[2D2] Neonatal heart rate monitoring at birth with hands-free foetal doppler
D Hutchon
Sheffield Hallam University, UK
There is a need for improved measurement and documentation of the neonatal heart rate immediately after birth, which currently relies on auscultation with a stethoscope. Measurement of the heart rate is a medical requirement within the first minute after birth in all babies. Heart rate at birth is the only reliable indicator of the health of the neonate, which does not establish breathing immediately. In sick neonates, pulse oximetry is usually available but does not provide an output for the first minute, even in healthy neonates. Although the electrocardiogram (ECG) is considered the gold standard, it may provide a false measurement due to pulseless electrical activity of the myocardium. Neonatal ECG technology is not routinely available at birth; however, prior to birth the foetal heart rate is routinely obtained and documented using a low-cost doppler ultrasound. Recently, the foetal doppler has been shown to be effective immediately after birth on the neonatal chest, but requires constant attention by the carer and may interfere with measures to provide positive pressure ventilation or other resuscitation measures. A foetal doppler ultrasound device has been extended to provide a hands-free sensor, which is secured on the neonatal chest by the surface tension of the transducer gel. The system also works well through polythene and provides a safe and effective neonatal heart rate monitor inside a sterile polythene bag for use at caesarean birth. The design features are presented and preliminary data showing the precordial doppler provides a heart rate closely equivalent to the heart rate from the gold standard ECG.
