Holding chambers versus nebulisers for beta-agonist treatment of acute asthma

In acute asthma inhaled beta-agonists are often administered to relieve bronchospasm by wet nebulisation, but some have argued that metered-dose inhalers with a holding chamber (spacer) can be equally effective. In the community setting nebulisers are more expensive, require a power source and need regular maintenance.

There is controversy as to whether wet nebulisers are better than metered dose inhalers with holding chambers to deliver beta2-agonist medications for acute asthma. Comparisons of hospital and home use are also of interest. The objective of this review was to assess the effects of holding chambers compared to nebulisers for the delivery of beta2-agonists for acute asthma.

We searched the Cochrane Airways Group trials register and the Cochrane Controlled Trials Register.

Randomised trials in adults and children (from two years of age) with asthma, where holding chamber beta2-agonist delivery was compared with wet nebulisation.

Two reviewers independently applied study inclusion criteria (one reviewer for the first version of the review), extracted the data and assessed trial quality. Missing data were obtained from the authors or estimated.

This review has been updated in 2001 to include 4 new trials and has now analysed 880 children and 444 adults included in 21 trials. Method of delivery of beta2-agonist did not appear to affect hospital admission rates. In adults, the relative risk of admission for holding chamber versus nebuliser was 0.88 (95% confidence interval 0.56 to 1.38). The relative risk for children was 0.65 (95% confidence interval 0.4 to 1.06). One study in children found a significantly shorter length of stay in the emergency department when the holding chamber was used, with a weighted mean difference of -0.62 hours, 95% confidence interval -0.84 to -0.40 hours. Adults' length of stay in the emergency department was similar for the two delivery methods. Peak flow and forced expiratory volume were also similar for the two delivery methods. Pulse rate was lower for holding chamber in children, weighted mean difference -7.8% baseline (95% confidence interval -10.2 to -5.3).

Metered-dose inhalers with holding chamber produced outcomes that were at least equivalent to nebuliser delivery. Holding chambers may have some advantages compared to nebulisers for children with acute asthma.