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BackgroundThe Neonatal Resuscitation Program (NRP) recommends using 100% O2 during chest compressions and adjusting FiO2 based on SpO2 after return of spontaneous circulation (ROSC). The optimal strategy for adjusting FiO2 is not known.MethodsTwenty-five near-term lambs asphyxiated by umbilical cord occlusion to cardiac arrest were resuscitated per NRP. Following ROSC, lambs were randomized to gradual decrease versus abrupt wean to 21% O2 followed by FiO2 titration to achieve NRP SpO2 targets. Carotid blood flow and blood gases were monitored.ResultsThree minutes after ROSC, PaO2 was 229 ± 32 mmHg in gradual wean group compared to 57 ± 13 following abrupt wean to 21% O2 (p

Author(s): Vali, Payam; Lesneski, Amy; Hardie, Morgan; Alhassen, Ziad; Chen, Peggy; Joudi, Houssam; Sankaran, Deepika; Lakshminrusimha, Satyan | Abstract: BackgroundThe neonatal resuscitation program (NRP) recommends interrupted chest compressions (CCs) with ventilation in the severely bradycardic neonate. The conventional 3:1 compression-to-ventilation (C:V) resuscitation provides 90 CCs/min, significantly lower than the intrinsic newborn heart rate (120-160 beats/min). Continuous CC with asynchronous ventilation (CCCaV) may improve the success of return of spontaneous circulation (ROSC).MethodsTwenty-two near-term fetal lambs were randomized to interrupted 3:1 C:V (90 CCs + 30 breaths/min) or CCCaV (120 CCs + 30 breaths/min). Asphyxiation was induced by cord occlusion. After 5 min of asystole, resuscitation began following NRP guidelines. The first dose of epinephrine was given at 6 min. Invasive arterial blood pressure and left carotid blood flow were continuously measured. Serial arterial blood gases were collected.ResultsBaseline characteristics between groups were similar. Rate of and time to ROSC was similar between groups. CCCaV was associated with a higher PaO2 (partial oxygen tension) (22 ± 5.3 vs. 15 ± 3.5 mmHg, p l 0.01), greater left carotid blood flow (7.5 ± 3.1 vs. 4.3 ± 2.6 mL/kg/min, p l 0.01) and oxygen delivery (0.40 ± 0.15 vs. 0.13 ± 0.07 mL O2/kg/min, p l 0.01) compared to 3:1 C:V.ConclusionsIn a perinatal asphyxiated cardiac arrest lamb model, CCCaV showed greater carotid blood flow and cerebral oxygen delivery compared to 3:1 C:V resuscitation.ImpactIn a perinatal asphyxiated cardiac arrest lamb model, CCCaV improved carotid blood flow and oxygen delivery to the brain compared to the conventional 3:1 C:V resuscitation. Pre-clinical studies assessing neurodevelopmental outcomes and tissue injury comparing continuous uninterrupted chest compressions to the current recommended 3:1 C:V during newborn resuscitation are warranted prior to clinical trials.

Background: Early hyperoxemia in neonates with perinatal acidemia is associated with higher incidence of hypoxic-ischemic encephalopathy (Kapadia et al J Peds 2013). Hence, judicious use of oxygen (O2) during resuscitation is warranted. In neonatal cardiac arrest at term gestation, current NRP guidelines recommend initiation of positive pressure ventilation (PPV) with 21% O2 and titration based on SpO2, but 100% O2 during chest compressions (CC). However, following return of spontaneous circulation (ROSC), a combination of hyperemia (due to hypercarbia) and hyperoxia can result in cerebral oxidative stress and reperfusion injury. Objective: Abrupt weaning of inspired O2 to 21% after ROSC followed by upward titration (21%O2-titrate up) will limit hyperoxia without altering cerebral oxygen delivery (C-DO2) compared to gradual weaning from 100% O2 with …

The 7th edition of the Textbook of Neonatal Resuscitation recommends administration of epinephrine via an umbilical venous catheter (UVC) inserted 2–4 cm below the skin, followed by a 0.5-mL to 1-mL flush for severe bradycardia despite effective ventilation and chest compressions (CC). This volume of flush may not be adequate to push epinephrine to the right atrium in the absence of intrinsic cardiac activity during CC. The objective of our study was to evaluate the effect of 1-mL and 2.5-mL flush volumes after UVC epinephrine administration on the incidence and time to achieve return of spontaneous circulation (ROSC) in a near-term ovine model of perinatal asphyxia induced cardiac arrest. After 5 min of asystole, lambs were resuscitated per Neonatal Resuscitation Program (NRP) guidelines. During resuscitation, lambs received epinephrine through a UVC followed by 1-mL or 2.5-mL normal saline flush. Hemodynamics and plasma epinephrine concentrations were monitored. Three out of seven (43%) and 12/15 (80%) lambs achieved ROSC after the first dose of epinephrine with 1-mL and 2.5-mL flush respectively (p = 0.08). Median time to ROSC and cumulative epinephrine dose required were not different. Plasma epinephrine concentrations at 1 min after epinephrine administration were not different. From our pilot study, higher flush volume after first dose of epinephrine may be of benefit during neonatal resuscitation. More translational and clinical trials are needed.

Background: Persisent pulmonary hypertension of the newborn (PPHN) is often secondary to lung disease such as meconium aspiration syndrome (MAS) and is characterized by extrapulmonary right-to-left or bidirectional shunting at the foramen ovale and/or patent ductus arteriosus (PDA). Shunting at the PDA results in reduced oxygen saturation (SaO2) and PaO2 in the postductual region. However, studies have not directly evaluated simultaneous preductal and postductal blood gases and direction of ductal shunt. Objective: To evaluate …

Neonatal resuscitation (NRP) guidelines suggest targeting 85–95% preductal SpO2 by 10 min after birth. Optimal oxygen saturation (SpO2) targets during resuscitation and in the post-resuscitation management of neonatal meconium aspiration syndrome (MAS) with persistent pulmonary hypertension (PPHN) remains uncertain. Our objective was to compare the time to reversal of ductal flow from fetal pattern (right-to-left), to left-to-right, and to evaluate pulmonary (QPA), carotid (QCA)and ductal (QDA) blood flows between standard (85–94%) and high (95–99%) SpO2 targets during and after resuscitation. Twelve lambs asphyxiated by endotracheal meconium instillation and cord occlusion to induce MAS and PPHN were resuscitated per NRP guidelines and were randomized to either standard (85–94%) or high (95–99%) SpO2 targets. Out of twelve lambs with MAS and PPHN, six each were randomized to standard and high SpO2 targets. Median [interquartile range] time to change in direction of blood flow across the ductus arteriosus from right-to-left, to left-to-right was significantly shorter with high SpO2 target (7.4 (4.4–10.8) min) compared to standard SpO2 target (31.5 (21–66.2) min, p = 0.03). QPA was significantly higher during the first 10 min after birth with higher SpO2 target. At 60 min after birth, the QPA, QCA and QDA were not different between the groups. To conclude, targeting SpO2 of 95–99% during and after resuscitation may hasten reversal of ductal flow in lambs with MAS and PPHN and transiently increase QPA but no differences were observed at 60 min. Clinical studies comparing low and high SpO2 targets assessing hemodynamics and neurodevelopmental outcomes are warranted.