Asthma Flashcards
What is asthma?
A disease characterised by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of the airways that changes in severity either spontaneously or as a result of therapy.
What word is asthma derived from?
Aazein - To pant heavily or gasp for breath
Why is asthma important?
Common
Dangerous
Expensive
What is the prevalence of asthma?
5.4 million on treatment incidence is higher in children but increasing in adults.
75% of hospital admissions for asthma are avoidable.
~1200 people die a year (women > men) 90% of deaths are preventable.
What is the cost to Nhs?
£1 billion a year
60,000 admissions/year
Asthma: the scale of the problem
5.4 million people living with asthma in the uk
Every 10 seconds someone is having a potentially life-threatening asthma attack in the uk
Every day, the lives of three families are devastated by the death of a loved one to an asthma attack - 2/3 of these deaths are preventable.
Pathophysiology of asthma
Airway inflammation mediated by the immune system - Increased airway reactivity - Airway narrowing - Spontaneously stimuli
Airway inflammation mediated by the immune system - Widespread narrowing of airways.
What is atopy?
-Atopy is the body’s predisposition to develop an antibody called immunoglobulin E (lgE) in response to exposure to environmental allergens and is an inheritable trait.
-Associated with allergic rhinitis, asthma, hay fever and eczema.
What does a structured clinical assessment for asthma look like?
Recurrent episodes of symptoms
Symptom variability
Absence of symptoms of alternative diagnosis.
Recorded observation of wheeze
Personal history of atopy
Historical record of variable PEF or FEV.
What are the symptoms of asthma?
Wheeze
Shortness of breath (dyspnoea), severity.
Chest tightness
Cough, paroxysmal, usually dry
Sputum (occasional)
What is normal peak expiratory flow rate?
80-100% of predicted
What type of hypersensitivity is asthma?
Type 1
What is the main cause of chronic bronchitis and emphysema?
Smoking
How is chronic bronchitis defined?
A chronic productive cough for 3 months out of a year, for at least 2 consecutive years.
What are the morphological changes in large airways in chronic bronchitis?
Mucus gland hyperplasia
Goblet cell hyperplasia
Inflammation and fibrosis
What are the morphological changes in small airways in chronic bronchitis?
Goblet cells appear
Inflammation and fibrosis.
How is emphysema pathologically defined?
Increase in the size of airspace distal to the terminal bronchiole arising from either dilation or from destruction of their walls and without obvious fibrosis.
What is the acinus?
Everything that is distal to the terminal bronchiole.
What are the 2 main types of emphysema?
Centri-acinar emphysema
Pan-acinar emphysema
Where does centriacinar emphysema usually effect?
Upper regions of lung lobes
Where does panacinar emphysema usually effect?
Lower regions of lung lobes
What would be seen on a chest x-ray of someone with emphysema?
Hyperinflated lungs, indicated by more ribs highlighted than usual.
What can alpha-1 antitrypsin deficiency cause?
Emphysema
What is the role of alpha 1 antitrypsin?
Inhibits elastase which prevents breakdown of lung tissue.
How does smoking cause emphysema?
Smoking decreases alpha-1-antitrypsin activity
It increases neutrophil and macrophage activity therefore increasing elastase production even further.
How does emphysema impact smaller airways?
Loss of alveolar attachments
What is cor pulmonale?
Abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels.
What causes cor pulmonale?
Pulmonary hypertension caused by chronic pulmonary vasoconstriction
What is the main symptom of asthma?
Wheeze
What % of causation of asthma is gene related?
30-80%
What 2 tests can be useful for determining a diagnosis of asthma in children?
Spirometry and nitrous oxide test
What are the features of a cough in a child with asthma?
Dry, nocturnal, exertional
In a child, what should you prescribe as a trial for suspected asthma?
Inhaled corticosteroid for a 2 month trial, then stop to see if symptoms return.
What are the ideal factors to diagnose asthma?
Wheeze
SOB
Parental asthma
Responsive to treatment
What are the goals of asthma treatment?
Minimal symptoms during day and night
Minimal need for reliever medication
No exacerbations
No limitation of physical activity
What mnemonic is used to measure control of asthma in children?
SANE
Short acting beta agonist/week
Absence school/nursery
Nocturnal symptoms/week
Exertional symptoms/week
What is the contrast of asthma treatment in children under 12 compared to adults?
Max dose ICS 800mg
No oral beta 2 tablet
No LAMAs
LTRA first line preventer in ,5s
Only 2 biologicals
How often would you need to use a beta 2 agonist to be considered uncontrolled?
More than 2 days a week
What is the adverse effects of inhaled corticosteroid steroids?
Height suppression (0.5-1cm)
What is the main leukotriene receptor antagonist?
Montelukast
What are the 2 types of delivery methods used in medication for asthma?
MDI/spacer
Dry powder device
Name 3 ways that lung composition can be increased when using metered dose inhaler (MDI)
Use spacer
Shake inhaler between puffs
Wash spacer monthly
What are the non-pharmacological treatments for asthma?
Reduce tobacco smoke exposure
Remove environmental triggers
What are the methods of drug administration used for treating acute and chronic asthma in children?
Chronic asthma - Inhaled steroids
Acute asthma - Oral steroids
What are the factors that determine level of treatment required in acute asthma exacerbation?
Respiratory rate
Heart rate
Oxygen sats
Work of breathing
Ability to complete sentences
When prescribing a LABA inhaler for a child, what 2 things are necessary?
Do not use without ics
Use as fixed dose inhaler
What is the prevalence of asthma in children?
10-15%
Give 3 proven risk factors for developing asthma
Hereditary
Maternal smoking
Occupation
Name triggers of asthma
Exercise
Cold air
Cigarette smoke
URTIs
Drugs (aspirin, NSAIDS)
Pets
Pollen
Name some differential diagnosis of asthma
COPD
Bronchiectasis
Cystic fibrosis
Lung tumour
Cardiac related disease
Name 4 tests that are used to try and diagnose asthma
Spirometry
Full pulmonary function test
Reversibility of bronchodilator
Variability of airflow obstruction
What are factors to consider when assessing acute asthma exacerbations?
Ability to speak
Heart rate
Respiratory rate
Peak expiratory flow rate
Oxygen saturation
What are the clinical features of someone having a moderate asthma exacerbation?
Able to speak in sentences
HR < 110
RR < 25
PEF - 50%-75% of predicted/best
SpO2 > 92%
PaO2 > 8pKa
What are the clinical features of someone having a severe asthma exacerbation?
Unable to finish sentences in one breath
Heart rate > 110
Respiratory rate > 25
PEF - 33-50% of predicted/best
SpO2 > 92%
PaO2 > 8pKa
What are the clinical features of someone having a life threatening asthma exacerbation?
Grunting
Exhaustion
Impaired consciousness
Bradycardia
Arrhythmia
Hypotension
PEF < 33% of predicted/best cyanosis
Silent chest
SpO2 < 92% (needs blood gas)
PaO2 < 8pKa
PaCO2 normal (4.6-6.0pKa)
Poor respiratory effect
What are the clinical features of someone having a near fatal asthma exacerbation?
Raised PaCO2
Requiring mechanical ventilation with raised inflation pressures
Name 4 non-pharmacological managements for asthma
Exercise
Smoking cessation
Weight management
Flu/pneumococcal vaccine
What are the 2 main SABA inhalers?
Salbutamol (MDI and DPI)
Terbutaline (DPI)
Name 3 oral therapies used to treat asthma
Leukotriene receptor antagonist
Theophylline
Prednisolone
Name 3 specialist therapies used to treat asthma
Omalizumab (anti-lgE)
Mepolizumab (anti-interleukin-5)
Bronchial thermoplasty
What treatment can be used for a patient having a mild/moderate asthma attack?
Increase inhaler use
Oral steroid
Treat trigger
Early follow up
Back up plan
What treatment can be used for a patient having a moderate/severe asthma attack?
Nebuliser - Salbutamol/Ipratropium
Oral/Iv steroid
Magnesium
Aminophylline
Triggers - Infection/allergen
Complications - CXR
Review
Level 2/3 care
What are some of the contrast between COPD and asthma?
Age of onset
Smoking history
Response to treatment
Treatment goals
Trajectory
What are some of the similarities between COPD and asthma?
Similar therapies
Same non-pharmacological interventions
What is the main difference between asthma and COPD?
Reversibility
Inhalers
Small dose of drugs
Delivery directly to the target organ (airways and lung)
Onset of effect is faster
Minimal systemic exposure
Systemic adverse effects are less severe and less frequent
What can complete control of asthma be defined as?
No daytime symptoms
No night time wakening
No need for rescue medication
No asthma attacks
No limitations on activity including exercise and normal lung function ( in practical terms FEV1 and/or PEF > 80%)
Minimal side effects from medication.
