Lung ultrasound versus chest radiography for the detection of early postoperative pulmonary complications in children undergoing cardiac surgery

Abstract Pulmonary complications are a major cause of morbidity following congenital heart surgery in children. This pilot study evaluated detection rates of point-of-care lung ultrasound (LUS) compared with chest X-ray (CXR) for early identification of postoperative pulmonary complications in pediatric cardiac surgery patients. This prospective observational pilot study enrolled 30 pediatric patients (aged < 4 years) undergoing congenital heart surgery (RACHS-1 categories 1–3) at a single tertiary center (March 2024–March 2025). LUS using a standardized 12-zone protocol was compared with bedside CXR at three assessment timepoints: within 6 h postoperatively (T1), pre-extubation (T2), and post-extubation (T3). Diagnostic agreement was assessed by Cohen’s kappa. Clinical outcomes were analyzed using multivariable logistic regression. LUS and CXR showed equivalent detection of pulmonary congestion at T1 (63.3%; p = 1.000). LUS detected higher rates of pleural effusion (40.0% vs. 6.7%; p = 0.002) and consolidation (56.7% vs. 33.3%; p = 0.069) at T1. Extubation failure occurred in 16.7% ( n = 5) and was associated with prolonged ICU stay, longer ventilation, and greater inotropic support (all p ≤ 0.040). On multivariable logistic regression, longer inotropic support duration was associated with lower odds of successful extubation (exploratory analysis, OR 0.52, p = 0.009); imaging variables were not significant (all p > 0.27); findings warrant cautious interpretation given the small sample. Conclusion : In this pilot cohort, LUS demonstrated higher detection rates for early postoperative pleural effusion and consolidation compared with CXR, supporting its role as a complementary bedside tool. Extubation outcomes were primarily driven by hemodynamic factors. Larger prospective studies are needed to confirm these preliminary findings. What is Known: • Postoperative pulmonary complications occur in up to 76% of children after cardiac surgery and prolong mechanical ventilation and ICU stay. • Chest X-ray is the standard bedside imaging tool but has limited sensitivity for early parenchymal and pleural pathology. What is New: • Lung ultrasound detected pleural effusion and consolidation at higher rates than CXR across all three postoperative timepoints. • Serial bedside LUS enabled dynamic longitudinal monitoring of complication resolution over 11 postoperative days, beyond what static CXR can provide.