Asthma And COPD Flashcards
Reversibility
Bronchodilator reversibility typically involves repeating spirometry testing 20 – 30 mins after administering a dose of bronchodilator (typically Salbutamol 2 x 200mcg puffs, ideally via a large volume spacer).
If there is ‘reversible’ airways obstruction, there will be an improvement in the FEV1/FVC ratio.
Asthma - should be offered to adults (17+), and considered in children with obstructive spirometry.
In adults, an improvement in FEV1 of 12% or more, together with an increase in volume of at least 200 mL is regarded as a positive result. An improvement of greater than 400 mL in FEV1 is strongly suggestive of asthma.
In children, an improvement in FEV1 of 12% or more is regarded as a positive result.
Serial PEFR measurement
Asking patients to measure their PEFR is common in the diagnosis and monitoring of asthma.
PEFR measures the maximum flow of air during expiration, which happens at the beginning of expiration and is the gradient of the spirometry volume-time graph at time 0.
• During diagnosis of asthma, it is common to ask patients to monitor their peak flow at last twice daily for 2 – 4 weeks.
As part of long term monitoring, it is common to ask patients to check their PEFR regularly.
Asthma - A value of more than 20% variability after monitoring at least twice daily for 2-4 weeks is regarded as a positive result.
In adults, offer monitoring of peak flow variability if the person has either normal spirometry, or obstructive spirometry and positive BDR, with a FeNO level of 39 ppb or less. Consider monitoring peak flow variability if the person has obstructive spirometry and negative BDR, and a FeNO level between 25 and 39 ppb.
In children (aged 5 to 16 years), offer monitoring of peak flow variability if they have either normal spirometry or obstructive spirometry, negative BDR, and a FeNO level of 35 ppb or greater.
PEF variability is usually calculated as the difference between the highest and lowest readings expressed as a percentage of the average PEF.
Exhaled Nitric Oxide test (FENO)
This is a newer test in primary care.
It measures Nitric Oxide levels in exhaled breath.
These levels are increased when there is active airways inflammation (as occurs in asthma).
In steroid-naive adults, a FeNO level of 40 parts per billion (ppb) or higher is considered a positive result.
Consider FeNO testing in children if there is diagnostic uncertainty. A FeNO level of 35ppb is considered a positive result in this group.
However, the levels may be affected by smoking and inhaled corticosteroids (which tend to reduce the level); and it is not always raised in people with asthma.
NICE suggests that
• Approximately 1 in 5 people with a negative FENO result will have asthma.
• Approximately 1 in 5 people with a positive FENO result will not have asthma.
Spirometry
involves a “forced expiration” – breathing out as quickly as possible from the maximal inspiratory level.
Spirometry results are often presented as volume-time curves.
• FVC = The volume breathed out during the forced expiration.
• FEV1 = The volume breathed out during the first second
• FEV1/FVC = The proportion of the FVC that is breathed out in the first second
• PEFR = The Peak Expiratory Flow Rate – the gradient of the graph at time 0, which corresponds to the highest
rate of flow of air from the lungs.
Four patterns are identified:
a) Normal spirometry – a normal FEV1, FVC and FEV1/FVC ratio.
b) Restrictive spirometry – a reduced FVC but with a normal FEV1/FVC ratio.
c) Obstructive spirometry – a normal FVC but with a reduced FEV1 and hence FEV1/FVC ratio. In obstruction,
the PEFR is also reduced.
d) A ‘mixed obstructive and restrictive picture’ – the FVC is reduced AND the FEV1/FVC ratio is reduced.
Asthma - should be offered to all symptomatic people over the age of five years.
The FEV1/FVC ratio less than 70% = airflow limitation.
Affected by ICS
Inhaler therapy
There are different types of inhaler:
a. MDIs – pressurised Metered Dose Inhalers – generates an ‘aerosol’ which is inhaled.
b. DPIs – dry powder inhalers – the ‘dry powder’ is inhaled
c. SMIs – soft mist inhalers – the ‘soft mist’ is inhaled.
b) There are different drug groups of inhaler:
a. SABA = Short Acting Beta Agonist
b. LABA = Long Acting Beta Agonist
c. SAMA = Short Acting Antimuscarinic (rarely used in asthma)
d. LAMA = Long Acting Antimuscarinic (rarely used in asthma)
e. ICS = Inhaled corticosteroids
c) Some inhalers contain single agents; some are combinations. Common combinations are:
a. ICS/LABA (can be used in asthma and COPD)
b. LABA/LAMA (mainly used in COPD)
c. ICS/LABA/LAMA (mainly used in COPD)
d) Spacers are useful devices which can improve inhaler technique.
Spacers are plastic devices with a mouthpiece at one end and a hole for a pressurized metered-dose inhaler (pMDI) to be inserted at the other.
They increase the proportion of the drug delivered to the airways and reduce the amount of drug deposited in the oropharynx (thereby reducing local adverse effects and reducing the amount of systemic absorption).
They are not interchangeable.
The drug is administered by single-dose actuations from the pMDI into the spacer, with each actuation followed by inhalation.
Tidal breathing can be used.
Spacers should be washed monthly.
Plastic spacers should be replaced at least every 12 months.
People requiring large doses of inhaled corticosteroids may require a specialised nebulizer - specialist.
In children aged between 5 and 12 years, a PMDI with a spacer is recommended.
In children aged between 0 and 5 years - specialist advice.
Spacer should be used by all people on high-dose inhaled corticosteroids, and by most elderly people using PMDIs.
Other factors to consider when choosing a delivery system include:
The ability of the person to develop and maintain an effective technique - may depend on factors eg age, dexterity, coordination, and inspiratory flow.
The suitability to lifestyle - portability and convenience.
The medication (and dose) being prescribed
Inhaler technique and spacer technique
Only prescribe the inhaler after the person has demonstrated an acceptable technique.
Reassess inhaler technique as part of a structured clinical review during follow-up.
Diagnosing asthma - def, symptoms, triggers, signs, history
Definition of asthma from NICE:
Asthma is a chronic respiratory condition associated with airway inflammation and hyper-responsiveness.
Symptoms - cough, wheeze, chest tightness, shortness of breath, and variable expiratory airflow limitation.
Triggers - exercise, allergen exposure, changes in weather, viral resp infections.
Symptoms may resolve spontaneously or in response to medication, and may sometimes be absent for weeks or months at a time.
Acute asthma exacerbation - onset of severe asthma symptoms, which can be life- threatening.
Diagnosis:
Take a structured clinical history. There is no single diagnostic test. Use clinical judgement based on the following:
Presence of more than one variable symptom of wheeze, cough, breathlessness, and chest tightness.
Symptoms are commonly episodic, diurnal (worse at night or in the early morning), and/or triggered by factors.
In children, symptoms may also be triggered by emotion and laughter.
In adults, symptoms may be triggered by use of non-steroidal anti-inflammatory drugs and beta-blockers.
Ideally, expiratory polyphonic wheeze (with multiple pitches and tones heard over different areas of the lung when the person breathes out) will be confirmed on auscultation.
Check for possible occupational asthma by asking - Are symptoms better on days away from work?
Personal/family history of other atopic conditions.
Use a previous record of skin-prick tests, blood eosinophilia of 4% or more, or a raised allergen-specific IgE to check atopic status, but do not offer these tests to support an asthma diagnosis.
The results of FeNO testing — should be used where possible to confirm eosinophilic airway inflammation to support an asthma diagnosis.
The results of objective tests to detect airway obstruction, when the person is symptomatic:
Spirometry
Bronchodilator reversibility (BDR)
Variable peak expiratory flow readings can support an asthma diagnosis if there is diagnostic uncertainty after initial assessment, a FeNO test, and/or objective tests to detect airway obstruction.
For children under the age of five years, or those who are unable to perform some or all objective tests, use clinical judgement.
If the person cannot perform a particular test, attempt to perform at least 2 other objective tests. When a child reaches five years of age, carry out objective tests.
Managing asthma
The aim of asthma management:
No daytime symptoms, No night-time waking due to asthma, No asthma attacks, No limitations on activity including exercise, Normal lung function (FEV1 and/or PEF > 80% predicted).
Assess the person’s baseline asthma status using the Asthma Control Questionnaire or the Asthma Control Test, and/or lung function tests.
Arrange specialist referral if occupational asthma is suspected.
Advise the person on avoiding asthma trigger factors.
Ensure that the person has their own peak flow meter and measures their peak flow regularly as part of their personalised asthma action plan.
Initiate drug treatment
Review the response to treatment in 4 to 8 weeks.
Explain when and how to use inhalers, and demonstrate the correct technique.
Medication:
Prescribe an inhaled short-acting beta-2 agonist (SABA) to all people with symptomatic asthma, to be used as reliever therapy as required.
In people with asthma with infrequent, short-lived wheeze, and normal lung function, occasional use of a SABA might be the only treatment necessary.
Good asthma control is associated with little need for use of a SABA.
Prescribe an inhaled corticosteroid (ICS) as preventer therapy for all people who:
Use an inhaled SABA three times a week or more, and/or
Have asthma symptoms three times a week or more, and/or
Are woken at night by asthma symptoms once weekly or more.
Start ICS at a low dose. Higher doses may be required in people who are smokers.
ICS should initially be used twice daily (except ciclesonide, which is used once daily).
Once good control is established, once-daily ICS at the same daily dose can be considered as maintenance therapy.
Add-on therapy + follow up
If the person’s asthma is not adequately controlled with low-dose ICS, consider a trial of an add-on therapy.
Before initiating an add-on therapy, recheck adherence, inhaler technique, and elimination of trigger factors.
For adults:
Consider offering a leukotriene receptor antagonist (LTRA) in addition to the low dose ICS.
Review the response to treatment in 4 to 8 weeks. Note: oral therapy, taken only at night.
If asthma is uncontrolled on a low dose of ICS and a LTRA, offer a long-acting beta-2 agonist (LABA) in combination with the ICS.
If asthma is still uncontrolled - MART regimen - consists of a single inhaler containing both ICS and a fast-acting LABA, which is used for both daily maintenance therapy and the relief of symptoms as required.
If still uncontrolled consider increasing ICS dose, specialist advice,
consider a trial of an additional drug (for example, a muscarinic receptor antagonist or theophylline), use of oral steroids (usually prednisolone).
Consider decreasing maintenance therapy once a person’s asthma has been controlled with their current maintenance therapy for at least 3 months.
Follow-up at least annually. More regular follow-up is also required in people undergoing treatment adjustment.
Pregnant women should be managed in the same way as any other individual with asthma.
If an inhaled ICS is contraindicated alternative preventer medications include:
An LTRA for children under five years old.
Sodium cromoglicate effective in children aged over five years.
Nedocromil sodium, which may be of benefit in adults
Theophyllines
For people who report that their asthma is exacerbated by exercise:
Alongside an ICS, consider use of an LTRA.
Advise use of a SABA immediately prior to exercise.
RF COPD
Smoker, passive smoking
Recurrent chest infections - CXR as could be immunocompromised
Pulmonary rehab - Grade 3 MRC
Trimbow - max inhaler
COPD normal sats = 88-99
Lower sats - nail polish
Asthma
Nitrofuratoin - breathlessness
NSAIDs - can cause asthma
Dry cough only - are they on Ramipril
Consider mould
COPD: causes
Smoking!
Alpha-1 antitrypsin deficiency
Chronic obstructive pulmonary disease (COPD)
chronic bronchitis and emphysema.
Features
cough: often productive
dyspnoea
wheeze
in severe cases, right-sided heart failure may develop resulting in peripheral oedema
The following investigations with suspected COPD:
spirometry to demonstrate airflow obstruction: FEV1/FVC ratio less than 70%. No BDR reversibility.
chest x-ray - hyperinflation,
bullae, also important to exclude lung cancer
FBC: exclude secondary polycythaemia
BMI
