what are some exaamples of respiratory pathologies?
- Chronic Obstructive Pulmonary Disease
- Asthma (obstructive)
- Congenital and genetic lung conditions
- Obstructive sleep apnoea
- Restrictive lung disease
- Lung cancer (restrictive)
- Respiratory muscle disorders
what does restrictive airway disease reduce?
lung capacity
how much air can be inhaled
what does obstructive airway disease reduce?
airflow
how much air can be moved out or into the lung
what are the syptoms of asthma?
- Shortness of breath
- Chest tightness or pain
- Wheezing during exhalation
- Coughing or wheezing attacks that are worsened by a respiratory
virus - Chronic cough
- Significantly variable breathlessness
- Night-time wakening with breathlessness and/or wheeze
- Significant diurnal or day-to-day variability of symptoms
what is asthma?
- A chronic inflammatory disorder of the airways with reversible airway obstruction and increased airway responsiveness to a variety of stimuli
- Variable airflow limitation that normalises with treatment or spontaneously
what are the environmental/ modifiable factors for triggering asthma?
- Allergens
- House dust mite
- Pets
- Fungal spores
- Pollens
- Infections
- E.g. LRTI
- Others
- Smoking
- Pollution
- Occupational hazards (e.g. flour, chemicals)
- Stress
- Exercise
- Cold air
what happens during an asthma attack to the brochus?
contracted airway smooth muscle
bronchoconstriction- bronchial smooth muscle contraction that narrows the airways in response to stimuli
what are the two types of inhalers?
meter-dose inhaler
dry powder inhalers
what percentage of the drug from the inhaler reaches the lungs with good inhaler technique?
20%
what percentage of the drug from the inhaler reaches the lungs with poor inhaler technique?
5%
what is a peak expiratory flow (PEF)?
a measure of how quickly you can blow air out of your lungs
how to measure a peak flow?
- Pull the counter (the red arrow) back as far as it will go to the top near the mouthpiece.
- Stand or sit upright – choose what’s most comfortable for you and always do it that way.
- Take the deepest breath you can.
- Make sure your mouth makes a tight seal around the mouthpiece.
- Blow as hard and as fast as you possibly can into the meter.
- Write down your score (the number next to the pointer).
- Do this three times in a row so you get three scores (all three scores should be roughly the same).
- Use the highest of these scores to fill in your peak flow diary.
what does a peak flow measure do for the diagnosis of asthma?
- Measure for 2-4 weeks
- More than 20% variability regarded as positive test
what does a peak flow measure do for someone with a diagnosis of asthma?
- Up to 20% lower than best is considered normal
- 20-50% lower than normal means action needs to be taken
- Medical help
- Action plan
