Cardiac output measurement in children: comparison of Aesculon^® cardiac output monitor and thermodilution

Abstract

Background

We compared cardiac output (CO) measurements by the non-invasive electrical velocimetry (Aesculon^®) monitor with the pulmonary artery catheter (PAC) thermodilution method in children.

Methods

CO values using the Aesculon^® monitor and PAC thermodilution were simultaneously recorded during cardiac catheterization in children. Measurements were performed under general anaesthesia. To compare, three consecutive measurements for each patient within 3 min were obtained. The means of the three values were compared using simple regression and Bland–Altman analysis. Data were presented as mean (sd). A mean percentage of <30% was defined to indicate clinical useful reliability of the Aesculon^® monitor.

Results

A total of 50 patients with a median (range) age of 7.5 (0.5–16.5) yr were enrolled in the study. Mean CO values were 3.7 (1.5) litre min⁻¹ (PAC thermodilution) and 3.1 (1.7) litre min⁻¹ (Aesculon^® monitor). Analysis for CO measurement showed a good correlation between the two methods (r=0.894; P<0.0001). The bias between the two methods was 0.66 litre min⁻¹ with a precision of 1.49 litre min⁻¹. The mean percentage error for CO measurements was 48.9% for the Aesculon^® monitor when compared with PAC thermodilution.

Conclusions

Electrical velocimetry using the Aesculon^® monitor did not provide reliable CO values when compared with PAC thermodilution. Whether the Aesculon^® monitor can be used as a CO trend monitor has to be assessed by further investigations in patients with changing haemodynamics.