Background: This randomised cross-over pilot study was undertaken in 10 cystic fibrosis children aged 10 to 63 months to describe lung absorption of tobramycin delivered by the PariLC+/PariTurboboyN (Pari GmbH) and the disposable NL9M/AtomisorBoxPlus (Diffusion Technique Française) nebulising systems.
Methods: Each child inhaled 300 mg tobramycin delivered with one or the other apparatus via a facemask in two separate and standardised sessions. Urine was collected for 6 h. Tobramycin concentrations determined by immunoprecipitation were expressed in mg per g of creatinine and compared by a Wilcoxon test for matched pairs. The influences of age, weight and Brasfield score on this parameter were evaluated by correlation tests, and those of sex, previous nebulisation treatment, and crying or coughing were evaluated by Student's t-test.
Results: The amount of tobramycin measured in urines was low and variable. Median values for urinary tobramycin concentration were 47.6 mg/g (14.9-79.6) with the PariLC+ and 42.6 mg/g (6.3-112.8) with the NL9M (p=0.6). PariLC+ delivered tobramycin in 22 min and NL9M in 12 min (p=0.005). Crying or coughing dramatically reduced the amount of tobramycin collected.
Conclusion: This pilot study shows that evaluation of nebulisers based on tobramycin renal excretion is feasible in young children with cystic fibrosis.