RESUMO
A severe acute asthma attack is defined by the presence of clinical signs of severity and/or a value of peak expiratory flow (PEF) < 30% predicted. The treatment is based mainly on inhaled beta 2 agonists and systemic corticosteroids. Nebulization is the route of administration of choice, because of its simplicity, its efficacy and its tolerability. Anticholinergics are indicated in association with nebulised beta 2 agonists. Response to treatment must be evaluated within an hour, permitting the early detection of "responders" or "non-responders" to the initial treatment. The great majority of deaths from acute asthma are avoidable, underlining the importance of preventive measures. Prevention is based on the control of the asthma by personalized ongoing treatment based on long-term inhaled corticosteroids and the use of oral corticosteroids in the treatment of exacerbations. However, a severe acute asthma attack can appear at any stage of severity of asthma, including controlled asthma, justifying the utilisation of action plans to treat exacerbations.