asthma Flashcards
what is an obstructive airways disease
conditions that cause the narrowing of the large, medium-sized and small airways
what are examples of obstructive airway diseases
asthma, COPD and bronchiectasis
what do obstructive airway diseases result in
air trapping and hyperinflation
what does an obstructive airways disease look like in spirometry
↓ FEV1
↔ FVC
↓ FEV1/FVC < 70%
what is FEV1
forced expiratory volume in 1s
what is FVC
forced vital capacity
what type of disease is asthma
reversible obstructive airways disease
what is asthma caused by
inflammation, hyper-responsiveness and narrowing of the bronchial tree
where does asthma occur
in a susceptible individual secondary to a variety of stimuli
what are the characterisations of asthma
recurrent attacks of breathlessness and wheezing
what is the severity of asthma like
varies in severity and frequency from person to person
what is the diagnosis criteria for asthma
no consistent diagnostic criteria
what are some symptoms that can cause a diagnosis of asthma?
more than one wheeze, breathlessness, chest tightness and cough
variable airflow obstruction
what is the death rate like for people with asthma in the UK?
3-5 daily
where does airway inflammation occur in asthma
when a genetically susceptible individual with atopy is exposed to certain environmental factors
what is atopy
the tendency to produce high amounts of Immunoglobulin E (IgE) when exposed to small amounts of an antigen
what are features of atopic individuals
- Atopic individuals have a high prevalence of asthma, allergic rhinitis, urticaria and eczema
- Atopic individuals will demonstrate positive reactions to antigens on skin prick testing
what can cause airway inflammation
sensitisation of atopic individual
inhilation of allergen
what is the two parts of the two phase response
early reaction and late reaction
how long is the early reaction in asthma
20 min
how long is the late reaction in asthma
6-12 hours later
what regulates the inflammatory response in asthma
T-helper lymphocytes regulate the inflammatory response in asthma.
What do Th2 cells secrete in the response to asthma
Th2 cells secrete pro-inflammatory interleukins and stimulate the release of IgE antibodies by plasma cells.
What is the role of Th1 cells in the response to asthma
Th1 cells down-regulate the atopic response in asthma.
What happens when IgE antibodies bind to receptors on mast cells and eosinophils?
When IgE antibodies bind to receptors on mast cells and eosinophils, they stimulate the release of histamine, prostaglandins, and cysteinyl leukotrienes.
What is the effect of histamine, prostaglandins, and cysteinyl leukotrienes on the airways?
The effect of histamine, prostaglandins, and cysteinyl leukotrienes on the airways is bronchoconstriction within minutes.
What are the targets for therapies in asthma?
The targets for therapies in asthma are the mediators of histamine, prostaglandins, and cysteinyl leukotrienes.
What distinguishes asthma from COPD?
The reversibility of bronchoconstriction distinguishes asthma from COPD.
What is the late phase response in asthma?
The late phase response in asthma is the infiltration of the smooth muscle layer by eosinophils, basophils, neutrophils, monocytes, and dendritic cells.
What is the result of the late phase response in asthm
The result of the late-phase response in asthma is
patchy desquamation of epithelial cells, increased number of mucus glands,
goblet cell hyperplasia,
hypertrophy and hyperplasia of airway smooth muscle,
contraction of smooth muscle,
narrowing of airways,
increased permeability of blood vessels,
increased mucus production,
mucus plugging,
acute inflammation resulting in edema.
What causes polyphonic wheezing in asthma?
Polyphonic wheezing in asthma is caused by narrowing of bronchi of different calibres.
What is dynamic hyperinflation in asthma?
Dynamic hyperinflation in asthma is the narrowing of bronchi less than 2 cm, leading to closure at low lung volumes, air trapping, increase in residual volume (RV), and increase in total lung capacity (TLC).
What happens with increased severity and chronicity of asthma?
With increased severity and chronicity of asthma, there is remodelling of the airways, collagen deposition, and fibrosis of the airway wall, leading to fixed narrowing.
What type of cells are associated with acute asthma?
Eosinophils are associated with acute asthma.
What type of cells are associated with persistent airway inflammation in asthma?
Neutrophils are associated with persistent airway inflammation in asthma.
What is “steroid-dependant” asthma?
“Steroid-dependant” asthma refers to asthma that is persistent and requires treatment with steroids to control symptoms.
what are examples of environmental triggers for acute asthma
- animal dander, HDM, grass and tree pollen, mould
- viral and bacterial infection
- atmospheric pollution: ozone (O3), SO2, NO, fumes, thunder storms
- perfumes, hair sprays, plug-ins
- cigarette smoking, passive smoking
- indoor fire, chlorine (swimming pool, cleaning products), paints
- cold air/change in temperature
what are some triggers for acute asthma
- Drugs:
- aspirin
- NSAIDS* NSAIDS = non-steroidal anti-inflammatory drugs
- β-blockers
- Physiological:
- pregnancy
- premenstrual
- exercise
- Occupational Asthma
what are the symptoms of asthma during exacerbations
- breathlessness
- Chest tightness
- Wheeze
- Cough
- Between exacerbations:
- Completely well
- Mild chest tightness
- Occasional wheeze
- Dry cough (cough-variant asthma)
What is diurnal variability in asthma?
Diurnal variability in asthma is worse at night and early morning and is linked to the Circadian rhythm.
What are the signs of acute asthma?
During an acute asthma exacerbation, the following may be present:
tachypnea (breathlessness with a raised respiratory rate),
tachycardia,
Polyphonic wheeze during inspiration and expiration,
signs of hyperinflation.
In severe cases,
cyanosis, a silent chest,
and bradycardia may also be present.
What should you expect from a clinical examination of someone with acute asthma?
A clinical examination of someone with acute asthma may be normal in between exacerbations.
What are the blood tests done for suspected asthma?
Full blood count and raised eosinophil count. Raised IgE and radioallergosorbent test (RAST) if a specific allergy is suspected.
What is the purpose of a skin prick test for allergens?
To test for allergens such as tree pollen, grass pollen, dog, cat, horse, feather, HDM, and aspergillus fumigatus.
What is the purpose of a chest X-ray (CXR) in suspected asthma?
To assess the lungs and look for any signs of lung damage or other abnormalities.
What is the purpose of peak flow (PEF) and PEF homework in suspected asthma?
To measure the airflow in the lungs and assess any diurnal variability in the patient’s breathing. A 20% or greater variability between morning and evening values suggests asthma.
What is the purpose of spirometry in suspected asthma?
To measure the amount of air a person can exhale and the speed at which they can exhale.
What is a full lung function test with reversibility to bronchodilator?
A test that measures the lung function before and after inhaling a bronchodilator (e.g. salbutamol) to assess the patient’s ability to reverse bronchoconstriction.
When is a HRCT (High-Resolution Computed Tomography) test done for suspected asthma?
If emphysema or bronchiectasis are suspected.
What is the purpose of a methacholine or histamine provocation test?
To assess the patient’s airways and determine their responsiveness to different stimuli.
When is a HRCT thorax done?
If bronchiectasis is a possibility.
What is the purpose of sputum analysis in suspected asthma?
To determine any underlying infections or inflammation in the lungs through microbiological analysis and differential cell count.
What does Spirometry show in asthma?
Spirometry will show obstruction, with reduced FEV1 and FEV1/FVC < 70%.
What is the significance of bronchodilator reversibility in asthma?
Reversibility to bronchodilator 20 minutes after 200 mcg inhaled salbutamol with the FEV1 increasing by at least 15% of baseline or by more than 200 ml is significant. Patients with COPD will have little or no reversibility.
What are the results of lung function test in asthma?
Lung function test shows an increase in Total Lung Capacity (TLC) and Residual Volume (RV) due to air trapping and normal Transfer Factor/Diffusing Capacity (TLCO/DLCO).
What is Fractional Exhaled Nitric Oxide (FENO)?
FENO is a measure of airways eosinophilic inflammation
What is the significance of a positive FENO test?
A positive FENO test (> 40ppb) supports the diagnosis of asthma.
Where can FENO test be done?
FENO test can be done in GP and hospital clinics.
What is the use of FENO test in monitoring treatment/compliance?
FENO test can be used to monitor treatment and look at compliance.
What can CXR show in mild asthma?
CXR may be normal in mild asthma.
What can CXR show in asthma with increased lung volumes?
CXR may show hyperinflation with increased lung volumes and flat diaphragms, with 6 anterior ribs or 10 posterior ribs in the mid-clavicular line and a vertical and narrow heart.
What does HRCT show in asthma?
HRCT will show air trapping.
What is one important aspect of the management of asthma?
One important aspect of the management of asthma is to avoid allergens if possible.
What are the forms of therapy for asthma management?
The forms of therapy for asthma management are inhaled therapy and oral therapy.
What guidelines are used for the management of asthma?
The British Thoracic Society (BTS) Guidelines are used for the management of asthma.
What is the management of acute exacerbation of asthma?
The management of acute exacerbation of asthma involves following the BTS Guidelines.
What are the aims of pharmacological management of asthma?
To control symptoms, achieve best possible pulmonary function, prevent exacerbations, reduce morbidity and mortality, and minimize side effects
What are the measures to monitor the effectiveness of asthma treatment?
Symptom control, FEV1 or PEF, frequency of exacerbations, morbidity and mortality, and side effects.
What are the two types of receptors found in bronchial mucosa?
Beta2-adrenoceptors, Muscarinic cholinergic receptors
where are beta2-adrenoreceptors found
in the smooth muscle of the airways from the trachea to the terminal bronchioles
what do the muscarinic cholinergic receptors d
eceive a parasympathetic nerve supply
what are the 5 routes of medication for the lungs?
Inhaled
Oral
Intravenous
Intramuscular
Subcutaneous
What is the most common route of administration for lung medication?
The most common route is inhaled administration, which can be done through an inhaler, nebuliser, or directly into the lungs.
What are the advantages of inhaled administration of lung medication?
The main advantage is that the medication can be delivered directly to the lungs, reducing the risk of systemic side effects. It also allows for better control of the dose and better symptom control.
What are the disadvantages of oral administration of lung medication?
The disadvantage of oral administration is that the medication has to be absorbed in the gut, which can be affected by factors such as food, acidity and enzymes in the gut. This can result in variations in the effectiveness of the medication.
What are the benefits of intravenous administration of lung medication?
Intravenous administration of lung medication provides a fast and direct route of delivery to the bloodstream, allowing for rapid symptom relief. However, it also has a higher risk of systemic side effects as the medication can affect the whole body.
What is the difference between intramuscular and subcutaneous administration of lung medication?
Intramuscular administration involves injecting the medication directly into muscle tissue, while subcutaneous administration involves injecting the medication into the tissue just below the skin. Both are less commonly used routes of administration for lung medication.
What are the principles of drug deposition in lungs?
Direct deposition into lungs through inhaler/nebuliser for rapid absorption
Aerosol suspension of fine particles of varying sizes
Systemic side effects from inhaled therapy are less than oral or intravenous therapy
Inhaler systems are relatively inefficient with only 8-15% of the drug reaching the lung
Particle distribution within lungs can be measured by radio-labelling and using a gamma camera
What factors determine drug deposition in lungs?
Size of the particle
Inspiratory flow rate
Distance needed for particle to travel (determined by method of inhalation)
Factors favouring distal particle sedimentation: small particle size, slow flow rate.
What are the different types of inhaled therapy?
SABA (short-acting β-2 agonist), LABA (long-acting β-2 agonist), SAMA (short-acting muscarinic antagonist), LAMA (long-acting muscarinic antagonist), ICS (inhaled corticosteroid)
What are Adrenergic Agonists
Adrenergic Agonists are drugs that act on the β-2 receptors in the smooth muscle of the bronchial mucosa
how do adrenergic Agonists work
They activate adenylate cyclase, which increases cAMP and activates protein kinase A. This leads to phosphorylation of several target proteins within the cell and a decrease in intracellular calcium concentration by active removal of calcium from the cell into intracellular stores, resulting in bronchodilation.
What is the stimulation of β2 adrenoreceptor?
Relaxation of smooth muscle (via AC which ↑ cAMP resulting in bronchodilation), stabilization mast cells and inhibit inflammatory mediator release, and enhanced mucociliary clearance and ↓ vascular permeability.
What is AMP?
second messenger
How does AMP function as a second messenger?
Ligand binding alters the conformation of the receptor, exposing the binding site for Gs protein
Association of the ligand-receptor complex with Gs protein weakens the affinity of Gs for GDP
GDP dissociates and allows GTP to bind, causing the α subunit to dissociate from the Gs complex and exposing its binding site for adenylyl cyclase
The α subunit activates adenylyl cyclase to produce cAMP, while dissociation of the ligand returns the receptor to its original conformation
Hydrolysis of GTP by the α-subunit returns the subunit to its original conformation, causing it to dissociate from the adenylyl cyclase (inactive) and reassociate with the βγ complex to reform Gs.
Gs-> camp-> calcium
what is salbutamol
Salbutamol is a short-acting bronchodilator (SABA) used for the treatment of asthma and COPD for symptom control
how is salbutamol administered
It is given via inhaler or nebulizer for symptom relief and rapid onset of action (within 10 minutes).
how long does the effects of salbutamol last
Its effects last for 3-5 hours
what are sideeffects of salbutamol
but it can cause side effects such as tachycardia, tremor, and agitation, which are dose-dependent and more likely with the intravenous route.
What are the symptoms that Salbutamol is used for?
Salbutamol is used for symptom control of asthma and COPD, such as breathlessness, chest tightness, and wheeze.
How is Salbutamol administered?
Salbutamol is given via inhaler or nebulizer.
What is the onset of action of Salbutamol?
The onset of action of Salbutamol is rapid, usually within 10 minutes.
How long do the effects of Salbutamol last?
The effects of Salbutamol are short-acting, lasting for 3-5 hours
What are the side effects of Salbutamol?
The side effects of Salbutamol include tachycardia, tremor, and agitation, which are dose-dependent and more likely with the intravenous route.
What is salmeterol used for?
Salmeterol is a long-acting B-adrenoceptor agonist used in the treatment of asthma and COPD.
How does salmeterol work?
Salmeterol relaxes smooth muscle and improves breathing by stimulating β-2 receptors in the airways.
When should salmeterol be used?
Salmeterol is always used in combination with an inhaled corticosteroid (ICS) and/or long-acting muscarinic antagonist (LAMA) for optimal control of airways.
What is the onset of action for salmeterol?
The onset of action for salmeterol is 30 minutes.
What is the duration of action for salmeterol?
The duration of action for salmeterol is 10-12 hours.
How do SAMA drugs work?
SAMA drugs block muscarinic receptors and inhibit cholinergic nerve-induced bronchoconstriction, leading to bronchodilation.
What is the mechanism of action of SAMA drugs?
SAMA drugs work by blocking the release of acetylcholine (Ach) near the airway smooth muscle, which causes bronchoconstriction.
When are SAMA drugs used?
SAMA drugs are used only in acute exacerbation of asthma
What are corticosteroids used for in the treatment of lung disease?
Corticosteroids are the most commonly used drugs for the treatment of lung disease apart from antibiotics.
How do corticosteroids work?
Corticosteroids are potent anti-inflammatory drugs that have a variety of systemic effects. They bind to glucocorticosteroid receptors in most cells in the body, leading to changes in the transcription of inflammatory/anti-inflammatory components.
What are the different routes of administration for corticosteroids?
Corticosteroids can be taken orally, inhaled, intravenously, or intranasally.
What is an example of an oral corticosteroid?
Prednisolone is an example of an oral corticosteroid.
What is an example of an inhaled corticosteroid?
Beclomethasone is an example of an inhaled corticosteroid.
What are some short-term side effects of oral steroids?
indigestion, skin bruising, insomnia, and psychosis are some short-term side effects of oral steroids.
What are some medium-term side effects of oral steroids?
Gastric ulcers, skin bruising, insomnia, psychosis, and weight gain are some medium-term side effects of oral steroids.
What are some long-term side effects of oral steroids?
Osteoporosis, growth retardation in children, weight gain, Cushingoid appearance, adrenal suppression, hypertension, and diabetes are some long-term side effects of oral steroids.
What are the advantages of systemic (IV or oral) administration of corticosteroids?
Systemic administration of corticosteroids allows for stronger effects as higher doses are available and action is unaffected by inspiratory effort/inhaler technique. It is also a better route in the ill and in emergency, but has more side effects, especially with long-term therapy.
What are the advantages of inhaled corticosteroids?
Inhaled corticosteroids have a localized effect, fewer side effects (some absorption occurs), and may prevent the drug from reaching affected areas due to the disease.
What are ICS?
ICS (inhaled corticosteroids) are the most effective preventer drugs for adults and children in asthma.
How should ICS be prescribed?
ICS should be prescribed twice a day.
What is the core drug for ICS?
The core drug for ICS is beclomethasone dipropionate (BDP).
What are the side effects of ICS?
The side effects of ICS include:
Reduced ability to fight infection
Fungal infections
Oral candidiasis
Dysphonia
What is advised after using ICS?
It is advised to gargle after using ICS.
How should ICS be used with an inhaler?
ICS should be used with a spacer for a pressurized metered-dose inhaler (pMDI) or a dry powder inhaler (DPI).
What is a pMDI?
A pMDI (pressurized metered dose inhaler) is a type of inhaler where the drug is dissolved in a propellant (hydrofluorocarbons) under pressure and a valve system releases a metered dose.
What is a DPI?
A DPI (dry powder inhaler) is a type of inhaler where the patient activates it by inspiration and the powdered drug is dispersed into particles.
What is an SMI?
An SMI (soft mist inhaler) is another type of inhaler.
What is the purpose of combination therapy in asthma and COPD?
The purpose of combination therapy in asthma and COPD is to increase efficacy, improve symptoms and quality of life, and reduce exacerbations.
What are the benefits of combination therapy?
The benefits of combination therapy include:
More convenient
Increased compliance
Cost-effective
Reduced risk of adverse events.
What is a spacer device?
A device that improves drug delivery and is recommended for use with all aerosol inhalers, including pMDI
What is a volumatic device?
A large spacer with a one-way valve that increases distance from actuator to the mouth, allows particles time to evaporate and slow down before inhalation
What are the benefits of using a volumatic device?
Larger proportion of particles deposited in lungs
Minimizes oropharyngeal drug deposition
Decreases incidence of oropharyngeal candidiasis
What is the recommended inhalation technique for using a spacer device?
Inhale using tidal breathing from the spacer device as soon as possible after a single actuation
What is a nebuliser?
A device that delivers a higher dose of drug to airways than an inhaler
What is the function of a nebuliser?
To turn a solution containing the drug into an aerosol for inhalation
What medications are commonly nebulized in the treatment of asthma or COPD?
Short-acting β-2 agonists (SABA) and anticholinergic medication
What is the use of nebulized SABA in asthma and COPD?
To treat patients with exacerbation of asthma or COPD
To assess airway reversibility in patients with asthma and COPD
What is theophylline?
A non-selective phosphodiesterase inhibitor
What is the mechanism of action of theophylline in reversing bronchoconstriction in asthmatic patients?
Increases intracellular cAMP concentration
Blocks adenosine receptor and decreases bronchoconstriction
What are the uses of theophylline in the treatment of respiratory diseases?
Treatment of asthma and COPD
What are the key elements of asthma management?
Avoidance of allergens
Smoking cessation
Inhaled therapy
Self-management plan
Regular review by trained healthcare professional
Stepwise approach according to symptoms
Up and down the asthma treatment ladder according to symptoms
What is the main principle for prescribing medication for asthma in adults in the NHS?
The main principle for prescribing medication for asthma in adults in the NHS is a stepwise approach, starting with the lowest effective dose and gradually increasing if necessary, based on symptom control and the risk of side effects.
What are the first-line treatments for adults with asthma in the NHS?
The first-line treatments for adults with asthma in the NHS are inhaled short-acting beta-2 agonists (SABAs) as needed for relief of symptoms, and inhaled corticosteroids (ICS) as a preventer therapy.
What are the options for combining preventer and reliever medications in adults with asthma in the NHS?
In adults with asthma in the NHS, the options for combining preventer and reliever medications include using an ICS/long-acting beta-2 agonist (LABA) combination, or a combination of an ICS with a separate LABA and SABA.
What is the role of oral steroids in the management of asthma in adults in the NHS?
Oral steroids are used as a short-term treatment for severe asthma exacerbations in adults in the NHS. They should not be used as a regular preventer therapy due to the risk of side effects.
What is the role of leukotriene modifiers in the management of asthma in adults in the NHS?
Leukotriene modifiers, such as montelukast, are an alternative option for adults with asthma in the NHS who are not well-controlled on an ICS/LABA combination, or who experience side effects from ICS.
What are the guidelines for monitoring and review of asthma in adults in the NHS?
In the NHS, adults with asthma should have regular review by a trained healthcare professional to assess their symptoms, medication usage, inhaler technique, and overall asthma control. The frequency of these reviews may vary depending on the severity of asthma and individual needs.
What is the purpose of preventer inhalers in asthma?
Preventer inhalers reduce inflammation in the bronchi by blocking the inflammatory pathway.
What is the first line treatment for asthma?
Inhaled corticosteroids are the first line treatment for asthma.
What is the treatment if inhaled corticosteroids are not effective?
Long acting β-2 agonist (LABA) with inhaled corticosteroids if still symptomatic.
What is the purpose of reliever inhalers in asthma?
Reliever inhalers cause bronchodilation of the airways for a few hours and improve symptoms.
What is a common type of reliever inhaler?
Short acting β-2 agonist (SABA) is a common type of reliever inhaler.
What is a Personalized Asthma Action Plan (PAAP)?
A PAAP is an easy-to-understand plan that lists daily medications, asthma triggers to avoid, and steps to take in case of worsening asthma, along with medical attention indicators. It is traffic light color-coded and includes 2-3 action points.
What are the benefits of a PAAP?
A PAAP improves asthma control, reduces emergency contacts with GP, and reduces hospital admissions.
When should a patient have an asthma review?
Patients should have an annual asthma review in their GP surgery.
What is the number of deaths per day from asthma exacerbation?
3 deaths per day
What are the reasons for death from asthma exacerbation?
Patient factors (poor compliance, not recognizing severe symptoms, not calling for urgent help), Health professional factors (lack of understanding of asthma, inappropriate advice, not recognizing severe asthma), and Health system factors (lack of resources, lack of training)
What is the first line of treatment for acute asthma?
Oxygen (ABC)
What are the high-dose nebulized options for acute asthma?
β-2 agonist (salbutamol), Ipratropium bromide nebuliser (Atrovent)
What is the advantage of combining salbutamol + atrovent for acute asthma?
Significantly greater bronchodilation than β-2 agonist alone
What is the role of systemic steroids in acute asthma?
Reduces mortality (prednisolone or hydrocortisone)
What is the role of antibiotics in acute asthma?
For bacterial chest infection
What is the role of intravenous magnesium sulfate in acute asthma?
IV magnesium sulfate
What is the role of aminophylline in acute asthma?
Aminophylline (methylxanthine)
What is the role of intravenous fluids in acute asthma?
IV fluids
What is the ICU option for severe acute asthma?
Intubation and ventilation
What is the criterion for discharge after admission for asthma
The patient should have stopped nebulized therapy and been on discharge medication for at least 24 hours prior to discharge
What is the value of PEFR for discharge after admission for asthma?
PEFR > 75% of best or predicted
What is the diurnal variability of PEFR for discharge after admission for asthma?
PEFR diurnal variability < 25%
What is the importance of checking inhaler technique prior to discharge?
Check inhaler technique
What is the importance of PAAP prior to discharge?
PAAP made and understood
What is the smoking cessation discussion prior to discharge?
Prescribe NRT and refer to SC clinic
What is the role of reducing dose of oral steroids prior to discharge?
Reducing dose of oral steroids
What is the follow-up review after discharge?
Review within 2 weeks (nurse/doctor)
