National guidelines set goals to improve care of asthmatic patients. Simple, straightforward objectives are set forth, including the prevention of chronic symptoms, maintaining normal lung function and activity levels, preventing exacerbations, and lessening the need for emergency department visits and hospitalizations. The guidelines set out a stepwise approach to classifying asthma severity and managing asthma symptoms.
This classification system (TABLE 1) is a continuum, and the disease can be expected to change from step to step during a patient’s lifetime. Factors that may influence a patient’s class of asthma include exposure to allergens, seasonal changes, and medication regimens. Classification is based on frequency of symptoms, need for inhaled beta2 agonists, nocturnal symptoms, and lung function based on peak expiratory flow rate (PEFR) and forced expiratory volume in the first second of exhalation (FEV1). Classifications range from mild-intermittent to mild-, moderate-, and severe-persistent. Treatment with both quick-relief medications and chronic anti-inflammatory therapy is dictated by a patient’s asthma classification.
|Table 1NAEPP Guidelines for Grading Asthma Severity Based on Symptoms|
|STEP ||SYMPTOMS||NIGHT-TIME |
|Step 4Severe Persistent||Continual symptomsLimited physical activity||Frequent||FEV1 or PEFR < or = to 60% predictedPEFR variability >30%|
|Step 3||Daily symptoms||> or = to 1 time a week||FEV1 or PEFR >60% but < or = to 80% predicted|
|Moderate Persistent||Daily use of inhaled short cting beta2 agonist |
Exacerbations affect activityExacerbations > or = to 2 times a week; may last days
|PEFR variability >30%|
|Step 2||Symptoms >2 times a week but <1 time a day||>2 times a month||FEV1 or PEFR > or = 80% predicted|
|Mild Persistent||Exacerbations may affect activity||PEFR variability 20%–30%|
|Step 1||Symptoms < or = to 2 times a week||< or = to 2 times a month||FEV1 or PEFR > or = to 80% predicted|
|Mild Intermittent||Asymptomatic and normal PEF between exacerbationsExacerbations brief (from a few hours to a few days); variable intensity||PEFR variability <20%|
|FEV1 = Forced Expiratory Volume at 1 second, PEFR = Peak expiratory Flow Rate, PEF variability = Variability between morning and evening PEF.|