PICU study cuts respiratory cultures 16% without detected harm

A breathing tube runs into a child’s airway, and a clinician must decide whether the mucus it carries signals a dangerous infection or bacteria simply living where bacteria are already common. In a study spanning 15 U.S. pediatric intensive care units, decision-support tools helped teams make that choice less reflexively: respiratory culture use fell 16% without detected harm in the measured outcomes.

The test is called an endotracheal aspirate culture, or EAC. It samples mucus from the breathing tube for signs of bacterial infection. The difficulty is that mechanical ventilation does not leave the respiratory tract sterile, so a positive culture can reflect harmless colonization rather than an infection that needs antibiotics. Testing too readily can therefore send treatment in the wrong direction.

Anna Sick-Samuels and Aaron Milstone at Johns Hopkins Children’s Center asked teams to use algorithms and checklists before ordering a culture. The prompts included fever, changes in ventilation support and changes in oxygen saturation. The analysis covered practices in 14 additional U.S. health systems from 2019 to 2023, building on earlier Johns Hopkins work that found a 40% reduction in culture use was possible without adding safety concerns.

Compared with the 24-month period before instruction, the 18 months after it saw monthly EAC testing decline from 7.80 to 6.55 cultures per 100 ventilator-days. Antibiotic prescribing, time on ventilation, hospital stay and readmissions showed no significant changes. The findings were published in JAMA Network Open; they describe a multi-hospital comparison, not proof that every intensive care unit will see the same result.

And so what, concretely? For children unlikely to have a respiratory infection, clinicians may be able to avoid a test that can trigger unnecessary antibiotics, while retaining a checklist for cases where symptoms change. That could reduce low-value testing and its downstream costs without changing the measured safety outcomes in this study. The approach still depends on clinical judgment and on recognizing signs that justify testing.