Study design (if review, criteria of inclusion for studies)
randomized, cross-over trial
Participants
adolescents with cystic fibrosis (CF)
Interventions
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 l/min. For System B, the volume fill was 4 ml and the flow 10 l/min.
Outcome measures
The mass median diameter (MMD) of aerosol, aerosol volume released by the two systems, intrathoracic deposition, lung deposition
Main results
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 plus or minus 0.04 ml) of gentamicin solution compared to System A (1.71 plus or minus 0.03 ml) during similar nebulization time. Intrathoracic deposition was 4.0 plus or minus 2.7% for System A and 7.1 plus or minus 2.8% for System B. Lung deposition in patients inhaling from System A and B was 3.2 plus or minus 1.8% and 6.2 plus or minus 2.1%, respectively (p < 0.05).
Authors' conclusions
This study demonstrates that operating conditions of the JN can markedly affect the dose of antibiotic deposited in the lung. using greater volume fill and higher flow rate markedly increases the intra pulmonary deposition of antibiotic in adolescents.