RESUMO
BACKGROUND: The need for establishing criteria that facilitate decision-making has lead to search for factors that could predict prognosis and response to treatment for asthma exacerbations. OBJECTIVE: To assess which clinical factors are associated with a rapid response to short-acting beta2 agonists during asthma exacerbations. PATIENTS AND METHODS: Two hundred and twenty consecutive adults with mild to moderate asthma crisis were included. Their medical history and physical examinations were completed and closely monitored: heart rate, respiratory rate, SO2, and FEV-1. They were initially treated with O2 and micronebulized albuterol (2.5 mg every 20' x 4). A FEV-1 > or = 80% of predicted and an improvement at 90' were considered as good response. RESULTS: One hundred and forty-four (65.5%) patients had a good response to micronebulized albuterol, while 76 (34.5%) required steroids and hospitalization. Early relapse rate (72 hours) in this study was low (3.4%) and it was associated to other factors, such as: upper airway infection (40%) and history of oral steroids usage in the previous year (80%). The variables associated to a good response were: < 6 hours since crisis started, no hospitalization or steroid use during a crisis in the last year, initial SO2 > or = 90% and initial FEV-1 > or = 60%. CONCLUSIONS: These variables are easily measured and predict a therapeutic response in asthma patients when first seen in the emergency room.