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Background and Purpose: Therapeutic hypothermia (TH) has become the standard care to reduce morbidity and mortality in neonates affected by moderate‐to‐severe hypoxic–ischaemic encephalopathy (HIE). Despite the use of TH for HIE, the incidence of mortality and disabilities remains high. Experimental Approach: Nerve growth factor (NGF) is a potent neurotrophin, but clinical use is limited by its pain eliciting effects. CHF6467 is a recombinant modified form of human NGF devoid of algogenic activity (painless NGF). Key Results: In rodent hippocampal slices exposed to oxygen and glucose deprivation, CHF6467 protected neurons from death and reverted neurotransmission impairment when combined with hypothermia. In a model of rat neonatal HIE, intranasal CHF6467 (20 μg kg−1) significantly reduced brain infarct volume versus vehicle when delivered 10 min or 3 h after the insult. CHF6467 (20 and 40 μg kg−1, i.n.), significantly decreased brain infarct volume to a similar extent to TH and when combined, showed a synergistic neuroprotective effect. CHF6467 (20 μg kg−1, i.n.) per se and in combination with hypothermia reversed locomotor coordination impairment (Rotarod test) and memory deficits (Y‐maze and novel object recognition test) in the neonatal HIE rat model. Intranasal administration of CHF6467 resulted in meaningful concentrations in the brain, blunted HIE‐induced mRNA elevation of brain neuroinflammatory markers and, when combined to TH, significantly counteracted the increase in plasma levels of neurofilament light chain, a peripheral marker of neuroaxonal damage. Conclusion and Implications: CHF6467 administered intranasally is a promising therapy, in combination with TH, for the treatment of HIE. [ABSTRACT FROM AUTHOR]

The optimal rate of rewarming after therapeutic hypothermia is unclear. Slow rewarming may reduce cardiovascular instability and rebound seizures, but there is little controlled evidence to support this. The present study aimed to determine whether slow rewarming can improve neuroprotection after 72 h of hypothermia. Fetal sheep (0.85 gestation) received sham occlusion (n = 8) or 30 min of global cerebral ischaemia followed by normothermia (n = 7), or hypothermia from 3 to 72 h with either fast, spontaneous rewarming within 1 h (n = 8) or slow rewarming at 0.5°C h−1 over 10 h (n = 8). Hypothermia improved EEG and spectral edge recovery, with no significant difference between fast and slow rewarming. Hypothermia reduced the number of seizures, with no significant difference in seizure activity between fast and slow rewarming. Hypothermia improved neuronal survival in the cortex, CA1, CA3, CA4 and dentate gyrus regions of the hippocampus, with no significant difference between fast and slow rewarming. Hypothermia attenuated microglia counts in the cortex, with no significant difference between fast and slow rewarming. The rate of rewarming after a clinically relevant duration of hypothermia did not affect neurophysiological recovery, neuronal survival or attenuation of microglia after global cerebral ischaemia in term‐equivalent fetal sheep. Key points: The rate of rewarming after 72 h of hypothermia did not affect recovery of EEG or spectral edge.There was no difference in the occurrence of seizures as a result of the rate of rewarming after hypothermia.The rate of rewarming after 72 h of hypothermia did not affect neuronal survival in the cortex or hippocampus. [ABSTRACT FROM AUTHOR]

Background: Acute ischemic stroke remains a major contributor to mortality and disability worldwide. The use of hypothermia has emerged as a promising neuroprotective strategy, with proven effectiveness in cardiac arrest and neonatal hypoxic-ischemic injury. Summary: This review explores the therapeutic potential of hypothermia in ischemic stroke by examining its impact on poststroke inflammatory responses. We synthesized evidence from basic and clinical studies to illustrate the inhibitory effects of hypothermia on poststroke brain inflammation. The underlying mechanisms include modulation of microglial activation and polarization; downregulation of key inflammatory pathways such as MAPKs, NF-KB, and JAK/STAT; protection of the blood-brain barrier integrity; and reduction of immune cell infiltration into the brain. We also discuss the current limitations of hypothermia treatment in clinical practice and highlight future research directions for optimizing protocols and evaluating its clinical efficacy in stroke patients. Key Messages: Therapeutic hypothermia (TH) has evolved significantly with advancements in medical technologies, especially with the introduction of automated cooling devices, both intravascular and surface based. However, a refined, highly individualized, and effective hypothermia protocol may stand robust against the devastating consequences of ischemic stroke, and we think it should become the future development goal. [ABSTRACT FROM AUTHOR]

Asphyxiated neonates often undergo therapeutic hypothermia (TH) to reduce morbidity and mortality. As perinatal asphyxia and TH impact neonatal physiology, this could also influence enzyme functionality. Therefore, this study aimed to unravel the impact of age, hypothermia and hypoxia on porcine hepatic cytochrome P450 (CYP) gene expression, protein abundance and activity. Hepatic CYP expression, protein abundance and activity were assessed in naive adult and neonatal Göttingen minipigs, alongside those from an (non‐survival) in vivo study, where four conditions—control (C), therapeutic hypothermia (TH), hypoxia (H), hypoxia and TH (H + TH)—were examined. Naive neonatal Göttingen minipigs exhibited 75% lower general CYP activity and different gene expression patterns than adults. In vitro hypothermia (33°C) decreased general CYP activity in adult liver microsomes by 36%. Gene expression was not different between TH and C while hypoxia up‐regulated several genes (i.e., CYP3A29 [expression ratio; ER = 5.1472] and CYP2C33 [ER = 3.2292] in the H group and CYP2C33 [ER = 2.4914] and CYP2C42 [ER = 4.0197] in the H + TH group). The medical treatment and the interventions over 24 h, along with hypoxia and TH, affected the protein abundance. These data on CYP expression, abundance and activity in young animals can be valuable in building physiologically‐based pharmacokinetic models for neonatal drug dose predictions. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the neuroprotective effects of local therapeutic hypothermia (LTH) in a model of focal ischemia induced by epipial application of Endothelin-1 to the somatosensory cortex of the rat brain by morphometric analysis of ischemic foci formed 3 hours after Endothelin-1 application. The size of ischemic foci was measured in serial coronal brain slices after staining with 2,3,5-triphenyltetrazolium chloride (TTC). It was found that cooling the cortical surface to 28°C using a subdural Peltier element at 0, 10 and 60 minutes delay after Endothelin-1 application, caused a significant reduction in the size of ischemic focus compared to normothermic conditions. The neuroprotective effects of LTH were inversely correlated with the delay of LTH onset from the time of Endothelin-1 application and were most pronounced with LTH initiated with the shortest (0 and 10 minutes) delay after Endothelin-1 application. The size of the ischemic focus was also found to correlate significantly with the degree of electrical activity suppression analyzed in parallel paper. Taken together, the results of morphological and electrophysiological analysis indicate pronounced neuroprotective effects of surface LTH, particularly significant at minimal LTH latency after ischemic onset, in a model of Endothelin-1-induced focal ischemia in the rat cerebral cortex. [ABSTRACT FROM AUTHOR]

Local therapeutic hypothermia (LTH) is one of the most promising methods for neuroprotection in cerebral ischemia. However, the efficacy of superficial LTH at clinically relevant delays after the onset of ischemic attack remains poorly understood. In the present study, we investigated the neuroprotective effects of LTH in a model of focal ischemia induced by epipial application of the vasoconstrictor Endothelin-1 in the somatosensory cortex region of the rat brain. The neuroprotective effects of LTH were assessed by the level of spontaneous and sensory-evoked electrical activity at different cortical depths using linear electrode arrays. We found that cooling the cortical surface to 28°C using a Peltier element starting from 0, 10, and 60 minutes after Endothelin-1 application caused a significant reduction in the degree of suppression of electrical activity in the ischemic focus formed in the cerebral cortex 3 hours after Endothelin-1 application. The neuroprotective effects of LTH were manifested by a higher level of spontaneous multiunit activity, higher power of the local field potential oscillations in theta, alpha and beta bands, as well in a greater amplitude and higher multiunit activity during sensory evoked responses. The neuroprotective effects of LTH were inversely correlated with the delay of LTH onset and were most pronounced with LTH initiated with minimal (0 and 10 minutes) delay after Endothelin-1 application. We also found that only LTH initiated simultaneously with Endothelin-1 application delayed the onsets of spreading depolarization waves and that LTH did not affect the amplitude of negative ultraslow potentials evoked by Endothelin-1. Taken together, the results of the electrophysiological analysis suggest neuroprotective effects of surface LTH, which are particularly pronounced when LTH is minimally delayed from the onset of the ischemic insult in the Endothelin-1-induced focal ischemia model. [ABSTRACT FROM AUTHOR]

Introduction: Eleclazine is a highly selective late sodium current inhibitor, possibly effective in reducing ventricular fibrillation (VF) in heart failure (HF) with ischemia-reperfusion (IR) injury. The electrophysiological effects of eleclazine at therapeutic hypothermia (TH) are unknown. We investigated the effects of eleclazine in suppressing VF in failing rabbit hearts with IR injury undergoing TH. Method: HF was induced by right ventricular pacing. An IR model was created using coronary artery ligation for 60 min, followed by reperfusion for 30 min. Hearts were excised and Langendorff-perfused for optical mapping and electrophysiological studies. Electrophysiological studies were repeated after TH (33°C) for 30 min or eleclazine (1 μm) infusion for 20 min. Results: In failing IR-injured hearts, eleclazine reduced action potential duration (APD) dispersion and accelerated intracellular Ca2+ uptake to suppress arrhythmogenic alternans but also exacerbated rate-dependent conduction slowing, resulting in neutral effects on VF inducibility at normothermia. TH increased VF severity. Eleclazine after TH ameliorated TH-induced APD dispersion and further depressed conduction to reduce VF inducibility and severity. TH after eleclazine also slowed conduction to a greater extent to reduce VF inducibility and severity by extrastimulus pacing. In control IR-injured hearts, eleclazine increased VF severity by dynamic pacing at normothermia, which was counteracted by TH. Conclusions: Eleclazine does not prevent VF at normothermia but reduces VF inducibility and severity by extrastimulus pacing at TH in isolated failing hearts with regional IR injury. [ABSTRACT FROM AUTHOR]

Background: The main focus of traumatic brain injury (TBI) management is prevention of secondary injury. Therapeutic hypothermia (TH), the induction of a targeted low core body temperature, has been explored as a potential neuroprotectant in TBI. The aim of this article is to synthesize the available clinical data comparing the use of TH with the use of normothermia in TBI. Methods: A systematic search was conducted through MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials for randomized clinical trials including one or more outcome of interest associated with TH use in TBI. Independent reviewers evaluated quality of the studies and extracted data on patients with TBI undergoing TH treatment compared with those undergoing normothermia treatment. Pooled estimates, confidence intervals (CIs), and risk ratios (RRs) or odds ratios were calculated for all outcomes. Results: A total of 3,909 patients from 32 studies were eligible for analysis. Pooled analysis revealed a significant benefit of TH on mortality and functional outcome (RR 0.81, 95% CI 0.68–0.96, I2 = 41%; and RR 0.77; 95% CI 0.67–0.88, I2 = 68%, respectively). However, subgroup analysis based on risk of bias showed that only studies with a high risk of bias maintained this benefit. When divided by cooling method, reduced poor functional outcome was seen in the systemic surface cooling and cranial cooling groups (RR 0.68, 95% CI 0.59–0.79, I2 = 35%; and RR 0.44, 95% CI 0.29–0.67, I2 = 0%), and no difference was seen for the systemic intravenous or gastric cooling group. Reduced mortality was only seen in the systemic surface cooling group (RR 0.63, 95% CI 0.53–0.75, I2 = 0%,); however, this group had mostly high risk of bias studies. TH had an increased rate of pneumonia (RR 1.24, 95% CI 1.10–1.40, I2 = 32%), coagulation abnormalities (RR 1.63, 95% CI 1.09–2.44, I2 = 55%), and cardiac arrhythmias (RR 1.78, 95% CI 1.05–3.01, I2 = 21%). Once separated by low and high risk of bias, we saw no difference in these complications in the groups with low risk of bias. Overall quality of the evidence was moderate for mortality, functional outcome, and pneumonia and was low for coagulation abnormalities and cardiac arrhythmias. Conclusions: With the addition of several recent randomized clinical trials and a thorough quality assessment, we have provided an updated systematic review and meta-analysis that concludes that TH does not show any benefit over normothermia in terms of mortality and functional outcome. [ABSTRACT FROM AUTHOR]

Fever control is essential in patients with severe traumatic brain injury (TBI). The efficacy of therapeutic hypothermia (TH) in severe TBI has been investigated over the last few decades; however, in contrast to experimental studies showing benefits, no evidence of efficacy has been demonstrated in clinical practice. In this review, the mechanisms and history of hypothermia were briefly outlined, while the results of major randomized controlled trials (RCTs) and meta-analyses investigating TH for adult TBI were introduced and discussed. The retrieved meta-analyses showed conflicting results, with a limited number of studies indicating the benefits of TH. Some studies have shown the benefits of long-term TH compared with short-term TH. Although TH is effective at lowering elevated intracranial pressure (ICP), reduced ICP does not lead to favorable outcomes. Low-quality RCTs overestimated the benefits of TH, while high-quality RCTs showed no difference or worse outcomes with TH. RCTs assessing standardized TH quality demonstrated the benefits of TH. As TBI has heterogeneous and complicated pathologies, applying a uniform treatment may not be ideal. A meta-analysis of young patients who underwent early cooling and hematoma removal showed better TH results. TH should not be abandoned, and its optimal usage should be advocated on an individual basis. [ABSTRACT FROM AUTHOR]

This review aims to serve as a foundational resource for general radiologists, enhancing their understanding of the role of Magnetic Resonance Imaging (MRI) in early prognostication for newborns diagnosed with hypoxic ischaemic encephalopathy (HIE). The article explores the application of MRI as a predictive instrument for determining long-term outcomes in newborns affected by HIE. With HIE constituting a leading cause of neonatal mortality and severe long-term neurodevelopmental impairments, early identification of prognostic indicators is crucial for timely intervention and optimal clinical management. We examine current literature and recent advancements to provide an in-depth overview of MRI predictors, encompassing brain injury patterns, injury scoring systems, spectroscopy, and diffusion imaging. The potential of these MRI biomarkers in predicting long-term neurodevelopmental outcomes and the probability of epilepsy is also discussed. [ABSTRACT FROM AUTHOR]

Seizures (SZ) are one of the main complications occurring in infants undergoing therapeutic hypothermia (TH) due to perinatal asphyxia (PA) and hypoxic ischemic encephalopathy (HIE). Phenobarbital (PB) is the first-line therapeutic strategy, although data on its potential side-effects need elucidation. We investigated whether: i) PB administration in PA-HIE TH-treated infants affects S100B urine levels, and ii) S100B could be a reliable early predictor of SZ. We performed a prospective case-control study in 88 PA-HIE TH infants, complicated (n=44) or not (n=44) by SZ requiring PB treatment. S100B urine levels were measured at 11 predetermined monitoring time-points from first void up to 96-h from birth. Standard-of-care monitoring parameters were also recorded. S100B significantly increased in the first 24-h independently from HIE severity in the cases who later developed SZ and requested PB treatment. ROC curve analysis showed that S100B, as SZ predictor, at a cut-off of 2.78 μg/L achieved a sensitivity/specificity of 63 and 84 %, positive/negative predictive values of 83 and 64 %. The present results offer additional support to the usefulness of S100B as a trustable diagnostic tool in the clinical daily monitoring of therapeutic and pharmacological procedures in infants complicated by PA-HIE. [ABSTRACT FROM AUTHOR]

Background: This study evaluates the effectiveness of Therapeutic Hypothermia (TH) in treating poor-grade aneurysmal subarachnoid hemorrhage (SAH), focusing on functional outcomes, mortality, and complications such as vasospasm, delayed cerebral ischemia (DCI), and hydrocephalus. Methods: Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, a comprehensive literature search was conducted across multiple databases, including Medline, Embase, and Cochrane Central, up to November 2023. Nine studies involving 368 patients were selected based on eligibility criteria focusing on TH in poor-grade SAH patients. Data extraction, bias assessment, and evidence certainty were systematically performed. Results: The primary analysis of unfavorable outcomes in 271 participants showed no significant difference between the TH and standard care groups (risk ratio [RR], 0.87). However, a significant reduction in vasospasm was observed in the TH group (RR, 0.63) among 174 participants. No significant differences were found in DCI, hydrocephalus, and mortality rates in the respective participant groups. Conclusions: TH did not significantly improve primary unfavorable outcomes in poor-grade SAH patients. However, the reduction in vasospasm rates indicates potential specific benefits. The absence of significant findings in other secondary outcomes and mortality highlights the need for further research to better understand TH's role in treating this patient population. [ABSTRACT FROM AUTHOR]

Background and Objectives: Although classical gross features are known in hypothermia victims, they lack specific diagnosis features. The aim of our study was to reveal specific brain and lung pathological features in a group of hypothermia-related fatalities. Materials and Methods: The study group comprised 107 cases from our files associated with hypothermia. Routine hematoxylin–eosin (H&E) staining and postmortem immunohistochemistry were performed. Results: The microscopic cerebral exam revealed diffuse perineuronal and perivascular edema, gliosis, mononuclear cell infiltration, acute brain injuries, focal neuronal ischemia, lacunar infarction, and variable hemorrhages. Variable alveolar edema, pulmonary emphysema, intra-alveolar and/or pleural hemorrhage, and bronchopneumonia, as well as other pre-existing lesions, were identified in lung tissue samples. Glial cells displayed S100β expression, while neurons showed moderate Hsp70 immunopositivity. Alveolar basal membranes exhibited diffuse ICAM-1 positive expression, while ICAM-1 and AQP-1 positivity was observed in the alveolar septum vascular endothelium. Statistical analysis revealed a significant correlation between S100β and Hps70 immunoexpression and cerebral pathological features, between ICAM-1 immunoexpression and alveolar edema and pulmonary emphysema, and between AQP-1 immunoexpression and pulmonary emphysema. Conclusions: Our results add supplementary data to brain and lung pathological findings in hypothermia-related fatalities, with potential therapeutic value in hypothermia patients. [ABSTRACT FROM AUTHOR]

To investigate the association between the presence and severity of seizures in asphyxiated newborns and their neurodevelopmental outcome at ages two and five years. Retrospective data analysis from a prospectively collected multicenter cohort of 186 term-born asphyxiated newborns undergoing therapeutic hypothermia (TH) in 11 centers in the Netherlands and Belgium. Seizures were diagnosed by amplitude-integrated electroencephalography (EEG) and raw EEG signal reading up to 48 hours after rewarming. Neurodevelopmental outcome was assessed by standardized testing at age two and five years. Primary outcome was death or long-term neurodevelopmental impairment (NDI) including cerebral palsy. Associations were calculated using univariate and multivariate logistic regression analyses adjusting for Thompson score and a validated brain magnetic resonance imaging (MRI) score. Seventy infants (38%) had seizures during TH or rewarming, and 44 (63%) of these needed two or more antiseizure medications (ASMs). Overall mortality was 21%. Follow-up data from 147 survivors were available for 137 infants (93%) at two and for 94 of 116 infants (81%) at five years. NDI was present in 26% at two and five years. Univariate analyses showed a significant association between seizures and death or NDI, but this was no longer significant after adjusting for Thompson and MRI score in the multivariate analysis; this was also true for severe seizures (need for two or more ASMs) or seizures starting during rewarming. The presence or severity of seizures in newborns undergoing TH for hypoxic-ischemic encephalopathy was not independently associated with death or NDI up to age five years after adjusting for several confounders. [ABSTRACT FROM AUTHOR]

Objective Therapeutic hypothermia (TH) is the standard treatment for hypoxic–ischemic encephalopathy (HIE). We surveyed parents of infants treated with TH about their experiences of communication and parental involvement in the neonatal intensive care unit (NICU). Study Design A 29-question anonymous survey was posted on a parent support (web site: https://www.hopeforhie.org) and sent to members via e-mail. Responses from open-ended questions were analyzed using thematic analysis. Results A total of 165 respondents completed the survey and 108 (66%) infants were treated with TH. 79 (48%) respondents were dissatisfied/neutral regarding the quality of communication in the NICU, whereas 127 (77%) were satisfied/greatly satisfied with the quality of parental involvement in the NICU. Six themes were identified as follows: (1) setting for communication: parents preferred face to face meetings with clinicians; (2) content and clarity of language: parents valued clear language (use of layman's terms) and being explicitly told the medical diagnosis of HIE; (3) immediate and longitudinal emotional support: parents required support from clinicians to process the trauma of the birth experience and hypothermia treatment; (4) clinician time and scheduling: parents valued the ability to join rounds and other major conversations about infant care; (5) valuing the parent role: parents desired being actively involved in rounds, care times, and decision-making; (6) physical presence and touch: parents valued being physically present and touching their baby; this presence was limited by the novel coronavirus disease 2019 (COVID-19)-related restrictions. Conclusion We highlight stakeholder views on parent involvement and parent–clinician communication in the NICU and note significant overlap with principles of trauma informed care: safety (physical and psychological), trustworthiness and transparency, peer support, collaboration and mutuality, empowerment, and voice and choice. We propose that a greater understanding and implementation of these principles may allow the medical team to more effectively communicate with and involve parents in the care of infants with HIE in the NICU. Key Points Parents of infants with HIE experience trauma both from the birth and the hypothermia treatment. Transparent communication and encouraging parental involvement can ameliorate this trauma. [ABSTRACT FROM AUTHOR]

Background and Objectives: The purpose of the study is to assess parental experiences of therapeutic hypothermia for moderate to severe hypoxic-ischemic encephalopathy with the goal of improving local clinical practice guidelines and fostering family-integrated care in neonates with hypoxic-ischemic encephalopathy. Methods: This single-center retrospective cross-sectional study included neonates and their parents registered in the Swiss National Asphyxia and Cooling Register between 2011 and 2021. Based on a literature review, an anonymous survey of parents of neonates with hypoxic-ischemic encephalopathy was developed and conducted using an online survey tool. Descriptive statistics were used to analyze the survey results. Results: The overall response rate to this survey was 64% (46/72). Sufficient information about hypoxic-ischemic encephalopathy was reported by 78% (36/46) of parents and sufficient information about the process of therapeutic hypothermia by 87% (40/46) of parents. The majority of parents indicated the need for, and at least a satisfactory perception of, professional (91%; 42/46) and emotional (87%; 40/46) support. Parents identified fostering family involvement and regular family communication that focuses on family integrated care as areas for improvement. Conclusions: There is still an unmet need for multidisciplinary teams to provide professional, empathetic, high quality, and family-integrated care to families with a neonate receiving therapeutic hypothermia for moderate or severe hypoxic-ischemic encephalopathy. [ABSTRACT FROM AUTHOR]

Brain maturity and many clinical treatments such as therapeutic hypothermia (TH) can significantly influence the morphology of neonatal EEG seizures after hypoxia–ischemia (HI), and so there is a need for generalized automatic seizure identification. This study validates efficacy of advanced deep-learning pattern classifiers based on a convolutional neural network (CNN) for seizure detection after HI in fetal sheep and determines the effects of maturation and brain cooling on their accuracy. The cohorts included HI–normothermia term (n = 7), HI–hypothermia term (n = 14), sham–normothermia term (n = 5), and HI–normothermia preterm (n = 14) groups, with a total of >17,300 h of recordings. Algorithms were trained and tested using leave-one-out cross-validation and k-fold cross-validation approaches. The accuracy of the term-trained seizure detectors was consistently excellent for HI–normothermia preterm data (accuracy = 99.5%, area under curve (AUC) = 99.2%). Conversely, when the HI–normothermia preterm data were used in training, the performance on HI–normothermia term and HI–hypothermia term data fell (accuracy = 98.6%, AUC = 96.5% and accuracy = 96.9%, AUC = 89.6%, respectively). Findings suggest that HI–normothermia preterm seizures do not contain all the spectral features seen at term. Nevertheless, an average 5-fold cross-validated accuracy of 99.7% (AUC = 99.4%) was achieved from all seizure detectors. This significant advancement highlights the reliability of the proposed deep-learning algorithms in identifying clinically translatable post-HI stereotypic seizures in 256Hz recordings, regardless of maturity and with minimal impact from hypothermia. [ABSTRACT FROM AUTHOR]

Introduction: Therapeutic hypothermia is a promising candidate for stroke treatment although its efficacy has not yet been demonstrated in patients. Changes in blood molecules could act as surrogate markers to evaluate the efficacy and safety of therapeutic cooling. Methods: Blood samples from 54 patients included in the EuroHYP‐1 study (27 treated with hypothermia, and 27 controls) were obtained at baseline, 24 ± 2 h, and 72 ± 4 h. The levels of a panel of 27 biomarkers, including matrix metalloproteinases and cardiac and inflammatory markers, were measured. Results: Metalloproteinase‐3 (MMP‐3), fatty‐acid‐binding protein (FABP), and interleukin‐8 (IL‐8) increased over time in relation to the hypothermia treatment. Statistically significant correlations between the minimum temperature achieved by each patient in the hypothermia group and the MMP‐3 level measured at 72 h, FABP level measured at 24 h, and IL‐8 levels measured at 24 and 72 h were found. No differential biomarker levels were observed in patients with poor or favorable outcomes according to modified Rankin Scale scores. Conclusion: Although the exact roles of MMP3, FABP, and IL‐8 in hypothermia‐treated stroke patients are not known, further exploration is needed to confirm their roles in brain ischemia. [ABSTRACT FROM AUTHOR]

Objective: We aimed to examine the association between placental abnormalities and neurodevelopmental outcomes in a multicenter cohort of newborn infants with hypoxic-ischemic encephalopathy (HIE) that underwent therapeutic hypothermia. We hypothesized that subjects with acute placental abnormalities would have reduced risk of death or neurodevelopmental impairment (NDI) at 2 years of age after undergoing therapeutic hypothermia compared to subjects without acute placental changes. Study Design: Among 500 subjects born at ≥36 weeks gestation with moderate or severe HIE enrolled in the High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, a placental pathologist blinded to clinical information reviewed clinical pathology reports to determine the presence of acute only, chronic only, or both acute and chronic histologic abnormalities. We calculated adjusted relative risks (aRRs) for associations between placental pathologic abnormalities and death or NDI at age 2 years, adjusting for HIE severity, treatment assignment, and site. Result: 321/500 subjects (64%) had available placental pathology reports. Placental abnormalities were characterized as acute only (20%), chronic only (21%), both acute and chronic (43%), and none (15%). The risk of death or NDI was not statistically different between subjects with and without an acute placental abnormality (46 vs. 53%, aRR 1.1, 95% confidence interval (CI): 0.9, 1.4). Subjects with two or more chronic lesions were more likely to have an adverse outcome than subjects with no chronic abnormalities, though this did not reach statistical significance (55 vs. 45%, aRR 1.24, 95% CI: 0.99, 1.56). Conclusion: Placental pathologic findings were not independently associated with risk of death or NDI in subjects with HIE. The relationship between multiple chronic placental lesions and HIE outcomes deserves further study. [ABSTRACT FROM AUTHOR]

Aim: The aim of the study was to determine whether overcooling (temperature <33°C) during passive hypothermia when transporting neonates with perinatal asphyxia increased the risk of short‐term neurological injury. Methods: A retrospective observational study was performed. Newborns transferred to the LaCardio neonatal unit between January 2021 and April 2022 with moderate and severe perinatal asphyxia and who received passive hypothermia during transport were included. A temperature of <33°C was considered overcooling. A composite outcome of neurological injury was defined by the presence of abnormalities on brain magnetic resonance imaging, video telemetry, seizure before discharge or both. Results: The study included 101 newborns. A total of 18 neonates had a temperature <33°C after transportation. Neurological injuries were present in 21.8% of the temperature <33°C group and 78.2% of the temperature ≥33°C group. Temperature <33°C at the end of transport (aOR 9.2, 95% CI 1.1–77.3) were associated with neurological injury before discharge from the unit. Conclusion: During transportation, overcooling in neonates with asphyxia increases the risk of neurological injury before discharge from the neonatal unit. It is important to qualify the transport team with adequate training and equipment for therapeutic hypothermia. [ABSTRACT FROM AUTHOR]

Background/aim: Hypoxic ischemic encephalopathy (HIE) is one of the common causes of mortality and morbidity in newborns. Despite therapeutic hypothermia, an important treatment with proven efficacy, the morbidity and mortality rates remain high. The aim of this study was to neurodevelopmentally evaluate patients who underwent therapeutic hypothermia. Material and method: Included herein were patients who underwent hypothermia between 2018 and 2020. Their medical files were reviewed retrospectively, and their demographic and clinical information was recorded. Patients whose contact information was available were called to the developmental pediatrics outpatient clinic for a neurodevelopmental evaluation. The Bayley Scales of Infant and Toddler Development 3rd Edition (Bayley-III) was used as the evaluation tool. Laboratory values and clinical parameters of the patients were further analyzed. Results: It was found that 42 patients underwent hypothermia in 3 years, of whom 14 (33.3%) had died. Of the 28 patients who were discharged, 20 children could be reached, and a neurodevelopmental evaluation was performed. Developmental delay in the cognitive area was detected in 11 (55%) patients, delay in the language area was found in 9 (45%) patients, and delay in the motor area was found in 11 (55%) patients. The correlation and regression analysis results determined that the time to start cooling was the most effective common factor in all 3 fields of scoring. Conclusion: The time to start cooling is related to the neurodevelopmental outcomes of patients with HIE. The earlier cooling is started, the better the neurodevelopmental results. Despite therapeutic hypothermia, the neurodevelopmental development of infants may be adversely affected. These patients should be followed-up neurodevelopmentally for a long time. [ABSTRACT FROM AUTHOR]

Neonatal hypoxic-ischemic encephalopathy refers to brain damage caused by perinatal asphyxia, which can cause death and permanent neurological impairment in severe cases. Therapeutic hypothermia reduces death or disability in term and near-term infants with moderate to severe hypoxic-ischaemic encephalopathy. The latest studies have further refined the key parameters of hypothermia, including the timing, depth of cooling, duration, subsequent rate of rewarming, and prevention of fever during delivery and resuscitation. The key to improving neurodevelopmental outcomes is early postnatal diagnosis and initiation of hypothermia. This article will review the research progress of mild therapeutic hypothermia in neonatal hypoxic-ischemic encephalopathy, and introduce commonly used hypothermia induction methods, clinical challenges and future development directions. [ABSTRACT FROM AUTHOR]

Targeted temperature management has been a cornerstone of post-cardiac arrest care for patients remaining unresponsive after return of spontaneous circulation since the initial trials in 2002 found that mild therapeutic hypothermia improves neurological outcome. The suggested temperature range expanded in 2015 in response to a large trial finding that outcomes were not better with treatment at 33° C compared with 36° C. In 2021, another large trial was published in which outcomes with temperature control at 33° C were not better than those of patients treated with a strategy of strict normothermia. On the basis of these new data, the International Liaison Committee on Resuscitation and other organizations have altered their treatment recommendations for temperature management after cardiac arrest. The new American Heart Association guidelines on this topic will be introduced in a 2023 focused update. To provide guidance to clinicians while this focused update is forthcoming, the American Heart Association's Emergency Cardiovascular Care Committee convened a writing group to review the TTM2 trial (Hypothermia Versus Normothermia After Out-of-Hospital Cardiac Arrest) in the context of other recent evidence and to present an opinion on how this trial may influence clinical practice. This science advisory was informed by review of the TTM2 trial, consideration of other recent influential studies, and discussion between cardiac arrest experts in the fields of cardiology, critical care, emergency medicine, and neurology. Conclusions presented in this advisory statement do not replace current guidelines but are intended to provide an expert opinion on novel literature that will be incorporated into future guidelines and suggest the opportunity for reassessment of current clinical practice. [ABSTRACT FROM AUTHOR]

Background: The present study was designed to assess the feasibility and reliability of a Continuous Glucose Monitoring System (CGMS) in a population of asphyxiated neonates during therapeutic hypothermia. Methods: This non-randomized feasibility study was conducted in the Neonatal Intensive Care Unit (NICU) facilities of Fondazione Policlinico A. Gemelli IRCSS. Infants matching the criteria for hypothermic treatment were included in this study and were connected to the CGMS (Medtronic, Northridge, CA, USA) within the first 12 h of life. Hypoglycemia was defined as a glucose value ≤ 47 mg/dL, and hyperglycemia was defined as a glucose value ≥ 180 mg/dL. Data obtained via the CGMS were compared with those obtained via a point-of-care blood glucometer (GTX). Results: The two measuring techniques were compared using the Modified Clarke Error Grid (MCEG). Sixteen infants were enrolled. The sensor had an average (standard deviation) duration of 93 (38) h. We collected 119 pairs of glycemia values (CGMVs) from the CGMS vs. GTX measurements. The CGMS detected twenty-five episodes of hypoglycemia and three episodes of hyperglycemia. All the CGMVs indicating hyperglycemia matched with the blood sample taken via the point-of-care glucometer. Conclusions: The use of a CGMS would be useful as it could detect more episodes of disglycemia than standard care. Our data show poor results in terms of the accuracy of the CGMS in this particular setting. [ABSTRACT FROM AUTHOR]

Therapeutic hypothermia (TH) is now standard of care for the neuroprotection of patients with moderate to severe hypoxic-ischemic encephalopathy (HIE). TH misuse results in increased medical complication rates and high health care resource utilization. Quality improvement (QI) methodology can address drift from clinical guidelines. Assessment of sustainability of any intervention over time is an integral part of the QI methodology. Our prior QI intervention improved medical documentation using an electronic medical record-smart phrase (EMR-SP) and demonstrated special cause variation. This study serves as Epoch 3 and investigates the sustainability of our QI methods to decrease TH misuse. A total of 64 patients met the diagnostic criteria for HIE. Over the study period, 50 patients were treated with TH, and 33 cases (66%) used TH appropriately. The number of appropriate TH cases between cases of misuse increased to an average of 9 in Epoch 3 from 1.9 in Epoch 2. Of the 50 cases, 34 (68%) had EMR-SP documentation included. Length of stay and TH complication rates did not vary between cases of TH misuse and appropriate TH use. Our study confirmed a sustained decrease in TH misuse, despite inconsistent use of EMR-SP. We speculate that culture change involving increased awareness of guidelines through education may have contributed more to a lasting change. [ABSTRACT FROM AUTHOR]

Globally, over the next few decades, more than 2.5 billion people will suffer from hearing impairment, including profound hearing loss, and millions could potentially benefit from a cochlea implant. To date, several studies have focused on tissue trauma caused by cochlea implantation. The direct immune reaction in the inner ear after an implantation has not been well studied. Recently, therapeutic hypothermia has been found to positively influence the inflammatory reaction caused by electrode insertion trauma. The present study aimed to evaluate the hypothermic effect on the structure, numbers, function and reactivity of macrophages and microglial cells. Therefore, the distribution and activated forms of macrophages in the cochlea were evaluated in an electrode insertion trauma cochlea culture model in normothermic and mild hypothermic conditions. In 10-day-old mouse cochleae, artificial electrode insertion trauma was inflicted, and then they were cultured for 24 h at 37 °C and 32 °C. The influence of mild hypothermia on macrophages was evaluated using immunostaining of cryosections using antibodies against IBA1, F4/80, CD45 and CD163. A clear influence of mild hypothermia on the distribution of activated and non-activated forms of macrophages and monocytes in the inner ear was observed. Furthermore, these cells were located in the mesenchymal tissue in and around the cochlea, and the activated forms were found in and around the spiral ganglion tissue at 37 °C. Our findings suggest that mild hypothermic treatment has a beneficial effect on immune system activation after electrode insertion trauma. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to examine whether the temperature difference between the jugular bulb and pulmonary artery (ΔTjb-pa) is associated with the neurological outcome of patients with severe traumatic brain injury (TBI). Methods: We conducted a post hoc analysis of a multicenter randomized controlled trial of mild therapeutic hypothermia (TH, 32.0–34.0°C) or fever control (FC, 35.5–37.0°C) for the patients with severe TBI. ΔTjb-pa averaged every 12 h and the variation in ΔTjb-pa were compared between patients with favorable (n = 39) and unfavorable (n = 37) neurological outcomes. These values were also compared in the TH and FC subgroups. Results: The average ΔTjb-pa values in patients with favorable and unfavorable outcomes were 0.24 ± 0.23 and 0.06 ± 0.36°C, respectively (P < 0.001). ΔTjb-pa trended significantly higher in the favorable outcome patients than in the unfavorable outcome patients throughout the 120 h after onset of severe TBI (P < 0.001). The variation in ΔTjb-pa from 0 to 72 h was significantly lower in the favorable outcome patients than in the unfavorable outcome patients (0.8 ± 0.8 vs 1.8 ± 2.5°C, respectively, P = 0.013). From 72 to 120 h, there was no significant difference in the variation in ΔTjb-pa. Significant differences between patients with favorable and unfavorable outcomes in ΔTjb-pa and the variation in ΔTjb-pa were similar in the TH subgroup, but not evident in the FC subgroup. Conclusions: A reduction in ΔTjb-pa and greater variation in ΔTjb-pa were associated with an unfavorable outcome in patients with severe TBI, especially those treated with TH. When treating severe TBI patients, it is important to understand that there will be differences in temperature reflecting the brain environment and the systemic temperature, depending on the severity and outcome of TBI during TH. [ABSTRACT FROM AUTHOR]

Introduction Hypokalemia is known to occur in association with therapeutically induced hypothermia and is usually managed by the administration of potassium (K+). Methods We reviewed data from 74 patients who underwent a therapeutic hypothermia protocol at our medical institution. Results In four patients in whom data on serum K+ and temperature were available, a strong positive correlation between serum K+ and body temperature was found. Based on the close positive relationship between serum K+ and total body temperature, we hypothesize that serum K+ decreases during hypothermia owing to decreased activity of temperature-dependent K+ exit channels that under normal conditions are sufficiently active to match cellular K+ intake via sodium/K+/adenosine triphosphatase. Upon rewarming, reactivation of these channels results in a rapid increase in serum K+ as a result of K+ exit down its concentration gradient. Conclusion Administration of K+ during hypothermia should be done cautiously and avoided during rewarming to avoid potentially life-threatening hyperkalemia. K+ exit via temperature-dependent K+ channels provides a logical explanation for the rebound hyperkalemia. K+ exit channels may play a bigger role than previously appreciated in the regulation of serum K+ during normal and pathophysiological conditions. [ABSTRACT FROM AUTHOR]

Systemic inflammatory conditions are often associated with hypothermia or hyperthermia. Therapeutic hypothermia is used in post-cardiac arrest and some other acute diseases. There is a need for more knowledge concerning the effect of various temperatures on the acute inflammatory response. The complement system plays a crucial role in initiating the inflammatory response. We hypothesized that temperatures above and below the physiologic 37 °C affect complement activation and cytokine production ex vivo. Lepirudin-anticoagulated human whole blood from 10 healthy donors was incubated in the presence or absence of Escherichia coli at different temperatures (4 °C, 12 °C, 20 °C, 33 °C, 37 °C, 39 °C, and 41 °C). Complement activation was assessed by the terminal C5b-9 complement complex (TCC) and the alternative convertase C3bBbP using ELISA. Cytokines were measured using a 27-plex assay. Granulocyte and monocyte activation was evaluated by CD11b surface expression using flow cytometry. A consistent increase in complement activation was observed with rising temperature, reaching a maximum at 41 °C, both in the absence (C3bBbP p < 0.05) and presence (C3bBbP p < 0.05 and TCC p < 0.05) of E. coli. Tem p erature alone did not affect cytokine production, whereas incubation with E. coli significantly increased cytokine levels of IL-1β, IL-2, IL-6, IL-8, IFN-γ, and TNF at temperatures > 20 °C. Maximum increase occurred at 39 °C. However, a consistent decrease was observed at 41 °C, significant for IL-1β (p = 0.003). Granulocyte CD11b displayed the same temperature-dependent pattern as cytokines, with a corresponding increase in endothelial cell apoptosis and necrosis. Thus, blood temperature differentially determines the degree of complement activation and cytokine release. • Blood temperature determined the complement activation and cytokine release. • Temperature per se increased complement activation. • Temperature affected cytokine production, when incubated with E. coli. • IL-1β increased maximum at 39 °C and decreased at 41 °C. [ABSTRACT FROM AUTHOR]

Hibernation-like episodes would be particularly interesting for clinical and spatial use if they could be observed and induced in humans. As animal hibernation differs from hypothermia with its control by a temperature-dependent clock, we undertook to find evidence that human hypothermia might affect the circadian clock system. We revisited Siffre's 1962 abyss experiment. Deprived of temporal information and showing signs of chronic hypothermia, Siffre underestimated his stay underground by 22 d. We show that the temperature-dependent clock equation for classical hibernators accurately predicts Siffre's subjective times, and we list potential conditions to be further explored for inducing hibernation-like bouts in humans. [ABSTRACT FROM AUTHOR]

Therapeutic hypothermia (TH) provides cardioprotection from ischemia/reperfusion (I/R) injury. However, it remains unknown how TH regulates metabolic recovery. We tested the hypothesis that TH modulates PTEN, Akt, and ERK1/2, and improves metabolic recovery through mitigation of fatty acid oxidation and taurine release. Left ventricular function was monitored continuously in isolated rat hearts subjected to 20 min of global, no‐flow ischemia. Moderate cooling (30°C) was applied at the start of ischemia and hearts were rewarmed after 10 min of reperfusion. The effect of TH on protein phosphorylation and expression at 0 and 30 min of reperfusion was investigated by western blot analysis. Post‐ischemic cardiac metabolism was investigated by 13C‐NMR. TH enhanced recovery of cardiac function, reduced taurine release, and enhanced PTEN phosphorylation and expression. Phosphorylation of Akt and ERK1/2 was increased at the end of ischemia but decreased at the end of reperfusion. On NMR analysis, TH‐treated hearts displayed decreased fatty acid oxidation. Direct cardioprotection by moderate intra‐ischemic TH is associated with decreased fatty acid oxidation, reduced taurine release, enhanced PTEN phosphorylation and expression, and enhanced activation of both Akt and ERK1/2 prior to reperfusion. [ABSTRACT FROM AUTHOR]

Therapeutic hypothermia significantly improves outcomes after neonatal hypoxic-ischemic (HI) encephalopathy but is only partially protective. There is evidence that cortical inhibitory interneuron circuits are particularly vulnerable to HI and that loss of interneurons may be an important contributor to long-term neurological dysfunction in these infants. In the present study, we examined the hypothesis that the duration of hypothermia has differential effects on interneuron survival after HI. Near-term fetal sheep received sham ischemia or cerebral ischemia for 30 min, followed by cerebral hypothermia from 3 h after ischemia end and continued up to 48 h, 72 h, or 120 h recovery. Sheep were euthanized after 7 days for histology. Hypothermia up to 48 h recovery resulted in moderate neuroprotection of glutamate decarboxylase (GAD)+ and parvalbumin+ interneurons but did not improve survival of calbindin+ cells. Hypothermia up to 72 h recovery was associated with significantly increased survival of all three interneuron phenotypes compared with sham controls. By contrast, while hypothermia up to 120 h recovery did not further improve (or impair) GAD+ or parvalbumin+ neuronal survival compared with hypothermia up to 72 h, it was associated with decreased survival of calbindin+ interneurons. Finally, protection of parvalbumin+ and GAD+ interneurons, but not calbindin+ interneurons, with hypothermia was associated with improved recovery of electroencephalographic (EEG) power and frequency by day 7 after HI. The present study demonstrates differential effects of increasing the duration of hypothermia on interneuron survival after HI in near-term fetal sheep. These findings may contribute to the apparent preclinical and clinical lack of benefit of very prolonged hypothermia. [ABSTRACT FROM AUTHOR]

The peripheral immune system plays a critical role in neuroinflammation of the central nervous system after an insult. Hypoxic-ischemic encephalopathy (HIE) induces a strong neuroinflammatory response in neonates, which is often associated with exacerbated outcomes. In adult models of ischemic stroke, neutrophils infiltrate injured brain tissue immediately after an ischemic insult and aggravate inflammation via various mechanisms, including neutrophil extracellular trap (NETs) formation. In this study, we used a neonatal model of experimental hypoxic-ischemic (HI) brain injury and demonstrated that circulating neutrophils were rapidly activated in neonatal blood. We observed an increased infiltration of neutrophils in the brain after exposure to HI. After treatment with either normothermia (NT) or therapeutic hypothermia (TH), we observed a significantly enhanced expression level of the NETosis marker Citrullinated H3 (Cit-H3), which was significantly more pronounced in animals treated with TH than in those treated with NT. NETs and NLR family pyrin domain containing 3 (NLRP-3) inflammasome assembly are closely linked in adult models of ischemic brain injury. In this study, we observed an increase in the activation of the NLRP-3 inflammasome at the time points analyzed, particularly immediately after TH, when we observed a significant increase in NETs structures in the brain. Together, these results suggest the important pathological functions of early arriving neutrophils and NETosis following neonatal HI, particularly after TH treatment, which is a promising starting point for the development of potential new therapeutic targets for neonatal HIE. [ABSTRACT FROM AUTHOR]

In the setting of acute ST-elevation myocardial infarction (STEMI), several randomized control trials (RCTs) suggested a potential benefit with the use of therapeutic hypothermia (TH). However, results from previous studies are contradictory. We performed a comprehensive literature search for studies that evaluated the efficacy and safety of adjunctive TH compared to the standard percutaneous coronary intervention (PCI) in awake patients with STEMI. The primary outcomes were the infarct size (IS) and microvascular obstruction (MVO) assessed by cardiac imaging at the end of follow-up. The secondary outcomes were major adverse cardiovascular events (MACE), procedure-related complications, and door-to-balloon time. Relative risk (RR) or the mean difference (MD) and corresponding 95 % confidence intervals (CIs) were calculated using the random-effects model. A total of 10 RCTs, including 706 patients were included. As compared to standard PCI, TH was not associated with a statistically significant improvement in the IS (MD: -0.87 %, 95%CI: −2.97, 1.23; P = 0.42) or in the MVO (MD: 0.11 %, 95%CI: −0.06, 0.27; P = 0.21). MACE and its components were comparable between the two groups. However, the TH approach was associated with an increased risk of infection and prolonged door-to-balloon time. Furthermore, there was a trend in the TH group toward an increased incidence of stent thrombosis and paroxysmal atrial fibrillation. According to our meta-analysis of published RCTs, TH is not beneficial in awake patients with STEMI and has a marginal safety profile with potential for care delays. Larger-scale RCTs are needed to further clarify our results. • Therapeutic hypothermia (TH) is proposed as an adjunctive strategy to reduce myocardial reperfusion injury in STEMI patients. • Our meta-analysis showed no benefit of TH in STEMI patients, with a marginal safety profile and potential for care delays. • Unless selective intracoronary hypothermia finds evidence of benefit, the clinical utility of this approach may be futile. • More RCTs are needed to validate our results. [ABSTRACT FROM AUTHOR]

To investigate the clinical, laboratory, electrophysiological, and imaging features associated with death or neurological impairment at 1 year of age in term neonates with hypoxic–ischemic encephalopathy (HIE) treated by therapeutic hypothermia (TH). This was a single-center retrospective and descriptive study conducted over a period of 2 years. We included consecutive term newborns with moderate or severe HIE who were treated by TH initiated within the sixth hour after birth and continued for 72 h,. For all patients, brain magnetic resonance imaging (MRI) was performed before the eighth day and a score was established; furthermore, at least two electroencephalograms were recorded. Among the 33 patients included, 20 neonates had a favorable outcome and 13 had an unfavorable outcome. Early clinical seizures (15% vs. 53.8%, p = 0.047), the persistence of a poor prognosis according to the electroencephalogram pattern after TH (0% vs. 69.2%, p = 0.0001), and an elevated score on the early brain MRI (2 vs. 11, p < 0.001) combined with a high lactate/ N -acetyl-aspartate ratio (0.52 vs. 1.33, p = 0.008) on spectroscopy were associated with death and a poor outcome. A combination of tools can help the medical team to establish the most reliable prognosis for these full-term neonates, to guide care, and to inform parents most appropriately and sincerely. [ABSTRACT FROM AUTHOR]

Initiation of therapeutic hypothermia (TH) within 6 h of life is a major concern for treating neonatal hypoxic ischemic encephalopathy (HIE). We aimed to determine clinical and healthcare organizational factors associated with delayed TH in a French population-based cohort of neonates with moderate/severe HIE. Time to reach a rectal temperature of 34 °C defines optimal and delayed (within and over 6 h, respectively) TH. Clinical and healthcare organizational factors associated with delayed TH were analysed among neonates born in cooling centres (CCs) and non-cooling centres (non-CCs). Among 629 neonates eligible for TH, 574 received treatment (91.3%). TH was delayed in 29.8% neonates and in 20.3% and 36.2% of those born in CCs and non-CCs, respectively. Neonates with moderate HIE were more exposed to delayed TH in both CCs and non-CCs. After adjustment for HIE severity, maternal and neonatal characteristics and circumstances of birth were not associated with increased risk of delayed TH. However, this risk was 2 to 5 times higher in maternities with < 1999 annual births, when the delay between birth and call for transfer (adjusted odds ratio [aOR] 2.47, 95% confidence interval [CI] [1.03 to 5.96]) or between call for transfer and admission (aOR 6.06, 95%CI [2.60 to 14.12]) was > 3 h and when an undesirable event occurred during transfer (aOR 2.66, 95%CI [1.11 to 6.37]. Conclusion: Increasing early identification of neonates who could benefit from TH and access to TH in non-CCs before transfer are modifiable factors that could improve care of neonates with HIE. Trial registration: The trial was registered at ClinicalTrials.gov (NCT02676063). What is Known: • International recommendations are to initiate therapeutic hypothermia before 6 h of life in neonates with moderate or severe hypoxic ischemic encephalopathy. What is New: •In this French population-based cohort of infants with hypoxic ischemic encephalopathy, nearly one-third of neonates eligible for treatment did not have access to hypothermia in the therapeutic window of 6 h of life.. • Among infants born in non-cooling centres, healthcare organizational factors involved in delayed care were the small size of maternities (1999 annual births), a time interval of more than 3 h between birth and call for transfer and between call for transfer and admission in neonatology, and the occurrence of an undesirable event during transfer. [ABSTRACT FROM AUTHOR]

A recent study published in eLife explores the potential of using a neuropeptide called neurotensin to reduce status epilepticus, a condition characterized by prolonged seizures. The researchers combined neurotensin with a molecule that can penetrate the blood-brain barrier and tested its effectiveness in mice. The conjugate successfully reached the brain, induced hypothermia, and reduced seizures, cognitive changes, and inflammation associated with status epilepticus. While the findings are promising, further research is needed to confirm the safety and efficacy of this approach. The study suggests that pharmacologically induced hypothermia could have broader implications for treating other forms of neural injury. [Extracted from the article]

This article, published in Equine Veterinary Education, discusses the efficacy of different digital hypothermia methods for cooling the equine hoof lamellae under clinically relevant conditions. The study aims to establish the relationship between hoof surface, hoof wall, and lamellar tissue temperature during distal limb cooling and evaluate the effectiveness of four cooling techniques in ambulatory horses. The results show that complete immersion of the distal limb in an ice and water mixture is the most effective method for cooling the digital lamellae. The high-volume ice water immersion method was found to be more effective than the low-volume ice water immersion method. [Extracted from the article]

Therapeutic hypothermia (TH) is effective for neonatal hypoxic–ischemic encephalopathy (HIE). The combination of abnormal myocardial repolarization and fatal arrhythmia in patients with accidental hypothermia has prompted clinical validation of the proarrhythmic potential of TH. However, to our knowledge, there have been few clinical studies on myocardial depolarization and repolarization abnormalities caused by TH in neonates. Therefore, we investigated the effects of TH on neonatal myocardial depolarization and repolarization by capturing the waveform changes in electrocardiograms (ECGs) associated with body temperature (BT) before and after TH. We included three neonates with HIE diagnosed at birth who were treated with TH in our hospital. The heart rate, RR interval, P wave duration, PR interval, QRS duration, QT interval, corrected QT (QTc) interval by Fridericia's formula, J point-T end (JT) interval, corrected JT (JTc) interval by Fridericia's formula, T peak-T end (Tpe) interval, Tpe/QT, and QRS/QTc were calculated retrospectively using an ECG. The correlations of ECG parameters recorded concurrently with 33 samples in which BT measurements were confirmed were performed. BT and heart rate were positively correlated (R: 0.589, p = 0.0003). BT was negatively correlated with Tpe/QT (R: − 0.470, p = 0.0058), the QTc interval (R: − 0.680, p < 0.0001), and the corrected JT interval (R: − 0.697, p < 0.0001). TH does not affect atrial or ventricular depolarization but prolongs the ventricular repolarization process in a temperature-dependent manner. [ABSTRACT FROM AUTHOR]

Decreased heart rate variability (HRV) may be a biomarker of brain injury severity in neonatal hypoxic-ischemic encephalopathy for which therapeutic hypothermia is standard treatment. While therapeutic hypothermia may influence the degree of brain injury; hypothermia may also affect HRV per se and obscure a potential association between HRV and hypoxic-ischemic encephalopathy. Previous results are conflicting. This study aimed to investigate the effect of hypothermia on HRV in healthy, anaesthetised, newborn piglets. Six healthy newborn piglets were anaesthetised. Three piglets were first kept normothermic (38.5–39.0 °C) for 3 h, then exposed to hypothermia (33.5–34.5 °C) for 3 h. Three piglets were first exposed to hypothermia for 3 h, then rewarmed to normothermia for 3 h. Temperature and ECG were recorded continuously. HRV was calculated from the ECG in 5 min epochs and included time domain and frequency domain variables. The HRV variables were compared between hypothermia and normothermia. All assessed HRV variables were higher during hypothermia compared to normothermia. Heart rate was lower during hypothermia compared to normothermia and all HRV variables correlated with heart rate. Hypothermia was associated with an increase in HRV; this could be mediated by bradycardia during hypothermia. [ABSTRACT FROM AUTHOR]

Background: Outcomes of postresuscitation shock after cardiac arrest can be affected by targeted temperature management (TTM). A post hoc analysis of the "TTM1 trial" suggested higher mortality with hypothermia at 33 °C. We performed a post hoc analysis of HYPERION trial data to assess potential associations linking postresuscitation shock after non-shockable cardiac arrest to hypothermia at 33 °C on favourable functional outcome. Methods: We divided the patients into groups with vs. without postresuscitation (defined as the need for vasoactive drugs) shock then assessed the proportion of patients with a favourable functional outcome (day-90 Cerebral Performance Category [CPC] 1 or 2) after hypothermia (33 °C) vs. controlled normothermia (37 °C) in each group. Patients with norepinephrine or epinephrine > 1 µg/kg/min were not included. Results: Of the 581 patients included in 25 ICUs in France and who did not withdraw consent, 339 had a postresuscitation shock and 242 did not. In the postresuscitation-shock group, 159 received hypothermia, including 14 with a day-90 CPC of 1–2, and 180 normothermia, including 10 with a day-90 CPC of 1–2 (8.81% vs. 5.56%, respectively; P = 0.24). After adjustment, the proportion of patients with CPC 1–2 also did not differ significantly between the hypothermia and normothermia groups (adjusted hazards ratio, 1.99; 95% confidence interval, 0.72–5.50; P = 0.18). Day-90 mortality was comparable in these two groups (83% vs. 86%, respectively; P = 0.43). Conclusions: After non-shockable cardiac arrest, mild-to-moderate postresuscitation shock at intensive-care-unit admission did not seem associated with day-90 functional outcome or survival. Therapeutic hypothermia at 33 °C was not associated with worse outcomes compared to controlled normothermia in patients with postresuscitation shock. Trial registration ClinicalTrials.gov, NCT01994772 [ABSTRACT FROM AUTHOR]

The early detection and stratification of asphyxiated infants at higher risk for impaired neurodevelopment is challenging. S100B protein is a well-established biomarker of brain damage, but lacks conclusive validation according to the "gold standard" methodology for hypoxic-ischemic encephalopathy (HIE) prognostication, i.e. brain MRI. The aim of the present study was to investigate the predictive role of urinary S100B concentrations, assessed in a cohort of HIE infants receiving therapeutic hypothermia (TH), compared to brain MRI. Assessment of urine S100B concentrations was performed by immunoluminometric assay at first void and at 4, 8, 12, 16, 20, 24, 48, 72, 96, 108 and 120-h after birth. Neurologic evaluation, routine laboratory parameters, amplitude-integrated electroencephalography, and cerebral ultrasound were performed according to standard protocols. Brain MRI was performed at 7–10 days of life. Overall, 74 HIE neonates receiving TH were included in the study. S100B correlated, already at first void, with the MRI patterns with higher concentrations in infants with the most severe MRI lesions. High S100B urine levels soon after birth constitute trustable predictors of brain injury as confirmed by MRI. Results support the reliability of S100B in clinical daily practice and open the way to its inclusion in the panel of parameters used for the selection of cases suitable for TH treatment. [ABSTRACT FROM AUTHOR]

Our core body temperature is held around 37 ∘ C by an effective internal thermoregulatory system. However, various clinical scenarios have a more favorable outcome under external temperature regulation. Therapeutic hypothermia, for example, was found beneficial for the outcome of resuscitated cardiac arrest patients due to its protection against cerebral ischemia. Nonetheless, practice shows that outcomes of targeted temperature management vary considerably in dependence on individual tissue damage levels and differences in therapeutic strategies and protocols. Here, we address these differences in detail by means of computational modeling. We develop a multi-segment and multi-node thermoregulatory model that takes into account details related to specific post-cardiac arrest-related conditions, such as thermal imbalances due to sedation and anesthesia, increased metabolic rates induced by inflammatory processes, and various external cooling techniques. In our simulations, we track the evolution of the body temperature in patients subjected to post-resuscitation care, with particular emphasis on temperature regulation via an esophageal heat transfer device, on the examination of the alternative gastric cooling with ice slurry, and on how anesthesia and the level of inflammatory response influence thermal behavior. Our research provides a better understanding of the heat transfer processes and therapies used in post-cardiac arrest patients. [ABSTRACT FROM AUTHOR]

Hypoxic ischemic encephalopathy (HIE) is an important cause of mortality and morbidity in newborns. The aim of this study is to evaluate the neurodevelopmental outcomes and rehabilition needs of infants followed up with a diagnosis of HIE who were treated with hypothermia in our unit. A total of 23 patients who met the criteria were retrospectively reviewed. Denver Developmental Screening Test II (Denver II DST) was used for the developmental screening. Patients were divided into groups as moderate and severe HIE based on Sarnat encephalopathy staging, as well as normal and abnormal groups based on Denver II DST results. Moderate HIE was detected in 17 (73.9%) patients, and severe HIE was detected in 6 (26.1%) patients. Patients with severe HIE were found to have lower apgar scores, more resistant metabolic acidosis, longer ventilation times, and more abnormal cranial magnetic resonance findings in the neonatal period (p<0.05). An abnormal Denver II DST was observed in 29.4% of individuals with moderate HIE and all patients with severe HIE (p:0.005). Speaking and fine motor impairments were more common in patients with severe HIE (p:0.018, p:0.014, respectively). Furthermore, cerebral palsy, epilepsy, and swallowing problems were also detected more frequently in patients with severe HIE (p: 0.035, p: 0.019, p: 0.011, respectively). Despite therapeutic hypothermia treatment, neurodevelopmental impairments were still seen in HIE neonates. Our findings showed that it is important to determine factors that may exacerbate the development of neurological sequelae in HIE patients for better followup and treatment approach. [ABSTRACT FROM AUTHOR]

Background: The practice of therapeutic hypothermia (TH) is widely used for neonatal hypoxic-ischemic encephalopathy (HIE) despite its corresponding feeding strategies are still controversial. This randomized controlled trial (RCT) demonstrated to evaluate the effect of early vs. delayed enteral nutrition on the incidence of feeding intolerance (FI) and other association during TH. Methods: This single center, parallel-group, and no-blinded RCT was processed in a level III, and academic neonatal intensive care unit. Infants who were diagnosed with HIE and undertaken TH from September 2020 to August 2021 were enrolled. Participants were randomized to receive enteral nutrition either during TH/rewarming (early enteral nutrition, EEN) or after TH (delayed enteral nutrition, DEN) according to a recommend enteral feeding protocol. All data were analyzed using SPSS 26.0 software with a p-value< 0.05 was considered statistically significant. Results: Ninety-two infants were enrolled after randomization, but 12 (13.04%) cases including 3 (3.26%) deaths were excluded from eventually analyzed, who did not initiate or discontinue the intervention. 80 cases (42 and 38 in the EEN and DEN group, respectively) who completed the interventions were eventually analyzed. Besides initial time of enteral feeds, two groups had processed the same feeding method. Total 23 (25.0%) cases developed FI, and no difference of morbidity was found between two groups (23.4% vs 26.7%, p = 0.595; Log Rank, p = 0.803). There was no case died or developed late-onset bloodstream and no difference of the incidence of hypoglycemia or weight gain was found (p > 0.05). The percentage of infants who had not reaching the goal of full enteral feeding volume between the two groups was similar (21.43% vs 23.68%, p = 0.809). The average time of parenteral nutrition, reaching full enteral feeds and hospital stay were shorter in the EEN group compared with the DEN group with significant differences (8.81 ± 1.67 vs 10.61 ± 2.06 days, p < 0.001; 9.91 ± 1.88 vs 12.24 ± 2.50 days, p < 0.001; 12.55 ± 4.57 vs 16.47 ± 5.27 days, p = 0.001 respectively). Conclusions: Compared with delayed enteral nutrition, introduction of early enteral nutrition according to a recommend feeding strategy for neonatal HIE undergoing TH may be feasible and safe.FI is frequent in this high-risk group of infants which should not be ignored during feeding process. Trial registration: The Chinese Clinical Trial Registry,ChiCTR2000038193, 2020-9-13, https://www.chictr.org.cn. [ABSTRACT FROM AUTHOR]

Objective: Temperature abnormalities are recognized as a marker of human disease, and the therapeutic value of temperature is an attractive treatment target. The objective of this synthetic review is to summarize and critically appraise evidence for active temperature management in critically ill patients.Data Sources: We searched MEDLINE for publications relevant to body temperature management (including targeted temperature management and antipyretic therapy) in cardiac arrest, acute ischemic and hemorrhagic stroke, traumatic brain injury, and sepsis. Bibliographies of included articles were also searched to identify additional relevant studies.Study Selection: English-language systematic reviews, meta-analyses, randomized trials, observational studies, and nonhuman data were reviewed, with a focus on the most recent randomized control trial evidence.Data Extraction: Data regarding study methodology, patient population, temperature management strategy, and clinical outcomes were qualitatively assessed.Data Synthesis: Temperature management is common in critically ill patients, and multiple large trials have been conducted to elucidate temperature targets, management strategies, and timing. The strongest data concerning the use of therapeutic hypothermia exist in comatose survivors of cardiac arrest, and recent trials suggest that appropriate postarrest temperature targets between 33°C and 37.5°C are reasonable. Targeted temperature management in other critical illnesses, including acute stroke, traumatic brain injury, and sepsis, has not shown benefit in large clinical trials. Likewise, trials of pharmacologic antipyretic therapy have not demonstrated improved outcomes, although national guidelines do recommend treatment of fever in patients with stroke and traumatic brain injury based on observational evidence associating fever with worse outcomes.Conclusions: Body temperature management in critically ill patients remains an appealing therapy for several illnesses, and additional studies are needed to clarify management strategies and therapeutic pathways. [ABSTRACT FROM AUTHOR]

Early brain injury is considered to be a primary reason for the poor prognosis of patients suffering from subarachnoid hemorrhage (SAH). Due to its pro-inflammatory activity, cold-inducible RNA-binding protein (CIRP) has been implicated in the ischemic brain insult, but its possible interplay with hypothermia in SAH treatment remains to be evaluated. One-hundred and thirty-eight Sprague-Dawley rats (300–350 g males) were randomly allocated into the following groups: sham-operated (Sham); SAH; and SAH + hypothermia (SAH + H), each comprised of 46 animals. After treatments, the brain tissues of the three groups were randomly collected after 12 h, 1 d, 3 d, and 7 d, and the expression levels of the CIRP and mitochondrial apoptosis pathway-related proteins Bax, Bcl-2, caspase-9, caspase-3, and cytochrome c measured using Western blotting and real-time PCR. Brain damage was assessed by TUNEL and Nissl staining, the electron microscopy of brain tissue slices as well as functional rotarod tests. Expression of CIRP, Bax, caspase-9, caspase-3, and cytochrome c as well as reduced motor function incidence were higher in the SAH group, particularly during the first 3 d after SAH induction. Hypothermia blunted these SAH responses and apoptosis, thereby indicating reduced inflammatory signaling and less brain cell injury in the early period after SAH. Hypothermia treatment was found to effectively protect the brain tissue from early SAH injury in a rat model and its further evaluation as a therapeutic modality in SAH patients requires further study. [ABSTRACT FROM AUTHOR]

Background: Therapeutic hypothermia significantly improves outcomes after moderate-severe hypoxic-ischemic encephalopathy (HIE), but it is partially effective. Although hypothermia is consistently associated with reduced microgliosis, it is still unclear whether it normalizes microglial morphology and phenotype.Methods: Near-term fetal sheep (n = 24) were randomized to sham control, ischemia-normothermia, or ischemia-hypothermia. Brain sections were immunohistochemically labeled to assess neurons, microglia and their interactions with neurons, astrocytes, myelination, and gitter cells (microglia with cytoplasmic lipid granules) 7 days after cerebral ischemia. Lesions were defined as areas with complete loss of cells. RNAscope® was used to assess microglial phenotype markers CD86 and CD206.Results: Ischemia-normothermia was associated with severe loss of neurons and myelin (p < 0.05), with extensive lesions, astrogliosis and microgliosis with a high proportion of gitter cells (p < 0.05). Microglial wrapping of neurons was present in both the ischemia groups. Hypothermia improved neuronal survival, suppressed lesions, gitter cells and gliosis (p < 0.05), and attenuated the reduction of myelin area fraction. The "M1" marker CD86 and "M2" marker CD206 were upregulated after ischemia. Hypothermia partially suppressed CD86 in the cortex only (p < 0.05), but did not affect CD206.Conclusions: Hypothermia prevented lesions after cerebral ischemia, but only partially suppressed microglial wrapping and M1 marker expression. These data support the hypothesis that persistent upregulation of injurious microglial activity may contribute to partial neuroprotection after hypothermia, and that immunomodulation after rewarming may be an important therapeutic target. [ABSTRACT FROM AUTHOR]

Myocardial infarction (MI) is the leading cause of death from coronary heart disease and requires immediate reperfusion therapy with thrombolysis, primary percutaneous coronary intervention, or coronary artery bypass grafting. However, myocardial reperfusion therapy is often accompanied by cardiac ischemia/reperfusion (I/R) injury, which leads to myocardial injury with detrimental consequences. The causes of I/R injury are unclear, but are multifactorial, including free radicals, reactive oxygen species, calcium overload, mitochondria dysfunction, inflammation, and neutrophil-mediated vascular injury. Mild hypothermia has been introduced as one of the potential inhibitors of myocardial I/R injury. Although animal studies have demonstrated that mild hypothermia significantly reduces or delays I/R myocardium damage, human trials have not shown clinical benefits in acute MI (AMI). In addition, the practice of hypothermia treatment is increasing in various fields such as surgical anesthesia and intensive care units. Adequate sedation for anesthetic procedures and protection from body shivering has become essential during therapeutic hypothermia. Therefore, anesthesiologists should be aware of the effects of therapeutic hypothermia on the metabolism of anesthetic drugs. In this paper, we review the existing data on the use of therapeutic hypothermia for AMI in animal models and human clinical trials to better understand the discrepancy between perceived benefits in preclinical animal models and the absence thereof in clinical trials thus far. [ABSTRACT FROM AUTHOR]

Significance: Sensorineural hearing loss has significant implications for quality of life and risk for comorbidities such as cognitive decline. Noise and ototoxic drugs represent two common risk factors for acquired hearing loss that are potentially preventable. Recent Advances: Numerous otoprotection strategies have been postulated over the past four decades with primary targets of upstream redox pathways. More recently, the application of mild therapeutic hypothermia (TH) has shown promise for otoprotection for multiple forms of acquired hearing loss. Critical Issues: Systemic antioxidant therapy may have limited application for certain ototoxic drugs with a therapeutic effect on redox pathways and diminished efficacy of the primary drug's therapeutic function (e.g., cisplatin for tumors). Future Directions: Mild TH likely targets multiple mechanisms, contributing to otoprotection, including slowed metabolics, reduced oxidative stress, and involvement of cold shock proteins. Further work is needed to identify the mechanisms of mild TH at play for various forms of acquired hearing loss. Antioxid. Redox Signal. 36, 1203–1214. [ABSTRACT FROM AUTHOR]