BackgroundLung edema is a significant factor in prolonged mechanical ventilation and extubation failure after cardiac surgery. This study assessed the predictive capability of point‐of‐care Lung Ultrasound (LUS) for the duration of mechanical ventilation and extubation failure in infants following cardiac procedures.MethodsWe conducted a prospective observational trial on infants under 1 year, excluding those with pre‐existing conditions or requiring extracorporeal membrane oxygenation. LUS was performed upon intensive care unit (ICU) admission and prior to extubation attempts. B‐line density was scored by two independent observers. The primary outcomes included the duration of mechanical ventilation and extubation failure, the latter defined as the need for reintubation or non‐invasive ventilation within 48 h post‐extubation.ResultsThe study included 42 infants, with findings indicating no correlation between initial LUS scores and extubation timing. Extubation failure occurred in 21% of the patients, with higher LUS scores observed in these cases (p = 0.046). However, interobserver variability was high, impacting the reliability of LUS scores to predict extubation readiness.ConclusionsLUS was ineffective in determining the length of postoperative ventilation and extubation readiness, highlighting the need for further research and enhanced training in LUS interpretation.