuse or have swallowing related problems due to neuromuscular problems or oesophageal disease.
What are causative agents of aspiration pneumonia?
Causative organisms include oral flora & anaerobes, though in-hospital aspiration increases risk for pseudomonas aeruginosa infection
What are causes of pneumonia in the immunocompromised patient?
Pneumocystis jiroveci, Aspergillus spp., Cytomegalovirus and others.