Airway Microbiome Changes After Artificial Airway Exchange in Critically-ill Pediatric Patients.

Collection of tracheal aspirates in either the PICU or NICU will occur. We will instill 1 mL of normal saline, then perform bag ventilation, and then suction out aspirate. Suctioning is routinely performed for tracheostomy and endotracheal tube hygiene - for instance, it is performed on tracheostomies by caregivers at home. The aspirates that will be collected will be clinically indicated and otherwise would be discarded. If the patients weren't enrolled in this research, the aspirates would have been collected anyways.