Bronchiectasis and chronic lung infection Flashcards
What are the risk factors for developing chronic pulmonary infection?
Abnormal host response - immunodeficiency (congenital/acquired) or immunosuppression (drug or malignancy)
Abnormal innate host defence - damaged bronchial mucosa, abnormal cilia, abnormal secretions
Repeated insult - aspiration or ndwelling material
Describe immunodeficiency’s in terms of a risk factor for developing chronic pulmonary infection?
Immunoglobulin deficiency (dont have enough antibodies)
- IgA deficiency - common, increased risk of acute infections
- Hypogammaglovulinaemia - rare, increased risk of acute and chronic infections (no antibodies at all)
- CVID - most common cause of immunodeficiency, reccurent chest infection
Hypo-spenism
Immune paresis
HIV
What does IgA line?
The mucous membrane, its the first line of defence, so if you have IgA deficiency then you lose that 1st line response, but its alright as you have other things to stop the pathogen
Describe immunosuppression in terms of a risk factor for developing chronic pulmonary infection?
Can be caused by the use of
- steroids
- azathioprine (arthritis and transplant rejection prevention)
- methotrexate (arthritis medication)
- Cyclophophamide - wipes out immunity and fertility very strong
- monoclonal antibodies (infliximab (crohns), TNFa (increased risk of TB)
- Chemotherapy
Describe the defective innate host defences in terms of a risk factor for developing chronic pulmonary infection?
Damaged bronchial mucosa - due to smoking, could cause pneumonias, malignancy etc
Abnormal cilia - Kartenager syndrome for example
Abnormal secretions - secretions so thick the cilia (normal) cant move them, example CF
Describe repeated insult in terms of a risk factor for developing chronic pulmonary infection?
Recurrent aspiration - vomiting, poor swallowing (MS), pharyngeal pouch (food gets stuck and stores in pouch)
Indwelling material - NG tube int he wrong place (In lung not stomach), Cherst drain, Inhaled foreign body (peanut)
Name some forms of chronic infections?
Intrapulmonary abscess Empyema - infection in the pleural space Chronic bronchial sepsis - recurrent infections Bronchiectasis - wide bronchioles... CF
Describe intrapulmonary abscesses?
Can present with acute infection
Weight loss is common
Lethary, tiredness, weakness
Cough +/- sputum (when an abscess bursts you will get sputum)
Usually a preceding illness of some sort
- pneumonia, post viral, foreign body
Describe how pneumonia can be a preceding illness and how you can get to abscess?
Flu –> Staph pneumonia –> cavitation pneumonia –> abscess
What does Streptococcus cause
Pneumonia
What might have caused multiple abscess in the lung?
If the bacteria has got into the bloodstream and cause bacteraemia
What is a septic emboli?
A septic embolism is a type of embolism that is infected with bacteria, resulting in the formation of pus. These may become dangerous if dislodged from their original location. Like other emboli, a septic embolism may be fatal. Common in drug users as they inject into their groin, DVT, infection and then PE + abscess
septic emboli usually lodge in the heart valves
Describe an empyema?
Pus in the pleural space
Most patients with pneumonia will develop pleural fluid
On a CT scan you will see an empyema looking like a banana shape around the outside.
What does a D sign on a CXR indicate?
Empyema
Describe bronchiectasis?
Localised irreversible dilatation of the bronchial tree
Involved bronchi are dilated, inflamed and easily collapsable
Airflow obstruction, imparted clearance of secretions
