Nebulized Gentamicin in Children with Cystic Fibrosis: Enhancing Antibiotic Lung Deposition by Increasing Flow Rate and Fill Volume

Abstract

ABSTRACT The aim of this study was to determine the influence of altering the nebulizer flow rate and volume fill on intrapulmonary deposition of nebulized gentamicin in adolescents with cystic fibrosis (CF). A single group of individuals inhaled randomly from two nebulization systems in a cross-over fashion. For System A, gentamicin 80 mg labeled with 4 mCi Tc 99m DTPA, diluted to 2 ml were placed in a jet nebulizer (JN) driven by an airflow of 5.5 1/min. For System B, the volume fill was 4 ml and the flow 10 1/min. The mass median diameter (MMD) of aerosol in System A and B was 4.4 m and 3.1 m, respectively. The nebulizer in System B released twice the volume (3.47 ± 0.04 ml) of gentamicin solution compared to System A (1.71 ± 0.03 ml) during similar nebulization time. Intrathoracic deposition was 4.0 ± 2.7% for System A and 7.1 ± 2.8% for System B. Lung deposition in patients inhaling from System A and B was 3.2 ± 1.8% and 6.2 ± 2.1%, respectively (p < 0.05). This study demonstrates that operating cond...