RESUMEN DE LA GUIA

Cada sección de esta Guía comienza con una lista de "Puntos clave" y "Diferencias con la Guía de 1991" y, seguidamente se describe brevemente el contenido de cada sección

PATOGENESIS Y DEFINICION

En la Guía de 1991 se enfatizaba el papel de la inflamación en la patogenesis del asma aunque la evidencia científica de la implicación de la inflamación en el asma no había hecho más que empezar. Ahora, en 1997, aunque el papel de la inflamaciñón sigue evolucionando como concepto, existe una base científica mucho más firme que indica que el asma resulta de una serie de interacciones complejas entre las células inflamatorias, los mediadiores y las células y tejidos que pertenecen a las vías respiratorias. De esta manera, el asma se define ahora como un desórden inflamatorio crónico de las vías respiratorias en el cual muchas células y elementos celulares juegan diveros papeles en paricular los mastocitos, eosinófilos, linfocitos T, neutrófilos y células epiteliales. En los sujetos susceptibles, esta inflamación causa episodios recurrentes de jadeos, dificultades respiratorios, opresión en el pecho y tos, en particular por la noche y por la mañana temprano. Estos episodios, están usualmente asociados a una obstrucción amplia pero variable de las vías respiratorias, a menudo reversible espontáneamente o con un tratamiento. Esta inflamación también ocasiona un aumento asociado de una hipersusceptibilidad bronquial a una variedad de estímulos.

COMPONENTE 1. Medidas de evaluación y monitorización

Evaluación inicial y diagnóstico del asma.

Es extremadamente importante realizar un diagnóstico correcto del asma. Se requiere un juicio clínico dado que los signos y síntomas varían ampliamente de un paciente a otro y dentro del mismo paciente con el tiepo. Para establecer un diagnóstico de asma, el clínico debe determinar que:

• existe una presencia de síntomas episódicos de obstrucción de las vías respiratorias
• la obstrución de la vías respiratorias es al menos parcialmente reversible
• están excluídos diagnósticos alternativos

Esta sección difiere a la Guía de 1991 en varios aspectos. Se ha modificado la clasificación del asma de ligero, moderado o severo a ligero intermitente, ligero peristente, moderado persistente y severo persistente para reflejar de forma más exacta las manifestaciones clínicas del asma

El Panel enfatiza que cualquier paciente en cualquier nivel de severidad puede padecer exacerbaciones ligeras, moderadas o sevaras. Además, la información sobre los jadeos infantiles y la disfunción de las cuerdas vovales ha sido expandida. Se han refinado las situaciones que aconsejan el envío de un paciente a un especialista en asma por parte de los médicos de atención primaria

Evaluación y monitorizaciones periódicas .

Para determinar si se han cumplido los objeticos de un tratamiento antiasmático, se requieren evaluaciones periódicas. Los objetivos de la terapia del asma son:

• Prevenir los síntomas crónicos y enojosos
• Mantener unos niveles de actividad nornal (incluyendo el ejercicio y otras actividades físicas)
• Prevenir las exacerbaciones recurrentes del asma y minimizar la necesidad de visistas a urgencias u hospitalizaciones
• Facilitar una farmacoterapia óptima sin efectos adversos o con reacciones adversas mínimas
• Cumplir las expectativas de los pacientes y de sus familias en lo que se refiere a su satisfaccción en los cuidados del asma

Se recomiendan para tipos de monitorización: síntomas y signos, función pulmonar, calidad de vida y situación funcional, farmacoterapia, comunicación paciente-facultativo y satisfacción del pacientes.

The Panel recommends that patients, especially those with moderate-to-severe persistent asthma or a history of severe exacerbations, be given a written action plan based on signs and symptoms and/or peak expiratory flow. As in the 1991 report, daily peak flow monitoring is recommended for patients with moderate-to-severe persistent asthma. In addition, the Panel states that any patient who develops severe exacerbations may benefit from peak flow monitoring. A complete review of the literature on peak flow monitoring was conducted, evidence tables were prepared, and the results of this analysis are summarized in the report.

COMPONENTE 2 : Control de los factores que contribuyen a agravar el asma

Exposure of sensitive patients to inhalant allergens has been shown to increase airway inflammation, airway hyperresponsiveness, asthma symptoms, need for medication, and death due to asthma. Substantially reducing exposures significantly reduces these outcomes. Environmental tobacco smoke is a major precipitant of asthma symptoms in children, increases symptoms and the need for medications, and reduces lung function in adults. Increased air pollution levels of respirable particu-lates, ozone, SO 2 , and NO 2 have been reported to precipitate asthma symptoms and increase emer-gency department visits and hospitalizations for asthma. Other factors that can contribute to asthma severity include rhinitis and sinusitis, gastroesophageal reflux, some medications, and viral respiratory infections. EPR-2 discusses environmental control and other measures to reduce the effects of these factors.

C O M P O N E N T 3 : Pharmacologic Therapy

EPR-2 offers an extensive discussion of the phar-macologic management of patients at all levels of asthma severity. It is noted that asthma pharma-cotherapy should be instituted in conjunction with environmental control measures that reduce exposure to factors known to increase the patient’s asthma symptoms. As in the 1991 report, a stepwise approach to pharmacologic therapy is recommended, with the type and amount of medication dictated by asthma severity. EPR-2 continues to emphasize that persis-tent asthma requires daily long-term therapy in addition to appropriate medications to manage asthma exacerbations. To clarify this concept, the EPR-2 now categorizes medications into two general classes: long-term-control medications to achieve and maintain control of persistent asthma and quick-relief medications to treat symptoms and exacerbations. Observations into the basic mechanisms of asthma have had a tremendous influence on therapy. Because inflammation is considered an early and persistent component of asthma, therapy for persis-tent asthma must be directed toward long-term suppression of the inflammation. Thus, EPR-2 continues to emphasize that the most effective medications for long-term control are those shown to have anti-inflammatory effects. For example, early intervention with inhaled corticosteroids can improve asthma control and normalize lung func-tion, and preliminary studies suggest that it may prevent irreversible airway injury. An important addition to EPR-2 is a discussion of the management of asthma in infants and young children that incorporates recent studies on wheez-ing in early childhood. Another addition is discussions of long-term-control medications that have become available since 1991—long-acting inhaled beta 2 -agonists, nedocromil, zafirlukast, and zileuton. Recommendations for managing asthma exacerba-tions are similar to those in the 1991 Expert Panel Report. However, the treatment recommendations are now on a much firmer scientific basis because of the number of studies addressing the treatment of asthma exacerbations in children and adults in the past 6 years.

C O M P O N E N T 4 : Education for a Partnership in Asthma Care As in the 1991 Expert Panel Report, education for an active partnership with patients remains the cornerstone of asthma management and should be carried out by health care providers delivering asthma care. Education should start at the time of asthma diagnosis and be integrated into every step of clinical asthma care. Asthma self-management education should be tailored to the needs of each patient, maintaining a sensitivity to cultural beliefs and practices. New emphasis is placed on evaluat-ing outcomes in terms of patient perceptions of improvement, especially quality of life and the abil-ity to engage in usual activities. Health care providers need to systematically teach and fre-quently review with patients how to manage and control their asthma. Patients also should be provided with and taught to use a written daily self-management plan and an action plan for exac-erbations. It is especially important to give a written action plan to patients with moderate-to-severe persistent asthma or a history of severe exacerbations. Appropriate patients should also receive a daily asthma diary. Adherence should be encouraged by promoting open communication; individualizing, reviewing, and adjusting plans as needed; emphasizing goals and outcomes; and encouraging family involvement. In summary, the 1997 Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma reflects the experience of the past 6 years as well as the increasing scientific base of published articles on asthma. The Expert Panel hopes this new report will assist the clinician in forming a valuable partnership with patients to achieve excellent asthma control and outcomes.

REFERENCIAS

Adams PF, Marano MA. Current estimates from the National Health Interview Survey, 1994. Vital Health Stat 1995;10:94. Centers for Disease Control and Prevention. Asthma mortality and hospitalization among children and young adults— United States, 1990-1993. MMWR 1996;45:350-353.

Centers for Disease Control and Prevention. Asthma-United States, 1989-1992. MMWR 1995;43:952-5.

National Asthma Education and Prevention Program. Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma. National Institutes of Health pub no 91-3642. Bethesda, MD, 1991.

National Heart, Lung, and Blood Institute. International Consensus Report on Diagnosis and Management of Asthma. National Institutes of Health pub no 92-3091. Bethesda, MD, 1992.

National Heart, Lung, and Blood Institute and World Health Organization. Global Initiative for Asthma. National Institutes of Health pub no 95-3659. Bethesda, MD, 1995.

U.S. Preventive Services Task Force. Guide to Clinical Preventive Health Services. Baltimore: Williams and Wilkins, 1989.