Lung ultrasound-driven improvements in pneumonia detection, antibiotic stewardship, and ventilation outcomes: A three-era study in a pediatric cardiac surgical intensive care unit.

Abstract

Backgrounds: Postoperative pneumonia significantly prolongs mechanical ventilation (MV) and intensive care unit (ICU) stay after pediatric cardiac surgery. Lung ultrasound (LUS) offers superior diagnostic accuracy compared with chest radiography, but its longitudinal impact on clinical outcomes remains unclear. We evaluated the effect of structured LUS implementation on pneumonia detection, antibiotic stewardship, and ventilatory outcomes in a pediatric cardiac surgical ICU (PCSICU).

Methods: This retrospective three-era study included all bronchoalveolar lavage (BAL) episodes performed for suspected postoperative pneumonia between 2019 and 2025. Patients were grouped as pre-LUS (2019-2020), LUS introduction (2021-2022), and established LUS (2023-2025). Outcomes included BAL positivity, antibiotic escalation, reintubation, and MV duration. In the established LUS era, pneumonia severity was classified using a structured 12-zone protocol into low-, moderate-, and high-yield categories. Categorical variables were compared using Chi-square tests and MV duration using Kruskal-Wallis with Bonferroni correction.

Results: A total of 313 BAL episodes were analyzed (48, 125, and 140 across the three eras). BAL positivity declined significantly from 70.8% in the pre-LUS era to 42.4% and 43.6% in the later eras (P = 0.0018). Among BAL-positive cases, antibiotic escalation increased progressively (52.9%, 62.3%, and 88.5%; P = 0.00027), while blind escalation among BAL-negative patients decreased markedly (50.0%, 20.8%, and 8.9%; P = 0.00060). Median MV duration decreased significantly from 95.5 h to 46.5 h across three eras (P = 0.00030). Higher LUS yield categories were strongly associated with BAL positivity (P < 0.001), reintubation (P = 0.0336), and Tier-3 antibiotic escalation.

Conclusion: Structured LUS adoption improved early pneumonia detection, antibiotic stewardship, and postoperative ventilatory outcomes. Routine LUS integration may significantly improve multidomain outcomes in PCSICUs.