Asthma: Helping Patients Breathe Easier

Nurse Practitioner, Oct 2004 by Murphy, Kevin R, Cecil, Beth, Sarver, Nancy L

Asthma is a chronic inflammatory airway disease characterized by wheezing, breathlessness, chest tightness, and coughing principally at night or in the early morning.1 Symptoms often are associated with widespread but variable airflow obstruction that can be reversed spontaneously or with treatment. The inflammation also can cause an increase in bronchial hyperresponsiveness to various stimuli.1 According to the American Lung Association, approximately 20 million Americans had symptoms of asthma in 2001.2 Asthma accounted for an estimated 10.4 million physician office visits, 1.8 million emergency department visits, and nearly 4,500 deaths in 2000.3 Asthma incurs considerable economic costs,4 and the physical and emotional burden of asthma can be significant, even for those patients with mild disease.5 Adherence to a guidelines-based treatment approach can greatly reduce the significant morbidity and associated health resources used due to asthma.67

In 2002, the National Asthma Education and Prevention Program's (NAEPP) Expert Panel provided an evidence-based update to the 1997 National Heart, Lung, and Blood Institute Guidelines for the Diagnosis and Management of Asthma. The 2002 update includes recommendations for the pharmacologie treatment, monitoring, and prevention of asthma. Joint recommendations for the management of asthma in pregnant women were issued by the American College of Allergy, Asthma, and Immunology (ACAAI) and the American College of Obstetricians and Gynecologists (ACOG) in 2000.

* Classification of Asthma Severity

The 1997 Guidelines for the Diagnosis and Management of Asthma defined a stepwise approach to the pharmacologic treatment of asthma based on severity. Four severity steps from mild-intermittent (Step 1) to severe-persistent (Step 4) are defined based on clinical features before treatment. Classification of disease severity in children 5 years or younger is based on symptoms, whereas classification in older patients is based on symptoms and pulmonary function.' Forced expiratory volume in 1 second (FEV^sub 1^) and peak expiratory flow (PEF) are the most common measures of pulmonary function. FEV^sub 1^ measures the volume of air in the first second of a forced exhalation maneuver after a deep inspiratory effort. At an early phase of forced expiration, the expiratory flow achieves maximal values. The highest flow is known as the peak expiratory flow rate (PEFR). Both measures are effort-dependent and can be performed in children as young as 4 years.

Patient asthma severity is designated by the most severe symptom or objective measure. For example, a patient with daily daytime symptoms would be classified with moderate-persistent disease despite pulmonary function and nighttime symptoms consistent with mild disease (i.e. FEV^sub 1^ ≥ 80%, PEF variability 20% to 30%, and nighttime symptoms ≤1 night per week). Based on patient-reported symptoms, most patients can be classified as having mild to moderate disease. In a recent survey of 2,509 adults and children with asthma based on symptoms, 40% of patients had mild-intermittent disease, 22% had mild-persistent disease, and 19% had moderate-persistent disease.8

* Pharmacologie Treatment of Asthma

Two medication types (controller and reliever) are used to treat patients with asthma. Long-term controller medications are used on a daily basis in patients with persistent asthma to achieve and maintain control of symptoms.1 The most effective controller medications are those that reduce inflammation.1 Reliever medications are used as needed for the quick relief of asthma symptoms.1 Reliever medications such as short-acting beta^sub 2^-adrenergic agonists (SABAs) provide symptom relief by alleviating airway obstruction and associated bronchoconstriction.1

Long-term controller treatment is recommended for adults and children with any severity of persistent asthma.9 Because asthma progression may occur more readily in very young children, it is especially important to consider controller treatment for symptomatic children younger than 5 years and likely to develop persistent disease.9 The diagnosis of asthma in these patients maybe difficult. However, new criteria for the use of controller treatment in very young children with symptoms of asthma are based in part on the likelihood of developing persistent disease.9 When choosing a long-term treatment, medication effectiveness, patient response to previous regimens, patient or family ability to correctly administer the medication, and anticipated adherence should be considered.9

* Mild-Intermittent Asthma

Recommendations for the treatment of patients with mildintermittent asthma have not changed from those of the 1997 guidelines. Controller medications are not recommended in these patients. Short-acting beta^sub 2^-adrenergic agonists are recommended as needed for symptom relief, but overuse indicates poor asthma control and the need to reconsider disease severity. For example, patients classified with intermittent asthma who use a SABA more than two times a week may need to initiate long-term controller treatment, consistent with a diagnosis of persistent disease.