Electrical impedance tomography in congenital heart disease: advancing non-invasive pulmonary perfusion assessment at bedside.

Abstract

Background: In congenital heart disease (CHD), the evaluation of pulmonary perfusion remains challenging, particularly in pediatric critically ill patients, where anatomical anomalies significantly impact pulmonary blood flow. We aim at demonstrating the reliability and the accuracy to investigate pulmonary perfusion in the presence of CHD by using electrical impedance tomography (EIT), a non-invasive, bedside, real-time, radiation-free imaging technique that assesses lung ventilation and perfusion.

Results: This methodologies series explores the application of EIT in three pediatric critically ill patients with CHD admitted to the Pediatric Intensive Care Unit at Papa Giovanni XXIII Hospital, Bergamo, Italy: (1) a newborn post-corrective surgery for transposition of the great arteries; (2) an infant post-repair of tetralogy of Fallot with bilateral pulmonary branch stenosis; and (3) an infant with severe hypoxemia following Stage I Norwood-Sano repair. EIT perfusion was performed by injecting a bolus of 0.5 ml/kg of 5% saline through a central venous catheter during an inspiratory hold and was compared to standard imaging techniques that assess pulmonary perfusion. EIT findings were consistent with conventional imaging modalities that are not available at bedside (i.e., computed tomography, magnetic resonance imaging, angiography) or that do not allow regional assessment of lung perfusion and are operator dependent (i.e., ultrasound), demonstrating the reliability and the accuracy of EIT assessment. EIT provided critical insights into ventilation-perfusion dynamics, allowing to identify perfusion defects and guiding clinical decisions.

Conclusions: This clinical investigation highlights the potential of EIT to improve pulmonary perfusion monitoring and clinical management of complex CHD cases in pediatric critically ill patients. Further research is needed to establish standardized protocols and validate the EIT clinical utility in larger cohorts.