Room air resuscitation-two decades of neonatal research

Parenteral Nutrition and Oxidant Load in Neonates

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

Neonatal parenteral nutrition affects the metabolic flow of glucose in newborn and adult male Hartley guinea pigs' liver

Extremely premature birth is associated with a permanent disruption of energy metabolism. The underlying mechanisms are poorly understood. The oxidative stress induced by parenteral nutrition (PN) during the first week of life is suspected to reprogram energy metabolism in the liver. Full-term male Hartley guinea pigs (to isolate PN from prematurity) receiving PN enriched or not with glutathione (to isolate PN effects from PN-induced oxidative stress effects) or an Oral Nutrition (ON) during the first week of life were used. At 1 week (neonatal) and 16 weeks (adult), measurements of liver glutathione (GSH and GSSG) and activities of three key enzymes of energy metabolism (glucokinase (GCK), phosphofructokinase (PFK), and acetyl-CoA carboxylase (ACC)) were performed. Differences between groups were reported if p ≤ 0.05 (Analysis of Variance). At 1 week, compared to ON, PN induced higher GSSG (oxidative stress), higher GCK activity, and lower PFK and ACC activity, the glutathione supplement prevented all PN effects. At 16 weeks, early PN induced lower GSSG (reductive stress) and lower GCK activity, which was prevented by added glutathione, and higher ACC activity independent of glutathione supplement. ACC was negatively associated (r2 = 0.33) with GSSG. Increased nicotinamide adenine dinucleotide phosphate levels confirmed the glucose-6-phosphate accumulation at 1 week, whereas our protocol failed to document lipid accumulation at 16 weeks. In adult male guinea pigs, neonatal exposure to PN affected glutathione metabolism leading to reductive stress (lower GSSG) and an altered metabolic flow of glucose. Partial prevention with glutathione supplementation suggests that, in addition to peroxides, other factors of PN are involved.

2019 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.

Parenteral nutrition and oxidant stress in the newborn: A narrative review

There is strong evidence that oxidant molecules from various sources contaminate solutions of parenteral nutrition following interactions between the mixture of nutrients and some of the environmental conditions encountered in clinical practice. The continuous infusion of these organic and nonorganic peroxides provided us with a unique opportunity to study in cells, in vascular and animal models, the mechanisms involved in the deleterious reactions of oxidation in premature infants. Potential clinical impacts of peroxides infused with TPN include: a redox imbalance, vasoactive responses, thrombosis of intravenous catheters, TPN-related hepatobiliary complications, bronchopulmonary dysplasia and mortality. This is a narrative review of published data.

Resuscitation of preterm newborns with low concentration oxygen versus high concentration oxygen

Objective:

It is well known that a brief exposure to 100% oxygen for only a few minutes could be toxic for a preterm infant. The effectiveness of neonatal resuscitation was compared with low concentration oxygen (30%) and high concentration oxygen (HOG) (100%).

Methods:

Thirty-two preterm neonates were born in Isfahan Shahid Beheshti hospital with gestational age of 29-34 weeks who required resuscitation were randomized into two groups. The resuscitation was begun with 30% O₂ in low concentration oxygen group (LOG). The infants were examined every 60-90 seconds and if their HR was less than 100, 10% was added to the previous FIO₂(fraction of inspired oxygen) until the HR increased to 100 and SO₂(saturation of oxygen) increased to 85%. In HOG resuscitation begun with 100% O₂ and every 60-90 seconds, FIO₂ was decreased 10 – 15% until the HR reached to 100 and SO₂ reached to 85%.

Findings:

The FIO₂ in LOG was increased stepwise to 45% and in HOG was reduced to 42.1% to reach stable oxygen saturation more than 85% at the fifth minute in both groups. At the first and third minutes after birth and there was no significant differences between groups in heart rate and after 1,2,4 and 5 minutes after the birth there was also no significant differences in SO₂ between groups, regardless of the initial FIO₂.

Conclusion:

We can safely initiate resuscitation of preterm infants with a low FIO₂(approximately 30%) oxygen and then oxygen should be adjusted with the neonates needs.

Hydrogen is neuroprotective and preserves cerebrovascular reactivity in asphyxiated newborn pigs

Hydrogen (H2) has been reported to neutralize toxic reactive oxygen species. Oxidative stress is an important mechanism of neuronal damage after perinatal asphyxia. We examined whether 2.1% H2-supplemented room air (H2-RA) ventilation would preserve cerebrovascular reactivity (CR) and brain morphology after asphyxia/reventilation (A/R) in newborn pigs. Anesthetized, ventilated piglets were assigned to one of the following groups: A/R with RA or H2-RA ventilation (A/R-RA and A/R-H2-RA; n = 8 and 7, respectively) and respective time control groups (n = 9 and 7). Asphyxia was induced by suspending ventilation for 10 min, followed by reventilation with the respective gases for 4 h. After euthanasia, the brains were processed for neuropathological examination. Pial arteriolar diameter changes to graded hypercapnia (5-10% CO2 inhalation), and NMDA (10(-4) M) were determined using the closed cranial window/intravital microscopy before and 1 h after asphyxia. Neuropathology revealed that H2-RA ventilation significantly reduced neuronal injury induced by A/R in virtually all examined brain regions including the cerebral cortex, the hippocampus, basal ganglia, cerebellum, and the brainstem. Furthermore, H2-RA ventilation significantly increased CR to hypercapnia after A/R (% vasodilation was 23 ± 4% versus 41 ± 9%, p < 0.05). H2-RA ventilation did not affect reactive oxygen species-dependent CR to NMDA. In summary, H2-RA could be a promising approach to reduce the neurologic deficits after perinatal asphyxia.

Establishing gas exchange and improving oxygenation in the delivery room management of the lung

One of the components of promoting good outcomes in high-risk neonates is supporting normal gas exchange while avoiding lung injury. Respiratory care in the first hour following birth plays an important role in stabilizing the infant with respiratory problems. The goal of this article is to review the causes of lung injury that can occur in the first hour and that could be prevented with careful respiratory support.

Exposure to supplemental oxygen and its effects on oxidative stress and antioxidant enzyme activity in term newborn lambs

The optimal oxygen concentration for the resuscitation of term infants remains controversial. We studied the effects of 21 versus 100% oxygen immediately after birth, and also exposure for 24 h to 100% oxygen, on oxidant lung injury and lung antioxidant enzyme (AOE) activities in term newborn lambs. Lambs at 139 d gestation were delivered and ventilated with 21% (RAR) or 100% (OXR) for 30 min. A third group of newborn lambs were ventilated with 100% O2 for 24 h (OX24). Oxidized glutathione levels in whole blood were significantly different among the groups with lower values in the RAR group, and these values correlated highly with partial pressure of arterial oxygen (Pao2). The reduced to oxidized glutathione ratio was significantly different among the groups, the ratio decreasing with increasing oxygen exposure. Lipid hydroperoxide (LPO) activity was significantly higher in the OXR and OX24 groups. AOE activity was higher in the whole lung and in red cell lysate in the OX24 group. Increased myeloperoxidase (MPO) activity, percent neutrophils, and proteins in lung lavage suggested inflammation in the OX24 group after maximal oxygen exposure. We conclude that even relatively brief exposure of the lung to 100% oxygen increases systemic oxidative stress and lung oxidant injury in ventilated term newborn lambs.

Chronic lung disease of prematurity: a short history

Chronic lung disease of prematurity (CLD) is commonly considered to be a consequence of assisted ventilation. However, prior to the description in 1967 of bronchopulmonary dysplasia (BPD), following ventilator therapy for respiratory distress syndrome, Wilson-Mikity syndrome (WMS) had been described in very preterm infants on minimal oxygen supplementation. In the 1970s and 1980s, many infants treated with assisted ventilation required prolonged mechanical ventilation after developing radiographic features of coarse infiltrates, severe hyperinflation, and microcystic changes, associated with hypercarbemia and the need for increased inspired oxygen concentrations. Some infants died and showed evidence of pulmonary fibrosis, obstructive bronchiolitis, and dysplastic change. The role of supplemental oxygen, positive pressure ventilation, and the immaturity of the lung have long been considered important in the etiology of CLD/BPD. More recently, the role of inflammation (particularly antenatal exposure to cytokines) and individual susceptibility (genetic predisposition) have assumed greater etiologic importance. The historical setting into which corticosteroid treatment for BPD was introduced is also discussed. After the licensing of exogenous surfactant to treat RDS in the early 1990s and more widespread use of prenatal corticosteroids in the mid-1990s, severe BPD became an unusual event. Gradually, the diagnosis of CLD, still often referred to as BPD, was based on an oxygen requirement at 36 weeks postmenstrual age. However, it is not clear that this 'new BPD' is substantially different from WMS. It is difficult to make prognostications about long-term lung function of these infants based on oxygen 'requirement' at 36 weeks, since supplemental oxygen is frequently used unnecessarily.

Resuscitation with 100%, compared with 21%, oxygen following brief, repeated periods of apnea can protect vulnerable neonatal brain regions from apoptotic injury

PURPOSE

To determine the effect of repeated intermittent apnea and resuscitation with 100% vs. 21% oxygen enriched gas on levels of key regulatory proteins contributing to cell death (Bax, Caspase-3) or protecting neurons from hypoxic/ischemic injury (Bcl-2, p-Akt, p-CREB).

METHODS

The anaesthetized, mechanically ventilated newborn piglets underwent 10 episodes of apnea with resuscitation either with 100% or with 21% oxygen. Following 6h recovery the animals were sacrificed painlessly, the brain dissected out and used to determine levels of Bcl-2, Bax, Caspase-3, p-Akt and p-CREB in the striatum, frontal cortex, midbrain and hippocampus were studied.

RESULTS

In hippocampus and striatum, Bcl-2 expression was higher with 100% vs. 21% group (173+/-29% vs. 121+/-31%, p<0.05 and 189+/-10% vs. 117+/-47%, p<0.01, respectively) whereas the Bax expression was lower (88+/-3% vs. 100+/-9%, p<0.05 and 117+/-5% vs. 133+/-10%, p<0.05, respectively). Expression of Caspase-3 in the striatum, was lower with 100% vs. 21% group (197+/-35% vs. 263+/-33%, p<0.05, respectively) but not different in the hippocampus. p-Akt expression was higher with 100% vs. 21% oxygen in the hippocampus and striatum (225+/-44% vs. 108+/-35%, p<0.01 and 215+/-12% vs. 164+/-16%, p<0.01, respectively). The p-CREB expression was higher with 100% vs. 21% oxygen resuscitation in the hippocampus (217+/-41% vs. 132+/-30%, p<0.01) with no changes in striatum. Much smaller or insignificant differences between 100% vs. 21% oxygen groups were observed in the frontal cortex and midbrain, respectively.

CONCLUSION

In neonatal piglet model of intermittent apnea, selectively vulnerable regions of brain (striatum and hippocampus) are better protected from apoptotic injury when resuscitation was conducted with 100%, rather than 21%, oxygen.

Executive summary of the workshop on oxygen in neonatal therapies: controversies and opportunities for research

One of the most complex areas in perinatal/neonatal medicine is the use of oxygen in neonatal therapies. To address the knowledge gaps that preclude optimal, evidence-based care in this critical field of perinatal medicine, the National Institute of Child Health and Human Development organized a workshop, Oxygen in Neonatal Therapies: Controversies and Opportunities for Research, in August 2005. The information presented at the workshop included basic and translational oxygen research; a review of completed, ongoing, and planned clinical trials; oxygen administration for neonatal resuscitation; and a review of the collaborative home infant monitoring evaluation study. This article provides a summary of the discussions, focusing on major knowledge gaps, with prioritized suggestions for studies in this area.

Reanimación del recién nacido

At birth approximately 10 % of term or near-term neonates require initial stabilization maneuvers to establish a cry or regular breathing, maintain a heart rate greater than 100 beats per minute (bpm), and good color and muscular tone. About 1 % requires ventilation and very few infants receive chest compressions or medication. However, birth asphyxia is a worldwide problem and can lead to death or serious sequelae. Recently, the European Resuscitation Council (ERC) and the International Liaison Committee on Resuscitation (ILCOR) published new guidelines on resuscitation at birth. These guidelines review specific questions such as the use of air or 100 % oxygen in the delivery room, dose and routes of adrenaline delivery, the peripartum management of meconium-stained amniotic fluid, and temperature control. Assisted ventilation in preterm infants is briefly described. New devices to improve the care of newborn infants, such as the laryngeal mask airway or CO2 detectors to confirm tracheal tube placement, are also discussed. Significant changes have occurred in some practices and are included in this document.