Asthma Flashcards
What is Asthma?
Asthma is a chronic inflammatory disorder of the airways resulting in reversible airway obstruction caused by inflammation, bronchoconstriction and mucus build up.
What can trigger asthma?
Asthma is triggered by some sort of antigen or allergen.
How does the trigger lead to the symptoms of asthma?
This causes inflammation driven by TH2 cells release of cytokines causing Type 1 hypersensitivity reaction resulting in airway narrowing from prostaglandins, histamines and leukotrienes. Over time remodelling occurs because of damaged epithelium and increased smooth muscle thickness.
These narrowed airways are due to tightened muscles constricting the airways, inflamed and thickened airway wall and excess mucus.
Discuss some common triggers?
Triggers: Pets, Dust, pollen, mould, cold air, exercise, medication, pollutants and fungus
What are the common symptoms of asthma?
- Wheeze – high pitched expiratory musical sound from narrowed airways due to compression or obstruction
- Breathlessness and difficulty breathing – exercise induced or due to triggers because you can’t expel air. Can assess respiratory rate, tracheal tug (bringing in of skin around the trachea), recession (around the lower back), nasal flaring and accessory muscle use. Breathlessness can occur due to exacerbations such as a cold or seasons.
- Tight chest -
- Cough – Usually worse at night, exercised induced and dry
What should you be checking for in the History?
Full history – ask when symptoms occur and how they affect life. Past Medical History – eczema and hay fever. Family History – atopy, smoking (passive or during pregnancy). Social History – mould in home, farm, wood burning fire and pets. Drug History – medications making it worse.
What examinations should you do for asthma?
Inspection – for eczema
Palpation – lung expansion is the same both side
Percussion – for resonance
Auscultation – listen for crackles etc.
How does Peak flow change for asthma patients during the day?
Test peak flow volume – asthma usually different between morning and afternoon.
Briefly describe the difference between obstructive and restrictive diseases
Obstruction – can get rid of all the air it just takes time due to slower rate.
Restrictive – change in actual amount than you can get rid of
Obstructive = FEV1/FVC ration <70%. With restrictive it’s normal as both have been reduced.
How is Asthma managed?
If Asthma is suspected you should trial bronchodilators for a month and review to see of their symptoms improves, or if their peak flow gets better. If yes continues to treat as asthma. Spirometry is gold standard for diagnosis.
Education of how to use inhalers properly. Prevention – change pillows and bedsheets every few years, fresh air and stop smoking.
There are 5 steps of treatment for asthma and the step you’re on is decided by your reaction to the different medications. You can Step up and step down and this may change throughout the year specially during seasonal changes.
What are the three main pharmacological treatments for asthma?
SABA – short acting beta agonists – Ventolin. If used more than 3 times a week or if nocturnal symptoms require a step up.
Steroid – Preventer inhibits inflammatory cells and inhibits inflammatory mediators. If symptoms not controlled, then step up
LABA – long acting Beta agonist – used in those patients who still have asthma symptoms despite steroid. Slower onset of action therefore not for an acute asthma attack.
What is an Acute asthma attack?
Sats > 92%, pulses 110, RR < 25, speech normal, minimal wheeze and PEFR > 75% predicted.
What is a moderate asthma attack?
Sats > 92%, pulses 110, RR < 25, speech normal, lots of wheeze and PEFR > 50-75% predicted.
What is a severe asthma attack?
Sats < 92%, pulses > 110, RR > 25, speech is laboured, No wheeze and PEFR > 35-50% predicted.
What is a life threatening asthma attack?
Sats < 92% on air and may be cyanosed, silent chest/poor respiratory effort due to exhaustion, altered consciousness and PEFR 35% predicted.
