Background: While bacteria identification on respiratory cultures is associated with poor short-term outcomes in children with bronchopulmonary dysplasia (BPD) and tracheostomies, the influence on longer-term respiratory support needs remains unknown. Objective: To determine if respiratory culture growth of pathogenic organisms is associated with ongoing need for respiratory support, decannulation, and death at 3 years post-tracheostomy placement in children with BPD and tracheostomies. Methods: This single center, retrospective cohort study included infants and children with BPD and tracheostomies placed 2010-2018 and >1 respiratory culture obtained in 36 months post-tracheostomy. Primary predictor was any pathogen identified on respiratory culture. Additional predictors were any Pseudomonas aeruginosa and chronic P. aeruginosa identification. Outcomes included continued use of respiratory support (e.g., oxygen, positive pressure), decannulation, and death at 3 years post-tracheostomy. We used Poisson regression models to examine the relationship between respiratory organisms and outcomes, controlling for patient-level covariates and within-patient clustering. Results: Among 170 children, 59.4% had a pathogen identified, 28.8% ever had P. aeruginosa, and 3.5% had chronic P. aeruginosa. At 3 years, 33.1% of alive children required ongoing respiratory support and 24.8% achieved decannulation; 18.9% were deceased. In adjusted analysis, any pathogen and P. aeruginosa were not associated with ongoing respiratory support or mortality. However, P. aeruginosa was associated with decreased risk of decannulation (aRR 0.48, 95% CI 0.23-0.98). Chronic P. aeruginosa was associated with lower survival probability. Conclusion: Our findings suggest that respiratory pathogens including P. aeruginosa may not promote long-term respiratory dysfunction, but identification of P. aeruginosa may delay decannulation.

Background: Among children with tracheostomies, little is known about how respiratory culture results differ between states with and without acute respiratory infections (ARI), or the overall test performance of respiratory cultures. Objective: To determine the association of respiratory culture organism isolation with diagnosis of ARI in children with tracheostomies, and assess test characteristics of respiratory cultures in the diagnosis of bacterial ARI (bARI). Methods: This single-center, retrospective cohort study included respiratory cultures of children with tracheostomies obtained between 2010-2018. The primary predictor was ARI diagnosis code at the time of culture; the primary outcomes were respiratory culture organism isolation and species identified. Generalized estimating equations were used to assess for association between ARI diagnosis and isolation of any organism while controlling for potential confounders and accounting for within-patient clustering. A multinomial logistic regression equation assessed for association with specific species. Test characteristics were calculated using bARI diagnosis as the reference standard. Results: Among 3,578 respiratory cultures from 533 children (median 4 cultures/child, IQR: 1-9), 25.9% were obtained during ARI and 17.2% had ≥1 organism. Children with ARI diagnosis had higher odds of organism identification (aOR 1.29, 95% CI 1.16–1.44). When controlling for covariates, ARI was associated with isolation of H. influenzae, M. catarrhalis, S. pneumoniae, and S. pyogenes. Test characteristics revealed a 24.3% sensitivity, 85.2% specificity, 36.5% positive predictive value, and 76.3% negative predictive value in screening for bARI. Conclusion: The utility of respiratory culture testing to screen for, diagnose, and direct treatment of ARI in children with tracheostomies is limited.