Broncho-Alveolar Lavage

The lower respiratory tract comprises structures that are usually sterile, contamination by occasional micro-organisms is usual. Acute bronchitis is usually caused by viruses and characteristed by acute inflammation of the bronchial tree, secondary bacterial infection may play a role in pathogenesis. Chronic bronchitis is defined by excessive mucus production with sputum production on most days for three consecutive months for more than two years, bacterial infection does not appear to initiate the disease but is probably significant in perpetuating it and in producing the characteristic acute exacerbations. Pneumonia occurs by four routes: colonisation of the upper airway, aspiration, inhalation and seeding via blood from a distant site of infection. clinical systoms of pneumonia are fever, chills, chest pain and cough, pneumonia is often associated with underlying diseases such as chronic obstructive airways disease (COAD), diabetes mellitus and those who are immunocompromised. Community acquired pneumonia can be associated with travel and exposure to animals.