**3. Current neonatal resuscitation guidelines**

Heart rate (HR) is the most important clinical indicator to evaluate the status of compromised newborns and to guide resuscitation efforts in the delivery room [3]. An increase in the newborn's HR remains the most reliable indicator of adequate ventilation [3]. Until recently, HR assessment in the newborn was achieved via (i) palpation of the umbilical cord, (ii) auscultation of the precordium, and/or

**169**

*A Porcine Model of Neonatal Hypoxia-Asphyxia to Study Resuscitation Techniques in Newborn…*

The current neonatal resuscitation guidelines recommend initiation of PPV if the HR is below 100 beats per minute (bpm). If HR does not increase in response to PPV, several ventilation corrective steps are recommended: (i) check the seal of the face mask, (ii) reposition the neonate's head in "sniffing" position, (iii) suction obstructing secretions, (iv) open the mouth to decrease resistance to gas flow, (v) increase the peak inflating pressure, and (vi) establish an advanced airway (intubate or use a laryngeal mask device). If the above ventilation corrective steps fail to improve HR and it decreases to below 60 bpm, CC and 100% oxygen are recommended. If HR persists below 60 bpm despite CC and 100% oxygen, administration of intravenous epinephrine is recommended at a dose of 0.01–0.03 mg/kg. If epinephrine administration is required prior to the establishment of intravenous access, it can be administered endotracheally at a higher dose of 0.05–0.1 mg/kg. The currently recommended technique of delivering CC to a neonate is using a coordinated 3:1 compression-to-ventilation ratio (3:1 C:V). This approach is comprised of 90 CC and 30 ventilation inflations per minute, with a pause after every third CC to deliver one effective ventilation. This technique achieves approximately 120 events per minute. The CC are delivered on the lower third of the sternum and to a depth of approximately one-third of the anterior–posterior chest diameter, and the 2-thumb-encircling hands technique is the preferred method. However the chest compression ratio recommendation is based more on expert opinion and consensus rather than strong scientific evidence, since there is currently very-low-

(iii) pulse oximetry [12]. In 2015, the neonatal resuscitation guidelines were updated to integrate the use of electrocardiography (ECG) as a tool for HR assessment immediately after birth [2–4]. This recommendation was based on observational data and small randomized controlled trials showing that ECG displays reliable HR faster than pulse oximetry [2–4]. However, the use of ECG does not

replace the need for pulse oximetry, but rather compliment it.

quality evidence to suggest otherwise, according to the guidelines [4].

Pulseless electrical activity (PEA) is a form of cardiac arrest characterized by cardiac electrical activity, detected by ECG, but with the absence of a detectable pulse [13]. Although PEA is a commonly seen cardiac rhythm in adult and pediatric resuscitations (referred to as a "nonshockable rhythm"), occurring in approximately 32 and 24% of cardiac arrests, respectively [14], its occurrence in neonatal resuscitation is unusual and not widely recognized. In response to the inclusion of ECG in the 2015 neonatal resuscitation guidelines, there has been a rise in awareness of PEA in neonatal resuscitation. ECG displaying PEA could falsely mislead health care providers into overestimating the HR and delay necessary resuscitation techniques. It is possible that PEA may be common in asphyxiated newborns but has been undetected in the clinical setting prior to the recent use of ECG in the delivery room. Recent case reports have raised concerns over the reliability of ECG use during neonatal resuscitation, and the detection of PEA has been cited as a potential limitation of ECG use to guide delivery room resuscitation [15, 16]. Data from studies in the pediatric population indicate decreased survival following resuscitation with PEA events [17, 18], however this is inconsistent throughout the literature. Recent case studies in newborn infants presenting with cardiac arrest with PEA rhythm, as indicated on ECG [15, 16], suggest dire outcomes. Further studies (animal and prospective clinical) are needed to determine the cause and actual incidence of PEA in order to improve the survival of newborns experiencing PEA in the delivery room.

**4. Pulseless electrical activity**

*DOI: http://dx.doi.org/10.5772/intechopen.89171*

### *A Porcine Model of Neonatal Hypoxia-Asphyxia to Study Resuscitation Techniques in Newborn… DOI: http://dx.doi.org/10.5772/intechopen.89171*

(iii) pulse oximetry [12]. In 2015, the neonatal resuscitation guidelines were updated to integrate the use of electrocardiography (ECG) as a tool for HR assessment immediately after birth [2–4]. This recommendation was based on observational data and small randomized controlled trials showing that ECG displays reliable HR faster than pulse oximetry [2–4]. However, the use of ECG does not replace the need for pulse oximetry, but rather compliment it.

The current neonatal resuscitation guidelines recommend initiation of PPV if the HR is below 100 beats per minute (bpm). If HR does not increase in response to PPV, several ventilation corrective steps are recommended: (i) check the seal of the face mask, (ii) reposition the neonate's head in "sniffing" position, (iii) suction obstructing secretions, (iv) open the mouth to decrease resistance to gas flow, (v) increase the peak inflating pressure, and (vi) establish an advanced airway (intubate or use a laryngeal mask device). If the above ventilation corrective steps fail to improve HR and it decreases to below 60 bpm, CC and 100% oxygen are recommended. If HR persists below 60 bpm despite CC and 100% oxygen, administration of intravenous epinephrine is recommended at a dose of 0.01–0.03 mg/kg. If epinephrine administration is required prior to the establishment of intravenous access, it can be administered endotracheally at a higher dose of 0.05–0.1 mg/kg. The currently recommended technique of delivering CC to a neonate is using a coordinated 3:1 compression-to-ventilation ratio (3:1 C:V). This approach is comprised of 90 CC and 30 ventilation inflations per minute, with a pause after every third CC to deliver one effective ventilation. This technique achieves approximately 120 events per minute. The CC are delivered on the lower third of the sternum and to a depth of approximately one-third of the anterior–posterior chest diameter, and the 2-thumb-encircling hands technique is the preferred method. However the chest compression ratio recommendation is based more on expert opinion and consensus rather than strong scientific evidence, since there is currently very-lowquality evidence to suggest otherwise, according to the guidelines [4].
