Lectures Flashcards
Describe asthma
A disease characterised by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of airways that changes in severity either spontaneously or as a result of therapy.
who are most likely to have asthma?
boys and women
Name triggers that can cause asthma
Allergens: House dust mites Found in pillows and beds Cats Once sensitized exposure is a major problem Grass pollen
Indoor pollution:
Fragrances, formaldehyde, sprays
Reduced exposure to microbes:
Children born on farms are less likely to develop asthma. They have more diverse exposure to endotoxins and bacteria which appears to reduce risk of asthma.
Obesity:
BMI, asthma, wheezing, airway hyperactivity
Diet:
Increases risk of asthma
antioxidants, n-3 polyunsaturated fatty acids
n-6 polyunsaturated fatty acids & vitamin D
Supplementation is ineffective in established disease
Smoking: Maternal smoking during pregnancy FEV1 Wheezy illness Airway responsiveness asthma, severity More likely to get asthma if grandmother smoked if mother didn’t and even more likely if both smoke.
Occupation:
Need to ask present and past jobs.
Environment which people work can increase risk of asthma. Eg. Working with laboratory animals, drugs, crustaceans, a cleaner
Atopy:
inappropriate production IgE in response to allergens
familial atopic tendency (maternal three times more influential compared to paternal)
genes that can influence asthma symptoms
Symptoms of asthma
¥ Wheeze (bronchoconstriction, luminal secretions)
¥ short of breath (dyspnoea) sooking in of the ribs with wheeze
¥ severity chest tightness (pain)
¥ cough, paroxysmal, usually dry
¥ sputum (occasional)
What signs can be used at a diagnosis for asthma?
Wheeze, SOB at rest Multitrigger Sinusoidal Atopy Parental asthma Responds to treatment
What questions should be asked during the clinical history?
PMH – childhood breathing problems, eczema
DXH – inhalers, beta blockers, aspirin
FMH – history of breathing problems
SH – pets, occupation, smoker, pyschosocial aspects
What is the phrase I use to remember the different occupation issues which can cause asthma?
crazy lisa is greatly excited, don’t cry
crustaceans lab animals isocyanates grains enzymes drugs colonphony
What is the phrase i use to remember the risk factors of asthma?
old mother dictates its risky always smoking, or asthma!
obesity medication diet indoor pollution reduced exposure to microbes atopy smoking occupation allergens
how many people die from asthma every year?
about 1000
what medication can exacerbate asthma?
aspirin, NSAIDs, B blockers
What deficiency in the diet can exacerbate asthma?
low vitamin C, D and E
what genes are involved in asthma?
IL-4, IL-5, IgE, ADAM-33
What does obstructive spirometry look like?
- increased functional residual volume
- increased total lung volume
- FEV1/FVC ratio will be below 70%
- FEV1 will be below 80%
air can get into the lungs normally but it is difficult for air to leave the lungs due to the constriction of the airways in the case of asthma.
What are the two aims of doing investigations for asthma?
to find evidence for:
- obstructive airflow
- and if the obstructive airflow is reversible
What are the investigations that should be done for asthma?
Lung volumes - check for COPD
Treat with B2 antagonists and steroids - to check for reversibility
CXR - check for hyperinflation and to rule out differential diagnoses
FBC - to check for infection (increased eosinophils/WBC)
Skin prick test - check for atopy
Blood gases - check if type I or type II respiratory failure
