How To Manage
Why should I read this
- Identify the clinical features that increase or decrease the probability of asthma in adults.
- Demonstrate factors that adult patients need an awareness of for their successful asthma management.
- Describe good, partial and poor asthma symptom control in adults and adolescents and how to address lack of asthma control in the first instance.
- Describe the stepwise approach to asthma treatment.
The New Zealand guidelines on adult asthma have been revised after 14 years. Today, there is an extensive choice of medication and medication combinations for the management of this condition, which allows for an effective management plan. Jim Reid, co-author of the guidelines, from Caversham Medical Centre, is associate professor and deputy dean of the Dunedin School of Medicine, and a GP with special interest in respiratory medicine. He provides an overview of asthma management in adults In November 2016, the Asthma and Respiratory Foundation of New Zealand published revised guidelines on adult asthma (N Z Med J 2016;129:1445, www.nzasthmaguidelines.co.nz). These guidelines replaced those previously published in 2002 which, over the years, have become outdated.
Asthma is a chronic, episodic inflammatory disorder of the airways. It is a major cause of chronic morbidity and even mortality. Currently, it accounts for about 70 deaths annually in New Zealand.
The inflammatory nature of asthma has been known since the early 1900s when it was described as such by Sir William Osler. Interestingly, he described it as "a frightening disease but one which never causes death". As we know, especially in New Zealand and with special application to the late 1970s and early 1980s, this statement is untrue. At that time, our mortality rate of about 6/100,000 was the highest in the world. This has dropped dramatically since then (now about 1.5/100,000), though the risk is still present.
Asthma is a disease state characterised by airflow limitation with a range of pathological changes that occur in the lung, including inflammatory cellular infiltration, smooth muscle hypertrophy, mucosal oedema, excess mucus production from goblet cell hyperplasia and, in severe asthma, epithelial desquamation.
The airflow between attacks is normal, or near normal, and the restriction occurring during attacks is reversible with appropriate treatment. In this way, it differs from chronic obstructive pulmonary disease (COPD), which is not fully reversible.
The inflammatory process in asthma is principally mast cell, eosinophil, T-lymphocyte and macrophage-mediated, in contrast to COPD, which is primarily neutrophil-driven, although evidence is emerging of the role of neutrophils in some asthma.
In the patient with asthma, the airways are hyper-responsive to a number of stimuli, they become obstructed and airflow is limited by bronchoconstriction, mucus plugs and increased inflammation.
Symptoms of asthma include wheeze, chest tightness, shortness of breath and cough.
The disease, while episodic, also has acute exacerbations, when symptoms become much worse and require more intensive treatment. These exacerbations may, in severe cases, cause death.
In the early 1900s, emphasis was placed on bronchodilatation because no effective anti-inflammatories were available until the introduction of the cromolyns in the mid-1960s and inhaled corticosteroids in the 1970s. Before these, treatment relied on agents such as ephedrine, theophylline and short-acting bronchodilators such as isoprenaline.
Today, the much more extensive choice of medication for the management of asthma allows for an effective management plan, which includes four components:
- diagnose, assess and monitor disease
- reduce risk factors
- manage stable asthma
- manage exacerbations.
Diagnosis based on history and response The diagnosis of asthma in adults is relatively easy (in contrast to asthma in children) and is based on a high degree of suspicion (see panel).
The presence of a set of symptoms and signs (see below) points to the diagnosis but, note, if the patient is between attacks, the examination may be entirely normal and emphasis should be placed on the clinical history. Asthma is an episodic disease and a careful history is paramount in reaching diagnosis (see Tables 1 and 2).
Symptoms of asthma include a history of:
- wheeze (including after exercise)
- cough, especially at night
- chest tightness accompanied by wheeze
- a seasonal pattern of symptoms
- association with hay fever/eczema/other atopic illness
- frequent "colds" involving cough and wheeze
- in some people " wheeze on exertion (exercise-induced asthma).
Signs of asthma include:
- expiratory wheeze on auscultation
- hyperinflated chest.
Lung function testing useful in diagnosis, management Lung function measurement provides not only confirmation of the diagnosis but it also indicates, in many cases, disease severity. Spirometry is the gold standard measurement of airway obstruction but, if a spirometer is unavailable, peak flow measurement is a viable option. Peak flow, however, is not helpful in COPD.
While levels of reversibility vary from guideline to guideline, the latest New Zealand guidelines state that a >10% increase in forced expiratory volume in one second (FEV1), or an increase of 200ml in the FEV1, 15 minutes following administration of a short-acting bronchodilator is an indication of reversibility. Note, reversibility is often absent between attacks, and repeated reversibility testing is often required to confirm the diagnosis.
There can be a substantial overlap in bronchodilator-induced reversibility between individuals with asthma, COPD and with no respiratory disease. As a result, sometimes, no clear-cut divisions can be reached. The literature is now describing an overlap syndrome " the coexistence of asthma and COPD (ACOS syndrome: asthma"COPD overlap syndrome).
Peak flow measurement is useful in both the diagnosis and condition management. Peak flow meters are relatively cheap and are accessible. A 15% increase in peak flow following bronchodilatation or, alternatively, 60L/min reversibility, is acceptable for a diagnosis. Again, note, this is not applicable with COPD.
A feature of asthma is diurnal variability in airflow. A patient can be supplied with a peak flow meter, and morning and evening peak flows recorded. A 15% variability supports a diagnosis of asthma. Similarly, readings can be taken before and after exercise. Reversibility should be recorded 15 minutes after giving four individual puffs of a short-acting beta-2 agonist via a spacer.
Additional investigations Airway responsiveness can be measured by challenge with methacholine, histamine or hypertonic saline.
A chest x-ray is usually not routinely required, but should be considered if:
- The diagnosis is uncertain
- The symptoms are not explained by asthma
- There is no response to treatment.
Classification of asthma There are also specific types of asthma, including exercise-induced asthma and occupational asthma (which requires a documented relationship between symptoms and the workplace). The mixed pattern of COPD and asthma (ACOS) is also difficult and, sometimes, can only be clarified by a trial of treatment.
Asthma can be classified by severity " intermittent asthma; mild, persistent asthma; moderate, persistent asthma; and severe, persistent asthma. However, this approach, while useful, is not as important considering the severity in relation to its responsiveness to treatment.
It is more important to classify the asthma, whether mild or severe, by the level of control with respect to therapy.
Management " a team, a plan and patient understanding The goals of successful management of adults with asthma include:
- minimal symptoms
- minimal use of rescue medication
- no or minimal exacerbations
- promotion of normal or near-normal lung function
- maintenance of near-normal activity levels
- maintenance of a regular review of therapy.
It is important to achieve these goals but not to over-treat the patient, especially with corticosteroids. To achieve this, the treatment goals are shared with the patient and, if appropriate, with family members. As with any ongoing disease, adequate control can only be achieved through a partnership between the patient and primary caregivers.
The patient must have an understanding of the disease and be empowered to modify therapy, within limits, according to symptoms. The patient should be conscious of the following:
- be aware of risk factors, and develop avoidance strategies with regards to allergies (eg, hypoallergenic bed covers if a dust mite allergy is present)
- understand the differences between medications " reliever, preventer and controller
- develop insight into when the asthma is deteriorating, and know what to do and when to do it
- seek appropriate assistance when the asthma has deteriorated.
All patients (even those with mild asthma) should have a written management plan, to inform them what to do when their asthma deteriorates (Figures 1, 2 and 3) Asthma control People with asthma have their asthma either controlled, partly controlled or uncontrolled, regardless of whether their condition is mild or severe (Table 3). There is a need to match the therapy with the severity and stability of the asthma, and the patient needs empowerment to do this. This should be part of the management plan. While the doctor needs to maintain an overview, the "fine tuning" should be the responsibility of the patient.
The asthma control test is an easy and practical way to assess control. People with asthma, as a group, have little idea about how good control can be and still assess their overall control as "good" when needing to use their reliever inhaler five or six times a day. The test is easily administered and gives the clinician a good idea of any improvement or deterioration of symptoms (Figure 4).
Medications The medications that provide the "backbone" of asthma therapy for adults in New Zealand are as follows:
- short-acting beta-agonists (SABAs); relievers
- long-acting beta-agonists (LABAs); controllers
- inhaled corticosteroids (IHCs); preventers
- combination LABAs and IHCs.
In the New Zealand asthma guidelines, the SABA is the universal rescue medication (except in SMART management where the single IHC/LABA is both preventer and reliever; SABAs should not be used with SMART). If a patient is requiring more than two doses of SABA per week (with perhaps the exception being in exercise-induced asthma), an IHC should be introduced (fluticasone 125µg twice daily, or 200µg of budesonide or beclomethasone twice daily. The dose of beclomethasone can be halved if the fine-particle product is used.
If control is not achieved after approximately one month " measured by SABA use and peak flow monitoring " add in a LABA. Again, if after a further month, control is not achieved (patient needs to use SABA more than three times a week), the dose of IHC should be increased (fluticasone 250µg twice daily, or beclomethasone 500µg or budesonide 400µg twice daily).
Pharmacological treatment In this stepwise approach to asthma management (Figure 5) patients step up and down as required to achieve and maintain control of their asthma and reduce the risk of exacerbations.
Other measures If control is still not achieved, theophylline can be considered, but this is very much a third-line medication. Theophylline is difficult to use (blood level measurements are needed), it is not without side effects and it has interactions with other drugs.
As there is a delay in the onset of action with IHCs, consideration could be given to a short course of systemic steroids (eg, prednisone 40mg for seven days). It is now generally accepted that long-term systemic steroid use should only be at the lowest possible dose and in the most severe cases of asthma.
Leukotriene receptor antagonists have limited use in adults and are funded for restricted use in New Zealand. However, they are effective in children. Similarly, the cromolyns (sodium cromoglycate, nedocromil) have largely been replaced by IHCs but may be effective in some individuals, especially nedocromil.
Combined therapies LABAs have been combined with IHCs in the same inhaler (fluticasone propionate and salmeterol as Seretide; and budesonide and eformoterol as Symbicort or Vannair; and fluticasone furoate and vilanterol as Breo) " Breo is given in a single daily dose. There is evidence these agents are more effective when given in combination.
LABAs should never be prescribed in asthma without an IHC, and this is a compelling reason why they should be prescribed as combination products for asthma.
Because the LABA eformoterol has a rapid onset of action, similar to a SABA, the combination with budesonide is being promoted as sole therapy for asthma (SMART therapy). The inhaler is used on a regular basis, as well as for rescue medication. This therapy is now recognised in the New Zealand asthma guidelines and is the recommended treatment for severe and brittle asthma. The "secret for success" with this mode of treatment is for a SABA not to be prescribed and the use of just the one inhaler recommended. This is the only way for this method to succeed.
How to address lack of asthma control If control of the patient's asthma is not achieved, it is important to perform the following:
- check the inhaler technique, and use a spacer on metered-dose inhalers (MDIs) if necessary
- check the inhaler technique
- check the inhaler technique (repetition deliberate)
- check adherence to treatment
- review the diagnosis.
What to do when exacerbations occur Patients need to learn what to do when their asthma deteriorates. Steps to take include the following:
- increasing the combined LABA/IHC inhaler if using SMART therapy by up to a maximum of six extra inhalations per day; a sum total of eight per day.
- increasing the SABA inhaler: use it up to hourly via a spacer " take one puff at a time then four breaths, up to a maximum of six puffs on each occasion (this is as effective as a nebuliser)
- starting systemic corticosteroids: use prednisone 40"60mg stat and each morning for up to 10 days " there is now no need to taper the steroids if taken for up to 10 days if the patient is not dependent on systemic steroids
- seeking medical attention if the asthma is not responding or is deteriorating.
When is hospitalisation required An attack of asthma is significant if the patient is distressed and cannot speak in sentences. Also, beware of the asthma patient who is obviously short of breath and who has little in the way of breath sounds. Hospitalisation should be considered when any of the following occurs:
- The asthma is severe and not responding to administration of SABAs
- The patient has had previous admission to the ICU for asthma
- The onset of symptoms has been rapid
- There are few or no support systems at home
- There is continuing cyanosis.
In all cases, at the very least, a peak expiratory flow rate should be performed before and after the administration of the SABA. Again, beware the non-responder.
Specific patients: Maori and pregnant women Maori with asthma are more likely to be hospitalised or die due to asthma. It is essential Maori patients and their whanau understand the potential severity of the disease and the need for effective treatment. Like all patients, the concept of prophylaxis (taking medication when there are no symptoms) is very difficult for Maori, and this needs very careful explanation.
Asthma in pregnancy needs to be treated in the conventional way and medications should be used "as normal".
The role of the pharmacist The pharmacist is an essential member of the healthcare team in the management of asthma. If a patient returns early to collect a repeat of their reliever inhaler, it should signal that the asthma is not well controlled and there is need for education or perhaps a suggestion that he/she should return to their doctor " especially if a cause is not apparent (poor inhaler technique or non-use of preventer). Similarly, alarm bells should ring if the prescription presenter declines the preventer and only wants the "blue one". This patient needs to understand that one inhaler only treats the symptoms, whereas the other prevents the symptoms from occurring. The pharmacist is in a unique position to identify these problems. Further reading
- NZ Adult Asthma Guidelines. Asthma and Respiratory Foundation NZ, 2016. Available online at www.nzasthmaguidelines.co.nz/
- Asthma Management Handbook 1996. National Asthma Council Australia. Available online at www.asthmahandbook.org.au/
- Guidelines for the Diagnosis and Management of Asthma. National Heart, Lung, and Blood Institute, 2007. Available online at http://bit.ly/2pym4GK
- Global Initiative for Asthma (GINA) www.ginasthma.com
- International Primary Care Respiratory Group www.theipcrg.org/
- Asthma and Respiratory Foundation of New Zealand www.asthmanz.co.nz/-