Is Deep Hypothermic Cardiac Arrest Mandatory in Aortic Arch Surgeries?

ABSTRACT Cannulation strategies in aortic arch surgeries are a matter of immense discussion. Majority of time deep hypothermic circulatory arrest (DHCA) is the way out, but it does come with its set of demerits. Here we demonstrate a case with aortic arch dissection dealt with dual cannulation strategy in axillary and femoral artery without need for DHCA and ensuring complete neuroprotection of brain and spinal cord without hinderance of time factor. Inception of new ideas like this may decrease the need for DHCA and hence its drawbacks, thus decreasing the morbidity and mortality associated.

Comparison between selective head cooling and whole-body cooling in neonatal therapeutic hypothermia / Comparação entre resfriamento seletivo da cabeça e resfriamento de corpo inteiro na hipotermia terapêutica neonatal

INTRODUCTION: Experimental evidence, as well as improved clinical studies of the reduction of brain injury and, improves the neurological outcome, in newborns with hypoxic-ischemic encephalopathy (HIE) occurring in therapeutic hypothermia (TH). OBJECTIVE: To verify the potential of hypothermic hypoxic-ischemic encephalopathy (HIE) therapy in neonatal asphyxia, based on literature data, comparing the benefits between selective head cooling (SHC) and whole-body cooling (WBC), see that the use of TH as a standard treatment in newborns with moderate or severe HIE has been adopted. METHODS: A search was performed in the PubMed and SciELO databases of human studies, using the keywords "Therapeutic Hypothermia", "Induced Hypothermia", and "Hypoxic-Ischemic Encephalopathy", "Selective cooling of the head", "Total body cooling" and its variables. RESULTS: Eleven articles were selected to compose the review, after detailed reading. There is a consensus, that the reduction of the risk of death or disability at 18 months of life in neonates with moderate to severe HIE, occurs to TH through the techniques of WBC or SHC. It was found in the studies that there is no difference in terms of adverse effects between the two methods. As for radiological changes, such as hypoxic-ischemic injuries and the incidence of seizures after cooling, they are more frequent with SHC. CONCLUSION: Both WBC and SHC demonstrated neuroprotective properties, although WBC provides a broader area of brain protection. However, no significant differences were found between the methods in terms of adverse effects and beneficial short or long-term results.

INTRODUÇÃO: Evidências experimentais, assim como estudos clínicos, sugerem a redução da lesão cerebral e melhora do desfecho neurológico, em recém-nascidos com encefalopatia isquêmica hipóxica (EHI) submetidos à hipotermia terapêutica (HT). OBJETIVO: Verificar a potencialidade da terapia hipotérmica de encefalopatia hipóxico-isquêmica (EHI) na asfixia neonatal, com base em dados da literatura, comparando os benefícios entre o resfriamento seletivo da cabeça (RSC) e o resfriamento de corpo inteiro (RCI), visto que o uso de hipotermia terapêutica (HT) como tratamento padrão em recém-nascidos com EHI moderada ou grave tem sido amplamente adotada. MÉTODOS: Foi realizada uma busca nas bases de dados PubMed e SciELO de estudos em humanos, utilizando-se as palavras-chave "Therapeutic Hypothermia", "Induced Hypothermia", "Hypoxic-Ischemic Encephalopathy", "selective head cooling", "whole body cooling" e suas respectivas variáveis. RESULTADOS: Foram selecionados 11 artigos para compor a revisão, após leitura detalhada. É consenso, a redução do risco de morte ou incapacidade aos 18 meses de vida nos neonatos com EHI moderado a grave, submetidos à HT através das técnicas de RCI ou RSC. Constatou-se diante dos estudos que não há diferença em termos de efeitos adversos entre os dois métodos. Quanto às alterações radiológicas, as lesões hipóxico-isquêmicas e incidência de convulsões após o resfriamento são mais frequentes com o RSC. CONCLUSÃO: Tanto RCI quanto o RSC demonstraram propriedades neuroprotetoras, embora o RCI proporcione uma área de proteção cerebral mais ampla. No entanto, não foram constatadas diferenças significativas entre os métodos quanto a efeitos adversos e a resultados benéficos em curto e longo prazo.

Effect of selective cerebral mild hypothermia on SUMO2/3 modification of Drp1 in a rat model of cerebral ischemia-reperfusion / 中华麻醉学杂志

Objective:To evaluate the effect of selective cerebral mild hypothermia on small ubiquitin-like modifier 2/3 (SUMO2/3) modification of dynamin-related protein 1 (Drp1) in a rat model of cerebral ischemia-reperfusion (I/R).Methods:Sixty clean-grade healthy male Sprague-Dawley rats, aged 6-8 weeks, weighing 240-260 g, were divided into 4 groups ( n=15 each) using a random number table method: sham operation group (S group), cerebral I/R group (I/R group), selective cerebral mild hypothermia group (HT group) and normal temperature group (NT group). The operation was performed under the monitoring of cerebral temperature and rectal temperature.Only the cervical blood vessels were exposed in S group, while focal cerebral I/R was induced by 2 h middle cerebral artery occlusion (MCAO) followed by 24 h reperfusion in anesthetized animals in the other three groups.In HT group and NT group, 4 and 37 ℃ normal saline was perfused through the left internal carotid artery at a rate of 80 ml·kg -1·h -1 for 15 min, respectively. Modified neurological severity score (mNSS) was assessed at 24 h of reperfusion. Then the rats were sacrificed under deep anesthesia, brains were removed, brain tissues were obtained for determination of the percentage of cerebral infarct size (by TTC staining), and the ischemic penumbra tissues in the cerebral cortex were removed for examination of the ultra-structural changes of mitochondria (with a transmission electron microscope) and for determination of the SUMO2/3 modification of Drp1 (by CO-IP), expression of total Drp1 (T-Drp1) and total cytochrome c (T-Cytc) (by Western blot), and expression of mitochondrial outer membrane Drp1 (M-Drp1) and cytoplasmic Cytc (C-Cytc) (by Western blot) after isolation of mitochondria and cytoplasm. Results:Compared with S group, the mNSS and percentage of cerebral infarct size were significantly increased, the expression of M-Drp1, T-Drp1, C-Cytc and T-Cytc was up-regulated, and SUMO2/3 modification of Drp1 in ischemic penumbra area was increased ( P<0.05), the fragmentation of mitochondria was aggravated, and cristae rupture and vacuolation were obvious in the other three groups. Compared with I/R group, the mNSS and percentage of cerebral infarct size were significantly decreased, the expression of M-Drp1, T-Drp1, C-Cytc and T-Cytc was down-regulated, SUMO2/3 modification of Drp1 was increased ( P<0.05), the fragmentation of mitochondria was significantly attenuated, and cristae rupture and vacuolation were weakened in HT group. There were no significant differences in these detection parameters between NT group and I/R group ( P>0.05). Conclusions:The mechanism by which selective cerebral mild hypothermia alleviates the cerebral I/R injury is related to increased SUMO2/3 modification of Drp1, decreased binding of Drp1 to mitochondrial outer membrane, and reduced mitochondrial excessive fission in rats.

Effects of mild hypothermia on microglia polarization and JAK2/STAT3 signaling pathway during cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

Objective:To investigate the effects of mild hypothermia on microglia polarization and janus kinase 2/signal transduction and transcriptional activation factor 3 (JAK2/STAT3) signaling pathway during cerebral ischemia-reperfusion (I/R) in rats.Methods:Forty-five clean-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 260-280 g, were divided into 3 groups ( n=15 each) by the random number table method: sham operation group (S group), cerebral I/R group (I/R) and mild hypothermia group (H group). In I/R group and H group, cerebral I/R was induced by middle cerebral artery occlusion using a nylon thread in anesthetized animals, the nylon thread was removed to restore the perfusion after 2 h of occlusion, and the rectal temperature was maintained at 36-37 ℃ during the period. Group H was wiped with 75% alcohol for 3 h starting from the time point immediately after reperfusion, and the rectal temperature was maintained at 32-33℃. Modified neurological severity score (mNSS) was evaluated at 24 h of reperfusion. Animals were then sacrificed for determination of the cerebral infarct size (using TTC staining), expression of M1 marker inducible nitric oxide synthase (iNOS), M2 marker arginase 1(Arg-1), phosphorylated JAK2(p-JAK2)and phosphorylated STAT3(p-STAT3)(by Western blot), expression of iNOS mRNA and Arg-1 mRNA (by quantitative polymerase chain reaction), and contents of interleukin-6 (IL-6) and IL-10 (by enzyme-linked immunosorbent assay). Results:Compared with group S, mNSS and cerebral infarct size were significantly increased, the expression of iNOS, Arg-1 protein and mRNA in cerebral ischemic penumbral zone was up-regulated, and the p-JAK2/JAK2 ratio, p-STAT3/STAT3 ratio, and contents of IL-6 and IL-10 were increased in the other two groups ( P<0.05). Compared with I/R group, mNSS and cerebral infarct size were significantly decreased, the expression of iNOS protein and mRNA in cerebral ischemic penumbral zone was down-regulated, the expression of Arg-1 and mRNA was up-regulated, and the p-JAK2/JAK2 ratio, p-STAT3/STAT3 ratio and IL-6 content were decreased, and the IL-10 content was increased in group H ( P<0.05). Conclusions:Mild hypothermia can promote the polarization shift of microglia from M1 to M2 phenotype during cerebral I/R and inhibit the central inflammatory responses, and the mechanism may be related to inhibition of JAK2/STAT3 signaling pathway in rats.

Role of SIRT1/NF-κB signaling pathway in mild hypothermia-induced promotion of microglial polarization during oxygen-glucose deprivation and restoration / 中华麻醉学杂志

Objective:To evaluate the role of Sirtuin 1/nuclear factor κB (SIRT1/NF-κB) signaling pathway in mild hypothermia-induced promotion of microglial polarization during oxygen-glucose deprivation and restoration (OGD/R).Methods:The well-grown BV2 microglia were divided into 4 groups ( n=36 each) using the random number table method: control group (group C), OGD/R group (group O), mild hypothermia group (group M), and mild hypothermia+ SIRT1 specific inhibitor EX527 group (group ME). Cells in group C were commonly cultured without any treatment. Cells in group O were subjected to 3 h of OGD followed by 21 h of restoration of O 2-glucose supply at 37 ℃. Cells in group M were subjected to 3 h of OGD followed by 21 h of restoration of O 2-glucose supply at 33 ℃. Cells in group ME were co-cultured with inhibitor EX527 (final concentration 5 nmol/L) for 12 h in the medium before OGD/R, and the other procedures were conducted as previously described in group M. The cell survival rate was detected by CCK-8 assay. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interleukin-10 (IL-10) in supernatant were detected by enzyme-linked immunosorbent assay. The expression of CD206, CD32, inducible nitric oxide synthase (iNOS) and arginine synthase 1 (Arg-1) mRNA was detected by quantitative real-time polymerase chain reaction. The expression of CD206 and CD32 was detected by immunofluorescent staining. The expression of iNOS, Arg-1, SIRT1, NF-κB p65 (p65) and acetylated NF-κB (Ac-p65) was detected by Western blot. Results:Compared with group C, the cell survival rate was significantly decreased, the concentrations of TNF-α, IL-6 and IL-10 in the supernatant were increased, the expression of CD206, Arg-1, CD32 and iNOS was up-regulated, the expression of SIRT1 was down-regulated, and the Ac-p65/p65 ratio was increased in group O ( P<0.05). Compared with group O, the cell survival rate was significantly increased, the concentrations of TNF-α and IL-6 in the supernatant were decreased, the concentration of IL-10 was increased, the expression of CD206, Arg-1 and SIRT1 was up-regulated, the expression of CD32 and iNOS was down-regulated, and the Ac-p65/p65 ratio was decreased in group M ( P<0.05). Compared with group M, the cell survival rate was significantly decreased, the concentrations of TNF-α and IL-6 in the supernatant were increased, the concentration of IL-10 was decreased, the expression of CD206, Arg-1 and SIRT1 was down-regulated, the expression of CD32 and iNOS was up-regulated, and the Ac-p65/p65 ratio was increased in group ME ( P<0.05). Conclusions:SIRT1/NF-κB signaling pathway is involved in mild hypothermia-induced promotion of microglial polarization during OGD/R.

Influential factors of neonatal hypoxic ischemic encephalopathy and the therapeutic effects of mild hypothermia at different time windows / 中国基层医药

Objective:To investigate the influential factors of neonatal hypoxic ischemic encephalopathy (HIE), and compare the therapeutic effects of mild hypothermia at different time windows and between different degrees of disease severity.Methods:Eighty-two neonates with HIE who were admitted to Jiaxing Maternity and Child Health Care Hospital from January 2016 to October 2021 were included in the patient group, and 123 concurrent healthy neonates were included in the control group. The influential factors of neonatal HIE were analyzed. Sixty-five neonates who received HIE were divided into four groups according to the time length between symptom onset and hospital admission (< 6 hours and 6-12 hours) and disease severity: group I (admission time < 6 hours, mild, n = 20), group II (admission time < 6 hours, moderate to severe, n = 15), group III (admission time 6-12 hours, mild, n = 17), and group IV (admission time 6-12 hours, moderate to severe, n = 13). Amplitude-integrated electroencephalography (aGGE) score was used as the evaluation criteria. The therapeutic effects of mild hypothermia were compared between different time windows and between different degrees of HIE. Results:Multivariable logistic regression analysis results revealed that the influential factors of neonatal HIE included gestational hypertension, gestational diabetes, pregnancy examination, delivery methods, amniotic fluid contamination, abnormal fetal membranes (placenta or umbilical cord), fetal distress, and neonatal asphyxia ( P < 0.05). All 65 neonates with HIE underwent mild hypothermia treatment for 72 hours. Before treatment, aGGE score in groups I, II, III and IV was 6.02 ± 1.74 points, 2.43 ± 1.82 points, 5.23 ± 1.95 points, and 2.72 ± 1.76 points, respectively. After treatment, it was 8.13 ± 2.03 points, 6.47 ± 1.87 points, 7.86 ± 1.92 points, and 3.52 ± 1.95 points, respectively. There was significant difference in aGGE score between before and after treatment in groups I, II and III ( t = 2.87, 3.55, 3.15, all P < 0.05). aGGE score in group IV did not differ significantly between before and after treatment ( P > 0.05). Before treatment, aGGE score in children with moderate to severe HIE was lower than that in children with mild HIE. After treatment, there was no significant difference in aGGE score between groups II and III ( P > 0.05). Conclusion:Pregnant women with gestational hypertension and gestational diabetes should be given intensive monitoring and learn HIE related knowledge to increase the frequency of prenatal examinations. If amniotic fluid contamination, abnormal fetal membranes (placenta or umbilical cord), fetal distress, or neonatal asphyxia occurs, timely monitoring and corresponding interventions should be given to the fetus. Mild hypothermia therapy has a certain therapeutic effect on different degrees of HIE. For moderate to severe neonates, treatment should be started within 6 hours to ensure the therapeutic effects of mild hypothermia.

Impacto de uma intervenção educativa no manejo da hipotermia terapêutica neonatal: estudo quase experimental / Impact of an educational intervention in the management of neonatal therapeutic hypothermia: a quasi-experimental study

Introdução: A hipotermia terapêutica é o tratamento indicado para encefalopatia moderada a grave em recém-nascidos. A terapia requer uma equipe de enfermagem capacitada e integrada, visando um cuidado qualificado, efetivo e seguro. Modelos teóricos têm sido desenvolvidos para auxiliar a incorporação de evidências científicas à prática dos enfermeiros, representando um desafio na área da saúde. A implementação de uma intervenção educativa, guiada pela estrutura i-PARIHS (Estrutura Integrada de Promoção da Ação na Implementação de Pesquisa em Serviços de Saúde), poderá preencher a lacuna entre a teoria e a prática, beneficiando a assistência e tornando os sujeitos ativos no manejo do recém-nascido em hipotermia terapêutica. Objetivo geral: avaliar o impacto de uma intervenção educativa, guiada pelo referencial teórico i-PARIHS, sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal no conhecimento, atitudes e práticas de enfermeiros. Objetivos específicos: analisar o conhecimento, atitude e prática dos enfermeiros sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica pré e pós-intervenção educativa; identificar as barreiras e facilitadores percebidos pelos enfermeiros sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal; implementar uma intervenção educativa, guiada pelo referencial i-PARIHS, para melhorar o conhecimento, a atitude e a prática dos enfermeiros sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal; comparar o conhecimento, atitude e prática dos enfermeiros após a intervenção educativa e os indicadores quanto ao manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica. Método: trata-se de um estudo de intervenção, do tipo quase-experimental, realizado com 29 enfermeiros de uma unidade intensiva neonatal, referência no Rio de Janeiro. O desfecho principal: conhecimento, atitudes e práticas dos enfermeiros no manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal A intervenção compreendeu três fases: pré-intervenção - intervenção educativa- pós-intervenção. A intervenção educativa contou com cinco encontros: "Asfixia Perinatal x Hipotermia Terapêutica", "Controle da temperatura", "Cuidados de enfermagem na HT: avaliação de dor", "Monitoramento neurológico" e "Cuidado Centrado na Família". Para a análise estatística utilizou-se de análise descritiva e aplicação dos testes Wilcoxon-Mann-Whitney e Mc Nemar, sendo o nível de significância adotado de 0,05. Resultados: a análise dos resultados do pré e pós-teste demonstrou um incremento no escore de acertos das questões sobre conhecimento, atitude e prática dos enfermeiros no manejo do recém-nascido submetido à hipotermia terapêutica na unidade intensiva neonatal, apresentando significância estatística para a maioria dos itens. Para a inovação foram construídos lembretes, fluxo de admissão para recém-nascido da instituição e uma cartilha para os pais como produto da intervenção com os enfermeiros. Conclusão: O resultado das auditorias realizadas, após a implementação das evidências, constatou uma transformação positiva da prática dos enfermeiros. A utilização da estrutura i-PARIHS evidenciou a necessidade e o valor de investir no engajamento das partes interessadas, na avaliação colaborativa do contexto e na cocriação de inovação usando facilitação qualificada. A intervenção educativa, guiada pela estrutura i-PARIHS, mostrou ter impacto no manejo do recém-nascido submetido à hipotermia terapêutica por enfermeiros.

Introduction: Therapeutic hypothermia is the currently indicated treatment for moderate to severe encephalopathy in newborns. Therapy requires a trained and integrated nursing team, aiming at qualified, effective and safe care. Theoretical models have been developed to help the incorporation of scientific evidence into nurses' practice, representing a challenge in the health area. The implementation of an educational intervention, guided by the i-PARIHS (Integrated Promoting Action on Research Implementation in Health Services Framework) framework, can fill the gap between theory and professional practice, benefiting care and making subjects active in the management of newborns with therapeutic hypothermia. General objective: to evaluate the impact of an educational intervention guided by the theoretical framework i-PARIHS, on the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive care unit on the knowledge, attitudes and practices of nurses. Specific objectives: to analyze the knowledge, attitude and practice of nurses on the management of newborns with perinatal asphyxia in pre- and post-educational therapeutic hypothermia; to identify barriers and facilitators perceived by nurses on the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive care unit; implement an educational intervention, guided by the i-PARIHS framework, to improve nurses' knowledge, attitude and practice on the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive care unit and compare the knowledge, attitude and practice of nurses after the participatory educational intervention program and indicators regarding the management of newborns with perinatal asphyxia in therapeutic hypothermia. Method: this is a quasi-experimental intervention study carried out with 29 nurses from a neonatal intensive care unit, a reference in Rio de Janeiro. The main outcome: knowledge, attitudes and practices of nurses in the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive unit The intervention comprised three phases: pre-intervention - educational intervention - post-intervention. The educational intervention had five meetings: "Perinatal Asphyxia x Therapeutic Hypothermia", "Temperature control", "Nursing care in HT: pain assessment", "Neurological monitoring" and "Family-Centered Care". For the statistical analysis, descriptive analysis and application of the Wilcoxon-Mann-Whitney and Mc Nemar tests were used, with the adopted significance level of 0.05. Results: the analysis of pre- and post-test results showed an increase in the correct score of questions about nurses' knowledge and practices in the management of newborns submitted to therapeutic hypothermia in the neonatal intensive care unit, showing statistical significance for most items. For innovation, reminders, admission flow for newborns at the institution and a booklet for parents were created as a product of the intervention with nurses. Conclusion: The result of the audits carried out, after the implementation of the evidence, found a positive transformation of the nurses' practice. Using the i-PARIHS framework highlighted the need and value of investing in stakeholder engagement, collaborative context assessment, and co-creation of innovation using qualified facilitation. The educational intervention guided by the i-PARIHS framework was shown to have an impact on the management of newborns with perinatal asphyxia in therapeutic hypothermia by nurses.

Effects of different densities of rat cardiac fibroblasts subjected to hypothermic hypoxia-reoxygenation on cardiomyocyte injury / 中华麻醉学杂志

Objective:To evaluate the effects of different densities of rat cardiac fibroblasts (RCF) subjected to hypothermic hypoxia-reoxygenation on cardiomyocyte injury and intercellular coupling.Methods:RCF was cultured in vitro and divided into 3 groups ( n=12 each) using a random number table method: RCF density 0.5×10 5 cells/ml group (T 0.5 group), RCF density 1.0×10 5 cells/ml group (T 1.0 group), and RCF density 2.0×10 5 cells/ml group (T 2.0 group). The three groups were placed in an anoxic device, into which 95% N 2 + 5% CO 2 was continuously blown at the speed of 5 L/min for 15 min, and then placed in a 4 ℃ refrigerator for 1 h for low temperature treatment.After completion of culture, cells were placed in a incubator containing 95% air + 5% CO 2 at 37 ℃ for 4 h of reoxygenation.After the end of culture, RCF in three groups were indirectly co-cultured with cardiomyocytes of the same density (1.0×10 5 cells/ml) in a Transwell chamber for 16 h, cardiomyocytes were seeded in the lower chamber of Transwell, and RCF were seeded in the upper chamber of Transwell.After the end of co-culture, cardiomyocytes were collected for determination of the cell viability (by CCK8 method), apoptosis rate (by flow cytometry), expression of connexin 43 (Cx43) mRNA (by real-time fluorescence quantitative polymerase chain reaction), and expression of Cx43 and phosphorylated Cx43 (p-Cx43) (by Western blot). Results:Compared with T 0.5 group, the cell viability, apoptosis rate and expression of Cx43, p-Cx43 and Cx43 mRNA were significantly decreased in T 1.0 and T 2.0 groups ( P<0.01). Compared with T 1.0 group, the cell viability, apoptosis rate and expression of Cx43 and p-Cx43 were significantly decreased ( P<0.01), and no significant change was found in expression of Cx43 mRNA in cardiomyocytes in T 2.0 group ( P>0.05). Conclusions:RCF subjected to hypothermic hypoxia-reoxygenation induces cardiomyocyte injury in a density-dependent manner in a certain range, and the mechanism may be related to down-regulation of the expression of Cx43 and reduction of the activity of Cx43.

Effects of exosomes derived from cardiac fibroblasts pretreated with sevoflurane on ventricular electrical conduction in isolated rat hearts subjected to hypothermic ischemia-reperfusion: a multi-electrode array mapping technique for measurement / 中华麻醉学杂志

Objective:To evaluate the effects of exosomes derived from cardiac fibroblasts pretreated with sevoflurane on ventricular electrical conduction in isolated rat hearts subjected to hypothermic ischemia-reperfusion (I/R) using the multi-electrode array mapping technique.Methods:Primary cardiac fibroblasts were extracted by differential adhesion in SPF Sprague-Dawley rats of either sex.Cardiac fibroblasts of passage 2-4 were treated with 2.5% sevoflurane for 1 h, and then cultured for 24-48 h to extract exosome.SPF healthy male Sprague-Dawley rats, aged 2-3 months, weighing 280-320 g, were divided into 3 groups ( n=8 each) using a random number table method: control group (group C), I/R group and sevoflurane-pretreated cardiac fibroblast-derived exosome+ IR group (group S+ IR). Hearts were perfused for 110-min equilibration in group C. After 20 min of equilibration, the perfusion was suspended for 60 min (global ischemia) followed by 30 min of reperfusion in IR and S+ IR groups.Exosomes 1 ml (200 μg) derived from cardiac fibroblasts pretreated with sevoflurane were injected through the tail vein at 48 h before surgery in group S+ IR, and the equal volume of normal saline was injected instead in C and IR groups.The cardiac conduction velocity (CV), conduction absolute inhomogeneity (P 5-95) and inhomogeneity index (P 5-95/P 50) were obtained at 20 min of equilibration (T 0) and 15 and 30 min of reperfusion (T 1, 2) using the microelectrode array attaching to the left ventricular surface of the isolated heart. Results:Compared with group C, CV was significantly decreased and P 5-95 and P 5-95/P 50 were increased at T 1 ( P<0.05), and no significant change was found at T 2 in group S+ IR ( P>0.05), and CV was significantly decreased and P 5-95 and P 5-95/P 50 were increased at T 1, 2 in group IR ( P<0.05). Compared with group IR, CV was significantly increased and P 5-95 and P 5-95/P 50 were decreased at T 1, 2 in group S+ IR ( P<0.05). Conclusions:Exosomes derived from cardiac fibroblasts pretreated with sevoflurane can improve ventricular electrical conduction in isolated rat hearts subjected to hypothermic I/R.

Effect of hypothermia on polarization of microglia and TLR4/NF-κB signaling pathway during oxygen-glucose deprivation/restoration / 中华麻醉学杂志

Objective:To evaluate the effect of hypothermia on the polarization of microglia and TLR4/NF-κB signaling pathway during oxygen-glucose deprivation/restoration (OGD/R).Methods:BV2 microglia were cultured in vitro and divided into 3 groups ( n=18 each) using the random number table method: control group (group C), group OGD/R and OGD/R plus hypothermia group (group OGD/R+ HT). Group C was cultured normally for 24 h. In group OGD/R, the cells were exposed to 5% CO 2-1% O 2 at 37 ℃ for 2 h in a glucose-free medium, followed by restoration of glucose and oxygen for 24 h. In group OGD/R+ HT, the high-glucose medium was replaced with a glucose-free medium, the cells were exposed to 5% CO 2-1% O 2 for 2 h in a 33 ℃ cryostat, followed by restoration of glucose and oxygen for 24 h. The cell survival rate was measured by CCK-8 assay.The expression of M1 microglia markers CD32 and iNOS protein and mRNA and M2 microglia markers CD206 and Arg-1 and mRNA was detected by immunofluorescence and real-time quantitative polymerase chain reaction.The expression of TLR-4 and NF-κB in cells was detected by Western blot, and the expression of TLR4 and NF-κB mRNA in cells was detected by real-time quantitative polymerase chain reaction.The concentrations of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 10 (IL-10) in the cell supernatant were detected by enzyme-linked immunosorbent assay. Results:Compared with group C, the cell survival rate was significantly decreased, the expression of CD32, iNOS, CD206, Arg-1, TLR4 and NF-κB protein and mRNA was up-regulated, and the concentrations of TNF-α, IL-1β and IL-10 in supernatant were increased in OGD/R and OGD/R+ HT groups ( P<0.05). Compared with group OGD/R, the cell survival rate was significantly increased, the expression of CD32, iNOS, TLR4 and NF-κB protein and mRNA was down-regulated, the expression of CD206 and Arg-1 protein and mRNA was up-regulated, the concentrations of TNF-α and IL-1β in supernatant were decreased, and the concentration of IL-10 was increased in group OGD/R+ HT ( P<0.05). Conclusions:Hypothermia can significantly inhibit microglia polarization toward M1 phenotype, increase microglia polarization toward M2 phenotype and inhibit the development of inflammatory responses during OGD/R, and the mechanism may be related to inhibition of TLR4/NF-κB signaling pathway.

Brain temperature changes and mild hypothermia treatment after subarachnoid hemorrhage / 国际脑血管病杂志

Subarachnoid hemorrhage (SAH) is a common and serious type of stroke. Studies have shown that multimodal monitoring of brain temperature, intracranial pressure and cerebral blood flow is helpful for the perioperative management of patients with SAH, and further improves the outcomes of patients. This article reviews the brain temperature changes and mechanism after SAH as well as the role of mild hypothermia treatment.

68Ga-PSMA PET/CT: effect of external cooling on salivary gland uptake / PET/CT com 68Ga-PSMA: efeitos do resfriamento externo na captação pelas glândulas salivares

Abstract Objective: To evaluate the effect that external cooling of the salivary glands (ECSG) has on the uptake of gallium-68-labeled prostate-specific membrane antigen (68Ga-PSMA), as an indirect assessment of the capacity of ECSG to reduce the local dose in lutetium-177-PSMA-617 radioligand therapy. Materials and Methods: Ten patients with prostate cancer were submitted to 68Ga-PSMA positron emission tomography/computed tomography with unilateral ECSG. The ECSG was started at 30 min before the injection of the radiotracer and maintained until the end of image acquisition (1 h after injection). Each salivary gland was assessed by determining the maximum, mean, and peak standardized uptake values (SUVmax, SUVmean, and SUVpeak, respectively). The volume of each gland was determined in a volume of interest delineated by a threshold SUVmax of 10%. Paired Student's t-tests were used in order to compare the results. Results: In terms of the SUV parameters, there were no statistically significant differences between the cooled and contralateral salivary glands. However, the mean volume was 27% lower in the cooled parotid glands than in the contralateral parotid glands (p = 0.004). Conclusion: The use of ECSG does not appear to reduce 68Ga-PSMA uptake by the salivary glands. In addition, there is yet no evidence that ECSG is effective in preventing salivary gland toxicity.

Resumo Objetivo: Avaliar o impacto do resfriamento externo de glândulas salivares (REGS) na captação de 68Ga-PSMA como marcador indireto dessa intervenção para redução da dose local na terapia com 177Lu-PSMA. Materiais e Métodos: Dez pacientes com câncer de próstata foram submetidos a PET/CT com 68Ga-PSMA com REGS unilateral. O resfriamento se iniciou 30 minutos antes da injeção do radiofármaco até o fim da aquisição de imagem, 1 hora após a injeção. Cada glândula foi avaliada para os valores de captação padronizados máximo, médio e pico (SUVmáx, SUVmédio e SUVpico, respectivamente). O volume foi definido por um isocontorno usando 10% do SUVmáx. Os resultados foram comparados com o teste t de Student. Resultados: Não houve diferença estatisticamente significante entre os valores de SUV das glândulas resfriadas e seus controles. Houve 27% de redução volumétrica (p = 0,004) nas parótidas resfriadas em comparação ao controle. Conclusão: Não houve redução da captação de 68Ga-PSMA nas glândulas salivares ao REGS. Atualmente não há evidências que suportem essa prática clínica.

Inserción "velamentosa", encefalopatía hipóxico-isquémica y rehabilitación neurológica: reporte de caso / Velamentous cord insertion, ischemic-hypoxic encephalopathy, and neurological rehabilitation: A case report

Resumen. La encefalopatía hipóxico-isquémica es una causa frecuente e importante de daño neurológico en recién nacidos a término y prematuros. Un evento centinela de esta condición es la vasa previa, específicamente cuando existe anormalidad de la placenta como la inserción "velamentosa" del cordón umbilical. Algunos reportes evidencian la asociación entre estas dos condiciones, pero son escasos los que dan cuenta del proceso de recuperación y del pronóstico neurológico de los niños afectados por ellas. Se presenta el caso de un paciente, con antecedentes de inserción "velamentosa" del cordón umbilical y encefalopatía hipóxico-isquémica, que recibió hipotermia terapéutica (cool cap). Se describe su proceso de rehabilitación neurológica y se calculó el porcentaje de probabilidad de presentar esta condición frente a la población sin estos factores. El niño tenía cinco años y el puntaje en su prueba de Apgar fue de 0 al minuto y de 2 a los 15 minutos. Desarrolló encefalopatía hipóxico-isquémica grave secundaria a una inserción "velamentosa" del cordón umbilical sin diagnóstico prenatal, con gran compromiso neurológico y multisistémico inicial. El proceso de recuperación incluyó el manejo inicial multidisciplinario en la unidad de cuidados intensivos neonatales y el inicio temprano de habilitación neurológica. Hoy el niño está escolarizado y en terapia integral, no presenta deficiencias motoras ni sensoriales en el examen físico, aunque la prueba neuropsicológica sugiere un riesgo de trastorno por déficit de atención e hiperactividad. Habitualmente, los niños con encefalopatía hipóxico-isquémica grave presentan discapacidad por deficiencias motoras, cognitivas o conductuales. El haber recibido hipotermia terapéutica y un manejo estructurado de rehabilitación redujo en gran medida las deficiencias esperadas y ha promovido un satisfactorio desarrollo físico y neurológico.

Abstract. Hypoxic-ischemic encephalopathy is a frequent and important cause of neurological problems in term and preterm newborns. A sentinel event of this entity is the vasa previa, specifically when there is an abnormality of the placenta such as a velamentous cord insertion. Some reports have shown the association between these two entities, but those regarding the recovery process and the neurological prognosis of children with both conditions are scarce. We present the case of a patient with a history of velamentous cord insertion and hypoxic-ischemic encephalopathy who received therapeutic hypothermia (cool cap). We describe his neurological rehabilitation process and we calculated the percentage of probability of presenting this condition compared to the population without these factors. The patient was a five-year-old boy with an Apgar index at birth equal to zero at one minute and equal to two at fifteen minutes who developed severe hypoxic-ischemic encephalopathy secondary to a velamentous cord insertion without prenatal diagnosis and a marked initial neurological and multisystemic compromise. The recovery process included early multidisciplinary management in the neonatal intensive care unit and a focus on early neurological habilitation. The patient is currently in school and he undergoes comprehensive therapies; on physical examination, he presents no motor or sensory deficiencies. His neuropsychological test suggests the risk of attention deficit hyperactivity disorder. Children with severe hypoxic-ischemic encephalopathy usually have disabilities due to motor, cognitive, and/or behavioral deficiencies. Having received therapeutic hypothermia and a structured rehabilitation process greatly reduced the expected deficiencies according to prognosis and have promoted satisfactory physical and neurological development.

Exploring the effect of acupuncture plus mild hypothermia on miRNA-204 and its target gene expressions in CIRI rat brain tissues based on MAPK signal pathway / 针灸推拿医学（英文版）

Objective: To explore the protective mechanism of acupuncture plus mild hypothermia for cerebral ischemia-reperfusion injury (CIRI) by observing the effects of acupuncture plus mild hypothermia on miRNA-204 and its target gene expressions in CIRI rat brain tissues. Methods: Sixty Sprague-Dawley rats were divided into a blank control group, a sham operation group, a model group, an acupuncture group, a mild hypothermia group and an acupuncture plus mild hypothermia group according to the random number table method (n=10). Except for the blank control group and the sham operation group, rats in the other 4 groups received CIRI modeling. After the model was successfully established, rats in the blank control group were bred routinely for 72 h without any interventions; rats in the sham operation group and the model group were bred routinely for 72 h, and only received binding without other interventions after surgery; rats in the acupuncture group were bred routinely for 72 h, and received acupuncture at Dazhui (GV 14), Baihui (GV 20) and Shuigou (GV 26) after binding; rats in the mild hypothermia group were bred routinely for 72 h, and received mild hypothermia intervention for 72 h after binding; rats in the acupuncture plus mild hypothermia group were bred routinely for 72 h, followed by receiving acupuncture as in the acupuncture group and mild hypothermia therapy as in the mild hypothermia group after binding. The neurological impairment score, cerebral infarction area ratio, the expressions of miRNA-204 and its target genes including Map3k8, Ntrk2 and Ppp3r1 in the ischemic hippocampus of each group were observed after 72 h of intervention. Results: Before intervention, compared with the blank control group and the sham operation group, the neurological impairment scores and the infarction area ratios of the modelled rats were statistically significantly increased (all P<0.01), indicating that the model was successful. After intervention, compared with the model group, the neurological impairment scores of the three intervention groups were significantly reduced (all P<0.01); compared with the acupuncture group and the mild hypothermia group, the infarction area ratio in the acupuncture plus mild hypothermia group was significantly reduced (both P<0.01); compared with the model group, the three intervention groups showed significant inhibition of miRNA-204 expression in brain tissues (all P<0.05), which was most significant in the acupuncture plus mild hypothermia group (P<0.01); compared with the acupuncture group and the mild hypothermia group, the Map3k8 expression in the acupuncture plus mild hypothermia group was significantly increased (both P<0.01), but there were no significant differences in Ntrk2 and Ppp3r1 expressions between groups (all P>0.05). Conclusion: Acupuncture, mild hypothermia, and acupuncture plus mild hypothermia reduced the neurological impairment score and the cerebral infarction area in CIRI rats, while acupuncture plus mild hypothermia showed the most significant effect. In regulating miRNA-204 target gene expressions, acupuncture plus mild hypothermia showed the same effect on Ntrk2 and Ppp3r1 expressions, while better effect on Map3k8 expression compared with either acupuncture or hypothermia.

Role of hsa_circ_0025853 in hypothermia-induced reduction of oxygen-glucose deprivation and restoration injury to neuroblastoma cells / 中华麻醉学杂志

Objective:To evaluate the role of hsa_circ_0025853 in hypothermia-induced reduction of oxygen-glucose deprivation and restoration (OGD/R) injury to neuroblastoma cells (SK-N-SH cells). Methods:SK-N-SH cells were cultured in vitro to the logarithmic phase and divided into 4 groups ( n=20 each) using a random number table method: control group (group C), group OGD/R, hypothermia group (group H) and hsa_circ_0025853 small interfering RNA (siRNA) plus hypothermia group (group S+ H). The cells were cultured in normal culture atmosphere in group C. The cells were subjected to OGD for 3 h followed by restoration of oxygen-glucose supply for 24 h in group OGD/R.The cells were subjected to OGD for 3 h followed by restoration of oxygen-glucose supply for 24 h at 32 ℃ in group H. The cells were transfected with siRNA at 48 h before establishing OGD/R model, and the other treatments were similar to those previously described in group H. At 24 h of restoration of oxygen-glucose, cell viability was measured by Cell Counting Kit-8, apoptosis rate were measured by flow cytometry.the expression of dynamin-related protein 1 (Drp1) mRNA and hsa_circ_0025853 was detected by quantitative real-time-polymerase chain reaction, and the expression of Drp1 protein was detected by Western blot. Results:Compared with group C, the cell viability was significantly decreased, the apoptosis rate of cells was increased, the expression of hsa_circ_0025853 was down-regulated, and the expression of Drp1 protein and mRNA was up-regulated in the other 3 groups ( P<0.05). Compared with group OGD/R, the cell viability was significantly increased, the apoptosis rate of cells was decreased, the expression of hsa_circ_0025853 was up-regulated, and the expression of Drp1 protein and mRNA was down-regulated in H and S+ H groups ( P<0.05). Compared with group H, the cell viability was significantly decreased, the apoptosis rate of cells was increased, the expression of hsa_circ_0025853 was down-regulated, and the expression of Drp1 protein and mRNA was up-regulated in group S+ H ( P<0.05). Conclusion:The mechanism by which hypothermia alleviates the OGD/R injury to SK-N-SH cells is related to the up-regulation of hsa_circ_0025853 expression, thus reducing the expression level of Drp1.

Effect of mild hypothermia on IRE1-XBP1 signaling pathway in endoplasmic reticulum in cortex in a rat model of focal cerebral ischemia-reperfusion / 中华麻醉学杂志

Objective:To evaluate the effect of mild hypothermia on inositol requiring enzyme 1-X-box binding protein 1 (IRE1-XBP1) signaling pathway in endoplasmic reticulum in cortex in a rat model of focal cerebral ischemia-reperfusion (I/R).Methods:Fifty-four clean-grade healthy male Sprague-Dawley rats, aged 8-10 weeks, weighing 200-230 g, were divided into 3 groups ( n=18 each) using a random number table method: sham operation group (group S), cerebral I/R group (group I) and mild hypothermia group (group T). Cerebral I/R was induced by inserting a nylon thread with rounded tip into the internal carotid artery which was occluded for 2 h and then released for reperfusion.The surface cooling was started immediately after reperfusion, and the rectal temperature was maintained at 32-34 ℃ for 3 h in group T. Blood vessels were only exposed, without occlusion in group S. The neurologic deficit was assessed and scored at 24 h of reperfusion.The animals were then sacrificed and the ischemic area of the cerebral cortex was removed for examination of the ultrastructure of the cells (with a transmission electron microscope), for determination of nerve cell apoptosis (using TUNEL), for detection of the expression of IRE1 and XBP1 (by Western blot) and for determination of the expression of IRE1 and XBP1 protein mRNA (using quantitative real-time polymerase chain reaction). Results:Compared with group S, the neurologic deficit scores were significantly increased, nerve cell apoptosis in the ischemic area of the cerebral cortex was increased, the expression of IRE1, XBP1 protein and mRNA was up-regulated ( P<0.05), the neuronal nuclei was degenerated and swollen, the nuclear membrane was fragmented and defective, the chromatin was pyknotic and marginalized, and the endoplasmic reticulum was dilated and cisternal in group I and group T. Compared with group I, the neurologic deficit scores were significantly decreased, nerve cell apoptosis in the ischemic area of the cerebral cortex was decreased, the expression of IRE1, XBP1 protein and mRNA was up-regulated ( P<0.05), and the damage to the ultrastructure of nerve cells was reduced in group T. Conclusion:The mechanism by which mild hypothermia alleviates focal cerebral I/R injury is associated with further activation of neuronal IRE1-XBP1 signaling pathway and alleviation of endoplasmic reticulum stress response in rats.

Hipotermia terapêutica na encefalopatia hipóxico-isquêmica neonatal: revisão integrativa / Therapeutic hypothermia in neonatal hypoxic-ischemic encephalopathy: integrative review / Hipotermia terapéutica em la encefalopatía hipóxico-isquémica neonatal: revisión integrativa

Objetivo: identificar evidências acerca do uso seguro da hipotermia terapêutica em recém-nascidos. Método: revisão integrativa realizada entre junho e julho de 2018, em fontes eletrônicas da Biblioteca Virtual de Saúde e PubMed, por meio da pergunta:"Que evidências podem subsidiar o cuidado de enfermagem voltado para a redução de sequelas em recém-nascidos submetidos à hipotermia terapêutica?".Foram eleitos nove artigos para análise, sendo oito internacionais e um nacional. Resultados:o resfriamento deve acontecer por 72 horas, com hipotermia leve. As indicações para inclusão no protocolo foram: primeiras seis horas de vida, idade gestacional maior que 35 semanas e acidose na primeira hora de vida.São cuidados essenciais: monitoração hemodinâmica, observação da pele, controle térmico retal, vigilância do Eletroencefalograma de Amplitude Integrada. Conclusão: a terapêutica apresenta benefícios, porém sua aplicação depende de protocolo institucional e treinamento das equipes com foco nas potenciais complicações.

Objective: to identify the evidence on safe use of therapeutic hypothermia in newborns. Method: integrative review of the literature, conducted between June and July of 2018, in electronic sources from the Virtual Health Library and PubMed, through the question: "What evidence can support nursing care aimed at reducing sequelae in newborns undergoing therapeutic hypothermia?". Analysis was conducted for nine selected article, being eight from international literature and one from Brazilian national literature. Results: cooling should occur for 72 hours with mild hypothermia. Indications for inclusion in the protocol were: first six hours of life, gestational age greater than 35 weeks and acidosis in the first hour of life. Essential care includes hemodynamic monitoring, skin observation, rectal thermal control, Integrated Amplitude Electroencephalogram surveillance. Conclusion: the therapy has benefits, but its application depends on institutional protocol and team training focusing on potential complications.

Objetivo: identificar la evidencia sobre el uso seguro de la hipotermia terapéutica en recién nacidos. Método: revisión integradora de la literatura, realizada entre junio y julio de 2018, en fuentes electrónicas de la Biblioteca Virtual de Salud y PubMed, a través de la pregunta: "¿Qué evidencia puede apoyar la atención de enfermería dirigida a reducir las secuelas en los recién nacidos que sufren hipotermia terapéutica?". Se realizaron análisis para nueve artículos seleccionados, ocho de literatura internacional y uno de literatura nacional brasileña. Resultados: el enfriamiento debe ocurrir durante 72 horas con hipotermia leve. Las indicaciones para la inclusión en el protocolo fueron: primeras seis horas de vida, edad gestacional mayor de 35 semanas y acidosis en la primera hora de vida. El cuidado esencial incluye monitoreo hemodinámico, observación de la piel, control térmico rectal, vigilancia integrada de electroencefalograma de amplitud. Conclusión: la terapia tiene beneficios, pero su aplicación depende del protocolo institucional y del entrenamiento del equipo, enfocándose en posibles complicaciones.

Hypothermia post-cardiopulmonary resuscitation with low inputs: an experience report / Hipotermia post-ressuscitación cardiopulmonar con bajos insumos: relato de experiencia / Hipotermia pós ressuscitação cardiopulmonar com baixos insumos: relato de experiência

ABSTRACT Objective: to report the experience of conducting directed temperature control of a post-cardiopulmonary resuscitation patient, with reduced and basic inputs available at the institution. Method: an experience report of directed temperature control in patient (age 15 years), after four hours of cardiopulmonary resuscitation in an Intensive Care Unit of a hospital in São Paulo State countryside in 2016, according to the protocol suggested by the American Heart Association, in 2015. There were applications of cold compresses, plastic bags with crushed ice and rectal temperature control. Results: after eight hours, temperature had reached 93.2 ºF. Body cooling was maintained for 24 hours. However, bags with crushed ice were used in the first 6 hours. Conclusion: conduct of nurses to obtain the body cooling with reduced and basic inputs was effective during the stay at the Intensive Care Unit.

RESUMEN Objetivo: relatar la experiencia de la conducción de control dirigido de la temperatura de una paciente después de la resucitación cardiopulmonar, con insumos reducidos y básicos disponibles en la institución. Método: el informe de experiencia de control direccionado de la temperatura en paciente (edad 15 años), después de cuatro horas de resucitación cardiopulmonar en una Unidad de Terapia Intensiva de un hospital del interior del estado de São Paulo, en el año 2016, conforme protocolo sugerido por la American Heart Association en 2015. Se utilizaron aplicaciones de compresas embebidas en agua helada, bolsas plásticas con hielo triturado y control de la temperatura rectal. Resultados: en ocho horas, la temperatura alcanzó los 34 ºC. El enfriamiento corporal se mantuvo durante 24 horas, sin embargo, las bolsas con hielo triturado se utilizaron en las primeras 6 horas. Conclusión: la conducta de los enfermeros para obtener el enfriamiento corporal con insumos reducidos y básicos, se mostró efectiva durante la permanencia en la Unidad de Terapia Intensiva.

RESUMO Objetivo: relatar a experiência da condução de controle direcionado da temperatura de uma paciente pós ressuscitação cardiopulmonar, com insumos reduzidos e básicos disponíveis na instituição. Método: relato de experiência de controle direcionado da temperatura em paciente (idade 15 anos) após quatro horas de ressuscitação cardiopulmonar em uma unidade de terapia intensiva de um hospital do interior do Estado de São Paulo, no ano de 2016, conforme protocolo sugerido pela American Heart Association 2015. Utilizou-se aplicações de compressas embebidas em água gelada, sacos plásticos com gelo triturado e controle da temperatura retal. Resultados: em oito horas a temperatura atingiu 34ºC. O resfriamento corporal foi mantido por 24 horas, todavia os sacos com gelo triturado foram utilizados nas primeiras 6 horas. Conclusão: a conduta dos enfermeiros para obter o resfriamento corporal com insumos reduzidos e básicos, mostrou-se efetiva durante a permanência na unidade de terapia intensiva.

Selective head cooling and whole body cooling as neuroprotective agents in severe perinatal asphyxia

SUMMARY INTRODUCTION The possibility that hypothermia has a therapeutic role during or after resuscitation from severe perinatal asphyxia has been a longstanding focus of research. Studies designed around this fact have shown that moderate cerebral hypothermia, initiated as early as possible, has been associated with potent, long-lasting neuroprotection in perinatal patients. OBJECTIVES To review the benefits of hypothermia in improving cellular function, based on the cellular characteristics of hypoxic-ischemic cerebral injury and compare the results of two different methods of cooling the brain parenchyma. METHODS Medline, Lilacs, Scielo, and PubMed were searched for articles registered between 1990 and 2019 in Portuguese and English, focused on trials comparing the safety and effectiveness of total body cooling with selective head cooling with HIE. RESULTS We found that full-body cooling provides homogenous cooling to all brain structures, including the peripheral and central regions of the brain. Selective head cooling provides a more extensive cooling to the cortical region of the brain than to the central structures. CONCLUSIONS Both methods demonstrated to have neuroprotective properties, although full-body cooling provides a broader area of protection. Recently, head cooling combined with some body cooling has been applied, which is the most promising approach. The challenge for the future is to find ways of improving the effectiveness of the treatment.

RESUMO INTRODUÇÃO A possibilidade de a hipotermia ter um papel terapêutico durante ou após a reanimação da asfixia perinatal grave tem sido um foco de pesquisa de longa data. Estudos desenhados em torno desse fato mostraram que a hipotermia cerebral moderada, iniciada o mais cedo possível, tem sido associada à neuroproteção potente e duradoura em espécies perinatais. OBJETIVOS Resumidamente, analisar os benefícios da hipotermia na melhoria da função celular, com base nas características celulares da lesão cerebral hipóxico-isquêmica e comparar os resultados de dois métodos diferentes de resfriamento do parênquima cerebral. MATERIAL E MÉTODOS Medline, Lilacs, SciELO e PubMed foram pesquisados para artigos registrados entre 1990 e 2019 nos idiomas português e inglês, com foco em estudos comparando segurança e eficácia do resfriamento corporal total com o resfriamento seletivo da cabeça com EHI. RESULTADOS Descobrimos que o resfriamento de corpo inteiro fornece resfriamento homogêneo para todas as estruturas cerebrais, incluindo as regiões periférica e central do cérebro. O resfriamento seletivo da cabeça fornece um resfriamento mais amplo para a região cortical do cérebro do que para as estruturas centrais. CONCLUSÕES Ambos os métodos demonstraram ter propriedades neuroprotetoras, embora o resfriamento de corpo inteiro forneça uma área mais ampla de proteção. Recentemente, o resfriamento da cabeça combinado com algum resfriamento corporal foi aplicado e essa é a maneira mais promissora. O desafio para o futuro é encontrar formas de melhorar a eficácia do tratamento.

Electrophysiological characteristics of myocardium after hypothermic ischemia-reperfusion in rats with different degrees of arrhythmia: an in vitro experiment / 中华麻醉学杂志

Objective To investigate the electrophysiological characteristics of myocardium after hypothermic ischemia-reperfusion (I/R) in rats with different degrees of arrhythmia using an in vitro experiment.Methods Healthy clean-grade male Sprague-Dawley rats,aged 2-3 months,weighing 300-400 g,were used in this study.The rats were sacrificed after anesthesia,and their hearts were rapidly excised.Sixteen Langendorff-perfused hearts were prepared and divided into 2 groups (n=8 each) by a random number table method:control group (group C) and hypothermic I/R group (group I/R).The hearts were made globally ischemic for 60 min followed by 30-min hypothermic (4 ℃) reperfusion to establish the model of hypothermic I/R injury.The occurrence and duration of arrhythmia and time of recovery of spontaneous heartbeat were recorded during reperfusion.The rats in group I/R were further divided into low-risk group (I/R-L group,ventricular arrhythmia score≤3 points) and high-risk group (I/R-H group,ventricular arrhythmia score＞3 points) according to the arrhythmia score.Monophasic action potential amplitude (MAPA),monophasic action potential (MAP) duration at 50％ and 90％ repolarization (MAPDs0 and MAPD90) and maximum ascending velocity (Vmax) of phase 0 in the endocardium,myocardium and epicardium of the left ventricular anterior wall were recorded at 30 min of equilibration (T0) and 15 and 30 min of reperfusion (T1,2).The effective refractory period (ERP) and ventricular fibrillation threshold (VFT) of the left ventricle were measured by programmed electrical stimulation,and the ERP/MAPD90 ratio was calculated.Results Compared with the baseline at T0,MAPA in the three layers was significantly decreased,and MAPD50 and MAPD90 were prolonged at T1,2 in I/R-L and I/R-H groups,and V in the three layers was decreased at T1,2 in I/R-H group (P＜0.05).MAPD50 and MAPD90 in the three layers were significantly shorter at T2 than at T1 in I/R-L and I/R-H groups (P＜0.05).Compared with group C,MAPDs0,MAPDg0 and ERP in the three layers were significantly prolonged at T1,2,the ERP/MAPDg0 ratio was decreased,and VFT was increased in I/R-L and I/R-H groups (P ＜ 0.05).Compared with I/R-L group,the duration of arrhythmia and MAPD90 and ERP in the three layers were significantly prolonged at T2,the ERP/MAPDg0 ratio was decreased,and VFT was increased in group I/R-H (P＜0.05).Conclusion Myocardial depolarization is inhibited,repolarization duration is prolonged,and electrophysiological stability is decreased after hypothermic I/R in the rats with arrhythmia,and the prolongation of myocardial repolarization and decrease in electrophysiological stability are more obvious in the rats at high risk of arrhythmia.