Asthma Flashcards
Symptoms of asthma
- Intermittent dyspnoea
- Cough (nocturnal)
- Wheeze
- Sputum production
(symptoms often worse at night/ in the morning)
Causes:
Reversible airway obstruction, 3 factos contributo to airway narrowing:
- bronchial muscle contraction (triggered by a variety of stimuli
- Mucosal swelling and inflammation (caused by mast cell and basophil degranulation and release of inflammatory mediators
- Increased muscles production.
Difference between intrinsic and extrinsic asthma
Intrinsic asthma (non-allergic) = occurs in adulthood, can be due to cigarette smoke, cold air, exercise. Tends to be persistent.
Extrinsic asthma: response to allergen, immune response, involved Fhx and usually starts in childhood. Can be associated with eczema and allergic rhinitis. Positive skin test can reveal extrinsic asthma.
Screening questions to ask in history.
Precipitating factors: Cold air, Exercise, Allergens (house dust mite/pollen/fur), Emotion, Infection, Smoking / passive smoking, B – blockers, NSAIDS
Note: B-blockers can precipitate asthma by causing bronchi constriction
Diurnal variation: this can be assessed in terms of symptoms (is cough worse in the morning) or in terms of peak flow.
Asthma would show a worse peak flow at 6.00 am – marked morning dipping of peak flow is common and can tip the balance into a serious attack, despite having a normal peak flow
Exercise: quantify exercise tolerance
Disturbed sleep: quantify as nights per week (a sign of severe asthma)
Acid reflux: 40-60% of individuals with asthma have reflux, treating it improves spirometry but not necessarily symptoms
Other atopic disease: Eczema, Hay fever, Allergy or FH
Allergens: pets, fur, dusty room,
Job: If symptoms remit at the weekend then the cause could be work; paint sprayers, work with animals, welders, food processors
To assess this can do peak flow variation during working schedule
Signs for asthma:
- tachypnoea
- audible wheeze
- hyperinflated chest
- hyper-resonant chest
- decreased air entry
- Polyphonic wheeze
Signs in severe attack
In a severe attack:
- Tachypnoea (RR >25/min)
- Tachycardic (>110/min)
- PEF (33-50% of predicted)
Signs in life threatening attack
Life threatening attack:
- Silent chest
- Cyanosis
- Bradycardia
- Exhaustion
- PEF <33% of predicted
- Confusion
- Feeble respiratory effort
Clinical features that increase the probability of a diagnosis of asthma in children.
More than one of the following symptoms - wheeze, cough, difficulty breathing, chest tightness - particularly if these are frequent and recurrent; are worse at night and in the early morning; occur in response to, or are worse after, exercise or other triggers, such as exposure to pets; cold or damp air, or with emotions or laughter; or occur apart from colds
Personal history of atopic disorder
Family history of atopic disorder and/or asthma
Widespread wheeze heard on auscultation
History of improvement in symptoms or lung function in response
to adequate therapy.
Clinical features that lower probability of asthma in children
Symptoms with colds only, with no interval symptoms
Isolated cough in the absence of wheeze or difficulty breathing
History of moist cough
Prominent dizziness, light-headedness, peripheral tingling
Repeatedly normal physical examination of chest when
symptomatic
Normal peak expiratory flow (PEF) or spirometry when
symptomatic
No response to a trial of asthma therapy
Clinical features pointing to alternative diagnosis
Management of chid with:
a) high probability of athma
b) low probability
c) intermediate probability
a) start trail treatment, review and assess response. Ensure correct technique.
b) consider more detailed investigation and specialist referral
c) if can perfrom spirometry and have evidence of airway obstruction assess change in FEV1 and PEF in response to bronchodilator and/or a trail of treatment for a specified treatment.
If significant reversibility, or treatment is beneficial, a diagnosis of athma is probable. Continue to treat as athma, but aim to find the minimum effective dose of therapy. At later point, consider a trailof reduction, or withdrawal.
If no significant reversibility consider other tests: consider atopic status, bronchodilator reversibility, bronchial hyper-responsiveness using methacholine, excersise or mannitol. Consider specialist referral.
Explain diagnosis in adult
Presentation + clinical assessment using spirometry.
High probability: trail treatment and assess response
Intermediate: test FEV1/FVC
- If <0.7 start trail treatment
- If >0.7 investigate other causes
Low probability: investigate other causes.
In brief explain the 5 steps of the BHS treatment guidelines
1: Short acting B2 agnonist for mild intermediate relief. Salbutamol
2. Steroid inhaler, for regular prevention. Beclometasone
3. LABA: salmeterol
4. Trails: Increased steroid dose or additional 4th drugs (theophylline or leukotriene receptor antagonist)
5. Oral daily steroid tablet
What is the stage 2 dose of beclometasone?
Advise on inhalation
200-800mcg/day. 400 starting dose.
Use spacer and rinse mouth after.
Stage 3:
what if benefit from LABA but still not adequate contol
What if no response
- Increase inhaled steroid to 800mcg
- stop LABA and either increased inhaled steroid or move to stage 4
What are the side effects of B2 agnoists?
Tachycardia Hypokalaemia Fine tremor Anxiety Paradoxical bronchospasm
