NEBULIZER PERFORMANCE - AFLM STUDY

This study was conducted by the AFLM in order to determine the perform ance characteristics of 12 commercially available nebulizers (6 ultras onic and 6 jet) used in the treatment of cystic fibrosis (CF). The neb ulizers were connected to a circuit which simulated the ventilation of a CF child and CF adult, and were tested using three drug solutions: tobramycin (T), colistin (C), and amiloride (A). Nebulizer performance was evaluated according to the volume of drug solution delivered in 1 0 min during the simulated inspiratory phase (VI), drug granulometry ( G%), drug concentration modification in the nebulizer reservoir (Delta C), and percentage of efficiently aerosolized drug (EA%). The ultraso nic devices delivered a significantly higher VI than the jet nebulizer s (p<0.0001) for all three study drugs. Ventilation rate did not influ ence VI. Regarding granulometry, higher percentages of T and A were fo und to be contained in droplets ranging from 0.5 to 5.0 mu m following ultrasonic nebulization. Drug concentration modifications were indepe ndent of the nebulizer used but were influenced by drug type; overconc entrations of T and A were observed (Delta C = +10.5 +/- 18.6 and +13. 4 +/- 8.9%, respectively). On average, the ultrasonic devices achieved a higher EA% than the jet nebulizers (17.3 +/- 6.7 and 9.7 +/- 9.6%, respectively). This study highlights the significant variability in pe rformance of different nebulizer types and emphasizes the importance o f accurately testing nebulizers prior to clinical use so that the most efficacious nebulizer/drug combinations may be prescribed.