The incidence of respiratory low tract infection in children with tracheostomy and the role of tracheal aspirate cultures: a retrospective study in a Tertiary Care Pediatric Department

Background: Children with tracheostomy are a complex population with comorbidities and special needs. Respiratory symptoms are frequent among this population, however it’s difficult to distinguish low respiratory tract infections (LRTI), that need for hospitalization and empirical antibiotic therapies, from other events. This could expose them to antibiotic overuse impacting their quality of life (QoL). There are no available guidelines for the diagnosis and management, and little is known about how tracheal aspirate culture results differ between states with and without LRTI. Objective: To investigate the rate of LRTI in our population of children with tracheostomy, describing their characteristics and the association of tracheal aspirate culture isolates with LRTI. Materials and methods: A single‐center, retrospective chart study including tracheal aspirate cultures obtained between 2018 and 2024 in children with tracheostomies, who were followed by Pediatric Palliative Care Center of Padova, Italy. All the patients with tracheostomy up to 23 years old and with at least one tracheal aspirate culture collected during an admission were included. LRTI definition included clinical criteria and reported antibiotic therapy. Demographics, comorbidities, needs, and long-term outcome data were collected. Results: 31 patients were included. 13 (42%) patients had a total of 26 episodes of LRTI (median 1, IQR 1-2) that required or during a hospitalization. The median age at the time of the sample was 3.8 years (IQR 1-7.9). A total of 141 tracheal aspirate cultures were collected, 18% were obtained during an LRTI and 67% showed an isolation. When comparing tracheal aspirate cultures obtained during LRTI episodes with those obtained from asymptomatic patients, the positivity rate was not significantly associated with LRTI. Cultures obtained during LRTI were more frequent in children who did not require ventilation and in those with G-tube (p = 0.042 and p < 0.001). No specific bacterium associated with LRTI episodes was found. Overall, Gram negative bacteria were the more prevalent isolates, in particular P. aeruginosa (22%, 27 isolates), followed by S. aureus (20%, 24 isolates). The sensitivity profile changes according to the clinical setting. A total of 35 antibiotic courses were reported, the most frequent was ceftriaxone for IV administration and amoxicillin-clavulanic acid for oral/enteral administration. The median treatment duration was 8 days (IQR 7-10). Conclusion: In our population of children with tracheostomy the most prevalent pathogens isolated were P. aeruginosa and S. aureus. Tracheal aspirate culture positivity was not associated with LRTI. Further studies are needed to clarify the role of tracheal aspirate cultures in guiding antibiotic therapy or in supporting clinical diagnosis of LRTI.