British guideline on the management of asthma in adults continued

Pharmacological management

• The aim of asthma management is control of the disease. Control is defined as:
  • no daytime symptoms
  • no night time awakening due to asthma
  • no need for rescue medication
  • no exacerbations
  • no limitations on activity including exercise
  • normal lung function (in practical terms FEV₁ and/or PEF >80% predicted or best)
  • minimal side-effects from medication

The stepwise approach

• Start treatment at the step most appropriate to initial severity
• Achieve early control
• Maintain control by:
  • stepping up treatment as necessary
  • stepping down when control is good
• Before initiating a new drug therapy practitioners should check compliance with existing therapies, and inhaler technique, and eliminate trigger factors
• Until May 2009 all doses of inhaled steroids in this section have been referenced against beclometasone (BDP) given via CFC-MDIs (metered dose inhaler). As BDP CFC is now unavailable, the reference inhaled steroid will be the BDP-HFA (hydrofluroalkane) product, which is available at the same dosage as BDP-CFC. Note that some BDP-HFA products are more potent and all should be prescribed by brand. Adjustments to doses will have to be made for other devices and other corticosteroid molecules (see Table 1)

Combination inhalers

• Combination inhalers are recommended to:
  • guarantee that the long-acting β₂ agonist is not taken without inhaled steroid
  • improve inhaler adherence

• Use of a single combination inhaler (SMART):
  • in selected adult patients at step 3 who are poorly controlled or in selected adult patients at step 2 (above BDP 400 μg/day who are poorly controlled), the use of budesonide/formoterol in a single inhaler as rescue medication instead of a short-acting β₂ agonist, in addition to its regular use as controller therapy has been shown to be an effective treatment regimen
  • when this management option is introduced the total regular dose of daily inhaled corticosteroids should not be decreased. The regular maintenance dose of inhaled steroids may be budesonide 200 μg twice daily or budesonide 400 μg twice daily
  • patients taking rescue budesonide/formoterol once a day or more should have their treatment reviewed. Careful education of patients about the specific issues around this management strategy is required

Stepping down

• Regular review of patients should be carried out as treatment is stepped down is important. When deciding which drug to step down first and at what rate, the severity of asthma, the side-effects of the treatment, the beneficial effect achieved, and the patient’s preference should all be taken into account
• Patients should be maintained at the lowest possible dose of inhaled steroid
  • reduction in inhaled steroid dose should be slow as patients deteriorate at different rates
  • reductions should be considered every three months, decreasing the dose by approximately 25–50% each time

Exercise-induced asthma

• For most patients, exercise-induced asthma is an expression of poorly controlled asthma and regular treatment including inhaled steroids should be reviewed
• If exercise is a specific problem in patients taking inhaled steroids who are otherwise well controlled, consider the following therapies:
  • leukotriene receptor antagonists
  • long-acting β2-agonists
  • chromones
  • oral β2-agonists
  • theophyllines
• Immediately prior to exercise, inhaled short-acting β2-agonists are the drug of choice

British guideline on the management of asthma in adults continued

Table 1: Equivalent doses of inhaled steroids relative to beclometasone dipropionate and current licensed age indications*

British guideline on the management of asthma in adults continued

Summary of stepwise management in adults

British guideline on the management of asthma in adults continued

Inhaler devices

Technique and training

• Prescribe inhalers only after patients have received training in the use of the device and have demonstrated satisfactory technique

β2-agonist delivery

• Acute asthma
  • children and adults with mild and moderate exacerbations of asthma should be treated by pMDI + spacer with doses titrated according to clinical response
• Stable asthma
  • in adults, a pMDI ± spacer is as effective as any hand held inhaler, but patients may prefer some types of dry powder inhaler (DPI)

Inhaled steroids for stable asthma

• In adults, a pMDI ± spacer is as effective as any DPI

CFC vs HFA propellant pMDI

• Salbutamol HFA can be substituted for salbutamol CFC at 1:1 dosing
• HFA-BDP pMDI may be substituted for CFC-BDP pMDI at 1:2 dosing. This ratio may not apply to reformulated HFA-BDP pMDIs
• Fluticasone HFA can be substituted for fluticasone CFC at 1:1 dosing

Prescribing devices

• The choice of device may be determined by the choice of drug
• If the patient is unable to use a device satisfactorily, an alternative should be found
• The patient should have their ability to use an inhaler device assessed by a competent healthcare professional
• The medication needs to be titrated against clinical response to ensure optimum efficacy
• Reassess inhaler technique as part of structured clinical review

Management of acute asthma

Assessment of severe asthma

• Healthcare professionals must be aware that patients with severe asthma and one or more adverse psychosocial factors are at risk of death
• Keep patients who have had near fatal asthma or brittle asthma under specialist supervision indefinitely
• A respiratory specialist should follow-up patients admitted with severe asthma for at least one year after the admission

Initial assessment

• Moderate asthma exacerbation:
  • increasing symptoms
  • PEF >50–75% best or predicted
  • no features of acute severe asthma
• Acute severe asthma, any one of:
  • PEF 33–50% best or predicted
  • respiratory rate >25/min
  • heart rate >110/min
  • inability to complete sentences in one breath
• Life threatening, in a patient with severe asthma any one of:
  • PEF <33% best or predicted
  • SpO2 <92%
  • PaO2 <8 kPa
  • normal PaCO2 (4.6–6.0 kPa)
  • silent chest
  • cyanosis
  • poor respiratory effort
  • arrhythmia
  • exhaustion, altered conscious level
• Near fatal
  • raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures

Criteria for admission

• Admit patients with any feature of:
  • a life threatening or near fatal attack
  • a severe attack persisting after initial treatment
• Patients whose peak flow is greater than 75% best or predicted one hour after initial treatment may be discharged from A&E, unless there are other reasons why admission may be appropriate

Treatment of acute asthma

• Oxygen:
  • give supplementary oxygen to all hypoxaemic patients with acute severe asthma to maintain an SpO₂ level of 94–98%. Lack of pulse oximetry should not prevent the use of oxygen
  • in hospital, ambulance, and primary care, nebulised β2-agonist bronchodilators should preferably be driven by oxygen
  • the absence of supplemental oxygen should not prevent nebulised therapy being given if indicated
• β2-agonist bronchodilators:
  • use high dose inhaled β2 agonists as first line agents in acute asthma and administer as early as possible. Reserve intravenous β2-agonists for those patients in whom inhaled therapy cannot be used reliably
  • in acute asthma with life threatening features, the nebulised route (oxygen-driven) is recommended
  • in severe asthma (PEF or FEV1 <50% best or predicted), and asthma that is poorly responsive to an initial bolus dose of β2-agonist, consider continuous nebulisation
• Steroid therapy:
  • give steroids in adequate doses in all cases of acute asthma
  • continue prednisolone 40–50 mg daily for at least five days or until recovery
• Ipratropium bromide
  • add nebulised ipratropium bromide (0.5 mg 4–6 hourly) to β2-agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2-agonist therapy
• Other therapies:
  • consider a single dose of IV magnesium sulphate for patients with:
    • acute severe asthma without a good initial response to inhaled bronchodilator therapy
    • life threatening or near fatal asthma
  • IV magnesium sulphate (1.2–2 g IV infusion over 20 mins) should only be used following consultation with senior medical staff
  • routine prescription of antibiotics is not indicated for acute asthma

Referral to intensive care

• Refer any patient:
  • requiring ventilatory support
  • with acute severe or life threatening asthma, failing to respond to therapy, as evidenced by:
    • deteriorating PEF
    • persisting or worsening hypoxia
    • hypercapnea
    • arterial blood gas analysis showing ↓pH, or ↑H+ concentration
    • exhaustion, feeble respiration
    • drowsiness, confusion
    • coma or respiratory arrest

full guidelines available from…
Scottish Intercollegiate Guidelines Network, Elliott House, 8–10 Hillside Crescent, Edinburgh EH7 5EA (Tel – 0131 623 4720 ) http://www.sign.ac.uk/guidelines/fulltext/101/index.html
The British Thoracic Society, 17 Doughty Street, London EC1N 2PL (Tel – 020 7831 8778)
http://www.brit-thoracic.org.uk/

British Thoracic Society, Scottish Intercollegiate Guideline Network. British guideline on the management of asthma: a national clinical guideline. 5th ed. Edinburgh: SIGN; 2012. (SIGN Guideline No. 101).