Asthma - Adults Flashcards
What is a definition of asthma?
Disease characterised by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of airways that changes in severity either spontaneously or a result of therapy
What are some common asthma symptoms?
Wheezing
Coughing
Chest tightness
Shortness of breath
Together with difficulty in expiration
Why is asthma important?
Common, dangerous and expensive
Explain the scale of the problem in asthma
Children - 10-15% of UK children
Adults - 5-10%
Importance as large no. of people have this
Explain the pathophysiology of asthma?
Airway inflammation mediated by the immune system causes widespread narrowing of airways. Also increases airway reactivity leading to airway narrowing spontaneously or in reaction to stimuli
What happens to the airway of an asthmatic during an attack?
Tightening of smooth muscles and wall is inflamed and thickened
Air then trapped in alveoli
What is atopy?
Is the body’s predisposition to develop an antibody called immunoglobulin E (IgE) in response to exposure to environmental allergens and is an inheritable trait
Associated with allergic rhinitis, asthma, hay fever and eczema
Explain genetics and asthma
Risk of asthma is increased if first degree family member has asthma or another atopic disease
Maternal copy is the most influential
Complex and poorly understood
What happens to respiration of child when there is maternal smoking during pregnancy?
Decrease in FEV1
Increase in wheezy illness
Increase chance of airway responsiveness
Increase in risk of asthma
Explain how occupation affects risk of asthma
10-15% of onset of adult asthma
Interactions with smoking and atopy
Ex. bakers, painters and shell fish workers
What can you look for in taking a history of someone who has respiratory symptoms?
Recurrent episodes of symptoms
Symptom variability
Absence of symptoms
Wheeze
Personal history of atopy
Historical record of variable PEFF or FEV1
What is evidence of variable symptoms?
Daily - nocturnal or early morning
Weekly - occupational, weekends or holidays
Annual - environmental allergens like pollen
What can be some triggers of asthma?
Exercise, cold air, cigarette smoke, perfumes, Upper respiratory infections, pets, pollens, food, drugs …
What are some other important aspects in the history taking?
PMH - childhood asthma, bronchitis or wheeze as child, eczema and Hayfever
Drugs - inhalers, beta blockers, aspirin, NSAIDS
and their effects
Family history and social history
What can a clinical examination of asthmatic patient show?
Breathless on exertion
Hyperinflated chest
Wheeze
Not very helpful in clinic and symptoms can be variable or not there
What else could a patient have that is not asthma but shows symptoms of wheeze, cough and breathlessness?
Generalised airflow obstruction - COPD, Bronchiectasis and CF
Localised airway obstruction - tumour or foreign body
Cardiac
In asthma, what are we looking for evidence of?
Airflow obstruction
Variability and/or reversibility of airflow obstruction
What happens to the FEV1 in airway obstruction?
Decreases
Ratio is then smaller
But can be normal in some people with asthma
What would you do next if spirometry showed there was obstruction?
Full pulmonary function testing which can exclude COPD/emphysema
Also can do Carbon Monoxide gas transfer - if reduced can show COPD
Then check reversibility to bronchodilator and oral corticosteroids
Explain reversibility to bronchodilators
15 minutes post 400g of inhaled salbutamol
15 mins post neb 2.5-5mg of salbutamol
If significant reversibility then FEV1 > 200ml and baseline > 12%
Explain reversibility to oral corticosteroids
Same measurements as bronchodilators. Monitor over 2 weeks by giving 0.6mg/kg. If significant and steady improvement then asthma
Peak flow and spirometry checked
What would you look for if normal spirometry?
Variability of airflow obstruction
Peak flow meter and chart twice daily for 2 weeks
Looking for nocturnal or morning dips
Variability > 20% on more than 3 days a week
Can do bronchial provocation and FeNO test
What is bronchial provocation?
Checks airway responsiveness
Breath in chemicals at increasing dose and check for responsiveness - FEV1 would fall
Ex. methacholine, histamine and mannitol
What is Nitric oxide test?
Nitric oxide can indicate inflammation in the lungs
FeNO exhaled is measured
What are other useful investigations to help exclude other disease?
Chest X-ray
Skin prick testing
Total and specific IgE - can show atopy
Full blood count
What 5 signs/tests help assess acute asthma severity?
Ability to speak
Heart rate
Respiratory rate
Peak flow
Oxygen saturation/ Arterial blood gases
Explain moderate acute asthma?
Able to complete full sentences
HR < 110
RR < 25
Sa > 92%
PaO2 > 8kPa
PEF 50-75%
Explain serve acute asthma?
Inability to complete sentences in one breath
HR > 110
RR > 25
Sa > 92%
PaO2 > 8kPa
PEF 33-50%
Explain life threatening acute asthma?
Grunting
Impaired consciousness, confusion
Cardiovascular instability
Cyanosis
Silent chest
Poor resp. effort
SaO2 < 92, PaO2 < 8kPa and PaCO2 normal
Explain near fatal acute asthma
Raised PaCO2 and should be blowing it off due to hyperventilation
Need for mechanical ventilation
What are the aims of asthma treatment and show complete control?
No daytime symptoms
No night time wakening
No need for rescue medication
No asthma attacks
No limitations on activity which include exercise and normal lung function
Minimal side effects of medication
What is non-pharmacological management of asthma?
Patient education and self management plans
Exercise
Smoking cessation
Weight management
Flu/ Pneumococcal vaccinations
What does an asthma action plan show?
What the patient needs to do to be on top of their asthma
Signs to look out for and what to do if it is getting worse
What to do if their having an asthma attack
Describe benefits of inhalers
Small dose of drugs
Delivery directly to target organ
Onset of effect is faster
Minimal systemic exposure
Systemic adverse effects are less severe and less frequent
What is a pMDI?
Metered Dose Inhaler
Canaster is pressurised
Take breath as medication is released - so need good coordination
What is the benefit of using a pMDI with a spacer?
Medication is accumulated in a chamber so requires less coordination than pMDI
What are positives and negatives with Dry powder inhalers (DPI)?
Open device which primes the medication then it is sucked up by patient
Need enough respiratory for this medication
Do not need coordination with breathing and letting medication out
Explain Short acting B2 agonists
SABAs work by relaxing smooth muscle of the airways
These are relivers - for symptom control for flares or triggers
Salbutamol - MDI and DPI
Terbutaline - DPI
What are the 3 pharmacological managements for asthma?
Inhaled therapy
Oral therapy - used in higher steps
Specialist treatments
What are the types of oral therapy?
Leukotriene receptor antagonist
Theophylline
Prednisolone - acute exacerbation, used with inhaler
What are specialist options for treating asthma?
Omalizumab - Anti-IgE
Mepolizumab - Anti-lnterleukin-5 (help come off oral steroids)
These modify asthma response
Bronchial thermoplasty
What are the signs of acute asthma severity?
If patient can not complete sentences in one breath
PEF, RR, HR
Life threatening - cyanosis, silent chest, consciousness, Hypotension
Near fatal - raised PaCO2 and need for mechanical ventilation
What would the treatment of a mild/moderate acute asthma attack?
Increase of inhaler use
Oral steroid
Treat trigger
Early follow up
Back up plan
What would be the treatment of a moderate/severe asthma attack?
Nebulisers - salbutamol/ ipratropium
Oral/IV steroid
Magnesium
Aminophylline
Triggers
Chest x-ray
Review, Possible level 2/3 care
What are the differences between Asthma and COPD?
Age of onset - asthma is younger
Smoking history - COPD more likely
Treatment goals and trajectory
Similar therapies, non-pharmacological interventions are the same (exercise, smoking and weight loss)
