Take a look at this recent Cochrane review.
Cates, C.J., Welsh, E.J. and Rowe, B.H., 2013. Holding chambers (spacers) versus nebulisers for beta‐agonist treatment of acute asthma. Cochrane database of systematic reviews, (9).
It looks at the question Are spacers or nebulizers better in managing acute asthma?
Why is this review useful?
In my experience, different hospitals do different things when managing asthma. In my previous hospital we gave 3 back-to-back salbutamol nebulizers (2.5mg or 5mg depending on the age/size). In my current hospital we give 3 x 20 minutely salbutamol inhalers via spacer.
What type of patients were included?
The studies included children being managed in ED, or in the community, with acute asthma.
Children with life-threatening asthma were excluded.
How many patients were included?
This review looked at 39 studies, encompassing 1897 children. It also looked at the evidence for use of spacers in adults.
What were the outcomes?
Primary outcomes: admission to hospital; duration of inpatient hospital stay.
Secondary outcomes: time in ED; change in respiratory rate; blood gases; pulse rate; tremor; symptom score; lung function; use of steroids; relapse rates.
What were the findings?
There was no significant benefit in using nebulizers rather than spacers to deliver beta agonists in preventing hospital admission. The time spent in ED was significantly shorter (mean 33 mins) with spacers.
Pulse rate after treatment was significantly lower in children who received treatment via a spacer and development of tremor was more common in children who received nebulized treatment.
There was no difference in lung function or oxygen saturation.
Other points to note…
The authors acknowledge the uncertainty in choosing the correct dose of salbutamol. The studies generally rely on titrating the treatment to the response of the patient and repeating doses as necessary. This is good advice for real life.
The type of spacer did not affect the outcome.
The studies compared inhalers to separate nebulisers (not continuous). In practice, many hospitals use continuous nebulizers which is thought to be more effective than separate nebulisers as it avoids rebound bronchoconstriction.
Metered-dose inhalers with a spacer can perform at least as well as nebulisers when delivering beta-agonists in children with acute asthma
Salbutamol does have systemic side effects – tremor and increased pulse rate were more common when using nebulisers