Respiratory Flashcards
(236 cards)
What are the surface antigens for influenza A?
- Haemagglutinin
2. Neuraminidase
What is the function of haemagglutinin?
Virus binding and entry to cells
What is the function of neuraminidase?
Cuts newly formed virus loose from infected cells and prevents it clumping together
What causes seasonal epidemics?
Antigenic drift
What causes pandemics?
Antigenic shift
How do new virus strains form?
Genetic reassortment
What are the symptoms of influenza?
- URT symptoms
- LRT symptoms
- Fever
- Headache
- Myalgia
What are the risk factors for influenza mortality?
- Chronic cardiac and pulmonary diseases
- Old age
- Chronic metabolic disease
- Chronic renal disease
- Immunosuppressed
What is the Rx of influenza?
- Oxygen
- Hydration/nutrition
- Tamiflu
What makes pandemics worse?
- More travel
- Bigger population
- Intensive farming
What will make coping with a pandemic better?
- Better nutrition
- Better supportive care
- Vaccination
- Antivirals
How was avian flu controlled?
- Cull affected birds
- Disinfect farms
- Control poultry movement
- Vaccinate workers
What is the Rx for swine flu?
- Oseltamivir
2. Zanamivir
What happens in containment phase?
- Identify cases
- Treat cases
- Contact tracing
- Large scale prophylaxis
What happens in treatment phase?
- Treat cases only
2. National flu pandemic service
What happens in type 1 respiratory failure?
Low PaO2, normal or low PaCO2
What happens in type 2 respiratory failure?
Low PaO2 and raised PaCO2
What can cause raised A-a gradient?
- Diffusion limitation
2. Shunt (right to left)
What is the pathophysiology of high altitude pulmonary oedema?
Exaggerated hypoxic pulmonary vasoconstriction
What is the Rx for high altitude pulmonary oedema?
- Descent
- Oxygen
- Pulmonary vasodilators e.g. nifedipine
What factors determine transfer factor?
- Alveolar volume
- Diffusing capacity of membrane
- Pulmonary capillary blood volume
What does low TLCO indicate?
- Thickening of alveolar-capillary membrane
2. Reduced lung volume
What does high TLCO indicate?
- Increased capillary blood volume
2. Pulmonary haemorrhage
What inhibits O2 transfer in ILD?
Thickening of alveolar layer