Accuracy of non-invasive measurement of cardiac output using electrical cardiometry in preterm infants during the transitional period: A comparison with transthoracic Doppler echocardiography

Abstract

This prospective observational study aimed to assess the agreement of cardiac output measurements obtained with transthoracic echocardiography (COECHO) and electrical velocimetry (COEV) and the impact of relevant variables on COEV accuracy in preterm infants during the transitional period. Simultaneous measurements of COEV and COECHO were performed in preterm infants < 32 weeks’ gestation and/or < 1500 g during the first 72 h of life. Bland–Altman analysis was performed and bias and mean percentage error (MPE) were calculated. The impact of a hemodynamically significant duct (hsPDA), ongoing cardiovascular drugs and ventilatory support was also assessed using a generalized least squares random-effects model. A total of 170 pairs of COEV-COECHO measurements were obtained from 65 preterm neonates. Mean bias was 9.7 ml/kg/min (95%CI 1.3–18.2) on day 1, 8.3 ml/kg/min (95%CI 0.3–16.4) on day 2, and 10.6 ml/kg/min (95%CI 4.5–16.6) on day 3 of life. The corresponding MPE was 7.2% (95%CI 4.8–10.6%), 7.5% (95%CI 4.7–12.8%) and 7.0% (95%CI 5.4–9.1%), respectively. A COEV overestimation was observed in the presence of hsPDA (mean bias = 17.0 ml/kg/min, 95%CI 7.1–30.8, p = 0.003) and during dobutamine treatment (mean bias = 12.5 ml/kg/min, 95%CI 1.5–22.4, p = 0.018). No significant differences were observed according to dopamine administration and respiratory support modality. Conclusion: Although a slight overestimation may occur during inotropic treatments and in the presence of a hsPDA, this study shows an acceptable accuracy and precision of COEV in preterm infants during postnatal transition, thus supporting the role for EV monitoring in this critical phase. (Table presented.)