SELECTED ARTICLES FROM THE RECENT LITERATURE 2004
10/12/04
Inhaled beta agonists administered by MDI/spacer vs nebulization for acute asthma exacerbations in young children
Summary
Background - The delivery of inhaled beta agonist such as albuterol (Alb) of acute asthma exacerbations in young children has typically been by power nebulizers. However, some (but not all) studies in recent years have shown equal efficacy in acute asthma flare when albuterol is inhaled by the child using either a nebulizer or a meter dose inhaler (MDI) with a valved spacer (holding chamber). Are the two methods of delivering inhaled Alb in young children really equally effective?
Findings - Castro-Rodriguez and Rodrigo of the Univ. of Chile in Santiago carried out a meta-analysis of reports of randomized, prospective, controlled trials comparing nebulized Alb vs. Alb delivered by MDI plus valved hold chamber (VHC) in the treatment of acute asthma exacerbations in children < 5 years old. In 6 trials involving 491 patients obtained from databases which met the authors criteria for inclusion, children who received Alb by MDI + VHC actually were admitted subsequently because of uncontrolled asthma less frequently than children of the same age treated with nebulized Alb (Odds Ratio (OR) = 0.42; p=0.002). This decreased admission rate following MDI + VHC treatment was even more striking in those children treated for moderate to severe asthma exacerbations (OR=0.27; p=0.003). The mean reduction in severity of asthma symptoms was also significantly greater in those treated with MDI + VHC than in those treated with nebulized Alb (p=0.0003).
Conclusions - The use of MDI + VHC was more effective than nebulization in delivery of inhaled beta-agonists to children <5 years old with moderate to severe acute asthma flares in terms of improving clinical scores and decreasing the need for hospitalization.
Reference
J Pediatr 2004;45:172-7
Editor's Comments
As a non-pediatrician, I have been puzzled by the somewhat conflicting results of previous studies comparing nebulization with MDI + VHC in the delivery of inhaled beta agonists in acute childhood asthma. Following discussion with a highly experienced Pediatric Allergist/Immunologist I now realize that there are a number of variables, which differ among these studies than can affect the authors' conclusions. For example: 1) the type of VHC used (most children < 5 years of age cannot adequately time activation of MDI with inhalation); 2) the number of MDI puffs inhaled in a treatment. The "standard" 2 puff MDI treatment is not equivalent to the delivery of Alb, 5 mg/ml by nebulizer; 3) the use of a facial mask vs. "blow by" in nebulization; 4) the outcome measure assessed (no mention of pulmonary function findings in the meta-analysis above.
It would not be surprising if MDI + VHC (with adequate number of puffs inhaled) was as effective as nebulization. What was surprising is that children treated with MDI + VHC did that much better, at likely a considerably reduced cost!
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