Introduction-Domiciliary nebulisers are frequently used in COPD however nebuliser cleaning practices are not followed leading to microbial contamination which may lead to serious exacerbations.We aimed to evaluate microbial contamination of home nebulisers in such patients.

Methods-Random microbiological assessment of domiciliary nebulisers was undertaken together with an enquiry into cleaning practices.50 subjects were included in the study.We also examined the effectiveness of cleaning practices in eradicating isolated microorganisms in a laboratory setting.

Results-The mean age of patients in this study was 60 years with 70% of patients having significant comorbidities including diabetes, hypertension and cardiac disease.50 nebuliser sets were obtained to evaluate for contamination.Potentially pathogenic bacteria colonisation was observed in 20 of 50 nebulisers(40%) and organisms isolated included Pseudomonas aeruginosa,Escherichia coli,Staphylococcus aureus& Klebsiella species.Candida was also found as fungal contamination.Cleaning of nebulisers with soap and water achieved complete eradication of Gram-positive bacteria and fungus.Gram-negative organisms were incompletely eradicated.We also found higher rates of COPD exacerbations in patients in whom pathogen was isolated as compared in those whose sets did not grew pathogenic flora i.e. 12(of 20) and 5 (of 30)patients respectively.

Conclusions-Nebulisers contaminated with pathogens are hazardousand may lead to devastating consequences.Perpetual colonisation is a potential concern in elderly patients of COPD with comorbidities.Importance of nebuliser cleanliness should always be emphasised while dealing such patients.