Optimizing Respiratory Culture Practices for Mechanically Ventilated Children - Brief Summary The number of mechanically ventilated children has grown 80-fold since the 1990s and ventilator- associated infections (VAIs) are a leading complication. In the absence of a gold standard, there is clinical uncertainty around the diagnosis of VAIs, and endotracheal aspirate cultures (EACs) are commonly obtained as a tool to assess for VAI. Although EAC results are not specific for infection versus colonization, many clinicians interpret bacterial growth in EACs as evidence of infection prompting treatment. Indeed, 50% of antibiotics used in the pediatric intensive care unit (PICU) are for VAIs. Thus, over-use of EACs contributes to unnecessary antibiotic treatment, compounding patient morbidity by promoting antibiotic resistance, antibiotic- associated adverse events, and increased healthcare costs. Diagnostic stewardship programs promoting the judicious use of EACs have significant potential to reduce unnecessary antibiotic use and improve the quality of care for thousands of ventilated children. The goal of this study is to (1) define nationwide EAC practices and identify optimal EAC practices in children with suspected VAIs, (2) assess key clinical outcomes after a pilot program implementing interventions to improve EAC practices, and (3) identify facilitators and barriers of EAC diagnostic stewardship programs to inform reproducible implementation strategies. Dr. Sick-Samuels is a faculty member in Pediatric Infectious Diseases at the Johns Hopkins University School of Medicine. She is committed to conducting patient-oriented research to develop, implement, measure the impact of, and disseminate diagnostic stewardship programs to improve the care of complex hospitalized patients. During this career-development award, she seeks to (1) develop expertise in implementation science and patient safety and quality research, (2) analyze clinical outcomes used in patient safety and quality research, (3) apply qualitative research methods to implementation science, and (4) prepare to conduct a multicenter hybrid effectiveness-implementation trial. Her primary mentor, Dr. Aaron Milstone, has extensive experience in clinical research and trials dedicated to prevention of antibiotic-resistance and healthcare- associated infections in children. Her co-mentors, Dr. Sean Berenholtz, is a national and international leader in patient safety and quality and prevention of ventilator-associated infections, and Dr. Jill Marsteller is a national expert in implementation science researching determinants of successful implementation and dissemination of evidence-based practices. Her advisors and collaborators have expertise in critical care medicine, infectious diseases, patient safety and quality, implementation science, human factors engineering, and biostatistics. This work will prepare her to develop an R01 proposal to conduct a multicenter effectiveness-implementation trial of EAC diagnostic stewardship. With this mentored research, the resource rich environment of Johns Hopkins University and the protected time to complete her training goals, Dr. Sick-Samuels will become an independent investigator leading diagnostic stewardship and implementation science research.