A Cochrane review included 2 studies with a total of 63 subjects; both concerned adults. An additional study including 14 children was identified. In the single high quality study budesonide in high dose (2000–8000 mcg) delivered by a jet nebuliser with inspiration-only inhalation was compared to budesonide 1600 mcg via large volume spacer. The nebuliser delivery led to higher morning peak expiratory flow values (25 l/min p<0.01), higher evening values (30 l/min, p<0.01), lower rescue beta-2 agonist use and symptom scores compared to the holding chamber delivery. The authors conclude that Cost, compliance and patient preference are important determinants of clinical effectiveness that still require further assessment.
Comment: The quality of evidence is downgraded by sparse data, inconsistency of results, and indirectness of evidence. It is not clear whether the observed difference in the only high-quality trial was an effect of nominal dose delivered or delivery system.