Ultrasound-Based Cardiac Output Monitoring During Pediatric Open-Heart Surgery in Children

Aim of the study. To evaluate the feasibility of using non-invasive hemodynamic monitoring technology based on Doppler ultrasound during open-heart surgery in children. Material and methods. Prospective, observational, single-center cohort study included 20 patients aged 10 to 34 months undergoing surgery for congenital heart defects. Ten patients underwent atrial septal defect closure (ASD group), other 10 patients had ventricular septal defect closure (VSD group). Cardiac output (CO) was measured in all patients to guide inotropic and infusion therapy adjustments at three control time points: (1) after intubation and before skin incision, (2) during the immediate post-bypass period with the chest open after weaning from cardiopulmonary bypass (CPB), and (3) after sternal closure and before transfer to the intensive care unit (ICU). Results. At time point 1, the CO values for both the ASD and VSD groups were within the normal reference range: 5.2 L/min [4.7; 5.5] and 5.1 L/min [4.6; 5.6], respectively. At time point 2, CO was measured in 15 of 20 patients, including 8 patients in the ASD group and 7 in the VSD group. Coverage was 75% because of the challenges of measuring 5 patients on the operating table. In the immediate post-bypass period, two patients with VSD (25%) developed hypotension with CO reduced to 3.6 L/min, which is lower than the age-related hemodynamic reference value (5.1 L/min). Inotropic support in these two patients was increased by switching from dopamine, 7 mcg/kg/min, to adrenaline at a dose of 0.05 mcg/kg/min, resulting in improvement of hemodynamic parameters and an increase in CO to 5.2 L/min and 5.0 L/min, respectively, compared to normal agerelated reference values (4.1; 6.1 L/min). After sternal closure, CO values in both groups did not differ significantly from age-related reference values. Conclusion. The USCOM cardiac output monitoring device can be used to manage intraoperative hemodynamics and adjust inotropic therapy even during open chest surgery. However, its routine use in all stages of surgery with median sternotomy is difficult because it requires more time to align the aortic valve projection.