OBJECTIVE: To investigate the effect of mild hypothermia on neurological function in rats with spinal cord injury (SCI) based on the adenosine monophosphate activated protein kinase (AMPK)/Nod-like receptor protein 3 (NLRP3) pathway. METHODS: Fifty 7-8 weeks old SPF male Sprague Dawley rats were used to establish rat model of SCI by Allen's method. Among them, 48 successfully modeled rats were randomly divided into SCI group, mild hypothermia group (SCI+mild hypothermia treatment), and Compound C group (SCI+mild hypothermia+intraperitoneal injection of 20 mg/kg AMPK/NLRP3 pathway inhibitor Compound C), with 16 rats in each group. Another 16 normal rats with laminectomy were selected as sham-operation group. Basso-Beattie-Bresnahan (BBB) score was used to evaluate the motor ability of rats at 1, 3, 7, 14 days after treatment. After 14 days, the rats were sacrificed, and the spinal cord histopathological morphology was observed by HE staining, the neuronal apoptosis in spinal cord tissue was detected by TUNEL assay, and the serum levels of interleukin 2 (IL-2), IL-6, transforming growth factor β ₁ (TGF-β ₁), malondialdehyde (MDA), and superoxide dismutase (SOD) were detected by ELISA. The expressions of AMPK/NLRP3 pathway proteins in spinal cord tissue, including B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cleaved-Caspase-9 were detected by Western blot. RESULTS: At 1 day after treatment, the rats in SCI group, mild hypothermia group, and Compound C group did not recover their motor ability. With the prolongation of time, the motor function of rats in each group gradually recovered. Among them, the BBB score of SCI group was significantly lower than that of sham-operation group and mild hypothermia group ( P<0.05), and the BBB score of Compound C group was significantly lower than that of mild hypothermia group ( P<0.05). Compared with the sham-operation group, the SCI group displayed obvious pathological changes in the spinal cord tissue, with disordered tissue architecture, inflammatory infiltration, and blurred interstitial boundaries. The neuronal apoptosis rate, Bax/Bcl-2 ratio, cleaved Caspase-9 expression, NLRP3 protein expression, serum IL-2, IL-6, and MDA levels were elevated, whereas serum TGF-β ₁, SOD levels, and spinal cord phosphorylation AMPK/AMPK protein expression significantly decreased ( P<0.05). Compared with the SCI group, the above phenomena significantly improved in the mild hypothermia group ( P<0.05), while the Compound C group showed the opposite trend of change compared to the mild hypothermia group ( P<0.05). CONCLUSION Mild hypothermia can attenuate neurological dysfunction after SCI in rats, potentially by activating the AMPK/NLRP3 pathway.
Animals ; Spinal Cord Injuries/physiopathology* ; Rats, Sprague-Dawley ; Male ; Rats ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Hypothermia, Induced ; Signal Transduction ; Spinal Cord/pathology* ; Apoptosis ; Interleukin-6/metabolism* ; Disease Models, Animal ; bcl-2-Associated X Protein/metabolism* ; Superoxide Dismutase/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Caspase 9/metabolism*

PURPOSE: To investigate the protective effect of sub-hypothermic mechanical perfusion combined with membrane lung oxygenation on ischemic hypoxic injury of yorkshire brain tissue caused by traumatic blood loss. METHODS: This article performed a random controlled trial. Brain tissue of 7 yorkshire was selected and divided into the sub-low temperature anterograde machine perfusion group (n = 4) and the blank control group (n = 3) using the random number table method. A yorkshire model of brain tissue injury induced by traumatic blood loss was established. Firstly, the perfusion temperature and blood oxygen saturation were monitored in real-time during the perfusion process. The number of red blood cells, hemoglobin content, NA⁺, K⁺, and Ca²⁺ ions concentrations and pH of the perfusate were detected. Following perfusion, we specifically examined the parietal lobe to assess its water content. The prefrontal cortex and hippocampus were then dissected for histological evaluation, allowing us to investigate potential regional differences in tissue injury. The blank control group was sampled directly before perfusion. All statistical analyses and graphs were performed using GraphPad Prism 8.0 Student t-test. All tests were two-sided, and p value of less than 0.05 was considered to indicate statistical significance. RESULTS: The contents of red blood cells and hemoglobin during perfusion were maintained at normal levels but more red blood cells were destroyed 3 h after the perfusion. The blood oxygen saturation of the perfusion group was maintained at 95% - 98%. NA⁺ and K⁺ concentrations were normal most of the time during perfusion but increased significantly at about 4 h. The Ca²⁺ concentration remained within the normal range at each period. Glucose levels were slightly higher than the baseline level. The pH of the perfusion solution was slightly lower at the beginning of perfusion, and then gradually increased to the normal level. The water content of brain tissue in the sub-low and docile perfusion group was 78.95% ± 0.39%, which was significantly higher than that in the control group (75.27% ± 0.55%, t = 10.49, p < 0.001), and the difference was statistically significant. Compared with the blank control group, the structure and morphology of pyramidal neurons in the prefrontal cortex and CA1 region of the hippocampal gyrus were similar, and their integrity was better. The structural integrity of granulosa neurons was destroyed and cell edema increased in the perfusion group compared with the blank control group. Immunofluorescence staining for glail fibrillary acidic protein and Iba1, markers of glial cells, revealed well-preserved cell structures in the perfusion group. While there were indications of abnormal cellular activity, the analysis showed no significant difference in axon thickness or integrity compared to the 1-h blank control group. CONCLUSIONS Mild hypothermic machine perfusion can improve ischemia and hypoxia injury of yorkshire brain tissue caused by traumatic blood loss and delay the necrosis and apoptosis of yorkshire brain tissue by continuous oxygen supply, maintaining ion homeostasis and reducing tissue metabolism level.
Animals ; Perfusion/methods* ; Disease Models, Animal ; Brain Injuries/etiology* ; Swine ; Male ; Hypothermia, Induced/methods*

At present, research on the efficacy of local physical cooling devices is mainly based on clinical observation, but there is relatively little research on evaluating the effectiveness of local cold therapy cooling and the penetration depth. This study is based on the research of the structure and morphology of local muscle tissue in the human body, as well as the heat transfer characteristics and mechanisms of the human body. A simulation phantom of human muscle tissue under temperature cycling was created, and the differences in evaluating the effectiveness of local cold therapy between the human body and the simulation phantom were compared. This provides a new evaluation method for evaluating the cooling effectiveness of local physical cooling equipment.
Humans ; Phantoms, Imaging ; Hypothermia, Induced/methods*

OBJECTIVES: To develop risk prediction models for postoperative hypothermia after transurethral holmium laser enucleation of the prostate (HoLEP) using machine learning algorithms. METHODS: We retrospectively analyzed the clinical data of 403 patients from our center (283 patients in the training set and 120in the internal validation set) and 120 patients from Weifang People's Hospital (as the external validation set). The risk prediction models were built using logistic regression, decision tree and support vector machine (SVM), and model performance was evaluated in terms of accuracy, recall, precision, F1 score and AUC. RESULTS: Operation duration, prostate weight, intraoperative irrigation volume, and being underweight were identified as the predictors of postoperative hypothermia following HoLEP. Among the 3 algorithms, SVM showed the best precision rate and accuracy in all the 3 data sets and the best area under the ROC (AUC) in the training set and validation set, followed by logistic regression, which had a similar AUC in the two data sets. SVM outperformed logistic regression and decision tree models in the validation set in precision, accuracy, recall, F1 score, and AUC, and performed well in the external validation set with better precision rate and accuracy than logistic regression and decision tree models but slightly lower recall rate, F1 index, and AUC value than the decision tree model. SVM outperformed logistic regression and decision tree models in precision, accuracy, F1 score, and AUC in the training set, but had slightly lower recall rate than the decision tree. CONCLUSIONS Among the 3 models, SVM has the best performance and generalizability for predicting post-HoLEP hypothermia risk to provide support for clinical decisions.
Humans ; Male ; Retrospective Studies ; Machine Learning ; Transurethral Resection of Prostate/adverse effects* ; Hypothermia/etiology* ; Prostatic Hyperplasia/surgery* ; Algorithms ; Lasers, Solid-State ; Risk Assessment ; Postoperative Complications ; Decision Trees ; Logistic Models ; Aged ; Middle Aged ; Support Vector Machine

OBJECTIVES: To investigate the relationship between hypothermia duration and postoperative complications in patients undergoing gynecological surgery. METHODS: Patients who underwent elective gynecological surgery at our hospital were consecutively enrolled between October 2020 and January 2022. Core temperature was continuously monitored intraoperatively, and early postoperative complications were collected. By adjusting the logistic regression model for potential confounding factors, the association of postoperative complications with the duration of hypothermia, the lowest body temperature below 36°‍C, and the hypothermia upon admission to postanesthesia care unit (PACU) or intensive care unit (ICU) were analyzed. Additionally, the potential inflection point in the relationship between the duration of hypothermia and the risk of postoperative complications was explored by using cumulative probability scatter plots and moving average sequences. RESULTS: The study included 370 patients, with 193 (52.2%) experiencing hypothermia and 177 (47.8%) not. Among them, 92 (24.9%) developed complications. The duration of hypothermia (adjusted odds ratio [OR] for each one-minute increase: 1.003; 95% confidence interval [CI]: 1.000-1.006, P=0.047) and hypothermia upon admission to PACU or ICU (adjusted OR: 1.980; 95% CI: 1.135-3.454, P=0.016) were associated with early postoperative complications. Notably, the cumulative incidence of postoperative complications tended to rise as the duration of hypothermia increased, with a potential inflection point observed at 120 minutes. CONCLUSIONS In gynecological surgery, the duration of hypothermia as well as hypothermia upon admission to PACU or ICU are associated with postoperative complications. Minimizing the duration of hypothermia may be clinically beneficial.
Humans ; Female ; Hypothermia/epidemiology* ; Postoperative Complications/etiology* ; Gynecologic Surgical Procedures/adverse effects* ; Prospective Studies ; Middle Aged ; Adult ; Intensive Care Units ; Time Factors ; Aged

OBJECTIVES: Postoperative hypothermia is a common clinical complication with a high incidence rate, potentially adversely affecting postoperative recovery. Transurethral holmium laser enucleation of the prostate (HoLEP) is a minimally invasive procedure for benign prostatic hyperplasia (BPH). Offering advantages such as minimal bleeding, broad indications, and rapid postoperative recovery. However, research on risk factors for postoperative hypothermia following HoLEP remains limited, and predictive models for guiding clinical practice are lacking. This study aims to develop a predictive model for assessing the risk of postoperative hypothermia in HoLEP patients and to identify relevant risk factors. METHODS: Clinical data from patients who underwent HoLEP at affiliated Hospital of Shandong Second Medical University were retrospectively collected. Patients were categorized into a hypothermia group and a non-hypothermia group based on whether postoperative hypothermia occurred. Preoperative, intraoperative, and postoperative indicators were compared between the 2 groups. Least absolute shrinkage and selection operator (LASSO) regression combined with logistic regression analysis was used to analyze clinical data. A predictive model for assessing the risk of postoperative hypothermia after HoLEP was constructed and internally validated using bootstrap resampling. RESULTS: A total of 403 patients were included in the analysis, among whom 85 patients developed postoperative hypothermia, with an incidence rate of 21.1%. Logistic regression analysis identified operative duration (OR=1.009, 95% CI 1.003 to 1.015), underweight status (OR=9.881, 95% CI 4.038 to 24.910), and prostate weight (OR=1.021, 95% CI 1.012 to 1.030) as independent risk factors for postoperative hypothermia, and these variables were incorporated into the nomogram model. Internal validation showed strong discriminative ability of the nomogram, with an area under the receiver operating characteristic curve (AUC) of 0.755 (95% CI 0.686 to 0.820) and a C-index of 0.832 (95% CI 0.787 to 0.865). The calibration curve demonstrated good consistency between predicted and observed outcomes. Decision curve analysis showed that the nomogram provided greater clinical utility when the risk threshold for postoperative hypothermia was between 8% and 97%. CONCLUSIONS This study developed a nomogram model for predicting the risk of postoperative hypothermia in HoLEP patients, providing clinicians with a simple and effective predictive tool for individualized risk assessment and preoperative decision-making.
Humans ; Male ; Nomograms ; Prostatic Hyperplasia/surgery* ; Lasers, Solid-State/adverse effects* ; Risk Factors ; Retrospective Studies ; Transurethral Resection of Prostate/methods* ; Postoperative Complications/epidemiology* ; Hypothermia/epidemiology* ; Middle Aged ; Aged

BACKGROUND: Emergence delirium (ED) is a kind of delirium that occured in the immediate post-anesthesia period. Lower body temperature on post-anesthesia care unit (PACU) admission was an independent risk factor of ED. The present study was designed to investigate the association between intraoperative body temperature and ED in elderly patients undergoing non-cardiac surgery. METHODS: This study was a secondary analysis of a prospective observational study. Taking baseline body temperature as a reference, intraoperative absolute and relative temperature changes were calculated. The relative change was defined as the amplitude between intraoperative lowest/highest temperature and baseline reference. ED was assessed with the confusion assessment method for intensive care unit at 10 and 30 min after PACU admission and before PACU discharge. RESULTS: A total of 874 patients were analyzed with a mean age of 71.8 ± 5.3 years. The incidence of ED was 38.4% (336/874). When taking 36.0°C, 35.5°C, and 35.0°C as thresholds, the incidences of absolute hypothermia were 76.7% (670/874), 38.4% (336/874), and 17.5% (153/874), respectively. In multivariable logistic regression analysis, absolute hypothermia (lowest value <35.5°C) and its cumulative duration were respectively associated with an increased risk of ED after adjusting for confounders including age, education, preoperative mild cognitive impairment, American Society of Anesthesiologists grade, duration of surgery, site of surgery, and pain intensity. Relative hypothermia (decrement >1.0°C from baseline) and its cumulative duration were also associated with an increased risk of ED, respectively. When taking the relative increment >0.5°C as a threshold, the incidence of relative hyperthermia was 21.7% (190/874) and it was associated with a decreased risk of ED after adjusting above confounders. CONCLUSIONS: In the present study, we found that intraoperative hypothermia, defined as either absolute or relative hypothermia, was associated with an increased risk of ED in elderly patients after non-cardiac surgery. Relative hyperthermia, but not absolute hyperthermia, was associated with a decreased risk of ED. REGISTRATION Chinese Clinical Trial Registry (No. ChiCTR-OOC-17012734).
Humans ; Aged ; Body Temperature ; Emergence Delirium ; Hypothermia ; Postoperative Complications/epidemiology* ; Prospective Studies

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common disease that affects brain function in neonates. At present, mild hypothermia and hyperbaric oxygen therapy are the main methods for the treatment of neonatal HIE; however, they are independent of each other and cannot be combined for synchronous treatment, without monitoring of brain function-related physiological information. In addition, parameter setting of hyperbaric oxygen chamber and mild hypothermia mattress relies on the experience of the medical practitioner, and the parameters remain unchanged throughout the medical process. This article proposes a new device for the treatment of neonatal HIE, which has the modules of hyperbaric oxygen chamber and mild hypothermic mattress, so that neonates can receive the treatment of hyperbaric oxygen chamber and/or mild hypothermic mattress based on their conditions. Meanwhile, it can realize the real-time monitoring of various physiological information, including amplitude-integrated electroencephalogram, electrocardiogram, and near-infrared spectrum, which can monitor brain function, heart rate, rhythm, myocardial blood supply, hemoglobin concentration in brain tissue, and blood oxygen saturation. In combination with an intelligent control algorithm, the device can intelligently regulate parameters according to the physiological information of neonates and give recommendations for subsequent treatment.
Infant, Newborn ; Humans ; Hypothermia, Induced/methods* ; Hypothermia/therapy* ; Hyperbaric Oxygenation ; Brain ; Electroencephalography ; Hypoxia-Ischemia, Brain/therapy*

OBJECTIVES: To investigate the clinical efficacy of mild therapeutic hypothermia (MTH) with different rewarming time on neonatal hypoxic-ischemic encephalopathy (HIE). METHODS: A prospective study was performed on 101 neonates with HIE who were born and received MTH in Zhongshan Hospital, Xiamen University, from January 2018 to January 2022. These neonates were randomly divided into two groups: MTH1 group (n=50; rewarming for 10 hours at a rate of 0.25°C/h) and MTH2 group (n=51; rewarming for 25 hours at a rate of 0.10°C/h). The clinical features and the clinical efficacy were compared between the two groups. A binary logistic regression analysis was used to identify the factors influencing the occurrence of normal sleep-wake cycle (SWC) on amplitude-integrated electroencephalogram (aEEG) at 25 hours of rewarming. RESULTS: There were no significant differences between the MTH1 and MTH2 groups in gestational age, 5-minute Apgar score, and proportion of neonates with moderate/severe HIE (P>0.05). Compared with the MTH2 group, the MTH1 group tended to have a normal arterial blood pH value at the end of rewarming, a significantly shorter duration of oxygen dependence, a significantly higher proportion of neonates with normal SWC on aEEG at 10 and 25 hours of rewarming, and a significantly higher Neonatal Behavioral Neurological Assessment score on days 5, 12, and 28 after birth (P<0.05), while there was no significant difference in the incidence rate of rewarming-related seizures between the two groups (P>0.05). There were no significant differences between the two groups in the incidence rate of neurological disability at 6 months of age and the score of Bayley Scale of Infant Development at 3 and 6 months of age (P>0.05). The binary logistic regression analysis showed that prolonged rewarming time (25 hours) was not conducive to the occurrence of normal SWC (OR=3.423, 95%CI: 1.237-9.469, P=0.018). CONCLUSIONS Rewarming for 10 hours has a better short-term clinical efficacy than rewarming for 25 hours. Prolonging rewarming time has limited clinical benefits on neonates with moderate/severe HIE and is not conducive to the occurrence of normal SWC, and therefore, it is not recommended as a routine treatment method.
Infant, Newborn ; Infant ; Child ; Humans ; Child, Preschool ; Prospective Studies ; Rewarming ; Hypoxia-Ischemia, Brain/therapy* ; Hypothermia, Induced/methods* ; Treatment Outcome ; Electroencephalography/methods*

Mild hypothermia, as a common means of intraoperative nerve protection, has been used in clinical practice. Compared with the traditional methods such as freezing helmet and nasopharyngeal cooling, hypothermic blood perfusion is considered to be a promising treatment for mild hypothermia, but it lacks experimental and theoretical verification of its cooling effect. In this study, the commercial finite element simulation software COMSOL combined the Pennes equation with the cerebrovascular network model to construct a new simplified human brain model, which was further used to simulate the cooling process of cerebral hypothermic blood perfusion. When the hypothermic blood perfusion was 33 ℃, the human brain could enter the mild hypothermic state within 4 minutes. By comparing with helmet cooling, the feasibility and efficiency of the blood perfusion scheme were verified. By comparing with the calculation results based on Pennes equation, the rationality of the model constructed in this study were verified. This model can non-intrusively predict the changes of brain temperature during surgery, and provide a reference for the setting of treatment parameters such as blood temperature, so as to provide personalized realization of safer and more effective mild hypothermia neuro protection.
Humans ; Hypothermia, Induced/methods* ; Hypothermia ; Hemoperfusion ; Brain/physiology* ; Body Temperature