Heart‐rate evaluation using fetal ultrasonic Doppler during neonatal resuscitation

Abstract

Background The objective of the present study was to verify the speed and accuracy of fetal ultrasonic Doppler (fetal Doppler) in measuring heart rate of newborns at rest, including preterm, low‐birthweight infants, and its efficacy during neonatal resuscitation, including cases of neonatal asphyxia. Methods A three‐lead electrocardiogram and fetal Doppler were used to measure resting heart rates in 100 newborns, including 48 preterm, low‐birthweight infants, at 0 to 72 h after birth. Times to display heart rate were compared between electrocardiogram and fetal Doppler by the Bland–Altman analysis and Wilcoxon signed‐rank test. The time required for the fetal Doppler to measure heart rate during neonatal resuscitation was also assessed. Results In 100 newborns, the mean error of the resting heart rate in 1,293 measurement points was 0.07 beats/min. To display the heart rate, the fetal Doppler required a median time of 5 s, and electrocardiogram required a median time of 10 s (P < 0.001). During neonatal resuscitation, the heart rate was measured within 10 s in 18 of 21 cases (86%) and displayed with a median time of 5 s; this was measured in all neonatal asphyxia cases (9/9, 100%). Conclusions Fetal Doppler can measure heart rate in newborns accurately and rapidly and is useful for evaluating heart rate not only at rest but also during neonatal resuscitation, especially in asphyxia.

The Use of Foetal Doppler Ultrasound to Determine the Neonatal Heart Rate Immediately after Birth: A Systematic Review

“…Agrawal et al and Kayama et al included a range of both healthy and asphyxiated neonates at term or preterm [5,7]. Zanardo et al [3], Shimabukuro et al [4], and Goenka et al [6].…”

“…In one study, the authors found that the Doppler ultrasound did not function well with crying and moving babies [7].…”

“…In a baby who is breathing, crying, or moving, determining the heart rate immediately after birth is not a priority, and Kayama et al showed that the application of Doppler ultrasound is sometimes difficult in these babies [7]. However, auscultation is likely to be just as limited, and the precise heart rate is of little importance in these healthy babies.…”

Amplification of Heart Sounds Using Digital Stethoscope in Simulation-Based Neonatal Resuscitation

“…Doppler ultrasound has been used to acquire HR during resuscitation and found to have similar accuracy to the ECG method while acquiring the signals faster, although the quality of signal during infant's movement and crying was a limitation. 7,8 The focus of amplification of heartbeat is not to acquire more accurate reading of the HR compared with other methods but to provide early and equal access to all members of the team about the most important information about the status of the infant (HR). The major advantage of our method (amplification) was the ability for all participants involved in the resuscitation to be aware of the HR of the infant, which we strongly believe made documentation and preparing for the next intervention by the team much easier.…”

“…Our study was unique for applying a new method of amplification of the heartbeat sounds and testing for recognition of rapid HR changes. Doppler ultrasound has been used to acquire HR during resuscitation and found to have similar accuracy to the ECG method while acquiring the signals faster although the quality of signal during infant's movement and crying was a limitation [8,9]. The focus of amplification of heartbeat is not to acquire more accurate reading of the HR compared to other methods but to provide early and equal access to all members of the team about the most important information about the status of the infant (HR).…”