Trust is good, control is better

Proper inhalation technique is not intuitive and must therefore be carefully trained and regularly reviewed. If performed inadequately, it is associated with increased side effects, poor treatment adherence, and impaired asthma control.

Bronchial asthma is one of the most common respiratory diseases, affecting more than 300 million people worldwide and 5-8% of the Swiss population [1,2]. Asthma is an obstructive airway disease characterized by chronic airway inflammation with increased airway responsiveness and characterized by reversible airflow limitation. Typically, recurrent varying symptoms and exacerbations are seen [3]. Common symptoms include whistling breathing, thoracic tightness, shortness of breath, and cough with or without sputum, and the cough can be particularly troublesome at night and early in the morning [4]. Acute asthma exacerbations result in significant patient morbidity and ultimately a large drain on available healthcare resources [3].

Therapy target

According to the current Global Initiative of Asthma (GINA) guidelines, the goal of asthma treatment is to achieve adequate asthma control (i.e., control of symptoms and risk factors) and reduction of exacerbations [3,5]. In addition to determining the severity of flow limitation (predilatory FEV1), the current GINA guidelines recommend a survey of asthma control using the Asthma Control Test (ACT, www.asthmacontroltest.com) (Fig. 1) and risk factors. Depending on asthma severity and asthma control, the adapted therapy level according to GINA should be applied (Fig. 2). The recently published Swiss guideline for the treatment of asthma has largely adopted the recommendation of GINA [6].

Therapy levels according to GINA

Topical administration of drug agents by inhalation is the preferred route of drug delivery. Through inhalation, a direct effect of the active ingredients on the respiratory tract can be achieved and systemic side effects can be largely reduced. In principle, a distinction is made between reliever drugs (short- and long-acting bronchodilators, SABA/LABA, anticholinergics LAMA) and controller drugs (inhaled steroids, ICS) [7]. Each patient should be equipped with a rapid-acting bronchodilator (SABA or formoterol) for emergency use. Inhaled steroids are part of the basic therapy of asthma as a controller from stage 2. Short-acting β-2-mimetics should be used only as relievers [7].

Data from a recently published study show that as an alternative to continuous therapy with low-dose ICS at level 2, demand therapy with a combination of budesonide and formoterol can be prescribed. Demand therapy was inferior to ICS treatment in terms of symptom control, but there was no difference in exacerbations between the regimens [8].

The GINA guidelines recommend “stepping up” with higher doses of ICS and the addition of LABA if control is inadequate. It should be noted that LABA should not be used in asthma without ICS [9]. Various fixed combinations of ICS and LABA are available. The combination of an ICS with formoterol (LABA with rapid onset of action) allows inhaled therapy with only one inhaler (a so-called single inhaler therapy, SIT), resulting in a reduction of exacerbations and good asthma control at a relatively low ICS dose [7].

If control of asthma remains inadequate, up-dosing of ICS to the maximum dose and, if necessary, the addition of a LAMA are indicated in the further course [7]. Depending on the clinical response, inhalation therapy can be supplemented with leukotriene antagonists (LTRA) from stage 3 and specific antibodies, so-called biologics (e.g. anti IL-5, anti IgE) from stage 5 for symptom control [7]. Peroral steroids are also used from stage 5 [7].

Inhalation systems

The individual active ingredients or any combinations of active ingredients are made available in different inhalation systems. For example, metered dose inhalers (pressurized Metered Dose Inhaler, pMDI) alone or in combination with an upstream chamber, powder inhalers (Dry Powder Inhaler, DPI), Soft Mist Inhalers (SMI) or moist inhalation systems are available in Switzerland. The fundamental desire for a universally usable inhalation system remains unfulfilled to date and poses a great challenge to the caregivers [10].

The severity of the disease and asthma control primarily determine the choice of agent used. Deciding this is primarily the responsibility of the attending physician. However, the selection of an inhalation system suitable for the patient should not be underestimated. This is because inadequately performed inhalation is associated with inadequate drug deposition, increased adverse side effects, poor treatment adherence, and impaired asthma control [11]. The most common causes of incorrect inhalation in DPI are insufficiently deep inhalation (89%), holding the breath too short after inhalation (83%), and incorrect complete expiration before performing inhalation (81%). For pMDI, the most common source of error is shown to be poor coordination between activation of the inhalation system and inhalation (91%), holding the breath too short after inhalation (83%), or inhaling too quickly (75%) [12].

Training of the inhalation technique

Professionals must ensure that the patient is trained in the correct inhalation technique and that this is regularly checked in the further course (Fig. 3) [13,14]. Such training can significantly improve inhalation technique [15]. In Switzerland, most physicians carry out the initial training themselves (90%) and supplement this mostly by handing out flyers (31%) or by additional training by the practice assistant (18%). However, systematic control of inhalation technique on the occasion of follow-up consultations takes place in only about one third of cases [12]. Primary care physicians play a key role here by ensuring that the inhalation system is used with proper inhalation technique. And they can take corrective action if necessary [16]. Proper inhalation technique is usually counterintuitive. Thus, professionals must also be trained accordingly. It has been shown that training professionals in proper inhalation technique has a positive impact on patients’ inhalation technique [17].

Conclusion

Asthma therapy is based on topical therapy with a reliever drug (each therapy level) and a controller drug (therapy level 2 and higher). A variety of different inhalation systems exist that are not inherently intuitive to use. After the physician has made the drug selection based on the therapeutic level, the patient can be involved in the selection of the inhalation system to optimize adherence. Proper inhalation technique must be trained and checked regularly.

Take-Home Messages

• The goal of asthma treatment is to achieve sufficient
• Asthma control as well as reduction of exacerbations.
• Asthma therapy is based on topical therapy with a reliever drug (each therapy level) and a controller drug (therapy level 2 and higher).
• Proper inhalation technique must be trained and checked regularly.
• Inadequate inhalation is associated with increased side effects, poor treatment adherence, and impaired asthma control.

Literature:

1. Global Asthma Report. 2018. www.globalasthmareport.org
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3. Global Initiative for Asthma (GINA): Pocket guide for asthma management and prevention. 2018. www.ginasthma.org
4. National Heart, Lung and Blood Institute (NIH): Asthma. www.nhlbi.nih.gov/
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17. Leung J, et al: Empowering family physicians to impart poper inhaler teaching to patients with COPD and asthma. Can Respir J 2015; 22(5): 266-270.

HAUSARZT PRAXIS 2018; 13(11): 15-18