Abstract
INTRODUCTION: The volume of colistimethate sodium (CMS) that can be administered in a single application using a vibrating mesh nebulizer (VMN) is related to the capacity of the nebulization chamber. This study designed and tested a nebulization chamber and assessed the effects of the diluent volume on colistin nebulization. METHODS: A bench study was conducted to evaluate the performance of the nebulization chamber. A 7-day clinical scenario involving the nebulization of two diluent volumes of CMS (6 and 12 mL) was simulated. Each diluent volume was nebulized for seven consecutive days. Particle size and viscosity were analyzed for four diluent volumes of CMS (3 mL, 6 mL, 9 mL, and 12 mL). RESULTS: After 7 consecutive days of nebulization, residual colistin crystals were observed in both diluent volumes, with a higher incidence in the 6-mL than in the 12-mL diluent volume. The VMN malfunctioned once on day 5 when using the 6 mL diluent volume. Nebulized colistin output was inversely correlated with diluent viscosity. CONCLUSION: The additional nebulization chamber facilitated the nebulization of a larger diluent volume of CMS in a single nebulization course. Larger diluent volumes resulted in fewer residual CMS crystals and lower diluent viscosity.