Clinicians often collect an endotracheal aspirate culture (EAC) on patients of all ages on breathing tubes to check mucus for signs of bacterial infection, a complication that can be deadly. Historically, however, clinical guidance about when and how often to take such cultures in children has been limited.
Now, infectious diseases specialists, including Anna Sick-Samuels and Aaron Milstone from Johns Hopkins Children's Center , report results of a new federally funded study of EAC culture ordering that suggests it is safe to test less under certain conditions in pediatric intensive care units.
The study addresses long-standing recognition by medical professionals that overuse of EAC culture testing can lead to unnecessary antibiotic therapy, an increase in antibiotic-resistant infections and unnecessary costs for young patients. Because the respiratory tract in patients on mechanical ventilation is not sterile to begin with since bacteria are normally found in this area of the body, part of the concern with EAC culture sampling is the difficulty in determining what is an infection in need of treatment and what is normal bacterial colonization that won't cause harm.
The new study, using data from 15 U.S. pediatric ICUs participating in the BrighT STAR respiratory collaborative , should advance the goal of standardizing culture testing, as well as reducing testing among patients unlikely to have lung infections in need of antibiotics, the researchers say.
The findings of their study , funded in part by the National Institutes of Health (NIH) and the Agency for Healthcare Research and Quality (AHRQ), were published July 31 in JAMA Network Open.
The new analysis builds on prior work from the Children's Center seeking to develop clinical decision support guidelines to assist clinicians' monitoring of respiratory health in patients with artificial airways in the PICU. That study, published in 2021 , showed a 40% reduction in culture use was possible without adding to safety concerns.
In the latest follow-up phase of the study, the investigators broadened their analysis of data from PICUs (median bed size was 30) in 14 additional health systems around the U.S. between 2019 and 2023.
For the new study, researchers assessed practices related to how often EACs were obtained among children on ventilation alongside other clinical and safety outcomes.
Participating PICU teams applied clinical decision support in the form of algorithms and checklists to consider signs and symptoms of respiratory infection, such as a fever or changes in ventilation support or oxygen saturation, to replace reflexive ordering practices with more deliberate decisions on whether or not to test patients with respiratory cultures, says Sick-Samuels, who is also an associate professor of pediatrics in the Johns Hopkins University School of Medicine.
Comparing EAC culture sampling in the 24 months in the pre-instruction period to the EAC culture testing in the 18 months following instruction, the research team found the monthly EAC rate across all the hospitals declined by 16% (7.80 to 6.55 cultures per 100 ventilator-days). They found no significant changes in the prescribing of antibiotics or other measures, including duration that the patients remained on ventilation, length of hospital stay and readmissions.
"The findings of this study show that it is feasible to reduce respiratory cultures among patients who do not have signs of a respiratory tract infection, and also that testing less was not associated with any patient harm, reinforcing the idea that thoughtfully testing less can be safe," Sick-Samuels says.
Other researchers from Johns Hopkins include Danielle Koontz, Nora Elhaissouni, Urmi Kumar, Anping Xie, Jill Marsteller and Elizabeth Colantuoni. Additional co-authors are Charlotte Woods-Hill from the University of Pennsylvania, Daniel Kelly from Harvard Medical School, and Troy Richardson and Sreejata Dutta from the Children's Hospital Association. This study was funded in part by grants from the NIH (K23HL161449, K24AI141580 and K23HL151381), AHRQ (R01HS028634) and the Donoghue Foundation.
No authors declared conflicts of interest under Johns Hopkins University School of Medicine policies.
