Assessment of the diagnostic potential of transpulmonary thermodilution in young children after radical correction of tetralogy of Fallot

Background: In congenital heart surgery, in particular upon the radical correction of tetralogy of Fallot in children aged up to 1 year, hemodynamic indicators determined routinely often do not enable to assess in full the individual hemodynamic profile of the patient and to develop an individualized protocol for targeted hemodynamic therapy. This circumstance stipulates the use of advanced hemodynamic monitoring, and specifically the transpulmonary thermodilution (PiCCO) technique. However, the use of this technique is limited by the lack of reference values for patients with this nosological form and in this specific age group. Objective: The study was aimed at determining reference indicators of transpulmonary thermodilution in children aged up to 1 year after radical correction of Tetralogy of Fallot to develop protocols of targeted hemodynamic therapy. Methods: This prospective cohort study was based on the transpulmonary thermodilution data of 30 patients aged up to 1 year after radical correction of Tetralogy of Fallot performed at the Meshalkin National Medical Research Center of the Ministry of Health of Russia from 2019 to 2022. Results: Right ventricular failure developed in 11 patients (36.7%). A risk factor for right ventricular dysfunction was pulmonary regurgitation of grade 2 or higher, which developed in 14 patients (46.7%). The average regurgitation volume was 18.8 (12.1; 19.5) ml. According to the PiCCO data, no right ventricular failure was detected in children in the early postoperative period. Conclusion: Standard hemodynamic monitoring parameters using the PiCCO system, recommended for adult patients, cannot be applied to children, especially tender-age infants, after radical correction of tetralogy of Fallot. Transpulmonary thermodilution parameters do not enable to detect right ventricular failure after radical correction of tetralogy of Fallot in children aged up to 1 year.