Electric velocimetry and transthoracic echocardiography for non-invasive cardiac output monitoring in children after cardiac surgery

Abstract
Objective: Assessment of cardiac output (CO) is essential in the management of children after cardiac surgery. Electric velocimetry (EV) is a newly developed monitoring method for CO and stroke volume (SV). However, applicability in a pediatric population, particularly after cardiac surgery, remains unclear. We sought to assess agreement of CO measured by EV and transthoracic Doppler echocardiography (TTE).
Design: Prospective observational study.
Setting: A cardiac intensive care unit (CICU) at a tertiary children’s hospital in Shizuoka, Japan.
Patients and participants: Children <18-year-old admitted to the CICU after cardiac surgery. Intervention: All patients underwent measurement of SV and CO using EV and TTE between 1 to 3 days after surgery. Measurements and results: Thirty patients were analyzed. We collected data on patient demographics, body surface area, vital signs, SV, CO, laboratory examination, drugs used, and type or surgery. There were significant correlations between EV and TTE in SV and CO values (r=0.909, p<0.001 and r=0.831, p<0.001, respectively). Bland-Altman analysis showed a good agreement between EV and TTE in SV and CO values (bias 1.33 mL, 0.08 L/min, and 0.02 L/min/m2, respectively, and limits of agreement -8.59 to 9.93 mL and -0.97 to 1.05 L/min, respectively). Mean percentage error for SV and CO values between EV and TTE were 13.76% and 13.19%, respectively. Conclusions: There is good correlation and clinical agreement between EV and TTE in measuring SV and CO. Electric velocimetry can be used in the hemodynamic monitoring of children after cardiac surgery. Electric velocimetry and transthoracic echocardiography for non-invasive cardiac output monitoring in children after cardiac surgery