Reliability evaluation of two non-invasive cardiac function monitoring methods for preterm infants′ early cardiac function monitoring

Objective To evaluate the consistency of ultrasonic cardiac output monitor (USCOM) and electric impedance (ICON) in cardiac function monitoring in preterm infants compared with echocardiography (ECHO). Methods All enrolled children were monitored with ECHO, USCOM and ICON on the 2nd and 7th day after birth.Heart rate (HR) and cardiac index (CI) were recorded. Results On the second day after birth, the CI measured by ECHO was (3.26±0.68) L/(min·m2), the CI measured by USCOM was (3.21±0.66) L/(min·m2), and the CI measured by ICON was (3.67 ±0.69) L/(min·m2), with an average percent error of 27.9% and 42.3%, respectively.On the 7th day after birth, the CI measured by ECHO was (3.53±0.57) L/(min·m2), the CI measured by USCOM was (3.47±0.59) L/(min·m2), and the CI measured by ICON was (3.73±0.67)L/(min·m2), with an average percent error of 25.8% and 28.3%, respectively. Conclusion Comparing USCOM with ECHO in cardiac output monitoring of preterm infants, the consistency is good at each time point after birth.Compared with ECHO, ICON has poor consistency in early postnatal cardiac index monitoring, but dynamic monitoring has a certain reference value after one week of birth. Key words: Premature infants; Cardiac function; Echocardiography; Electric impedance; Ultrasonic cardiac output monitoring