Obstructive lung disease Flashcards
what are the 3 major components of asthma
- Chronic inflammation
- Variable (reversible) airflow limitation
- Obstructive airflow
- History of respiratory systems (e.g. wheeze shortness of breath, chest tightness and cough) vary in length and intensity
what are the risk factors of asthma
- Smoke
- Chemicals
- Animals
- Pollen
- Air pollution
- Medicine
- Exercise
- Cold air
- Stress
- Viruses
- Dust
- Mould
- consequence of gene-environement interactions
what does a heterogeneous condition mean in asthma
means that it is in children and adults
name some obstructive lung diseases
asthma and COPD
for someone with asthma was does the volume time graph look like
The volume that they are over to expire over a given period of time is significantly less than someone who is normal thus asthma has airflow limitation
what does the histopathology look like of asthma
- Thickening of the basement membrane
- Airway smooth muscle hypertrophy (increase in volume)
- Leukocyte infiltration
- Goblet cell hyperplasia (increase in number) and mucus hypersecretion
what are two types of asthma
T2-type asthma
non-T2 type asthma
what is T2 type asthma
- allergic asthma and exercise induced asthma
- tends to start in childhood
- leads to late onset eosinophilic asthma
- aspirin exacerbated respiratory disease
what is non T2 type asthma
- obesity associated asthma
- smoking related neutrophilic asthma
- smooth muscle mediated paucigranulocytic asthma
- adult onset asthma
describe the T cell response to asthma
- Dendritic cell causes activation of TH2 cell
- TH2 cells are activated : there Central role is Release inflammatory mediators:
- interleukin-4 (IL-4) and IL-13 = Stimulates B cells to synthesize IgE
- IL-5 = Eosinophil activation
- ## IL-9 = mast cell proliferation – this causes an increased histamine production and further activation of mast cells
what are the symptoms of asthma in children
isolated symptoms of cough, wheeze and shortness of breath are neither sensitive nor specific for asthma
what are the symptoms of asthma in adults
- Almost all children with asthma have intermittent cough, wheeze and/or exercise induced symptoms, but only about a quarter of children with these symptoms have asthma
how can an allergen cause asthma
- Allergens activate sensitized mast cells by crosslinking surface-bound IgE molecules ( which are surface bound mast cells) this leads to degranulation and to release several bronchoconstrictor mediators (e.g. histamine) by mast cells, histamine then leads to bronchoconstriction
what can increase the probability fo asthma from the diagnosis
- Patients/Parents/Guardians: wheeze often used to describe any abnormal respiratory noise
- Important: distinguish wheezing – a continuous, high pitched musical sound coming from the chest – from other respiratory noises, such as stridor
- Wheeze heard by a healthcare professional on auscultation is an important sign that increases the probability of asthma
how can you diagnose asthma properly
previous and current medical history + lung function tests
what tests do you use in order to work out ofthey have asthma
- PEF charting
- challenge test
- skin prick IgE
- blood eosinophils
- FEV1
- spirometry
- then if you have suspected asthma give medication and treatment and if they have a good response to this then it is likely that they have asthma
what is the volume in a volume time graph
this is the volume of air that you can breathe out in a fixed volume mervouver/forced
what is the reduced volume over a period of time in someone with asthma in a volume time graph
- In an individual with asthma due to narrowing with the airways there is airflow limitation due to narrowing of the airways
- After treatment with a bronchodilator there is significant improvement with an FEV1 there is volume that you can breath out in one second
- There is improvement in FEV1 and the total volume of air they are able to breath out
describe the pathway of the flow volume graph
At the red line someone has taken a deep breath in
The initially expriation is rapid and very fast
Then it slows down as you cant breath out anymore and your hitting residual volume this causes the reduce in the flow rate in the green line
what is the maximum flow rate is a flow volume graph
PEF is the maximum flow rate
what happens to the PEF in patients with asthma
- it can be reduced