Impact of bradycardia or asystole on neonatal cardiopulmonary resuscitation at birth.

BACKGROUND

Fetal hypoxia from intrapartum events can lead to absent heart rate (HR) or bradycardia at birth requiring aggressive neonatal resuscitation. Neonatal resuscitation guidelines do not differentiate bradycardia (HR <100 beats/min) from absent HR at birth. Given that HR is the primary determinant of resuscitation, we hypothesize that infants with no HR at 1 min would require more extensive resuscitation with worse clinical outcome than infants with bradycardia at 1 min.

METHODS

A retrospective analysis was performed in infants born between 1 January 2000 and 31 December 2015 with no HR at 1 min (defined as Apgar score [AS] = 0 at 1 min; absent HR [AHR] group) or bradycardia at 1 min (AS = 1 at 1 min). Patient demographics, resuscitation characteristics and clinical outcomes were analyzed in both the groups.

RESULTS

Apgar score was significantly lower in the AHR group over time. The AHR group had significantly higher rates of intubation, chest compression (CC) and i.v. epinephrine (i.v. epi); resulting in longer duration of CC, time to HR > 100 beats/min and duration of resuscitation. Systematic hypotension and death were higher in the AHR group. On logistic regression, CC and cord pH were significantly correlated with AS = 0 at 1 min. Gestational age, birthweight, AS at 5 min, cord pH and first blood gas pH after resuscitation were related to overall mortality.

CONCLUSIONS

Infants with AHR at 1 min did worse than infants with bradycardia. Education focused on effective positive pressure ventilation and early use of i.v. epinephrine is essential for successful resuscitation of the depressed newborn.