Managing acute, severe asthma: Part 1

In evaluating patients with acute asthma, look for signs associated with increased risk, such as accessory muscle use, respiratory rate greater than 30 breaths per minute, heart rate greater than 120 beats per minute, and pulsus paradoxus greater than 12 mm Hg. Since severity of wheezing does not correlate well with the degree of airway obstruction, it is important to measure peak expiratory flow rate; a value less than 50% of predicted generally indicates a severe attack. A short-acting β₂-agonist may be given by either metered-dose inhaler or nebulizer; the latter is often preferred because it requires less coordination and instruction. Subcutaneous administration of a short-acting β₂-agonist may be appropriate for patients who cannot comply with or do not respond to inhaled therapy. Systemic corticosteroids are usually indicated, and supplemental oxygen may be needed to maintain oxygen saturation above 90%. Ipratropium by inhalation is an option for patients with severe obstruction who do not respond to standard therapies.