Continuous versus Intermittent Beta Agonists Given During an Asthma Attack

10 for prevented hospital admission

Benefits in NNT

1 in 10 were helped (preventing hospital admission)
90% saw no benefit
10.0% were helped by preventing hospital admission

Harms in NNT

None were harmed (serious side effects)
0% were harmed by drug side effects
View As:

Efficacy Endpoints

Hospital Admission

Harm Endpoints

Tachycardia, tremor


There were 8 studies (N=461) included, 3 of patients with mild-moderate attacks and 5 of patients with severe attacks. There was 1 pediatric study, 1 pediatric-adult and the remaining 6 were adult only. There was variability between the studies in terms of dosing, duration of therapy, and co-interventions. Generally in the continuous groups, 10-30 mg of albuterol was administered in normal saline over a period of 2-4 hours, with 1 study group receiving only 5mg and a separate study lasting 6 hours. The control groups received 2.5-5.0 mg of albuterol in nebulized form over the same period of time compared to the respective experimental groups. Specifically, 3 groups received q20 minute nebulizers, 3 q30 minute nebulizers and 2 q1 hour nebulizers.


The patients from the “severe” studies (baseline admission rate 40%) contributed 91% of the weight of this review, so it is not clear whether these results should be generalized to all asthma patients presenting with acute exacerbations. Also, a significant potential benefit to continuous nebulizers is decreased patient time in the ED and utilization of staff resources. Unfortunately, most studies did not report this outcome so it is not clear whether there is an important impact in this regard.


Ashley Shreves, MD


January 10, 2010