Asthma accounts for nearly 500000 h...

Asthma accounts for nearly 500000 hospitalizations, 2 million crisis department visits, and 5,000 deaths in the United States each year. (1) Despite an increased understanding of pathophysiology and treatment options, the disease remains undertreated. Asthma guidelines have been established to address the disparity between scientific knowledge and actual management, and these guidelines have been updated lately to answer several key clinical questions. Part I of this two-part article reviews the updated guidelines, examines the supporting evidence behind the changes, and discusses the clinical implications of diagnosing and treating asthma in children and adults. Part II (2) will discuss the medical management of asthma.

The Updated Guidelines

The National Asthma Education and Prevention Program (NAEPP) person specially versed Panel, organized by the National Institutes of Health's National Heart, Lung and children Institute, was convened in 1989 to improve asthma care in the United States. The panel published its first establish of asthma guidelines in 1991; six years later it released a other set of guidelines. (3)

Clinical guidelines are most numerous valuable if they are based in succession the most current research. This is especially important for asthma, given about of the recently available medications and the vast number of studies published in newly come years. The NAEPP decided that an efficient approach would be to update the guidelines upon a periodic basis, and to focus forward key clinical questions rather than rewrite the entire guideline. These position statements will be published as NAEPP master-hand Report Updates. The most fresh update (4) was published in 2002 and events to come updates will be incorporated into a Web-based version of the existing guidelines (http://www.nhlbi.nih.gov/guidelines/asthma/asthgdln.htm).

Diagnosis and Classification

Aspects of asthma management that remain unchanged in the updated guidelines are the diagnosis of asthma and the use of a classification theory to determine severity of the disease. Unlike diseases in which objective numeric values are used to establish a diagnosis (eg hypertension, diabetes), asthma is a clinical diagnosis that incorporates genetic predisposition and clinical symptoms with objective measures of lung function (Table 1) (3)

Before making the diagnosis of asthma, physicians should determine whether other conditions could be causing a patient's symptoms (Table 2) (3) Spirometry, not just the use of peak expiratory grow (PEF) meters, is critical for diagnosing and managing asthma. The NAEPP commits the use of spirometry for initial assessment, evaluation of answer to treatment, and assessment of airway function at least each one to two years. (3) However, physicians should note that patients with asthma can have normal lung function.

Disease severity is determined by the agency of pulmonary function measurements, asthma symptoms, and the ne for free medication (Table 3). (3) Several factors can complicate the assessment of asthma severity. First, disease classification is based forward the symptoms the patient had before starting treatment. one time treatment has begun, classification becomes more difficult. inferior asthma is a variable disease. Studies have shown that patients with asthma rarely remain in the same category above time, (5) and that patients themselves frequently underestimate their symptoms and thus are classified incorrectly. (6) Furthermore, the now passing classification system does not take activity horizontal into consideration. One study (7) base that asthma initially classified as mild was plenteous more severe when patients' activity evens were considered. When activity horizontal was included in the classification order 93 percent of the patients had persistent asthma, and 77 percent had moderate to strict asthma. (7)

Finally, objective measures of pulmonary function, in the same state [i]or[/i] condition as PEF and forced expiratory convolution in one second (FE[V.sub.1]), do not always correlate with the severity or oftenness of asthma symptoms.8 For example, common study9 found that although a decrease in FE[Vsub1] was predictive of an asthma attack in the following year, more than 25 percent of subject of attention participants with normal lung function had a following asthma attack.

The previous NAEPP guidelines noted that underdiagnosis and inappropriate therapy contribute substantially to asthma morbidity and mortality. (3) Despite the newly come updates to the guidelines, the diagnosis of asthma and classification of its severity (an essential consideration in selecting asthma medications) remain challenging.

Monitoring

The updated guidelines address pair key clinical questions about the monitoring of patients with asthma: whether written asthma action plans improve issues compared with medical management alone, and whether written action plans based upon PEF monitoring improve outcomes more than plans based forward symptoms. However, the data to support the use of action plans with and without PEF monitoring were inconclusive.

Written action plans and PEF monitoring have been considered essential composings of asthma self-management education. (10) Written action plans acknowledge patients how to adjust medications and rule their environment to manage their asthma upon normal days and during attacks, and encourage them to ask care before an attack begins. PEF monitoring frequently is included in these plans, and numeric values obey as indicators that patients should take certain actions.