Nebulised antibiotic therapy is an established, safe and effective therapy for cystic fibrosis with chronic pseudomonas infection resulting in improved pulmonary function and reduced hospitalisation. Despite similar respiratory disease, this therapy has not been evaluated in children with non cystic fibrosis bronchiectasis. This study evaluates the suitability of a gentamicin solution and nebuliser combination for use in this population.
Materials and methods: Four millilitres of gentamicin (80 mg) in saline delivered by a PARI LC plus nebuliser and PARI Turboboy N compressor was used. The pH, osmolarity, chloride concentration and aerosol particle size was determined. Ten children with non cystic fibrosis bronchiectasis received nebulised antibiotic and had peak gentamicin concentrations measured in sputum and serum. Pulmonary function was measured pre and post nebulisation.
Results: The solution had an osmolarity of 199 mOsm/l, pH of 4.1, chloride concentration of 75 mmol/l and the aerosol a mass median aerodynamic diameter of 3.3 microm. Nebulisation was well tolerated, with no significant change in FEV1. Peak serum levels were at the threshold of detectability (0.3 mg/l). Sputum concentrations had a mean of 624 mg/g and lower 95th confidence interval 25 times the minimum inhibitory concentration for the predominant infecting organism, Haemophilus influenzae.
Conclusion: Nebulisation of 80 mg of gentamicin in saline achieved bactericidal concentrations in sputum, was well tolerated and had negligible systemic absorption making it a suitable choice for this population.