BTS/SIGN have updated information on the management of acute asthma, managing asthma in pregnant women, and the use of pharmacological therapies, says Dr Hilary Pinnock


Some important changes have been made to the British Thoracic Society (BTS) and Scottish Intercollegiate Guidelines Network (SIGN) British guideline on the management of asthma in the latest update now available on both their websites (brit-thoracic.org.uk and sign.ac.uk).1 A key focus of the 2009 update is the management of patients with acute asthma, with important messages for healthcare professionals in ‘front-line’ clinical care. The section on asthma in pregnancy has clear recommendations that we will need to share with our midwifery colleagues.

Revisions in the 2009 guideline

The updated section on acute asthma contains two main messages: the first reinforces the importance of objective assessment and recording of severity, and the second makes a strong recommendation for the use of oximetry in primary care, and clarifies the role of oxygen in managing the acute exacerbation. The section on asthma in pregnancy provides further reassurance on the safety of using drugs for asthma in this group of patients and reinforces previous recommendations on the importance of monitoring these women and maintaining good asthma control. Details on the pharmacological management of asthma have also been updated, including a useful summary of the new chlorofluorocarbon (CFC)-free inhaled steroids and an update on therapeutic options at step 3.1 Table 1 summarises the key changes from the updated BTS/SIGN guideline.

Table 1: Key messages and recommendations from the BTS/SIGN guideline1

GradeRecommendation
Acute asthma: preventing deaths
B Healthcare professionals must be aware that patients with severe asthma and one or more adverse psychosocial factors are at risk of death
  All patients with asthma should be asked about past reactions to beta blockers and non-steroidal anti-inflammatory drugs
Acute asthma: objective assessment
  Oxygen saturation monitors should be available for use by all healthcare professionals assessing acute asthma in both primary and secondary care settings. Patients with SpO2 <92% require further assessment
Acute asthma: management
C Give supplementary oxygen to all hypoxaemic patients with acute severe asthma to maintain an SpO2 level of 94%–98%
A Use high-dose inhaled ?2 agonists as first-line agents in acute asthma and administer as early as possible
  Metered-dose inhalers with spacers can be used for patients with exacerbations of asthma other than life threatening
A Give steroids in adequate doses in all cases of acute asthma
B Routine prescription of antibiotics is not indicated for acute asthma
Asthma in pregnancy
C Monitor pregnant women with moderate/severe asthma closely to keep their asthma well controlled
B Counsel women with asthma regarding the importance and safety of continuing their asthma medications during pregnancy to ensure good asthma control
C Give drug therapy for acute asthma as for the non-pregnant patient, including systemic steroids
Pharmacological management and inhaler devices
? Long-acting inhaled ?2 agonists should only be started in patients who are already on inhaled corticosteroids
B Prescribe inhalers only after patients have received training in the use of the device and have demonstrated satisfactory technique
SpO2=saturation of peripheral oxygen

Management of acute asthma

Avoiding deaths
The chapter starts with a salutary reminder that asthma results in 1200 deaths each year in the UK,2 and that primary care clinicians can take steps to reduce this risk. Markers of increased risk that can be identified in primary care include a previous episode of life-threatening asthma, the presence of psychosocial problems,3 over-reliance on ‘reliever’ medication, and poor engagement with routine care. Pilot work demonstrates that maintaining an asthma register and flagging the notes of patients at risk of life-threatening asthma are feasible in general practice,4 and may facilitate opportunistic provision of routine care and prompt access to acute management. Computer prescribing systems should enable healthcare professionals to avoid iatrogenic harm by warning that beta blockers (including eye drops) are contraindicated in patients with asthma, and providing an alert if a non-steroidal anti-inflammatory drug is prescribed for a patient with a prior adverse reaction.

Objective assessment and recording of severity
The key message for clinicians is that the severity of an asthma attack should be assessed objectively and the result clearly recorded for clinical and medico-legal reasons. Failure to undertake an adequate assessment results in under recognition of severity, and risks consequent under treatment.5,6 The levels of severity for adults and children are summarised in Tables 2 and 3. In primary care, the level of severity is based on the:

  • clinical detection of respiratory distress—is the patient too breathless to complete sentences in one breath? Heart rate and respiratory rate are useful clinical measurements which should be routinely recorded
  • peak expiratory flow rate at presentation—ideally this should be compared to the patient’s best peak flow (or predicted if this is not known), but it should be noted that peak flows taken in an acute situation in young children can be misleading if the child is not familiar with the technique
  • measurement of oxygen saturation (SpO2)—patients with SpO2 <92% (irrespective of whether the patient is on air or oxygen), or other features of life-threatening asthma require referral for further assessment.1 In children, where clinical signs may correlate poorly with severity of airflow obstruction, oxygen saturation is an essential objective measurement.7

Treatment pathways are determined by the level of severity and the simple practice of explicitly recording whether the patient is in the ‘moderate’, ‘severe’ or ‘life-threatening’ category would seem a pragmatic first step to ensuring correct management.

Oxygen
Oxygen is under used in primary care.6 Many patients with acute asthma are hypoxaemic, and all clinicians providing care for people with acute asthma should have access to an oximeter, and ideally oxygen. Oxygen should be given to maintain saturation between 94% and 98%.1

Use of ?2 agonists and steroids
The BTS/SIGN guideline recommendations on pharmacological treatment for acute asthma emphasise the importance of prompt administration of short-acting ?2 agonists. The guideline recommends that repeated actuations of a pressured metered-dose inhaler through a spacer device are as effective as using a nebuliser, and may reduce side-effects.1,8 The ?2 agonist should be given one puff at a time and inhaled separately with five tidal breaths.1 A nebuliser, however, may be better for treating people with life-threatening asthma, but ideally should be given with oxygen to prevent the risk of exacerbating hypoxaemia, which can occur with a nebuliser.9 Patients with severe attacks may benefit from the addition of an anticholinergic, which can lead to faster recovery and shorter admissions.1

Treatment dosage and duration for oral steroids should be as follows:1

  • in children aged 2–5 years, 20 mg for 3 days
  • in children aged >5 years, 30–40 mg for 3 days
  • in adults, 40–50 mg for a minimum of 5 days or until the patient has recovered.

Treatment with inhaled steroids should be maintained (or commenced). As the infective trigger is likely to be viral, antibiotics are not indicated for the management of acute asthma.1

Admission and follow up
An important decision for primary care healthcare professionals is whether admission is necessary. Patients with life-threatening asthma, and those with severe asthma who have not shown a good, objective response to emergency bronchodilation should be referred to secondary care for further assessment.1 Other factors that will influence this decision include past history of life-threatening attacks, unfavourable social circumstances, and attacks occurring later in the day. If referral is not necessary, clear arrangements for ‘safety-netting’ and early follow up need to be made.1

Acutely wheezy infants and children
The diagnosis, assessment, and management of acute asthma are particularly difficult in infancy. Many wheezy episodes are triggered by viral infections and treatment is not always effective. In infants with probable asthma, a ?2 agonist delivered through a spacer and 10 mg of soluble prednisolone are recommended.1

Recent evidence suggests that short courses of leukotriene-receptor antagonists, initiated by parents at the onset of asthma symptoms or an upper respiratory tract infection, can reduce symptoms in children with mild exacerbations.10 The guideline warns that this should not be extrapolated to those with moderate or severe attacks, or to adults, and should not prevent the appropriate use of steroids.1

Table 2: Levels of severity of acute asthma exacerbations in adults1

LevelClinical features
Near-fatal Raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures
Life-threatening Any one of the following in a patient with severe asthma:
Clinical signs
Measurements
  • Altered conscious level
  • Exhaustion
  • Arrhythmia
  • Hypotension
  • Cyanosis
  • Silent chest
  • Poor respiratory effort
  • PEF <33% best or predicted
  • SpO2 <92%
  • PaO2 <8 kPa
  • ‘normal’ PaCO2 (4.6–6.0 kPa)
Acute severe Any one of:
  • PEF 33%–50% best or predicted
  • respiratory rate ?25/min
  • heart rate ?110/min
  • inability to complete sentences in one breath
Moderate exacerbation
  • Increasing symptoms
  • PEF >50%–75% best or predicted
  • No features of acute severe asthma
Brittle
  • Type 1: wide PEF variability (>40% diurnal variation for >50% of the time over a period >150 days) despite intense therapy
  • Type 2: sudden severe attacks on a background of apparently well-controlled asthma
PaCO2=partial pressure of carbon dioxide in arterial blood; PEF=peak expiratory flow; SpO2=saturation of peripheral oxygen; PaO2=partial pressure of oxygen in arterial blood
British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. A national clinical guideline. Edinburgh: SIGN, 2009. Reproduced with kind permission. Available at: brit-thoracic.org.uk and sign.ac.uk

Table 3: Levels of severity of acute asthma exacerbations in children aged over 2 years1

LevelClinical features
 
Life-threatening Any one of the following in a child with severe asthma:
Clinical signs
Measurements
  • Silent chest
  • Cyanosis
  • Poor respiratory effort
  • Hypotension
  • Exhaustion
  • Confusion
  • SpO2 <92%
  • PEF <33% best or predicted
Acute severe
  • Inability to complete sentences in one breath; too breathless to talk or feed
  • SpO2 <92%
  • PEF 33%–50% best or predicted
  • Pulse:
    • >140 in children aged 2–5 years
    • >125 in children aged >5 years
  • Respiratory rate:
    • >40 breaths/min aged 2–5 years
    • >30 breaths/min aged >5 years
Moderate exacerbation
  • Able to talk in sentences
  • SpO2 ?92%
  • PEF ?50% best or predicted
  • Heart rate
    • ?140/min in children aged 2–5 years
    • ?125/min in children >5 years
  • Respiratory rate
    • ?40/min in children aged 2–5 years
    • ?30/min in children >5 years
SpO2=saturation of peripheral oxygen; PEF=peak expiratory flow
British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. A national clinical guideline. Edinburgh: SIGN, 2009. Reproduced with kind permission. Available at: brit-thoracic.org.uk and sign.ac.uk

Asthma in pregnancy

Treatment as usual
The guideline section on asthma in pregnancy has been revised in collaboration with an obstetric physician and the underlying message is clear: a healthy mother is crucial, and the drugs commonly used to treat asthma are safe both in pregnancy and lactation.1 Asthma control is affected by pregnancy: about a third of women will improve, a third will experience increased symptoms (often at about 6 months), and a third will remain the same.11 Women can be reassured that if good control of asthma can be achieved and maintained throughout the pregnancy, there is little or no increased risk to mother or foetus.1

In general, the drugs used to control asthma (inhaled steroids, long- and short-acting ?2 agonists) are safe, and pregnant women should, therefore, be encouraged to take their usual medicines in order to maintain control. It is not recommended that leukotriene-receptor antagonists are initiated during pregnancy because evidence on these drugs is still limited, although patients who are already receiving them may continue if they are of benefit.1

Drug therapy for acute exacerbations should be given as for the non-pregnant woman, with the caveat that acute severe asthma in pregnancy should be managed in hospital by a respiratory physician and an obstetrician. The possible (but not proven) small risk of cleft palate associated with the use of oral steroids in the first trimester is far outweighed by the risk of inadequately treating an acute exacerbation.1

The challenge for primary care
Pregnant women who have long-term conditions (e.g. diabetes, epilepsy, or heart or kidney failure) are referred for close monitoring as soon as pregnancy is confirmed, but this is not routinely done for asthma. The updated guideline emphasises the need to monitor asthma during pregnancy,1 and the challenge for primary care is to work with midwives and practice nurses to ensure that every pregnant mother is:

  • asked about a history of asthma at her booking visit
  • reviewed in the practice asthma clinic for assessment of control and adjustment of medication to maintain control with the minimum necessary dose—referral to a specialist clinic should be considered if good control cannot be achieved in primary care
  • provided with a personalised self-management plan that advises on symptoms of deterioration and appropriate action.

Pharmacological management of asthma

There have been minor updates to the guideline section on the pharmacological management of asthma.

Withdrawal of CFC-containing inhalers
In previous guidelines, CFC-containing beclometasone dipropionate (BDP) has been used as the reference inhaled steroid. Over the last year, CFC-containing inhaled steroids have been withdrawn, and the updated guideline now refers to the equivalent CFC-free product. There has also been an increase in the range of products available, each with their own delivery characteristics and licensed age indications.

Prescribers will need to be vigilant when switching between products to ensure that the dose of inhaled steroid is not effectively reduced (potentially threatening control) or increased (potentially undermining the normally favourable risk/benefit profile). Table 4 compares the range of different steroid preparations and their relative potency to CFC-containing BDP.1

Inhaled steroids and long-acting ?2 agonists
The BTS/SIGN guideline reviewed the evidence on the safety of long-acting ?2 agonists and endorsed the advice of the Medicines and Healthcare products Regulatory Agency that these should only be prescribed with inhaled steroids.12 One benefit of using a combination inhaler is that it prevents patients from stopping their inhaled steroid and using long acting ?2 agonists as monotherapy.1

The advice on the use of the budesonide/formoterol combination inhaler as both a controller and reliever medication has been updated. It was previously recommended as an option for patients with uncontrolled asthma at step 3 of the guideline (i.e. already on an inhaled steroid and a long-acting ?2 agonist). More recent evidence suggests that it may be considered for patients currently at step 2 who are receiving above 400 ?g BDP daily and who require a step up in medication.13 The switch should be made to a maintenance dose of inhaled steroid that is equivalent to previous treatment. Patients require careful counselling and should be informed of the importance of seeking advice if their control is not restored in a few days; and their action plan should be revised to ensure that they understand when they should take additional doses.1

Inhaler devices
The chapter on inhaler devices has been reviewed, but no changes have been made. The core message is never to assume that patients can use the device they are being prescribed.14 All prescribers have a responsibility to check inhaler technique before they prescribe an inhaled treatment, and if necessary to select a more suitable device.1

Table 4: Equivalent doses of inhaled steroids relative to beclometasone dipropionate and current licensed age indications1

    UK licence covers
Steroid Equivalent dose
(µg)
>12 years 5–12 years <5 years
Beclometasone dipropionate CFC
400
No longer available
Beclometasone
Clenil modulite
400
? ? ?
Clickhaler ? Aged over 6 years ?
Aerobec Autohaler ? ? ?
Asmabec Clickhaler ? Aged over 6 years ?
Dry powder (Becodisks) ? ? ?
Easyhaler ? ? ?
Pulvinal ? Aged over 6 years ?
Filair ? ? ?
Qvar 200–300 ? ? ?
Fostair 200 Aged over 18 years ? ?
Budesonide
Turbohaler 400 ? ? ?
Metered-dose inhaler ? ? Aged over 2 years
Easyhaler ? Aged over 6 years ?
Novolizer ? Aged over 6 years ?
Symbicort ? Aged over 6 years ?
Symbicort (regular and as required dosing) Aged over 18 years ? ?
Fluticasone
Metered-dose inhaler (HFA) 200 ? ? Aged over 4 years
Accuhaler ? ? Aged over 4 years
Seretide HFA ? ? Aged over 4 years
Seretide (Accuhaler) ? ? Aged over 4 years
Mometasone 200 ? ? ?
Ciclesonide 200–300 ? ? ?
Ciclesonide is a new inhaled steroid. Evidence from clinical trials suggests that it has less systemic activity and fewer local oropharyngeal side effects than conventional inhaled steroids. The clinical benefit of this is not clear as the exact efficacy to safety ratio compared to other inhaled steroids has not been fully established.
Non-CFC beclometasone is available in more than one preparation, and the potency relative to CFC beclometasone is not consistent between these.
HFA=hydrofluoroalkane
British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. A national clinical guideline. Edinburgh: SIGN, 2009. Reproduced with kind permission. Available at: brit-thoracic.org.uk and sign.ac.uk

Summary

The 2009 update of the BTS/SIGN guideline focuses attention on the management of acute asthma with crucial recommendations about objective assessment and recording of severity. The strong recommendation for the use of oximetry in acute asthma is relevant to all primary care clinicians. Practices should ensure that pregnant women with asthma are routinely reviewed and reassured that their usual asthma treatments are safe during pregnancy and lactation. The guideline includes information on the switch to CFC-free inhaled steroids and updates the advice on the use of long-acting ?2 agonists.

Key Points

  • Objectively assess and record the level of severity of acute asthma
  • Routinely use oximetry in acute asthma and give oxygen to maintain saturation between 94% and 98%
  • Women with asthma who are pregnant should be:
    • informed about the importance of good asthma control
    • reviewed regularly
    • encouraged to take their usual medication
  • Women with acute severe asthma who are pregnant should be managed in hospital by a respiratory physician and an obstetrician
  • Prescribers should ensure that the steroid dose is equivalent when changing patients from CFC-containing inhalers to CFC-free products
  • Inhaler technique should always be checked
 
CFC=chlorofluorocarbon
  • Asthma represents an important cause of avoidable mortality and emergency admissions to hospital
  • The BTS/SIGN guideline should be used to inform and agree local care pathways for the management of acute asthma
  • These pathways could:
    • define the relative roles of staff, including ambulance service providers, and criteria for referral to local hospitals
    • be built into contracts with local primary care services, out-of-hours providers, and walk-in centres
  • PBC consortia should ensure that primary care providers responding to urgent cases have access to oxygen and pulse oximetry
  • A retrospective review of recent asthma admissions may yield important learning needs to address with both local providers and patients
  • Tariff price for emergency asthma admission without complications = £1025 for adults, £709 for childrena
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