British Guideline on the Management of Asthma - Global

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British Guideline on the Management of Asthma - Global

Transcript Of British Guideline on the Management of Asthma - Global

The British Thoracic Society Scottish Intercollegiate Guidelines Network
British Guideline on the Management of Asthma
Quick Reference Guide
May 2008 revised May 2011

British Thoracic Society Scottish Intercollegiate Guidelines Network
British Guideline on the Management of Asthma
Quick Reference Guide
The College of Emergency Medicine
May 2008 Revised May 2011

ISBN 978 1 905813 29 2
First published 2003 Revised edition published 2008 Revised edition published 2009 Revised edition published 2011
SIGN and the BTS consent to the photocopying of this QRG for the purpose of implementation in the NHS in England, Wales, Northern Ireland and Scotland.
British Thoracic Society, 17 Doughty Street, London WC1N 2PL
www.brit-thoracic.org.uk
Scottish Intercollegiate Guidelines Network Elliott House, 8 -10 Hillside Crescent, Edinburgh EH7 5EA
www.sign.ac.uk

DIAGNOSIS IN children
Initial clinical assessment
B Focus the initial assessment in children suspected of having asthma on: ƒƒ presence of key features in history and examination ƒƒ careful consideration of alternative diagnoses.
Clinical features that increase the probability of asthma
ƒƒ 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
ƒƒ Personal history of atopic disorder ƒƒ Family history of atopic disorder and/or asthma ƒƒ Widespread wheeze heard on auscultation ƒƒ History of improvement in symptoms or lung function in response
to adequate therapy.
Clinical features that lower the probability of asthma
ƒƒ Symptoms with colds only, with no interval symptoms ƒƒ Isolated cough in the absence of wheeze or difficulty breathing ƒƒ History of moist cough ƒƒ Prominent dizziness, light-headedness, peripheral tingling ƒƒ Repeatedly normal physical examination of chest when
symptomatic ƒƒ Normal peak expiratory flow (PEF) or spirometry when
symptomatic ƒƒ No response to a trial of asthma therapy ƒƒ Clinical features pointing to alternative diagnosis
With a thorough history and examination, a child can usually be classed into one of three groups: ƒƒ high probability – diagnosis of asthma likely ƒƒ low probability – diagnosis other than asthma likely ƒƒ intermediate probability – diagnosis uncertain.
 Record the basis on which a diagnosis of asthma is suspected.

Applies only to adults

Applies to all children

Applies to children 5-12

Applies to children under 5

General

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DIAGNOSIS IN children
high probability of asthma
 In children with a high probability of asthma: ƒƒ start a trial of treatment ƒƒ review and assess response ƒƒ reserve further testing for those with a poor response.
low probability of asthma
 In children with a low probability of asthma consider more detailed investigation and specialist referral.
intermediate probability of asthma
 In children with an intermediate probability of asthma who can perform spirometry and have evidence of airways obstruction, assess the change in FEV1 or PEF in response to an inhaled bronchodilator (reversibility) and/or the response to a trial of treatment for a specified period: ƒƒ if there is significant reversibility, or if a treatment trial is beneficial, a diagnosis of asthma is probable. Continue to treat as asthma, but aim to find the minimum effective dose of therapy. At a later point, consider a trial of reduction, or withdrawal, of treatment. ƒƒ if there is no significant reversibility, and treatment trial is not beneficial, consider tests for alternative conditions.
c In children with an intermediate probability of asthma who can perform spirometry and have no evidence of airways obstruction: ƒƒ consider testing for atopic status, bronchodilator reversibility and if possible, bronchial hyper-responsiveness using methacholine, exercise or mannitol ƒƒ consider specialist referral.
 In children with an intermediate probability of asthma who cannot perform spirometry, offer a trial of treatment for a specified period: ƒƒ if treatment is beneficial, treat as asthma and arrange a review ƒƒ if treatment is not beneficial, stop asthma treatment, and consider tests for alternative conditions and specialist referral.
In some children, particularly the under 5s, there is insufficient evidence for a firm diagnosis of asthma but no features to suggest an alternative diagnosis. Possible approaches (dependent on frequency and severity of symptoms) include: ƒƒ watchful waiting with review ƒƒ trial of treatment with review ƒƒ spirometry and reversibility testing.
Remember - The diagnosis of asthma in children is a clinical one. It is based on recognising a characteristic pattern of episodic symptoms in the absence of an
alternative explanation.

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Applies only to adults

Applies to all children

Applies to children 5-12

Applies to children under 5

General

Presentation with suspected asthma in children
Clinical assessment

HIGH PROBABILITY diagnosis of asthma likely

INTERMEDIATE PROBABILITY diagnosis uncertain or poor response to asthma treatment

LOW PROBABILITY other diagnosis likely

Trial of asthma treatment

Consider tests of

+VE

lung function*

-VE

and atopy

Consider referral
Investigate/ treat other condition

Response? Yes No

Response? No Yes

Continue treatment and find minimum effective dose

Assess compliance and inhaler technique. Consider further
investigation and/or referral

Further investigation. Consider referral

Continue treatment

* Lung function tests include spirometry before and after bronchodilator (test of airway reversibility) and possible exercise or methacholine challenge (tests of airway responsiveness). Most children over the age of 5 years can perform lung function tests.

Applies only to adults

Applies to all children

Applies to children 5-12

Applies to children under 5

General

3

Initial assessment

DIAGNOSIS IN ADULTS

The diagnosis of asthma is based on the recognition of a characteristic pattern of symptoms and signs and the absence of an alternative explanation for them. The key is to take a careful clinical history.

 Base initial diagnosis on a careful assessment of symptoms and a measure of airflow obstruction:
ƒƒ in patients with a high probability of asthma move straight to a trial of treatment. Reserve further testing for those whose response to a trial of treatment is poor.
ƒƒ in patients with a low probability of asthma, whose symptoms are thought to be due to an alternative diagnosis, investigate and manage accordingly. Reconsider the diagnosis of asthma in those who do not respond.
ƒƒ the preferred approach in patients with an intermediate probability of having asthma is to carry out further investigations, including an explicit trial of treatments for a specified period, before confirming a diagnosis and establishing maintenance treatment.

d Spirometry is the preferred initial test to assess the presence and severity of airflow obstruction.
Clinical features that increase the probability of asthma
ƒƒ More than one of the following symptoms: wheeze, breathlessness, chest tightness and cough, particularly if: ~~ symptoms worse at night and in the early morning ~~ symptoms in response to exercise, allergen exposure and cold air ~~ symptoms after taking aspirin or beta blockers
ƒƒ History of atopic disorder ƒƒ Family history of asthma and/or atopic disorder ƒƒ Widespread wheeze heard on auscultation of the chest ƒƒ Otherwise unexplained low FEV1 or PEF (historical or serial readings) ƒƒ Otherwise unexplained peripheral blood eosinophilia

Clinical features that lower the probability of asthma

ƒƒ Prominent dizziness, light-headedness, peripheral tingling ƒƒ Chronic productive cough in the absence of wheeze or breathlessness ƒƒ Repeatedly normal physical examination of chest when symptomatic ƒƒ Voice disturbance ƒƒ Symptoms with colds only ƒƒ Significant smoking history (ie > 20 pack-years) ƒƒ Cardiac disease ƒƒ Normal PEF or spirometry when symptomatic*

* A normal spirogram/spirometry when not symptomatic does not exclude the diagnosis of asthma. Repeated measurements of lung function are often more informative than a single assessment.

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Applies only to adults

Applies to all children

Applies to children 5-12

Applies to children under 5

General

Presentation with suspected asthma in adults Presentation with suspected asthma
Clinical assessment including spirometry (or PEF if spirometry not available)

HIGH PROBABILITY diagnosis of asthma likely

INTERMEDIATE PROBABILITY diagnosis uncertain

LOW PROBABILITY other diagnosis likely

FEV1/ FVC <0.7
Trial of treatment

FEV1/ FVC >0.7

Investigate/ treat other condition

Response? Yes No

Response? No Yes

Continue treatment

Assess compliance and inhaler technique. Consider further
investigation and/or referral

Further investigation. Consider referral

Continue treatment

Applies only to adults

Applies to all children

Applies to children 5-12

Applies to children under 5

General

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NON-PHARMACOLOGICAL MANAGEMENT
There is a common perception amongst patients and carers that there are numerous environmental, dietary and other triggers of asthma and that avoiding these triggers will improve asthma. Evidence that non-pharmacological management is effective can be difficult to obtain and more studies are required.

Allergen avoidance Breastfeeding
Modified milk formulae
Nutritional supplementation

PROSPECTS FOR THE PRIMARY PREVENTION OF ASTHMA

Research Findings

Recommendation

There is no consistent evidence of benefit from domestic aeroallergen avoidance. Evidence of protective effect in relation to early asthma.
Trials of modified milk formulae have not included sufficiently long follow up to establish whether there is any impact on asthma.

Insufficient evidence to make a recommendation.
C B reast feeding should be encouraged
for its many benefits, and as it may also have a potential protective effect in relation to early asthma.
In the absence of any evidence of benefit from the use of modified infant milk formulae it is not possible to recommend it as a strategy for preventing childhood asthma.

There is limited, variable quality evidence investigating the potential preventative effect of fish oil, selenium and vitamin E intake during pregnancy.

There is insufficient evidence to make any recommendations on maternal dietary supplementation as an asthma prevention strategy.

Immunotherapy Microbial exposure Avoidance of tobacco smoke
Fish oils and fatty acid

More studies are required to establish whether immunotherapy might have a role in primary prophylaxis.

No recommendation can be made at present.

This is a key area for further work with longer follow up to establish outcomes in relation to asthma.

There is insufficient evidence to indicate that the use of dietary probiotics in pregnancy reduces the incidence of childhood asthma.

Studies suggest an association between maternal smoking and an increased risk of infant wheeze.

C P arents and parents-to-be should be
advised of the many adverse effects that
smoking has on their children including
increased wheezing in infancy and
increased risk of persistent asthma.

DIETARY MANIPULATION

Research Findings

Recommendation

Results from studies are inconsistent and further research is required.

No recommendation for use.

Electrolytes Weight reduction

Limited intervention studies suggest either negligible or minimal effects.
Studies show an association between increasing body mass index and symptoms of asthma.

No recommendation can be made at present.
C Weight reduction is recommended in
obese patients with asthma to promote general health and to improve asthma control.

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Applies only to adults

Applies to all children

Applies to children 5-12

Applies to children under 5

General
AsthmaChildrenProbabilityTreatmentResponse