Topical antibiotics on tracheostoma prevents exogenous colonization and infection of lower airways in children

Introduction: Patients requiring long-term ventilation are at high risk of lower airway infections, generally of endogenous development. Patients on l ong-term ventilation, in particular via a tracheostomy, may develop tracheo bronchitis or pneumonia of exogenous pathogenesis, ie, caused by microorgan isms not carried in the oropharynx. The frequency of exogenous colonization or infection has previously been reported to be as high as 33%. A prospect ive observational cohort study of 2 years was undertaken to evaluate the ef ficacy of topical antibiotics in the prevention of exogenous colonization o r infection of the lower airways. The antibiotic combination of polymyxin E and tobramycin in a 2% paste was applied four times a day on the tracheost oma. Materials and methods: A total of 23 children (median age, 4.1 months; rang e, 0 to 215 months) were enrolled in the study from September 1, 1996, unti l August 30, 1998, Surveillance samples of the oropharynx were obtained bef ore tracheostomy and thereafter tn ice weekly. Diagnostic samples of the lo n er airways were taken once weekly and on clinical indication. Results: Fourteen children (61%) had a total of 16 episodes of tracheal col onization or infection with 20 potentially pathogenic microorganisms, Only one child had tracheobronchitis with Streptococcus pneumoniae and Haemophil us influenzae during the e-year study. Of the 16 colonization episodes, 12 (75%) were of primary endogenous pathogenesis, ie, caused by microorganisms present in the oropharynx at the time of tracheostomy. Community microorga nisms including S pneumoniae, H influenzae, Moraxella (Branhamella) catarrh alis, and Staphylococcus aureus were the predominating bacteria. Three pati ents acquired nosocomial bacteria Pseudomonas aeruginosa and Hafnia alvei i n the oropharynx, subsequently followed by secondary colonization of the lo wer airways, There was one failure of the prophylaxis: one patient (4%) had exogenous colonization with Pseudomonas pickettii, Conclusion: Topical antibiotics applied to the tracheostoma were found to b e effective in reducing the exogenous route of colonization of the lon er r espiratory tract, compared with clinical experience and the literature. Thi s promising technique requires further evaluation in randomized trials.