Immediate heart rate changes in late preterm infants receiving resuscitation in the delivery room

Abstract

Objectives: Assess heart rate (HR) trends in the minutes following delivery in late preterm infants 34-36 6/7 weeks with spontaneous respirations and compare trends in infants with delayed transition requiring interventions and assess the direct potential impact of these interventions on HR changes.

Design: Prospective observational single center study in 20 late preterm infants born via cesarean section utilizing the NeoBeat which uses dry electrode technology to obtain blinded HR measures in infants with spontaneous respirations versus infants requiring interventions i.e.: positive pressure ventilation, continuous positive airway pressure or suctioning.

Results: Initial HR in spontaneously breathing infants (n = 8) was higher versus those requiring interventions, differences that persisted through five minutes. Iatrogenic bradycardia ranging from 65 to 90 beats/minute was induced by interventions in five(42%) of 12 infants.

Conclusions: Initial HR in spontaneously breathing late preterm infants was significantly higher compared to infants who received interventions. Respiratory interventions induced sudden unanticipated bradycardia in many cases.

Figure 1

Heart rate changes in spontaneously beathing infants (open circles) and those receiving interventions (closed circles) at baseline, and at 60,120,180 240 and 300 seconds. Note the lower HR in the infants receiving interventions as compared to those spontaneously breathing. Asterix reflect significant differences. See text for details

Figure 2

Normal heart rate (HR) pattern in an infant spontaneously breathing. Note the beat-to-beat variability in the pattern over time

Figure 3

HR tracing in an infant delivered limp and apneic. The NeoBeat was placed at 34 seconds of life. The initial HR acquired by NeoBeat was 135 beats/minute (bpm). PPV was initiated at 60 seconds of life (Arrow) and continued through five minutes. There was a fall in HR within 20 seconds of initiation of PPV to 64 bpm. An EKG and pulse oximeter was placed at 110 seconds of life. Initial HR noted on the EKG at 120 seconds of life was 68 bpm which matched the NeoBeat HR. Ventilation corrective steps which included suctioning were implemented with an increase in HR over the subsequent 90 seconds. Subsequent management included brief CPAP. Infant was subsequently transferred to the NICU on RA.

Figure 4

An infant was born vigorous and crying with copious secretions. . At 70 seconds of life, the initial HR as determined by the NeoBeat was 150 bpm. Oropharyngeal catheter suctioning was attempted in the setting of copious secretions. This was associated with an immediate drop in HR to a nadir of 70 bpm as well as the development of apnea. PPV was initiated at approximately 180 seconds of life (Arrow). An EKG was placed shortly after at 200 seconds of life with a documented HR of 80 bpm which matched the NeoBeat HR. Ventilation corrective steps were implemented with a brief increase in HR to greater than 100 bpm. However the HR decreased to less than 100 bpm. Following arrival of the resuscitation team and optimization of ventilation the HR increased to > 120 BPM with the subsequent initiation of spontaneous respirations. Infant was subsequently transferred to the NICU on CPAP.