Asthma in Adults and Adolescents

Background

• Asthma is a chronic inflammatory disorder of the airways with bronchial hyperresponsiveness producing symptoms related to limited airflow that can be reversed.
• Incidence of self-reported asthma is 7%-10% of adults; most had asthma as a child.
• Asthma triggers include allergens, medications (particularly aspirin and nonsteroidal anti-inflammatory drugs), and environmental factors such as tobacco smoke and occupational exposure.
• Complications include secondary bacterial or viral lower respiratory infections, those associated with chronic use of inhaled or oral glucocorticosteroids, respiratory failure, and rarely death.
• There is poorer prognosis among the 5%-10% who do not respond well to standard treatment; with increased mortality also in patients who require intubation, had past history of severe disease, and have specific psychosocial factors.

Evaluation

• Suspect asthma in patients with history of recurrent wheeze, difficulty breathing, feeling of tightness in the chest, or cough for whom other diagnoses such as chronic obstructive pulmonary disease or heart failure do not explain the symptoms.
• Spirometry is used to determine the presence of obstruction, variability of airflow limitation, and degree of reversibility (generally defined as combination of increase in forced expiratory volume in 1 second [FEV₁] > 200 mL and ≥ 12% from baseline after inhalation of short-acting bronchodilator).
• Bronchial provocation with a methacholine challenge test can be considered to diagnose airway hyperresponsiveness in patients with FEV₁ ≥ 65% predicted in patients with diagnostic uncertainty.
• Characterize asthma severity based on symptoms, spirometry results, and medication use to help guide treatment decisions. Assess retrospectively (after several months of controller treatment), with severity determined by level of treatment required to control symptoms and exacerbations:
  • mild - well controlled with step 1 or 2 treatment (as-needed inhaled corticosteroids (ICS)-formoterol alone or with low-intensity controller treatment, such as low dose ICS, leukotriene receptor agonist, or chromones), with no distinction between intermittent or mild persistent asthma
  • moderate - well controlled with step 3 treatment (low- or medium-dose ICS-long-acting beta agonists [LABAs])
  • severe - requires high-dose ICS-LABA to prevent it from becoming uncontrolled, or remains uncontrolled despite treatment
• Pulse oximetry is often performed routinely in patients with suspected lung disease, and is especially useful in patients with respiratory distress (mild, moderate, severe).
• Consider fractional exhaled nitric oxide (FE_NO) testing as adjunct to diagnostic evaluation only if there is diagnostic uncertainty from history, clinical course and findings, and spirometry (including bronchodilator responsiveness testing), or if spirometry is not feasible (Weak recommendation).
• Evaluate the potential role of allergens in patients with persistent asthma.
  • Obtain patient history to determine sensitivity to seasonal allergens.
  • Consider skin testing or in vitro tests (such as radioallergosorbent test [RAST]) to determine sensitivity to perennial indoor allergens to which patient may be exposed.
• Consider a chest x-ray if there is a suspected complication or alternate diagnosis.

Management

• For emergency care, see Asthma Exacerbation in Adults and Adolescents.
• Prescribe an inhaled short-acting beta agonist (SABA) to all patients with asthma for acute symptom control in conjunction with an inhaled corticosteroid (Strong recommendation); SABA use alone is not recommended.
• For initial management (when patient first presents with symptoms, see Asthma Stepwise Management in Adults and Adolescents.
• Personalize asthma treatment based on severity, stepping treatment up and down as needed to achieve asthma control with lowest level of medication:

Table 1. GINA Stepwise Management of Asthma in Adults and Adolescents ≥ 12 Years Old

• Alternatives include mast cell stabilizers, antileukotrienes, or methylxanthines for patients not wholly responsive to usual regimen.
• Provide asthma self-management education to instill patients with the skills needed to control asthma and improve outcomes (Strong recommendation).
• Consider prescribing peak flow monitor for long-term daily monitoring only if the patient has moderate or severe persistent asthma or history of severe exacerbations (Weak recommendation).
• Consider subcutaneous allergen immunotherapy if the patient has allergic asthma (Weak recommendation).
• Consider the addition of tiotropium to inhaled corticosteroid (with or without LABA) to reduce symptoms or severe exacerbations in patients with inadequately controlled asthma.
• Encourage regular physical activity and a diet high in fruit and vegetables for the general health benefits.
• Consider alternative asthma treatments that may provide benefit, such as breathing exercises (breathing retraining), relaxation techniques, or yoga.
• Seek a consultation with an asthma specialist for patients with difficult-to-control symptoms or moderate persistent asthma (Weak recommendation) and all patients with severe persistent asthma (Strong recommendation).
• Follow-up:
  • Consider evaluating the level of asthma control in 2-6 weeks and increasing to the next level of care if asthma is inadequately controlled (Weak recommendation).
  • Consider following the stable patient in 1- to 6-month intervals; consider increasing to 3-month interval if step down in therapy is anticipated (Weak recommendation).
  • Consider repeating spirometry every 1-2 years to assess the maintenance of airway function.