Concentration of gentamicin in bronchial secretions of children with cystic fibrosis of tracheostomy. (Comparison between the intramuscular route, the endotracheal instillation and aerosolization).

The levels of gentamicin in blood and in secretions of the tracheobronchial 
tree were measured in 14 children (8 with cystic fibrosis and 
6 with tracheostomy) in a cross over fashion after the administration 
of 40 mg of gentamicin by aerosol or by endotracheal injection. 
High levels of gentamicin (greater than 20 mug/ml) within the bronchial 
secretions were observed in 7 children after aerosolization and in 11 
children after endotracheal instillation. Corresponding blood levels were low (less than 
3 mug/ml) in all patients and no detectable levels were found 
in 10 children after aerosolization and in 6 children after endotracheal 
instillation. No significant differences were observed between children with cystic fibrosis 
and those with tracheostomy. Since intramuscular injection of gentamicin (a single 
dose of 1.5 mg/kg) resulted in low levels of gentamicin within 
the bronchial secretions (less than 2 mug/ml in 10 patients, among 
whom 4 had undetectable levels); it is concluded that the administration 
of an antibiotic such as gentamicin, directly to the trachea by 
endotracheal injection or by aerosolization might prove to be helpful when 
the infection is confined mainly to the tracheo-bronchial tree. 