Acute asthma and other recurrent wheezing disorders in children.

www.aafp.org/afp Volume 88, Number 2 ◆ July 15, 2013 Not all acute wheezing is caused by asthma or bronchospasm, particularly in children younger than 2 years. If bronchodilators do not improve symptoms, alternative diagnoses (e.g., infection, foreign body) should be considered. Although no evidence exists to support the use of oxygen in acute asthma, it is known to be effective and should be administered when oxygen saturation levels fall below 94% in all cases of acute asthma. Although there is little evidence to support the use of inhaled bronchodilators, they remain one of the first-line treatment choices for acute asthma. • In mild to moderate acute asthma, beta2 agonists may be equally as effective from a metered dose inhaler/spacer combination compared with a nebulizer for control of acute symptoms, and may be associated with a shorter duration of stay in the emergency department and reduced adverse effects. • In severe acute asthma, we do not know whether there is a difference between continuous and intermittent nebulized beta2 agonists. • Caution: Inhaled salbutamol has been associated with hypokalemia and tremor. The only indication for ipratropium bromide for acute childhood asthma is in combination with salbutamol for acute severe wheezing. Although there is little evidence to support the use of oral corticosteroids, they remain one of the first-line treatment choices for acute asthma. • In mild to moderate asthma, oral corticosteroids are known to be more effective than placebo. We do not know whether high-dose inhaled corticosteroids and oral corticosteroids differ in effectiveness because we found insufficient evidence. For severe asthma, the addition of intravenous salbutamol, aminophylline, or magnesium sulfate is effective compared with the addition of placebo. • In severe acute asthma, we do not know whether intravenous aminophylline and salbutamol differ in effectiveness because we found insufficient evidence from one small randomized controlled trial. • Caution: Intravenous salbutamol and aminophylline have been associated with cardiac arrhythmias. Salbutamol has been associated with hypokalemia, and aminophylline has been associated with nausea. Intravenous theophylline can cause cardiac arrhythmias and convulsions if therapeutic blood concentrations are exceeded. This is one in a series of chapters excerpted from the Clinical Evidence Handbook, published by the BMJ Publishing Group, London, U.K. The medical information contained herein is the most accurate available at the date of publication. More updated and comprehensive information on this topic may be available in future print editions of the Clinical Evidence Handbook, as well as online at http://www. clinicalevidence.bmj.com (subscription required).