Holding chambers versus nebulisers for inhaled steroids in chronic asthma

BACKGROUND: Inhaled corticosteroids are available in the form of a suspension for nebulisation, although the role of this mode of therapy in the treatment of chronic asthma is still unclear. OBJECTIVES: To assess the efficacy and safety of inhaled corticosteroids delivered via nebuliser versus holding chamber for the treatment of chronic asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group Trial Register (1999) and reference lists of articles. We contacted the authors of studies and pharmaceutical companies for additional studies and hand-searched the British Journal of Clinical Research, European Journal of Clinical Research and major respiratory society meeting abstracts (1997-1999). Date of last search August 2005. SELECTION CRITERIA: Randomised controlled trials comparing nebuliser to holding chamber in the delivery of inhaled corticosteroids for the treatment of chronic asthma. All age groups of patients were considered. Two reviewers assessed articles for inclusion; two reviewers independently assessed included studies for methodological quality. DATA COLLECTION AND ANALYSIS: One reviewer extracted data; authors were contacted to clarify missing information. Quantitative analyses were undertaken using Review Manager 4.1 with MetaView 3.1. MAIN RESULTS: Two studies were selected for inclusion (63 subjects), both concerned adults. An additional small study including 14 children was identified for the 2005 update. Methodological quality was variable. Due to design differences it was not appropriate to pool the studies. The single high quality study compared budesonide 2000-8000 mcg delivered via Pari Inhalier Boy jet nebuliser with inspiration-only inhalation 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 (30L/min, p<0.01), lower rescue beta2 agonist use and symptom scores compared to the holding chamber delivery. AUTHORS' CONCLUSIONS: Budesonide in high dose delivered by the particular nebuliser used in the only double-blinded study that could be included in this review was more effective than budesonide 1600 mcg via a large volume spacer. However, it is not clear whether this was an effect of nominal dose delivered or delivery system. Cost, compliance and patient preference are important determinants of clinical effectiveness that still require further assessment. Future studies are needed to evaluate the relative effectiveness of inhaled corticosteroids delivered by different combinations of nebuliser/compressor compared to holding chamber. Moreover, further studies assessing these delivery methods are needed in infants and pre-school children, as these are groups that are likely to be considered for treatment with nebulised corticosteroids.