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The 2015 neonatal resuscitation guidelines added ECG to assess an infant’s heart rate when determining the need for resuscitation at birth. However, a recent case report raised concerns about this technique in the delivery room. We report four cases of pulseless electrical activity during neonatal cardiopulmonary resuscitation in levels II–III neonatal intensive care units in Canada (Edmonton [n=3] and Winnipeg [n=1]).Healthcare providers should be aware that pulseless electrical activity can occur in newborn infants during cardiopulmonary resuscitation. We propose an adapted neonatal resuscitation algorithm to include pulseless electrical activity. Furthermore, in compromised newborns, heart rate should be assessed using a combination of methods/techniques to ensure accurate heart rate assessment. When ECG displays a heart rate but the infant is unresponsive, pulseless electrical activity should be suspected and chest compression should be started.

Aim We recently demonstrated that asphyxiated piglets commonly had bradycardia displayed on electrocardiography (ECG) while no carotid blood flow (CBF) or audible heart sounds could be detected. Such pulseless electrical activity (PEA) in newborn infants has not previously been thoroughly described. The aim of this study was to further investigate the occurrence of non-perfusing cardiac rhythms in asphyxiated piglets and the potential implications for the success of cardiopulmonary resuscitation (CPR) and short-term survival. Methods Neonatal piglets (1–4 days, 1.7–2.4kg) had their right common carotid artery exposed and enclosed with a real-time ultrasonic flow probe. Heart rate (HR) was continuously measured and recorded using ECG. This allowed simultaneous monitoring of HR via ECG and CBF. The piglets were asphyxiated until cardiac arrest, defined as no CBF and no audible beat upon precordial auscultation. CPR was performed until return of spontaneous circulation (ROSC, defined as a HR ≥100 bpm). ECG traces were retrospectively assessed. Results Nine out of 21 piglets (43%) had QRS-complexes on their ECG while no CBF and no audible heart sounds could be detected. Five (56%) of the piglets with PEA and 12/12 (100%) piglets with asystole at cardiac arrest obtained ROSC (p = 0.02). Thirty-three per cent of the piglets with PEA versus 58% with asystole survived to 4 hours post-ROSC (p = 0.39). Conclusion Cardiac arrest in the presence of a non-perfusing cardiac rhythm on ECG is common in asphyxiated piglets. Clinical arrest in the presence of a non-perfusing cardiac rhythm on ECG may reduce the success of CPR.

Background: In 2015, the neonatal resuscitation guidelines incorporated the use of electrocardiography (ECG) to monitor heart rate of newborns. However, previous studies have indicated that cardiac arrest with pulseless electrical activity rhythm (PEA) may occur in the delivery room, rendering this method problematic.Objective: To evaluate the accuracy of ECG and auscultation to assess heart rate during PEA.Methods: A total of 45 piglets (age 1–3 days, weight 1.7–2.3 kg) were exposed to 30 min normocapnic alveolar hypoxia followed by asphyxia until asystole, achieved by disconnecting the ventilator and clamping the endotracheal tube. During asphyxia, heart rate (HR) was assess using auscultation, ECG, and carotid blood flow (CBF). At the time of asystole (defined as zero CBF) HR auscultated using a neonatal/infant stethoscope was compared to ECG traces.Results: The median (IQR) duration of asphyxia was 325 (200–491) s. In 8 (18%) piglets, CBF, ECG, and auscultation identified asystole. In 22 (49%) piglets no CBF and no audible heart sounds, were observed, while ECG displayed a HR ranging from 17 to 75/min. Fifteen (33%) piglets remained bradycardic (defined as HR of < 100/min) after 10 min of asphyxia, which was identified by CBF, ECG, and auscultation. The overall accuracy of ECG and auscultation in the detection of HR were 51 and 80%, respectively (p = 0.004).Conclusion: In cases with PEA ECG is not superior in correctly identifying HR in newborn piglets.