Asthma Flashcards
Asthma is airway hyper-responsiveness, leading to what 3 things?
(1) Bronchospasm - a constriction of smooth muscle in small airways (bronchi and bronchioles)
(2) Airway inflammation
(3) (2) leading to increased mucus production
What is the main feature of asthma which means it stands out from other lung diseases?
It is reversible
Why is it not diagnosed in those under 2 yrs old?
It is difficult to distinguish between viral-induced wheeze and frequent URTIs
Symptoms:
List some of the symptoms people with asthma get? - 2
The symptoms tend to have a diurnal variation. What does that mean?
What are common precipitants? - list them
Intermittent dyspnoea
Cough - usually dry but can be productive
Worse at night and in the morning - peak flow lowest in the morning
Cold air Exercise Emotion Allergens (dust, mites) Infection Smoking Pollution
How would you ask about asthma symptoms during:
- Exercise
- Sleep
Why does asthma cause GORD?
Ask about exercise tolerance - maybe 20 minutes running
Quality of nights per wk
Asthma flare-ups can cause the lower oesophagal sphincter to relax, allowing stomach contents to flow back, or reflux, into the oesophagus. Some asthma medications (especially theophylline) may worsen reflux symptoms.
What other atopic diseases may they have?
Eczema
Hayfever
Allergy
What could you ask them about their home?
Do they have any pets?
What type of carpet are they using?
Are they using feather pillows
Are they using floor cushions?
What question could you ask to the see work is a trigger
Do the symptoms get worse when you are off work or over the weekend?
Signs:
Mild:
On examination - 2
Breath sounds?
HR?
Sign of SOB?
Tachypnoea
Wheeze
Hyperinflation
Reduced air entry
Incomplete sentences
Severe asthma signs:
Why are the lungs hyper resonant on percussion?
Pulsus paradoxus happens in a severe attack.
- What is it?
- How is it found out?
- Why does it happen?
Due to lungs being hyperinflated with air in COPD, or patients having an acute asthmatic attack.
A BP drop of at least 10 mm Hg with each inspiration.
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This is enough of a difference to cause a noticeable change in the strength of your pulse.
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Hyperinflation puts extra pressure on the veins carrying unoxygenated blood from the heart to the lungs.
As a result, blood backs up in the right ventricle
This causes extra pressure to build up on the right side of the heart, which presses against the left side of the heart.
Difficulty breathing from bronchospasm during acute asthma causes the patient to increase negative pressure in the thorax (hyperinflate) to compensate. The increased effort has an effect similar to that of backward pressure on circulation from the circulatory conditions listed above. Or, it could be seen as similar to the effect of positive pressure ventilation as described.
Signs of life-threatening attack?
Silent chest Confusion Exhaustion Cyanosis Bradycardia
Features which suggest asthma?
Features which suggest something else:
- What symptoms suggests a panic attack?
- What symptoms suggest pneumonia/bronchiectasis?
Reversibility to bronchodilators Episodic time course Triggers Eczema and hay fever present ======= Dizziness and tingling
Productive cough
Investigations:
Spirometry - under what value is the FEV1/FVC ratio which confirms obstructive disease?
What can be used to test for reversibility?
How much improvement in FEV1 suggests reversibility?
What type of monitoring is done which could show >20% variability which suggests asthma?
Above what age are people tested?
<0.7
Bronchidilator reversability (BDR) test
> 12% improvement
Peak expiratory flow (PEF)
> 5 yrs
Investigations - EXTRAs:
What would you see on CXR in an adult?
How may you look for an allergy? - 2
Hyperinflation may be shown - radiopenia
Allergy testing - skin prick testing or allergen-specific IgE
General Management:
Where are guidelines taken from?
What is used to monitor disease?
What is used to document symptoms?
What vaccine are they advised to take annually?
Lifestyle changes? - list them
Flu vaccine - done via nasal spray in kids
British Thoracic Society
PEFR monitoring
A symptom diary
Smoking cessation - it also weakens the effect of steroids
Avoid precipitants
Weight loss
Inhaler technique
Emergency advice
