At a glance
- The update includes new focus on monitoring asthma control as the goal for asthma therapy and distinguishing between classifying asthma severity and monitoring asthma control
- Emphasis is placed on impairment and risk as the two key domains of severity and control, and multiple measures for assessment.
- Modifications were made in the stepwise approach to managing asthma long term.
The National Asthma Education and Prevention Program of the National Heart, Lung, and Blood Institute has issued new guidelines for managing asthma (Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma). This summary of the recommendations will delineate differences from the previous two “Expert Panel Reports,” as the Guidelines are called.
Asthma is a complex disorder of the airways that is characterized by variable and recurring symptoms, airflow obstruction, bronchial hyper-responsiveness, and an underlying inflammation. Researchers have determined that inflammation plays a crucial role and that there is a great deal of variability in its patterns from patient to patient. Although current therapy with anti-inflammatory medication is effective in controlling symptoms, studies show that such treatment does not appear to prevent progression of underlying disease severity.
Measures of asthma assessment and monitoring
One key change in the new Guidelines is the concept of differentiating between asthma severity and control. Once asthma has been diagnosed, classify its severity, defined as “the intrinsic intensity of the disease process” and “measured most easily and directly in a patient who is not receiving long-term-control therapy.” The classifications of severity are intermittent, mild-persistent, moderate-persistent, and severe-persistent (there is no longer a mild-intermittent classification). This change was made to emphasize that “patients who have intermittent asthma can have severe exacerbations.” Note that asthma severity does not always correspond with the intensity of exacerbations.
Impairment and future risk determine asthma severity. Impairment refers to “the frequency and intensity of symptoms and functional limitations the patient is experiencing,” whereas risk is “the likelihood of either asthma exacerbations, progressive decline in lung function (or for children, reduced lung growth), or risk of adverse effects from medication.”
Evaluation of impairment includes the patient’s recall of symptoms over the past two to four weeks (nighttime awakenings, short-acting beta2-agonist use, interference with normal activity), as well as spirometry for adults and children older than five years of age. Updated tables divided by age group (0-4 years, 5-11 years, older than 12 years through adult) assign severity based on the information collected.
The assessment of risk is a new concept. The same figures identifying the criteria for severity also provide the criteria for risk, according to age. Children aged 4 years and younger are considered to be at increased risk if they have two or more asthma exacerbations requiring oral steroids in a period of six months or they have four or more wheezing episodes lasting more than one day in a period of one year and in the presence of risk factors for persistent asthma. Children who meet the above criteria should be classified as mild-, moderate-, or severe- persistent asthmatics and started on long-term control therapy.
The Guidelines define asthma control as “the degree to which the manifestations of asthma (symptoms, functional impairments, and risks of untoward events) are minimized and the goals of therapy are met.” The degree of impairment and risk with medication will determine which category the patient falls into. Assessment of post-therapy impairment includes symptom recall of the previous two to four weeks (i.e., nighttime awakenings, interference with normal activity, short-acting beta2-agonist use, and lung-function testing for children older than 5 years of age). In adults and youths aged 12 years and older, there are also three self-assessment questionnaires that can be used (the Asthma Control Questionnaire, Asthma Therapy Assessment Questionnaire, and Asthma Control Test).
These are filled out by the patient and/or caregiver before a provider is seen. For monitoring asthma control, the domain of risk will include an assessment of exacerbations requiring oral systemic corticosteroids, as well as treatment-related adverse effects and reduction in lung growth in children or progressive loss of lung function in adults.
Long-term control medications
Corticosteroids: The preferred long-term control therapy for all age groups is still inhaled corticosteroids. “The Expert Panel concludes that inhaled corticosteroids are the most potent and consistently effective long-term control medication for asthma.” They also “improve asthma control more effectively in both children and adults than leukotriene receptor antagonists or any other single, long-term control medication.”
Cromolyn sodium and nedocromil: Mast-cell stabilizers are recommended only as alternative medications for patients who have mild-persistent asthma.
Immunomodulators: “Omalizumab (anti-IgE) is a monoclonal antibody that prevents binding of [immunoglobulin E] to the high-affinity receptors on basophils and mast cells.” Omalizumab may be considered for severe asthma patients aged 12 years or older who have allergies. Anaphylaxis is a possible adverse effect of this immunomodulator.
Leukotriene modifiers: These are alternative but not preferred treatment options for patients with mild-persistent asthma. The leukotriene modifiers may also be used in addition to inhaled corticosteroids, but for adults and youths aged 12 years and older, long-acting beta2-agonists are the preferred add-on therapy.
Long-acting beta2-agonists: In patients aged 5 years or older, a combination of an inhaled corticosteroid and a long-acting beta2-agonist is an equally preferred option over increasing the dose of inhaled corticosteroids. Because clinical trials demonstrated an uncommon but increased risk for severe asthma exacerbations and asthma-related deaths, long-acting beta2-agonists should never be used as monotherapy. The health-care provider should weigh the beneficial effects of long-acting beta2-agonists against the increased risk for severe exacerbations.
Methylxanthines: Theophylline is used as an alternative therapy for patients with mild-persistent asthma. It may also be used as an adjunctive therapy if the patient is aged 5 years or older.
Anticholinergics: “Ipratropium bromide provides additive benefit to short-acting beta2-agonists in the emergency care setting, not the hospital setting.” In patients who do not tolerate short-acting beta2-agonists, ipratropium bromide may be used as an alternative bronchodilator.
Short-acting beta2-agonists: Albuterol, levalbuterol, and pirbuterol are the drugs of choice for acute symptom relief and for exercise-induced bronchospasm prevention. These medications should be used before exercise and as needed for acute symptoms. An increased need for short-acting beta2-agonists more than two days a week for acute symptom relief signifies asthma is not controlled, and therapy should be adjusted accordingly.
Systemic corticosteroids: Oral systemic corticosteroids are not short-acting, but they are often used in moderate and severe asthma exacerbations. They help to speed recovery and to prevent recurrence of exacerbations.