Induced hypothermia for neonatal hypoxic-ischemic encephalopathy: pathophysiology, current treatment, and nursing considerations

Application Effect Analysis of Clinical Nursing Pathway in the Care of Neonatal Hypoxic-Ischemic Encephalopathy

This research focuses on the effectiveness of the clinical nursing pathway (CNP) in the treatment of infant hypoxic-ischemic encephalopathy (NHIE). This research enrolled 120 cases of NHIE admitted to the First Affiliated Hospital of Heilongjiang University of Chinese Medicine, including 70 cases (research group, the Res) who received CNP intervention and 50 cases (control group, the Con) treated by routine nursing pathway intervention. The psychomotor development index (PDI), mental development index (MDI), neurodevelopment (ND), physique growth, and incidence of adverse events (AEs) were recorded and analyzed. The results identified that in comparison with the Con (1) the PDI and MDI were obviously better in the Res 6 months postintervention; (2) the Res had significantly superior ND of behavioral capacity, passive tone, active tone, primitive reflex, and general assessment 1 month after intervention, as well as physical development of body weight, height, and head circumference after 40 days of birth, (3) the incidence of total AEs within 40 days was statistically lower in the Res. As a result, CNP is considerably superior to the traditional nursing pathway in the treatment of NHIE, and it merits clinical promotion.

Nursing care in therapeutic hypothermia in neonates with hypoxic-ischaemic encephalopathy. Review of the literature

INTRODUCTION

Hypoxic-ischaemic encephalopathy is one of the main causes of neurological damage in the new-born. Therapeutic hypothermia is the current treatment to reduce mortality and disability in new-borns with this condition.

OBJECTIVE

To identify nursing care in new-borns with severe to moderate EHI, treated with active therapeutic hypothermia.

MATERIALS AND METHODS

A review of the scientific literature was carried out in different databases (PubMed, Lilacs, IBECS, Cinhal, OvidSP, Cuiden, Embase and Cochrane Plus) over the last five years. The documentary assessment was carried out by peers and the quality was evaluated using the CEBM and GRADE scales.

RESULTS

Of the 22 articles selected and reviewed, it is evident that therapeutic hypothermia is effective in reducing the mobility and mortality of neo-nates with hypoxic-ischaemic encephalopathy. Nursing care during hypothermia treatment focuses on four basic pillars: general care for stabilisation of the new-born, preparation of the material, administration of medical treatment in all its phases and emotional support of the family.

CONCLUSIONS

Therapeutic hypothermia is effective in reducing the sequelae and mortality of neonates with hypoxic-ischaemic encephalopathy. Nursing care is essential throughout the treatment, in the early detection of complications in the infant and psychological support for parents. It is essential for nurses to receive training in this care.

Pterostilbene induces Nrf2/HO-1 and potentially regulates NF-κB and JNK-Akt/mTOR signaling in ischemic brain injury in neonatal rats

Hypoxic-ischemic (HI) brain injury has a high occurrence rate of 1-4 per 1000 live births and is the leading cause of neurological disabilities. Despite the improvement in neonatal care, the effectiveness of current therapeutic strategies is limited, and thus, additional therapies with better results are of much needed. Pterostilbene is a stilbenoid possessing numerous preventive and therapeutic properties. The current study aimed to assess whether pterostilbene exerted protective effects in neonatal rats against experimentally induced ischemic brain injury. Pterostilbene was administered via oral gavage from postnatal day 3 to day 8. Rat pups that were seven-day-old were exposed to hypoxic-ischemic insult via ligation of the common carotid artery and hypoxic environment exposure. Pterostilbene treatment reduced neuronal loss and infarct volume. Pterostilbene administration regulated the NF-κB pathway, and the levels of inflammatory mediators (Nitric oxide, TNF-α, IL-1β, and IL-6) were reduced. HI-induced oxidative stress was significantly reduced by pterostilbene, as presented by decreased production of malondialdehyde and reactive oxygen species. Levels of glutathione were enhanced by pterostilbene. Pterostilbene regulated Nrf2/HO-1 and JNK expression and activated the PI3K/Akt-mTOR signals. These findings suggest that pterostilbene is a candidate compound for the treatment of neonatal HI.

Nursing care in therapeutic hypothermia in neonates with hypoxic-ischaemic encephalopathy. Review of the literature

INTRODUCTION

Hypoxic-ischaemic encephalopathy is one of the main causes of neurological damage in the new-born. Therapeutic hypothermia is the current treatment to reduce mortality and disability in new-borns with this condition.

OBJECTIVE

To identify nursing care in new-borns with severe to moderate hypoxic-ischaemic encephalopathy, treated with active therapeutic hypothermia.

MATERIALS AND METHODS

A review of the scientific literature was carried out in different databases (PubMed, Lilacs, IBECS, Cinhal, OvidSP, Cuiden, Embase and Cochrane Plus) over the last five years. The documentary assessment was carried out by peers and the quality was evaluated using the CEBM and GRADE scales.

RESULTS

Of the 22 articles selected and reviewed, it is evident that therapeutic hypothermia is effective in reducing the mobility and mortality of neo-nates with hypoxic-ischaemic encephalopathy. Nursing care during hypothermia treatment focuses on four basic pillars: general care for stabilisation of the new-born, preparation of the material, administration of medical treatment in all its phases and emotional support of the family.

CONCLUSIONS

Therapeutic hypothermia is effective in reducing the sequelae and mortality of neonates with hypoxic-ischaemic encephalopathy. Nursing care is essential throughout the treatment, in the early detection of complications in the infant and psychological support for parents. It is essential for nurses to receive training in this care.

Therapeutic hypothermia and Type II errors: Do not throw out the baby with the ice water

After initial enthusiasm for mild therapeutic hypothermia (TH) treatment after brain injuries, including global cerebral ischemia after cardiac arrest, subsequent trials suggested similar benefit using only targeted temperature management (TTM), with fewer side effects. Globally, effective treatment of brain ischemia with TH has declined. Recent data suggest, however, that TH to 33°C may be superior to TTM. We review the background and rationale underlying TH and TTM. We present previously published data from our own laboratory that confirms TH to 33°C provides superior brain cytoprotection, compared to 35°C or 37°C, over a range of delays to treatment and several durations of TH. We illustrate that the treatment effect size of either or 35 is superior to 37, but the effect size difference between 33 and 35, although significant, is small. We estimate that to demonstrate the superiority of TTM over TH, a clinical trial would need between 3,000 and 9,000 patients depending on the desired treatment effect size. Our review and our own data suggest that TH to 33°C is superior to TTM to 36°C, but an extremely large clinical trial would be needed to demonstrate the difference.

Geniposide attenuates neonatal mouse brain injury after hypoxic-ischemia involving the activation of PI3K/Akt signaling pathway

Perinatal hypoxic-ischemia (HI) is a leading cause of acute mortality and neurologic complications in newborns. Geniposide, a natural product extracted from the herb Gardenia jasminoides, has been shown to possess neuroprotective effects in neurologic deficits. This study aims to investigate whether Geniposide has therapeutic potential to HI brain injury and the underlying mechanisms. C57/bl6 mice were subjected to HI insult on postnatal day 10. Geniposide (20 mg/kg b.w.) was administered intragastrically every day after HI insult for 7 successional days. Then mice at P18 were sacrificed and brain tissues were collected for further analysis. Geniposide treatment significantly inhibited cell apoptosis, reduced serum IgG leakage into brain tissue, attenuated astrogliosis and microgliosis, prevented loss of pericytes, loss of tight junction and adherens junction proteins. The PI3K/Akt signaling pathway, which related proteins were downregulated after HI insult, was activated by Geniposide treatment. Geniposide treatment after neonatal HI insult attenuated HI-induced cell apoptosis, IgG leakage, microgliosis, astrogliosis, pericytes loss and junction protein degradation. Geniposide could protect against HI-induced brain injury, which might be through the activation of PI3K/Akt signaling pathway.

A Rho-kinase inhibitor reverses learning and memory deficits in a Rat model of chronic cerebral ischemia by altering Bcl-2/Bax-NMDAR signaling in the cerebral cortex

The current study investigated whether a Rho-kinase inhibitor alleviated impairments in a rat model of chronic cerebral ischemia and examined the specific pathological mechanisms by which Rho-kinase impacts neuronal damage and cognitive dysfunction. Adult Sprague-Dawley rats underwent permanent bilateral carotid artery occlusion (BCAO) to establish our chronic cerebral ischemia model. Chronic Y27632 administration reversed the abnormal behaviors of BCAO-treated rats in the Morris water maze. We performed Western blot analyses of the apoptosis-related proteins Bcl-2 and Bax to examine the potential mechanism underlying the beneficial effects of Y27632 on cerebral ischemia and showed for the first time that Y27632 reversed the decrease in the Bcl-2/Bax ratio in BCAO model rats. Y27632 restored the depression of NR2A- and NR2B-containing N-methyl-d-aspartate receptors (NMDARs) in the cerebral cortex of BCAO model rats. We also investigated these effects on middle cerebral artery occlusion (MCAO) model rats and observed some differences between the two models. In summary, our data provide evidence supporting the hypothesis that Rho-kinase inhibitors exert neuroprotective effects on cerebral ischemia. The Bcl-2/Bax-NMDAR signaling pathway in the cerebral cortex may be responsible for the protective effects of the Rho-kinase inhibitor, and this pathway may represent a pharmacological target for curative clinical strategies.

Mangiferin Potentiates Neuroprotection by Isoflurane in Neonatal Hypoxic Brain Injury by Reducing Oxidative Stress and Activation of Phosphatidylinositol-3-Kinase/Akt/Mammalian Target of Rapamycin (PI3K/Akt/mTOR) Signaling

Background

Hypoxic-ischemic brain injury in the perinatal period is a main cause of perinatal mortality and neurologic complications in neonates and children. Recent studies have focused on the neuroprotective effect of anesthetic drugs. The volatile anesthetic isoflurane has been shown to exert neuroprotective effects in cerebral ischemia. Mangiferin is a natural polyphenol with various pharmacological properties, including antioxidant and ant-tumor effects. This study aimed to determine whether mangiferin potentiates the neuroprotective effects of isoflurane and also if mangiferin when administered alone exerts neuroprotective effects following hypoxic-ischemic brain injury.

Material/Methods

Sprague-Dawley rats were subjected to cerebral hypoxic ischemia on postnatal day 10 (P10). Mangiferin (50, 100, or 200 mg/kg b.w.) was intragastrically administered from P3 to P12 and 1 h prior to insult on the day of ischemic induction. At 3 h after hypoxia-ischemia (HI) insult, separate groups of rat pups were exposed to isoflurane (1.5%) for 6 h. Following 48 h of HI, the rats were sacrificed and brain tissues were used for analysis.

Results

Mangiferin treatment attenuated neuronal apoptosis and reduced cerebral infarct volume. The expression of cleaved caspase-3 and apoptotic cascade proteins were regulated. The levels of reactive oxygen species (ROS) and malondialdehyde were reduced by mangiferin and/or isoflurane exposure. The levels of antioxidant glutathione were considerably raised under HI injury, which was modulated by mangiferin and isoflurane exposure. The PI3K/Akt signaling pathway, which was downregulated following HI insult, was activated by mangiferin and/or isoflurane.

Conclusions

This study reveals the potent neuroprotective efficacy of mangiferin against HI-induced brain injury via effectively modulating apoptotic pathways, ROS levels, and PI3K/Akt cascades while potentiating protective effects of isoflurane.

Therapeutic Strategies for Leukodystrophic Disorders Resulting from Perinatal Asphyxia: Focus on Myelinating Oligodendrocytes

Perinatal asphyxia results from the action of different risk factors like complications during pregnancy, preterm delivery, or long and difficult labor. Nowadays, it is still the leading cause of neonatal brain injury known as hypoxic-ischemic encephalopathy (HIE) and resulting neurological disorders. A temporal limitation of oxygen, glucose, and trophic factors supply results in alteration of neural cell differentiation and functioning and/or leads to their death. Among the affected cells are oligodendrocytes, responsible for myelinating the central nervous system (CNS) and formation of white matter. Therefore, one of the major consequences of the experienced HIE is leukodystrophic diseases resulting from oligodendrocyte deficiency or malfunctioning. The therapeutic strategies applied after perinatal asphyxia are aimed at reducing brain damage and promoting the endogenous neuroreparative mechanisms. In this review, we focus on the biology of oligodendrocytes and discuss present clinical treatments in the context of their efficiency in preserving white matter structure and preventing cognitive and behavioral deficits after perinatal asphyxia.

Role of Antioxidants in Neonatal Hypoxic-Ischemic Brain Injury: New Therapeutic Approaches

Hypoxic-ischemic brain damage is an alarming health and economic problem in spite of the advances in neonatal care. It can cause mortality or detrimental neurological disorders such as cerebral palsy, motor impairment and cognitive deficits in neonates. When hypoxia-ischemia occurs, a multi-faceted cascade of events starts out, which can eventually cause cell death. Lower levels of oxygen due to reduced blood supply increase the production of reactive oxygen species, which leads to oxidative stress, a higher concentration of free cytosolic calcium and impaired mitochondrial function, triggering the activation of apoptotic pathways, DNA fragmentation and cell death. The high incidence of this type of lesion in newborns can be partly attributed to the fact that the developing brain is particularly vulnerable to oxidative stress. Since antioxidants can safely interact with free radicals and terminate that chain reaction before vital molecules are damaged, exogenous antioxidant therapy may have the potential to diminish cellular damage caused by hypoxia-ischemia. In this review, we focus on the neuroprotective effects of antioxidant treatments against perinatal hypoxic-ischemic brain injury, in the light of the most recent advances.

Effects of NMDA-Receptor Antagonist on the Expressions of Bcl-2 and Bax in the Subventricular Zone of Neonatal Rats with Hypoxia-Ischemia Brain Damage

Neonatal hypoxia-ischemia brain damage is an important cause of death by affecting prognosis of neural diseases. It is difficult to find effective methods of prevention and treatment due to the complexity of its pathogenesis. N-methyl-D-aspartate (NMDA), as an excitotoxicity amino acids, has proven to play an important role in hypoxic-ischemic. However, the exact effects of the NMDA subunits, NR2A and NR2B, during hypoxic-ischemic have not been investigated in detail. Therefore, we sought to study whether the NMDA receptor antagonist could confer neuroprotective effects in a neonatal rat hypoxia-ischemia model. The effects of intraperitoneal injections of different drugs, namely MK-801 (0.5 mg/kg), NVP-AAM077 (5 mg/kg), and Ro25-6981 (5 mg/kg), on the expressions of anti-apoptotic protein Bcl-2 and apoptosis protein Bax in the subventricular zone were analyzed by immunohistochemical staining to explore the roles of NMDA subunits (NR2A and NR2B) in hypoxic-ischemic. We found that the NR2B antagonist (Ro25-6981) could inhibit hypoxic-ischemic with the increasing Bcl-2 expression. NR2A antagonists (NVP-AAM077) can increase cerebral hypoxia-ischemia in neonatal rats, promoting the expression of apoptotic protein Bax.

Autophagy activation involved in hypoxic-ischemic brain injury induces cognitive and memory impairment in neonatal rats

Hypoxic-ischemic brain injury (HIBI) in neonates can lead to lifelong cognitive and memory impairment, but protective strategies are lacking at present. It has been demonstrated that autophagy plays a critical role in HIBI, while the function of autophagy in cognitive and memory impairment induced by HIBI in neonates has not been tested. In this study, we tested the impact of autophagy on the impairment of cognitive function and memory in HIBI neonatal rats by using a Morris water maze and investigated its possible mechanisms, which were established as HIBI model by ligating the left common carotid artery in neonatal rats, followed by 2-h hypoxia. The expression of microtubule-associated protein 1 light chain 3 (LC3)-II increased in HI group 24 h after HI in neonatal rats, while Sequestosome 1 (P62/SQSTM1), phosphorylated cAMP-response element-binding protein (p-CREB) decreased (compared with the sham group, p < 0.05), which were shown in the same left hippocampus CA3 region by immunofluorescence analysis. Brain injury of neonatal rats was aggravated significantly at 7 day after HI, coinciding with the results of Morris water maze. An autophagy inhibitor, 3-methyladenine (3-MA) pretreatment significantly attenuated the increase of LC3II and the loss of P62/SQSTM1 and p-CREB, ameliorated neuronal death, and improved the results of Morris water maze. Our results demonstrate that HIBI in neonatal rats induced excessive autophagy flux, which aggravated brain injury and induced cognitive and memory impairment during adolescence. Inhibition of autophagy reversed the results partly and improved the function of spatial learning and memory by attenuating the reduction of p-CREB. The use of autophagy modulators in the immature brain would create new opportunities for protective strategies clinically in the future.

Cost-effective therapeutic hypothermia treatment device for hypoxic ischemic encephalopathy

Despite recent advances in neonatal care and monitoring, asphyxia globally accounts for 23% of the 4 million annual deaths of newborns, and leads to hypoxic-ischemic encephalopathy (HIE). Occurring in five of 1000 live-born infants globally and even more in developing countries, HIE is a serious problem that causes death in 25%–50% of affected neonates and neurological disability to at least 25% of survivors. In order to prevent the damage caused by HIE, our invention provides an effective whole-body cooling of the neonates by utilizing evaporation and an endothermic reaction. Our device is composed of basic electronics, clay pots, sand, and urea-based instant cold pack powder. A larger clay pot, lined with nearly 5 cm of sand, contains a smaller pot, where the neonate will be placed for therapeutic treatment. When the sand is mixed with instant cold pack urea powder and wetted with water, the device can extract heat from inside to outside and maintain the inner pot at 17°C for more than 24 hours with monitoring by LED lights and thermistors. Using a piglet model, we confirmed that our device fits the specific parameters of therapeutic hypothermia, lowering the body temperature to 33.5°C with a 1°C margin of error. After the therapeutic hypothermia treatment, warming is regulated by adjusting the amount of water added and the location of baby inside the device. Our invention uniquely limits the amount of electricity required to power and operate the device compared with current expensive and high-tech devices available in the United States. Our device costs a maximum of 40 dollars and is simple enough to be used in neonatal intensive care units in developing countries.