Pulseless electrical activity: a misdiagnosed entity during asphyxia in newborn infants?

Newborn heart rate monitoring methods at birth and clinical outcomes: A systematic review

Aim

Compare heart rate assessment methods in the delivery room on newborn clinical outcomes.

Methods

A search of Medline, SCOPUS, CINAHL and Cochrane was conducted between January 1, 1946, to until August 16, 2023. (CRD 42021283438) Study Selection was based on predetermined criteria. Reviewers independently extracted data, appraised risk of bias and assessed certainty of evidence.

Results

Two randomized controlled trials involving 91 newborns and 1 nonrandomized study involving 632 newborns comparing electrocardiogram (ECG) to auscultation plus pulse oximetry were included. No studies were found that compared any other heart rate measurement methods and reported clinical outcomes. There was no difference between the ECG and control group for duration of positive pressure ventilation, time to heart rate ≥ 100 beats per minute, epinephrine use or death before discharge. In the randomized studies, there was no difference in rate of tracheal intubation [RR 1.34, 95% CI (0.69-2.59)]. No participants received chest compressions. In the nonrandomized study, fewer infants were intubated in the ECG group [RR 0.75, 95% CI (0.62-0.90)]; however, for chest compressions, benefit or harm could not be excluded. [RR 2.14, 95% (CI 0.98-4.70)].

Conclusion

There is insufficient evidence to ascertain clinical benefits or harms associated with the use of ECG versus pulse oximetry plus auscultation for heart rate assessment in newborns in the delivery room.

Does ECG monitoring affect resuscitation for neonates with pulseless electrical activity in the delivery room? A simulated, pilot, crossover randomised trial

OBJECTIVE

To evaluate whether ECG monitoring impacts resuscitative steps during simulated neonatal resuscitation in the setting of pulseless electrical activity (PEA) in the delivery room.

DESIGN

This pilot, crossover randomised controlled trial recruited providers in teams of three who participated in two simulation scenarios (PEA with and without ECG monitoring). Teams were randomised to one scenario and then crossed over. All sessions were video-recorded. The primary outcome was time to pulse check once the manikin was programmed to become pulseless. The secondary outcomes were total pulse checks, time to positive pressure ventilation, intubation, chest compressions and administration of epinephrine, and teams' quotes and behaviours during resuscitation. The primary outcome was analysed using Kaplan-Meier survival curve. The secondary outcomes were compared with Wilcoxon signed-rank test. The quotes were analysed using content analysis with pattern coding.

RESULTS

Eighty-two healthcare providers were approached and 30 consented (10 teams). The mean time to check the pulse once the manikin was pulseless was 38.5 s (SD 30.1) without ECG vs 88.1 s (SD 46.1) with ECG (p<0.01). There was a significantly decreased number of pulse checks with the ECG compared with without (p<0.01). Time to intubation, chest compressions, start of positive pressure ventilation and epinephrine administration was not different between the groups. Quotes/behaviours revealed false reassurance and over-reliance on ECG monitoring, repeated pulse check errors and troubleshooting behaviours.

CONCLUSIONS

ECG monitoring in simulated neonatal resuscitation results in delayed recognition of a pulseless state, decreased number of pulse checks and a possible false sense of security. Simulated resuscitation clinical endpoints are unaffected.

Vasopressin versus epinephrine during cardiopulmonary resuscitation of asphyxiated newborns: A study protocol for a prospective, cluster, open label, single-center, randomized controlled phase 2 trial - The VERSE-Trial

Introduction

Current neonatal resuscitation guidelines recommend the use of epinephrine during neonatal cardiopulmonary resuscitation (CPR). However, newborns receiving epinephrine continue to have high rates of mortality and neurodevelopmental disability. The infrequent need for neonatal CPR, coupled with an inability to consistently anticipate which newborn infants are at risk of requiring CPR, explains the lack of high-quality evidence (i.e., large randomized clinical trials) to better guide healthcare providers in their resuscitative effort. Therefore, we need neonatal data to determine the optimal vasopressor therapy during neonatal CPR. The current pilot trial will examine the efficacy of vasopressin versus epinephrine during CPR of asphyxiated newborn infants.

Methods and analysis

The trial will be a prospective, cluster, open label, single-center, randomized controlled trial on two alternative cardiovascular supportive medications. This study will assess the primary outcome of time to return of spontaneous circulation (ROSC) in newborns requiring CPR in the delivery room who were treated with either vasopressin (intervention) or epinephrine (control). Secondary outcomes such as infant mortality and other clinical outcome measures will also be collected. An estimated 20 newborns will be recruited, and comparisons will be made between asphyxiated infants treated with either drugs.

Ethics and dissemination

This study has been approved by the Research Ethics Board at the University of Alberta (June 16, 2023). Study findings will be published in peer-reviewed journals, presented at conferences, and communicated to relevant participants and stakeholders.Trial registration: ClinicalTrial.gov Identifier: NCT05738148. Registered February 21, 2023.

A Pilot Randomized Trial of Heart Rate Monitoring Using Conventional Versus a New Electrocardiogram Algorithm during Neonatal Resuscitation at Birth

Current guidelines support the use of a cardiac monitor during neonatal resuscitation. Infants born preterm randomized to a novel electrocardiogram algorithm displayed a heart rate sooner than the conventional electrocardiogram algorithm. Although resuscitation outcomes were not different, the availability of an earlier heart rate may benefit neonatal providers during high-risk resuscitations. TRIAL REGISTRATION: ClinicalTrials.govNCT04587934.

Recent Update on Neonatal Resuscitation

Every 5 y, the International Liaison Committee on Resuscitation publishes consensus on cardiopulmonary resuscitation, and emergency cardiovascular science and treatment recommendations. The latest update on neonatal resuscitation guidelines was published in 2020. Here, the authors review the important changes in the recent recommendations, including initial steps of resuscitation, umbilical cord management, management of nonvigorous infants born through meconium-stained amniotic fluid, sustained inflation in preterm infants, epinephrine, vascular access, timing of discontinuation of resuscitative effort, and team briefing and debriefing.

Delivery room ultrasound study to assess heart rate in newborns: DELIROUS study

During neonatal resuscitation in the delivery room, heart rate guides clinical intervention, and although different methods have been evaluated as auscultation, pulse oximetry, and electrocardiography, they have various limitations. This was a prospective observational study which aim was to evaluate the accuracy and speed of ultrasound for measuring neonatal heart rate compared with stethoscope, pulse oximetry, and electrocardiography. Simultaneous determinations of heart rate using stethoscope, ultrasound, pulse oximetry, and electrocardiography were performed. Fifty term newborns were included. There were no differences according to the turn on time of the ultrasound, pulse oximetry, and electrocardiography (p = 0.666), but the placement time and the detection time from birth were shorter for ultrasound (p < 0.001). A stronger positive correlation was detected between ultrasound and electrocardiography at 90 (Rho = 0.926), and 120 s (Rho = 0.920) with p < 0.001. The Bland-Altman analysis showed a bias of - 2.23 (p = 0.129) between ultrasound and electrocardiography at 90 s, and a bias of 0.44 (p = 0.092) at 120 s. Instead, the bias between auscultation and electrocardiography at 90 s was - 6.71 (p = 0.131), and at 120 s was of - 4.67 (p = 0.793).Conclusions: Ultrasound is a fast method to detect heart rate in the delivery room and has a good correlation with stethoscope and electrocardiography. What is Known: • During neonatal resuscitation in the delivery room, heart rate guides clinical intervention, and although different methods have been evaluated, they have various limitations. What is New: • Heart rate ultrasound is a good and fast method to detect HR in the delivery room with a good correlation with electrocardiography and stethoscope.

Is Chest Compression Superimposed with Sustained Inflation during Cardiopulmonary Resuscitation an Alternative to 3:1 Compression to Ventilation Ratio in Newborn Infants?

Approximately 0.1% for term and 10-15% of preterm infants receive chest compression (CC) in the delivery room, with high incidence of mortality and neurologic impairment. The poor prognosis associated with receiving CC in the delivery room has raised concerns as to whether specifically-tailored cardiopulmonary resuscitation methods are needed. The current neonatal resuscitation guidelines recommend a 3:1 compression:ventilation ratio; however, the most effective approach to deliver chest compression is unknown. We recently demonstrated that providing continuous chest compression superimposed with a high distending pressure or sustained inflation significantly reduced time to return of spontaneous circulation and mortality while improving respiratory and cardiovascular parameters in asphyxiated piglet and newborn infants. This review summarizes the current available evidence of continuous chest compression superimposed with a sustained inflation.

Accurate neonatal heart rate monitoring using a new wireless, cap mounted device

AIM

A device for newborn heart rate (HR) monitoring at birth that is compatible with delayed cord clamping and minimises hypothermia risk could have advantages over current approaches. We evaluated a wireless, cap mounted device (fhPPG) for monitoring neonatal HR.

METHODS

A total of 52 infants on the neonatal intensive care unit (NICU) and immediately following birth by elective caesarean section (ECS) were recruited. HR was monitored by electrocardiogram (ECG), pulse oximetry (PO) and the fhPPG device. Success rate, accuracy and time to output HR were compared with ECG as the gold standard. Standardised simulated data assessed the fhPPG algorithm accuracy.

RESULTS

Compared to ECG HR, the median bias (and 95% limits of agreement) for the NICU was fhPPG -0.6 (-5.6, 4.9) vs PO -0.3 (-6.3, 6.2) bpm, and ECS phase fhPPG -0.5 (-8.7, 7.7) vs PO -0.1 (-7.6, 7.1) bpm. In both settings, fhPPG and PO correlated with paired ECG HRs (both R²  = 0.89). The fhPPG HR algorithm during simulations demonstrated a near-linear correlation (n = 1266, R²  = 0.99).

CONCLUSION

Monitoring infants in the NICU and following ECS using a wireless, cap mounted device provides accurate HR measurements. This alternative approach could confer advantages compared with current methods of HR assessment and warrants further evaluation at birth.

Delivery Room Management of Asphyxiated Term and Near-Term Infants

Approximately 800,000 newborns die annually due to birth asphyxia. The resuscitation of asphyxiated term newly born infants often occurs unexpected and is challenging for healthcare providers as it demands experience and knowledge in neonatal resuscitation. Current neonatal resuscitation guidelines often focus on resuscitation of extremely and/or very preterm infants; however, the recommendations for asphyxiated term newborn infants differ in some aspects to those for preterm infants (i.e., respiratory support, supplemental oxygen, and temperature management). Since the update of the neonatal resuscitation guidelines in 2015, several studies examining various resuscitation approaches to improve the outcome of asphyxiated infants have been published. In this review, we discuss current recommendations and recent findings and provide an overview of delivery room management of asphyxiated term newborn infants.

Heart Rate Assessment during Neonatal Resuscitation

Approximately 10% of newborn infants require some form of respiratory support to successfully complete the fetal-to-neonatal transition. Heart rate (HR) determination is essential at birth to assess a newborn’s wellbeing. Not only is it the most sensitive indicator to guide interventions during neonatal resuscitation, it is also valuable for assessing the infant’s clinical status. As such, HR assessment is a key step at birth and throughout resuscitation, according to recommendations by the Neonatal Resuscitation Program algorithm. It is essential that HR is accurate, reliable, and fast to ensure interventions are delivered without delay and not prolonged. Ineffective HR assessment significantly increases the risk of hypoxic injury and infant mortality. The aims of this review are to summarize current practice, recommended techniques, novel technologies, and considerations for HR assessment during neonatal resuscitation at birth.

Improving newborn heart rate assessment using a simple visual timer

OBJECTIVE

Newborn resuscitation relies on accurate heart rate (HR) assessment, which, during auscultation, is prone to error. We investigated if a 6 s visual timer (VT) could improve HR assessment accuracy during newborn simulation.

DESIGN

Prospective observational study of newborn healthcare professionals.

SETTING

Three-phase developmental approach: phase I: HR auscultation during newborn simulation using a standard clock timer (CT) or the VT; phase II: repeat phase I after using a bespoke training app (NeoRate); phase III: following the Newborn Life Support course, participants assessed random HRs using the CT or VT.

MAIN OUTCOME MEASURES

HR accuracy (within ±10 beats/min, correct HR category, i.e. <60, 60-100 and >100 beats/min), assessment time and error-free rates were compared.

RESULTS

Overall, 1974 HR assessments were performed with participants more accurate using the VT for ±10 beats/min (70% CT vs 86% VT, p<0.001) and correct HR category (78% CT vs 84% VT, p<0.01). The VT improved accuracy across all three phases. Additionally, following app training in phase II, the HR accuracy of both the CT and VT improved. The VT resulted in faster HR assessment times of 11 s (IQR 9-13) compared with the CT at 15 s (IQR 9-23, p<0.001). Error-free scenarios increased from 24% using the CT to 57% using the VT (p<0.001), with a shorter assessment time (CT 116 s (IQR 65-156) vs VT 53 s (IQR 50-64), p<0.001).

CONCLUSION

Using a VT to assess simulated newborn HR combined with a training app significantly improves accuracy and reduces assessment time compared with standard methods. Evaluation in the clinical setting is required to determine potential benefits.

Neonatal monitoring during delivery room emergencies

Fetal to neonatal transition after birth is a complex, well-coordinated process involving multiple organ systems. Any significant derangement in this process increases the risk of death and other adverse outcomes, underlying the importance of continuous monitoring to promptly detect and correct these derangements by effective resuscitative support. In recent years, there has been increasing efforts to move from subjective and discontinuous monitoring to more objective and continuous monitoring of different physiological parameters. Some of them like pulse oximetry for arterial oxygen saturation and electrocardiography for heart rate monitoring are now part of resuscitation guidelines whereas others like respiratory function monitoring, near infrared spectroscopy, or amplitude integrated electroencephalography are being evaluated. In this review, we describe some of the physiological parameters that can be monitored during delivery room emergencies and review the evidence for some of the monitoring technologies currently being evaluated.

Cardiac arrest with pulseless electrical activity rhythm in newborn infants: a case series

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.

Cardiopulmonary resuscitation in newborn infants with ultrasound in the delivery room

Point of care ultrasound has emerged as useful tool in cardiac arrest situations in adult population. Despite of these, there is not a protocol for cardiopulmonary resuscitation in the delivery room for newborns. We describe two case were ultrasound helped to rule out the cardiopulmonary arrest case and we propose and algorithm were ultrasound is integrated in the newborn resuscitation and may help to diagnose the cardiac arrest cause.

Randomised study comparing heart rate measurement in newly born infants using a monitor incorporating electrocardiogram and pulse oximeter versus pulse oximeter alone

AIM

To determine whether IntelliVue (ECG plus Masimo pulse oximeter (PO)) measures heart rate (HR) in low-risk newborns more quickly than Nellcor PO (PO alone).

METHODS

Unmasked parallel group randomised (1:1) study.

RESULTS

We studied 100 infants, 47 randomised to IntelliVue, 53 to Nellcor. Time to first HR was shorter with IntelliVue ECG than Nellcor (median (IQR) 24 (19, 39) vs 48 (36, 69) s, p<0.001). There was no difference in time to display both HR and SpO₂ (52 (47, 76) vs 48 (36, 69) s, p=0.507). IntelliVue PO displayed initial bradycardia more often than the Nellcor (55% vs 6%). Infants monitored with IntelliVue were handled more frequently and for longer.

CONCLUSIONS

IntelliVue ECG displayed HR more quickly than Nellcor PO. IntelliVue PO often displayed initial bradycardia. Infants monitored with IntelliVue were handled more often. Study of ECG in high-risk infants is warranted.

Non-perfusing cardiac rhythms in asphyxiated newborn piglets

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.

Monitoring heart rate in the delivery room

Resuscitation algorithms and guidelines highlight the importance of heart rate (HR) in determining interventions and assessing their effect. However, the actual HR values used are historical based upon normal physiology, and HR at birth may be affected by mode of delivery and timing of cord clamping as well as respiratory status and condition at delivery. Furthermore, the most accurate and effective ways to assess and monitor HR in the newborn infant are only now becoming established. This article examines the importance of HR values and the most widely used methods of estimation as well as some newer modalities which are being developed.

Electrocardiography vs. Auscultation to Assess Heart Rate During Cardiac Arrest With Pulseless Electrical Activity in Newborn Infants

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.