Surveillance Tracheal Aspirate Cultures Do Not Reliably Predict Bacteria Cultured at the Time of an Acute Respiratory Infection in Children With Tracheostomy Tubes

Background: The aim of this study was to characterize the practice of routinely obtaining tracheal aspirate cultures in children with tracheostomy tubes and to analyze the appropriateness of using this information to guide antibiotic selection for treatment of subsequent lower respiratory infections. Methods: Pediatric otolaryngologists and pulmonologists were surveyed regarding surveillance culture practices. Records of children with tracheostomy tubes from January 1, 2003, through December 31, 2007, were reviewed. Consecutive cultures were compared for similarity of bacteria and antibiotic sensitivity when a clinic culture preceded a culture from when the child was ill and received antibiotics and when a hospital culture preceded a hospital culture from a separate hospitalization. Results: Seventy-nine of 146 pulmonologists and five of 33 otolaryngologists obtained routine surveillance tracheal aspirate cultures (P<.001); 97% of pulmonologists used these cultures to guide subsequent empiric therapy. There were 36 of 170 children with one or more eligible pairs of cultures. Nearly all children had a change in flora in their tracheal cultures. Limiting empiric antibiotic choices to those that would cover microbes isolated in the previous culture likely would not have been effective in covering one or more microbes isolated in the second culture in 56% of pairs with the first culture from hospitalization vs 30% with the first culture from an outpatient setting (P=.15). Conclusions: This study demonstrated that there are significant changes in bacteria or antibiotic sensitivity between consecutive tracheal cultures in children with tracheostomy tubes. Use of prior tracheal cultures from these children was of limited value for choosing empiric antibiotic therapy in treating acute lower respiratory exacerbations. Surveillance cultures, thus, are an unnecessary burden and expense of care. CHEST 2012; 141(3):625-631