ABSTRACT
Asthma is characterized by chronic airway inflammation and variable airway obstruction that can lead to persistent symptoms as well as intermittent acute exacerbations. Asthma exacerbations (also referred to as acute asthma or asthma attacks) are episodes with progressive onset of increased breathlessness, wheezing, cough, or chest tightness, either alone or in combination. A decline in peak expiratory fl ow (PEF) occurs during an exacerbation and is a more reliable indicator of the severity of airfl ow limitation than symptoms alone. Severe exacerbations of asthma are potential life-threatening and represent a common medical emergency. Death is caused by acute respiratory failure due to airfl ow limitation.
