RESUMO
STUDY OBJECTIVE: To compare the in vitro performance of an ultrasonic nebulizer and a jet nebulizer in producing a respirable aerosol of tobramycin solution for injection. DESIGN: In vitro observational study DEVICES: Ultrasonic and jet nebulizers. INTERVENTION: Output was determined by measuring the difference in nebulizer weight before and after nebulizing 3 ml of tobramycin injection solution. Mass median aerodynamic diameter (MMAD) and respirable mass were determined by sampling tobramycin aerosol into a cascade impactor. MEASUREMENTS AND MAIN RESULTS: Mean (SD) output was 1.14 (0.09) ml/minute for the ultrasonic nebulizer and 0.64 (0.08) ml/minute (p<0.001) for the jet nebulizer. Mean MMAD for the jet nebulizer (2.31 [0.10] microm) was less than that of the ultrasonic nebulizer (2.81 [0.17] microm, p<0.001). The majority of tobramycin aerosol produced was in the respirable range for both the ultrasonic (65.1% [4.10%]) and jet (60.6% [0.73%], p=0.008) nebulizers. CONCLUSION: Despite small, clinically unimportant differences in aerosol size and respirable fraction, either device would be acceptable to administer tobramycin injection solution.
