Effects of heat waves on heat stroke in Shanghai, 2013—2023 / 环境与职业医学

Background The substantial health damage attributed to heat waves, along with their increasing intensity and frequency in the context of global warming, highlights the importance of exploring the health effects of heat waves. Objective To calculate the excess heat stroke cases during heat waves in the summer of 2013—2023 in Shanghai, analyze the association between heat waves and heat stroke, and to further explore the modifying effects of heat wave characteristics on heat stroke. Methods Using a retrospective ecological study design, data on heat stroke cases were collected from the heat stroke case reporting system of the Chinese Center for Disease Control and Prevention, and concurrent meteorological data from Xujiahui Meteorological Station. A heat wave was defined as at least 3 consecutive days with daily maximum temperature meeting or exceeding 35 ℃ in this study, excess heat stroke cases related to heat waves were assessed as the difference between the numbers of heat stroke cases observed on a given day and the corresponding 31 d (15 d before and after that day) moving average, and statistical analyses using generalized linear model based on time series study were performed to assess the impact of heat waves on heat stroke. Results Overall 25 heat waves during the study period were observed, leading to a total of estimated 792.6 extra heat stroke cases. The risk of heat stroke significantly increased during heat waves (RR=2.60, 95%CI: 2.08, 3.26), but no statistically significant differences in heat wave effects were observed among different genders, ages, or regions. In terms of the timing of heat waves, the risk of heat stroke was highest during the first heat wave (RR=3.58, 95%CI: 2.82, 4.55), which was significantly higher than that during the second heat wave (RR=2.19, 95%CI: 1.66, 2.90), and no significant effect was observed during the third or subsequent heat waves. The impact of heat waves on heat stroke persisted for more than 4 d, with the risk higher on the fourth day and beyond (RR=2.95, 95%CI: 2.28, 3.83), significantly higher than on the first day of heat wave (RR=1.74, 95%CI: 1.18, 2.56). Conclusion Heat waves had a substantial effect on heat stroke in Shanghai from 2013 to 2023, and special attention need to be paid to heat waves with early onset and long duration.

Epidemiological characteristics of heat stroke and association between heatwave and heat stroke in Jinan City, 2017—2022 / 环境与职业医学

Background In recent years, regional high-temperature weather in summer occurs frequently in China. Heat stroke is the most representative meteorological disease caused by high temperature. In order to improve monitoring, early warning, prevention, and control of heat stroke, it is of great significance to understand the epidemiological characteristics of heat stroke and the associated impact of heatwave. Objective To understand the epidemiological characteristics of heat stroke cases in Jinan City, and to explore the effects of heatwave exposure on heat stroke. Methods Case reports of heat stroke and daily data of meteorological factors in Jinan City from 2017 to 2022 were collected. We described the temporal, population, and regional distribution characteristics of heat stroke cases in Jinan City, and used a time-stratified case-crossover design combined with conditional logistic regression model to explore the effects of heatwave exposure on heat stroke under 12 heatwave definitions (different combinations of intensity and duration). The cut-off percentiles used for heatwave definitions were the 90th (P90), 95th (P95), 97.5th (P97.5), and 99th (P99) percentiles of daily mean temperature; the durations were ≥ 2 d, ≥ 3 d, and ≥ 4 d, respectively. Pi(k), where i is temperature threshold, and k is duration. For example, the definition of a heatwave was notated as P90(2), indicating that the daily mean temperature is ≥ P90 and lasts for ≥ 2 d. Alternatively, lag01 denotes the cumulative lag effect with a 1 d lag, and so on. Results A total of 1394 cases of heat stroke were reported in Jinan City from 2017 to 2022, including 581 mild cases and 813 severe cases, and 85 deaths were reported, with a cumulative fatality rate of 6.10%. The cases of heat stroke reported each year during the study period were concentrated from June to August and peaked in July (665 cases, 47.70%). The sex ratio of males to females in heat stroke cases was 2.02:1. A high incidence of heat stroke was in 50-89 years, with a smaller peak occurring in the age group of 50-59 years and a larger peak in the age group of 70-79 years, respectively. The high-incidence areas of heat stroke were distributed in the western part of Jinan City where city centers situated (Tianqiao District, 274 cases, 19.66%; Huaiyin District, 223 cases, 16.00%) and in the surrounding rural areas (Pingyin County, 254 cases, 18.22%). The effect of heatwave exposure on heat stroke was statistically significant during the study period. The largest effect estimates for the effect on heat stroke occurred under the heatwave definitions of P99(2), P97.5(3), and P97.5(4) at lag04, lag03, and lag04, where corresponding OR (95%CI) values were 9.27 (4.71, 14.24), 8.95 (6.17, 12.98), and 8.22 (4.91, 13.78), respectively. The exposure-response curve showed that the risk of heat stroke tended to increase with the increase of average daily temperature. Conclusion July is the key period for the occurrence of heat stroke among Jinan City residents, while male cases are predominant, more serious cases, age concentration in the 50-89 years. The occurrence of heatwave can further increase the risk of heat stroke with a significant lag effect.

Impact of therapeutic plasma exchange intervention timing and liver injury periodization on the prognosis of patients with exertional heat stroke / 中国输血杂志

【Objective】 To explore the prognostic impact and clinical application value of therapeutic plasma exchange(TPE) intervention timing and liver injury periodization in patients with exertional heat stroke(EHS). 【Methods】 Data of 127 EHS patients from the First Medical Center of the General Hospital of the People′s Liberation Army from January 2011 to December 2023 were collected, then divided into the death group and the survival group based on therapeutic outcomes and into 5 stages according to the dynamic changes of ALT, AST, TBIL and DBIL. According to propensity score matching analysis, 11 patients in the survival group and 12 patients in the death group were included in the statistical analysis, and 20 of them were treated with TPE. The changes in indicators and clinical outcomes before and after TPE were observed, in order to evaluate the impact of intervention timing on prognosis. 【Results】 Among the 23 patients, 14 had no liver injury or could progress to the repair phase, resulting in 3 deaths(with the mortality rate of 21.43%), while 9 patients failed to progress to the repair phase, resulting in 9 deaths(with the mortality rate of 100%), with significant differences(P<0.05). The mortality rate of the first TPE intervention before the third stage of liver injury was 23.08%(3/13), while that of intervention after reaching or exceeding the third stage was 85.71%(6/7), and the difference was statistically significant(P<0.05). 【Conclusion】 TPE should be executed actively in EHS patients combined with liver injury before the third phase to lock its pathological and physiological processes, thereby improving prognosis and reducing mortality.

A Case of Heat Stroke with Presumed Spinal Cord Lesions / The Japanese Journal of Rehabilitation Medicine

A 76-year-old woman was found unconscious in her home one morning in August. She was subsequently diagnosed and treated for heat stroke by her physician. However, 55 days later, she was transferred to our hospital presenting with symptoms of dementia, dysarthria, dysphagia, moderate bilateral upper extremity paralysis, severe lower extremity paraplegia, and loss of deep tendon reflexes. Cerebellar ataxia in her upper extremities and no sensory disturbance in her extremities were also noted. She required assistance when eating and upon excretion, as well as the use of a wheelchair. She was rehabilitated for one month and was subsequently able to urinate on her own. However, her physical function and ability to carry out daily activities did not improve. As a result, she was evaluated further using nerve conduction studies and needle electromyography, the results of which suggested spinal cord lesions (anterior horn cells or ventral roots). In 1985, Delgado et al. reported a case of central nervous system sequelae after heat stroke. In their case, flaccid quadriplegia, bladder-rectal disorder, and sweating dysfunction were observed, but no sensory disturbance was detected. They described pathological findings of lesions in the anterior horn, the medial lateral horn, and the ventral root of the spinal cord. Based on this, it is highly likely that spinal cord lesions were also caused by heat stroke in our case. Although there are few reports of spinal cord lesions as a sequela of heat stroke, this case highlights the need to carefully monitor patients of heat stroke for such pathological conditions.

Prognostic value of neutrophil-to-lymphocyte ratio in patients with severe heat stroke / 中华急诊医学杂志

Objective:To investigate the value of neutrophil-to-lymphocyte ratio (NLR) in predicting the prognosis of patients with severe heat stroke.Methods:A retrospective analysis was performed on patients with severe heat stroke hospitalized in the ICU of Changzhou No. 2 People's Hospital from June 2013 to September 2019. The patients were divided into the survival group and death group according to their 30-day survival. The basic data of the patients were recorded. Blood routine, liver and kidney function parameters, troponin, brain natriuretic peptide, myocardial enzyme spectrum, blood coagulation routine, and acute physiology and chronic health evaluation (APACHE)Ⅱ were analyzed within 24 h after admission. Multivariate COX regression analysis was used to screen the risk factors of 30-day death. Spearman correlation test was used to analyze the correlation between NLR and APACHEII score. Receiver operating characteristic (ROC) curves were drawn to assess the predictive value of NLR for the 30-day death in patients with severe heat stroke. Kaplan-Meier survival curve was used to analyze 30-day cumulative survival of high-risk patients.Results:A total of 115 patients with severe heat stroke were included in this study, and they were divided into the survival group ( n=92) and the death group ( n=23) according to the prognosis. NLR in the death group was significantly higher than that in the survival group ( P<0.05). Multivariate COX regression analysis showed that NLR was an independent risk factor for death after adjusting confounders ( HR=1.091, 95% CI: 1.049-1.136, P<0.001). Spearman correlation test showed a correlation between NLR and APACHEII score ( r=0.655, P<0.001). ROC curve analysis showed that NLR had the greatest predictive value for 30-day death, with an area under ROC curve (AUC) of 0.787, a sensitivity of 82.6%, a specificity of 67.4%, and the cut-off value of 7.35. Kaplan-Meier survival analysis curve shows that patients in the below NLR cut-off value group had a significantly higher 30-day survival rate than those in the above NLR cut-off value group ( P<0.001). Conclusions:The increased NLR is a high risk factor for death in patients with severe heat stroke, and helps predict the prognosis of patients with severe heat stroke.

Epidemiological characteristics and risk assessment of occupational diseases caused by physical factors in Guangdong Province, 2013-2022 / 中国职业医学

Objective To analyze the epidemiological characteristics of occupational diseases caused by physical factors in Guangdong Province from 2013 to 2022, and to evaluate the key risk points of its incidence. Methods The data of newly diagnosed and suspected occupational diseases caused by physical factors in Guangdong Province from 2013 to 2022 were collected from the Occupational Diseases and Hazards Monitoring Information System under China Disease Prevention and Control Information System, and were analyzed retrospectively. The key risk points of occupational diseases caused by physical factors were evaluated. Results A total of 661 cases of occupational diseases caused by physical factors were reported in Guangdong Province from 2013 to 2022, showing an overall increasing trend, with an average annual growth rate of 29.6%. The major occupational diseases caused by physical factors were occupational hand-arm vibration disease and occupational heat stroke, accounting for 59.5% and 39.6%, respectively. The nine prefecture-level cities of Pearl River Delta region accounted for 98.5% of the new cases. The cases were distributed mainly in the manufacturing industry (77.0% of the cases). A total of 294 enterprises were involved in the analysis of newly diagnosed occupational diseases caused by physical factors. Occupational hand-arm vibration cases appeared to be significantly aggregated in specific enterprises, and other disease cases were mostly sporadic. The types of enterprise registration were mainly Hong Kong-, Macao-, and Taiwan-invested enterprises and domestic-funded enterprises, accounting for 53.1% and 41.4%, respectively. In terms of enterprise size, large-scale and small-scale enterprises accounted for 56.5% and 21.4% of cases, respectively. A total of 27.4% of workers with occupational diseases caused by physical factors were identified as suspected occupational diseases before be diagnosed as occupational diseases, all of which were hand vibration disease and heat stroke In the future, attention should be paid to the risks of mass events of occupational hand-arm vibration disease, outbreaks of occupational heat stroke, and missed diagnosis of suspected occupational hand-arm vibration disease. Conclusion Among all occupational diseases caused by physical factors in Guangdong Province, attention should be paid on occupational hand-arm vibration disease and occupational heat stroke. Occupational hand-arm vibration disease has a high risk of group morbidity. Construction workers and sanitation workers have a high potential risk of occupational heat stroke.

A case report of heat stroke with early severe brain edema / 环境与职业医学

Heat stroke can be divided into two types: exertional and classic, mainly manifested as a clear history of exposure to hot temperature/high heat environment or intense physical activity in hot environment, core temperature exceeding 40 ℃, accompanied by central nervous system changes (altered consciousness, epilepsy, psychiatric symptoms, etc.) and multiple organ damage, including respiratory failure, impaired liver and kidney function, rhabdomyolysis, coagulation disorders, abdominal distension, and diarrhea. Its pathology may be manifested as organ endothelial cell damage, inflammatory response, extensive thrombosis, and bleeding tendency. The main treatment measures are cooling therapy, and when combined with other organ damage, organ support or replacement therapy should be carried out in time, including blood transfusion to improve coagulation function and blood purification therapy. Hyperbaric oxygen therapy may improve the prognosis of patients with ischemic hypoxic encephalopathy. We reported a case of a firefighter with sudden impaired consciousness and high fever during forest fire fighting. The patient was sent to a local hospital and his head computed tomography (CT) results showed unclear cerebral gyrus, suggesting severe cerebral edema, and finally diagnosed as heat stroke. After being transferred to Liuzhou Workers' Hospital, his condition continued to deteriorate and signs of multiple organ failure appeared. The patient's cerebral edema was reversed and further development of heat stroke was prevented through early cooling, sedation and anti-epilepsy, endotracheal intubation ventilator-assisted breathing, anti-infection, fluid resuscitation, infusion of fresh frozen plasma and platelets to improve coagulation function, immunomodulatory therapy, renal replacement therapy, and timely artificial liver therapy. Hyperbaric oxygen therapy was ordered during the rehabilitation phase, and the patient recovered well at discharge, leaving no obvious neurological sequelae. Its prognosis is much better than that predicted at admission.

Research progress on effect of unfolded protein response in heat stroke / 解放军医学杂志

Heat stroke(HS)is a serious life-threatening disease caused by heat injury and characterized by a core body temperature>40℃with central nervous system dysfunction and multi-organ failure.The main pathophysiological manifestations of HS are the thermal acute phase response and thermoregulatory imbalance.Proteins are particularly sensitive to heat,and the thermal environment can cause massive protein denaturation,resulting in the deposition of unfolded and misfolded proteins in the cytoplasm,causing cellular dysfunction and even death.The unfolded protein response(UPR),mainly divided into the endoplasmic reticulum UPR and the mitochondrial UPR,is an important physiological process that helps proteins to fold correctly or degrade irretrievably denatured proteins.This paper summarizes the regulatory mechanisms of UPR,the relationship between UPR and severe diseases,as well as the relationship between HS and UPR to provide new ideas for the treatment of HS.

Analysis of clinical features and risk factors of heat stroke patients with infection / 中华急诊医学杂志

Objective:To investigate the clinical features and risk factors of infection in patients with heat stroke (HS).Methods:The patients with HS who were admitted to the emergency departments of seven hospitals, including West China Hospital of Sichuan University, the Second Affiliated Hospital of Chengdu Medical College and so on, between July 01, 2020 and September 30, 2022 were retrospectively analyzed. The basic characteristics and laboratory test results of the patients were collected. The patients were divided into infected group and non-infected group according to the etiological results, and the differences in clinical characteristics between the different groups were compared. Multivariate logistic regression was used to screen variables, and the predictive model was established and ROC curve was performed to compare the predictive efficiency with SOFA score.Results:During the study period, a total of 183 patients with HS were included, and 156 patients were finally included for analysis according to the inclusion and exclusion criteria. Among them, 58 cases (37.2%) were in the infected group. The mortality of infected group was significantly higher than that of non-infected group (41.4% vs. 25.5%, P < 0.05). Compared with the patients in non-infected group, the infected gourp serum procalcitonin, direct bilirubin, alanine transaminase (ALT), creatinine, lactate dehydrogenase (LDH), creatine kinase isoenzymes, myoglobin, activated partial thromboplastin time (APTT) and respiratory support ratio at admission were significantly higher and albumin level was lower in infected group (all P < 0.05). Multivariate logistic regression analysis showed that myoglobin, ALT, APTT and respiratory support required at admission were independent risk factors for HS co-infection. A prediction model was constructed based on these four indicators, and the area under ROC curve of the prediction model was 0.846, which was better than SOFA score (0.732, P < 0.05). Conclusions:The prognosis of patients with heat stroke complicated with infection were obviously poor. Myoglobin, ALT, APTT and need for respiratory support at admission are risk factors for HS complicated with infection. The prediction model based on these four indicators is better than SOFA score for the early identification of the HS patients with infection.

Dachaihu decoction protects intestinal mucosal barrier in severe heat stroke rats by inhibiting Toll-like receptor 4/nuclear factor-κB signaling pathway / 中国中西医结合急救杂志

Objective To explore the effect of Dachaihu decoction on the Toll-like receptor 4/nuclear factor-κB(TLR4/NF-κB)signaling pathway and gastrointestinal mucosal barrier in rats with severe heat stroke.Methods Sixty SPF grade Sprague-Dawley(SD)male rats were divided into normal control group,model group,Dachaihu decoction standard dose group and Dachaihu decoction high dose group of 15 rats in each group.The heat stroke model was replicated in the rats at temperature(40.5±0.5)℃and humidity(65.0±2.0)%;the normal control group was not treated.From 6 hours after mold making,drug intervention was carried out in the Dachaihu decoction high dose group and the Dachaihu decoction standard dose group of 3.38 g·kg-1·d-1 and 1.69 g·kg-1·d-1,every 8 hours for 2 days.Equal amounts of normal saline were administered to the normal control group and model group.At 6,24 and 48 hours after the molding,5 mL abdominal main artery blood from 5 rats were randomly collected from each group,and the blood was obtained by enzyme-linked immunosorbent assay(ELISA)to determine the levels of tumor necrosis factor-α(TNF-α),interleukin-1(IL-1),D-lactic acid,intestinal fatty acid-binding protein(I-FABP).At the same time,the ileum tissue was retained,and the protein expression of TLR4 and NF-κB in intestinal tissue was determined by Western blotting.Some of the ileal tissue was obtained for hematoxylin-eosin(HE)staining,and the intestinal histopathological changes were observed under light microscopy.Results The normal control group of rats had no significant change,and the other three groups showed heatstroke symptoms after mold making.The overall mortality in drug group were significantly lower than that in the model group[3.3%(1/30)vs.20.0%(3/15),P＜0.05].Compared with the normal control group,the serum IL-1,TNF-α,I-FABP,D-lactic acid and the protein expression levels of TLR4 and NF-κB in the model group,Dachaihu decoction standard dose group and Dachaihu decoction high dose group all increased.Compared with the model group,at 24 hours and 48 hours after molding in the Dachaihu decoction standard dose group and Dachaihu decoction high dose group,the serum IL-1,TNF-α,I-FABP,D-lactic acid and the protein expression levels of TLR4 and NF-κB significant decreased[24 hours:TNF-α(ng/L):69.20±4.32,59.37±4.31 vs.76.99±5.02,IL-1(ng/L):132.68±4.93,112.59±9.64 vs.146.75±10.12,I-FABP(mmol/L):504.35±22.23,453.37±32.38 vs.542.58±13.83,D-lactic acid(mmol/L):114.55±8.52,90.57±3.09 vs.127.87±8.37,protein expression of TLR4(A value):1.50±0.08,1.23±0.01 vs.1.86±0.08,protein expression of NF-κB(A value):1.61±0.05,1.21±0.05 vs.1.97±0.08;48 hours:TNF-α(ng/L):58.46±5.13,38.98±5.53 vs.90.21±3.02,IL-1(ng/L):119.12±4.57,84.12±5.08 vs.170.20±6.21,I-FABP(mmol/L):436.04±27.63,321.85±22.03 vs.618.79±12.31,D-lactic acid(mmol/L):87.35±6.84,70.38±4.33 vs.154.14±10.83,protein expression of TLR4(A value):1.19±0.05,1.10±0.13 vs.2.09±0.06,protein expression of NF-κB(A value):1.15±0.09,0.97±0.08 vs.2.20±0.02,all P＜0.05].The expression levels of TNF-α,I-FABP,TLR4 and NF-κB protein in Dachaihu decoction high dose group decreased significantly at 24 hours and 48 hours compared with the standard dose group,however,IL-1 and D-lactic acid decreased significantly at 48 hours after molding(all P＜0.05).The pathology observation showed that,compared with the model group,the intestinal mucosa villus,the lamina propria drop and haemorrhage was decreased in the Dachaihu decoction standard dose group and Dachaihu decoction high dose group.Telangiectasia was reduced and no ulcer formation was observed.Conclusion Dachaihu decoction can inhibit TLR4/NF-κB signaling pathway,reduce intestinal inflammatory response,thus reduce gastrointestinal damage,and protect the gastrointestinal mucosal barrier in rats with severe heatstroke.

Correlation analysis between thromboelastography and liver injury related indexes in patients with heat stroke / 中国热带医学

@#Abstract: Objective To analyze the correlation between the thromboelastography (TEG) indexes and the indexes related to liver injury in patients with heat stroke, and explore the diagnostic value of TEG indexes for liver injury in patients with heat stroke. Methods A total of 95 patients with exertional heat stroke (EHS) admitted to 924 Hospital of the Joint Service Support Force of the People's Liberation Army of China from August 2020 to July 22 were selected, and divided into a non-liver injury group (55 cases) and a liver injury group (40 cases) according to whether there was liver injury. TEG instrument was used for the detection of thromboelastography to record the TEG parameters, including reaction time (R), agglutination time (K), α angle, maximum amplitude (MA value), and coagulation complex index (CI). The levels of glutamic transaminase (AST), alanine aminotransferase (ALT), total bilirubin (TBil), albumin (ALB) were detected by automatic biochemical analyzer. Pearson's method was applied to analyze the correlation between thromboelastography indexes R, K, α angle, CI and liver function indexes AST, ALT, TBil, ALB in patients with heat stroke after liver injury. Receiver operating characteristic curve (ROC) was applied to analyze the predictive value of thromboelastography indexes R, K, α angle, CI and combined detection for liver injury in patients with heat stroke. Results Compared with the non-liver injury group, the AST, ALT and TBil levels in patients with heat stroke in the liver injury group were higher (t=26.174, 16.923, 18.414, P<0.05), while the ALB level was lower (t=24.596, P<0.05); compared with the non-liver injury group, the R and K of patients with heat stroke in the liver injury group were higher (t=58.014, 52.862, P<0.05), and the α angle and CI were lower (t=46.853, 60.717, P<0.05); R was positively correlated with AST and ALT (r=0.532, 0.610, P<0.001), and negatively correlated with ALB (r=-0.551, P<0.001) in patients with heat stroke complicated with liver injury; K was positively correlated with AST, ALT and TBil (r=0.661, 0.531, 0.504, P<0.001); α angle was negatively correlated with AST and ALT (r=-0.473, -0.448, P<0.01), and positively correlated with ALB (r=0.539, P<0.001); CI was negatively correlated with AST, ALT and TBil (r=-0.458, -0.505, -0.549, P<0.001); the area under the curve (AUC) of thromboelastography indexes R, K, α angle and CI in predicting liver injury in patients with heat stroke was 0.807 (sensitivity of 70.0%, specificity of 81.6%), 0.831 (sensitivity of 77.5%, specificity of 85.5%), 0.747 (sensitivity of 67.5%, specificity of 74.5%), and 0.788 (sensitivity of 77.5%, specificity of 83.6%), respectively. The AUC of combined detection to predict liver injury in patients with heat stroke was 0.967 (sensitivity of 92.5%, specificity of 91.9%). Conclusions The thromboelastography indexes are correlated with the indexes related to liver injury in patients with heat stroke, and the thromboelastography indexes are helpful to diagnose liver injury in patients with heat stroke.

Manifestaciones clínicas, diagnóstico y tratamiento del golpe de calor / Clinical Manifestations, Diagnosis and Management of Heat Stroke

Introducción: El golpe de calor es una enfermedad que fue descrita hace más de 2000 años, sin embargo, los cambios climáticos que se han presentado en las últimas décadas han permitido que su prevalencia esté en aumento. Se considera una entidad compleja en la cual existe un compromiso importante de la termorregulación corporal y, en consecuencia, del resto de sistemas. Objetivos: Orientar al abordaje adecuado y óptimo de conceptos clínicos, epidemiológicos, factores el riesgo, presentación clínica y repercusión sobre los diferentes sistemas. Métodos: Se realizó una revisión de la literatura científica de personas con golpe de calor, en quienes se evaluaron sus factores asociados, métodos diagnósticos y manejos terapéuticos. Se realizó una búsqueda de la literatura en las siguientes bases de datos: Pubmed/Medline, Science Direct, Scopus, DOAJ, Embase, Cochrane, Direme, Redalyc y SciELO. Conclusiones: El golpe de calor es una urgencia médica que implica un manejo rápido y óptimo dado su morbilidad y mortalidad, lo cual puede minimizarse si se cumplen los objetivos de tratamiento. El enfriamiento por inmersión en agua helada, por convección o evaporación son las medias más usadas. Evitar la falla multiorgánica es el segundo objetivo terapéutico(AU)

Introduction: Heat stroke is a disease described more than 2000 years ago; however, the climatic changes that have occurred in recent decades have allowed an increase in its prevalence. It is considered a complex entity in which there is an important compromise of body thermoregulation and, consequently, of the rest of the systems. Objectives: To define important concepts concerning heat stroke, risk factors, clinical presentation and repercussions on the different systems, as well as to guide an appropriate and optimal management. Methods: A review of the scientific literature about people with heat stroke was carried out to assess its associated factors, diagnostic methods and therapeutic management. A literature search was performed in the following databases: Pubmed/Medline, Science Direct, Scopus, DOAJ, Embase, Cochrane, Bireme, Redalyc, and SciELO. Conclusions: Heat stroke is a medical emergency that requires rapid and optimal management given its morbidity and mortality, which can be minimized if management goals are met. Cooling by immersion into ice water, convection or evaporation are the most commonly used measures. Avoidance of multiorgan failure is the second therapeutic objective(AU)

Climate change and demand of emergency care in Japan / Journal of Rural Medicine

Both the frequency and severity of heat stress-related health problems have been increasing globally, probably due to global warming. The Intergovernmental Panel on Climate Change published a landmark climate report, the 6th Assessment Report, which shocked the world. It emphasized that anthropogenic activities, such as the combustion of fossil fuels, oil, gas, and coal, were responsible for climate change. The combination of population aging, and increased temperatures has meant that the number of people requiring emergency transport for heatstroke has been increasing in Japan from 2008 to 2020. The increase in ambient temperatures and the number of patients requiring emergency transport were strongly correlated (Spearman correlation coefficient: r=0.669 and P=0.008). Like many human activities, medical care is resource intensive and contributes significantly to climate change through the consumption of energy and water, as well as the emission of greenhouse gases. As healthcare professionals, we need to be cognizant of how our eco-friendly activities both on and off the job can contribute to saving both the patients and us.

Design and application of a cooling device based on the phase-change material for heat stroke / 中华危重病急救医学

Heat stroke is a critical and health-threatening disease, triggered by thermal stimulus and progressing rapidly. It can give rise to multiple organ dysfunction syndrome (MODS), resulting in a high mortality rate. Nearly 30% of survivors will suffer with different sequelae, for instance, the neurological sequelae. Currently, the early rapid cooling is the focus of therapy for heat stroke. Therefore, it is imperative to design a cooling module suitable for the treatment of heat stroke in the field and in the hospital to realize the goal of early rapid cooling and the effective targeted temperature management (TTM). The cooling device is composed of a cooling blanket and a cooling cap. The blanket and cap are made by temperature changeable fabric. The cooling blanket comprises a backing layer, a buffer layer, a flexible heat conduction capsule body, a temperature changing component, a fixed part and a temperature sensor. The cooling cap includes a main body and two side ears, in which the main body is worn on the top of the patient's head, and the front is equipped with a flexible display screen, which is convenient for real-time monitoring the temperature of the temperature change component of the cooling blanket. The lateral ear can wrap the patient's ears and neck, and the tympanic membrane thermometer is designed to monitor the tympanic membrane temperature in real time. The tympanic membrane thermometer is also designed at the ear to monitor the tympanic auditory canal temperatures in real time.Continuous dynamic temperature monitoring can guide the duration of cooling treatment and stop cooling in time. The cooling component is portable, easy to operate, real-time temperature monitoring, excellent cooling effect and reusable. It is used for on-site first aid, transportation and continuous cooling for patients with heat stroke in the ward.

Development and evaluation of a predictive nomogram for survival in heat stroke patients: a retrospective cohort study / 世界急诊医学杂志（英文）

@#BACKGROUND: This study aimed to establish an effective nomogram to predict the survival of heat stroke (HS) based on risk factors. METHODS: This was a retrospective, observational multicenter cohort study. We analyzed patients diagnosed with HS, who were treated between May 1 and September 30, 2018 at 15 tertiary hospitals from 11 cities in Northern China. RESULTS: Among the 175 patients, 32 patients (18.29%) died before hospital discharge. After the univariate analysis, mechanical ventilation, initial mean arterial pressure <70 mmHg, maximum heart rate, lab results on day 1 (white blood cell count, alanine aminotransferase, creatinine), and Glasgow admission prediction score were included in multivariate analysis. Multivariate Cox regression showed that invasive ventilation, initial mean arterial pressure <70 mmHg (1 mmHg=0.133 kPa), and Glasgow admission prediction score were independent risk factors for HS. The nomogram was established for predicting 7-d and 14-d survival in the training cohort. The nomogram exhibited a concordance index (C-index) of 0.880 (95% confidence interval [95% CI] 0.831-0.930) by bootstrapping validation (B=1,000). Furthermore, the nomogram performed better when predicting 14-d survival, compared to 7-d survival. The prognostic index cut-off value was set at 2.085, according to the operating characteristic curve for overall survival prediction. The model showed good calibration ability in the internal and external validation datasets. CONCLUSION: A novel nomogram, integrated with prognostic factors, was proposed; it was highly predictive of the survival in HS patients.

Research progress in mechanism and protection of high temperature environment influencing the body function / 中华创伤杂志

The thermal environment increases the risk of thermal injury for persons under high temperature environment. A full understanding of the effects and hazards of the thermal environment on the human body is of great significance to improve the awareness of persons under high temperature environment and reduce occupational heat damage during work. The authors mainly review the thermal environment from aspects of the definition, mechanism of its influence on main functional systems of the human body, influencing factors of heat stress and progress of protection, so as to provide references for the identification and protection of heat-induced diseases for workers under high temperature environment.

Ruifuping pectin protects against intestinal mucosal injury in the rat exertional heat stroke model / 中华危重病急救医学

Objective:To evaluate the intestinal function in rats with exertional heat stroke (EHS) and explore the protective role of Ruifuping pectin (RFP) against heat related intestinal mucosal injury.Methods:One hundred and twenty healthy special pathogen free (SPF) male Sprague-Dawley (SD) rats were randomly divided into normothermic control group, EHS model group, hyperthermic plus drinking water group (H 2O+EHS group) and hyperthermic plus pectin group (RFP+EHS group) with 30 rats in each group. The rats in the H 2O+EHS group and RFP+EHS group were given water 20 mL/kg or RFP 20 mL/kg orally for 5 days during adaptive training period. After 1 week, the temperature control range was adjusted to (37±1)℃ using the temperature control treadmill, and the rat model of EHS was reproduced by one-time high temperature exhaustive exercise. No rehydration intervention was given during the training adaptation period in the EHS model group. The rats in the normothermic control group were maintained to room temperature (25±2)℃ and humidity (55±5)% without other treatment. Behavior tests including withdraw response, righting, and muscle strength were performed immediately after onset of EHS. Blood of inferior vena cava was collected, and the serum inflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-1β, IL-10)] and activity of diamine oxidase (DAO) were detected by enzyme linked immunosorbent assay (ELISA). The intestinal mucosa was collected, after hematoxylin-eosin (HE) staining, and Chiu score was performed to assess EHS induced pathological changes under light microscope. Results:The rats in the EHS model group had behavioral, inflammatory and pathological changes, such as delayed withdraw response and righting, decreased forelimb pulling, increased inflammatory index, and obvious intestinal mucosal injury, which indicated that the reproduction of the EHS model was successful. There was no significant difference in above parameters between the H 2O+EHS group and the EHS model group except that the inflammatory index in the RFP+EHS group was improved. Compared with the EHS model group, the withdraw reflex to pain and righting after RFP pretreatment in the RFP+EHS group were significantly improved (righting score: 1.4±0.2 vs. 0.3±0.2, withdraw reflex to pain score: 1.0±0.1 vs. 0.2±0.1, both P < 0.05), the muscle strength was significantly increased (N: 13.0±0.5 vs. 8.2±0.6, P < 0.01). The levels of pro-inflammatory factors in the RFP+EHS group were significantly lower than those in the EHS model group [TNF-α (ng/L): 67.5±9.2 vs. 194.3±13.7, IL-6 (ng/L): 360.0±54.1 vs. 981.2±84.4, IL-1β (ng/L): 33.7±9.0 vs. 88.7±6.1, all P < 0.01], while the level of anti-inflammatory factor IL-10 was higher than that in the EHS model group (ng/L: 208.7±10.5 vs. 103.7±7.0, P < 0.01). The degree of intestinal mucosal injury in the RFP+EHS group was less severe than that in the EHS model group, and the Chiu score and DAO were significantly lower than those in the EHS model group [Chiu score: 1.5±0.2 vs. 3.8±0.0, DAO (U/L): 83.7±6.7 vs. 128.7±10.5, both P < 0.05]. Conclusions:High temperature training can damage the intestinal barrier function, and induce endotoxemia and systemic inflammatory response syndrome (SIRS) in rats. Oral prophylactic RFP can protect the intestinal barrier function, alleviate SIRS, and promote the recovery of basic nerve reflex and muscle strength after the occurrence of EHS in rats.

Design and application of a split first aid suit for heat stroke / 中华危重病急救医学

In the trend of global warming and the increasing number of participating in high-intensity sports, the incidence of heat stroke is increasing year by year. Heat stroke is categorized to the class of heat emergent diseases. If there is no quick and effective treatment, the mortality rate is as high as 50%. Early, rapid, and effective cooling is the key point in the treatment of heat stroke. The early recognition and rapid lowering the core body temperature to 38.9 ℃ within 30 minutes of exertional heat stroke results in better clinical outcome with the fewest complications, however, the "golden 30 minutes" is far from enough to complete emergency transport and evaluation. Therefore, it is urgent to develop a first aid suit for heat stroke suitable for field treatment and transportation, so as to achieve the treatment goal of early rapid and effective cooling in field environment. For this purpose, the medical staff of the department of critical care medicine of the Eighth Medical Center of the Chinese People's Liberation Army General Hospital designed and developed the split first aid suit, which is suitable for heat stroke patient in the harsh environment lacking medical supplies and water during transportation. The medical staff who designed the first aid suit obtained a National Utility Model Patent of China (ZL 2020 2 1627326.4). The split heat stroke first aid suit is composed of four main parts: a sleeveless coat, a hat, sleeves and wrapped pants. All of them are made by temperature changeable fabric which is a composite material made by fine porous silica gel particles and potassium nitrate. The cuffs of the sleeveless top of the clothes part and the sleeves are connected as a whole by the connecting pieces; and the front end of the hem of the clothes part and the wrapped trousers are also connected as a whole by the connecting pieces, which is convenient for fixing and transportation. In order to control the water injection quantity, the water injection bag and the corresponding components are designed to ensure the same amount of water can be injected to the heat stroke first aid suit at each time, so the same frigorific effect can be attainable. The service temperature is 14-18 ℃, so it will not cause local frostbite to patients when used for a long time. This split-type first aid suit can be used in the movement, rescue and transportation of heat stroke patients. It is easy to carry and use with accurate cooling effect with low cost, moreover, it is reusable and can be widely used for on-site emergency and transportation of heat stroke patients.

The mechanism of Pin1 mediated oxidative stress of vascular endothelial cells involved in severe heat stroke induced acute lung injury / 中华急诊医学杂志

Objective:To explore the molecules mechanism of Pin1 in severe heat stroke induced acute lung injury by observing Pin1 regulate oxidative stress and apoptosis formation in pulmonary microvascular endothelial cells (PMVECs) and lung tissue in heat stressed mice.Methods:In vitro, a PMVECs heat stress (HS) model was established. In the control group, PMVECs were placed in a standard 37 °C, 5% CO 2 cell incubator; in the HS group, PMVECs were placed in a 43 °C cell incubator for 2 h, then the cells were further incubated at 37 °C for 1, 3, 6 or 12 h. PMVECs were pretreated with Pin1 inhibitor Juglone (1 μmol/L) 1 h before 43 °C of HS. In vivo, a severe heat stroke mouse model was established. In the HS group, the mice were kept at the simulation of climate chamber with temperature (35.5±0.5) °C, humidity (60±5)%, the rectum temperature in mice was measured by the anal rectal temperature table, when the temperature reached 42 °C, the heat exposure was stopped, and the mice were sacrificed at 1, 3, 6 or 12 h after HS. In the control group, the mice were kept at room temperature (25±0.5) °C. Mice received daily intraperitoneal administration of Pin1 inhibitor Juglone (1 mg/kg) for 3 d before HS. The protein level of Pin1, cleaved caspase-9 and cleaved caspase-3 were analyzed by Western blot, the level of O 2-˙ in cells was observed by DHE staining and fluorescence microscopy, the levels of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in lung tissue were measured by ELISA, the pathological changes of mice in different group were detected by HE staining, and the expression of Pin1 in the lung tissue of different groups was detected by immunohistochemical staining, the apoptosis rate of the lung tissue in different groups was tested by TUNEL staining. Results:At 1 h after HS, the protein expression of Pin1 in PMVECs and lung tissue began to increase in a rewarming time-dependent manner ( F=771.6, P<0.05; F=1 035, P<0.05). Cleaved caspase-9 protein in PMVECs and lung tissue started to increase at 3 h post-HS, then increased with a rewarming time-dependent manner ( F=729.8, P<0.05; F=1 773, P<0.05). The protein expression of cleaved caspase-3 in PMVECs and lung tissue also started to increase at 3 h after HS and the expression continued to be increased with prolonged rewarming time, and the trend was consistent with cleaved caspase-9 ( F=1 084, P<0.05; F=1 252, P<0.05). In addition, HS induced the increased release of O 2-˙ from PMVECs, HS induced the imbalance of oxidation-antioxidant system in lung tissue of mice after HS which verified by the continuous release of MDA ( F=114.2, P<0.05) and the continuous inhibition of SOD activity ( F=99.15, P<0.05). Compared with the HS group, pretreatment with Pin1 inhibitor Juglone in PMVECs and mice before HS significantly inhibited the protein expression of Pin1, cleaved caspase-9 and cleaved caspase-3 (all P<0.05), pretreatment with Pin1 inhibitor greatly reduced the release of O 2-˙ in PMVECs after HS, and promoted the restore of the oxidation-antioxidant system balance of lung tissue in mice with severe heat stroke. In addition, compared with the HS group, inhibiting the expression of Pin1 significantly decreased HS induced MDA release [(11.53±0.84) nmol/mL vs (9.65±0.69) nmol/mL, t=12.52, P<0.05], promoted the restore of SOD activity [(41.18±3.45) U/mL vs (57.52±4.83) U/mL, t=5.57, P<0.05] and improved the pathological damage of lung tissue as well as decreased the occurrence of apoptosis in post-HS mice. Conclusion:It was confirmed that Pin1 is involved in heat stress induced acute lung injury mainly through mediating oxidative stress response and apoptosis.

Endoplasmic reticulum stress and NOD-like receptor protein 3 involves in intestinal mucosal injury induced by severe heat stroke / 中华急诊医学杂志

Objective:To observe whether endoplasmic reticulum stress and NOD-like receptor protein 3 (NLRP3) inflammasome activation were involved in severe heat stroke induced intestinal mucosal injury and to investigate the potential protective effect of the endoplasmic reticulum stress inhibitor 4-phenylbutyric acid (4-PBA).Methods:Thirty male BALB/c mice were randomly (random number) assigned to 3 groups: the control group, heat stroke group (HS), and 4-PBA pretreatment group (4-PBA+HS, 4-PBA 120 mg/kg, intraperitoneal injection). Mice in the control group were placed at room temperature, while mice in the HS group and 4-PBA+HS group were placed in a prewarmed chamber [temperature (35.5±0.5) °C, humidity (60.0±5.0)%]. A rectal temperature (Tc) that reached 42 °C was considered to indicate severe heat stroke. The concentrations of malondialdehyde (MDA) and superoxide dismutase (SOD) in intestinal homogenate were analyzed by a colorimetric method, serum interleukin-1β (IL-1β) and interleukin-18 (IL-18) were assessed by ELISA, intestinal histopathology was evaluated by hematoxylin and eosin (HE) staining, intestinal ultrastructure was observed by electron microscopy, and the protein expression of GRP78, CHOP, NLRP3 and cleaved caspase-1 were analyzed by Western blot. Data were statistically analyzed by ANOVA test and LSD- t multiple comparison test if homogeneous variance, or analyzed by Welch test and Dunnett's T3 multiple comparison test if heterogeneous variance. Results:The concentration of MDA in the HS group was increased ( t=14.243, P<0.01), while SOD was decreased compared with that in the control group ( t=7.781, P<0.01), and the concentrations of serum IL-1β and IL-18 were significantly elevated ( t=12.664, P<0.01; t=16.240, P<0.01). Under light microscopy, extensive destruction of small intestinal villi and inflammatory cell infiltration were observed in the intestines of mice with severe heat stroke. Transmission electron microscopy showed that endoplasmic reticulum structures were significantly expanded, and mitochondria were vacuolated in the intestines of mice with severe heat stroke. Compared with those in the control group, the protein expression levels of GRP78, CHOP, NLRP3 and cleaved caspase-1 in the small intestine were elevated in the HS group ( t=14.824, P <0.01; t=12.667, P<0.01; t=9.298, P<0.01; and t=6.588, P=0.001). Compared with those in the HS group, mice in the 4-PBA pretreatment group exhibited reduced concentrations of MDA ( t=9.167, P<0.01), increased SOD ( t=6.077, P<0.01) , and reduced serum IL-1β and IL-18 levels ( t=4.889, P= 0.001; t=5.693, P<0.01). In addition, 4-PBA pretreatment significantly alleviated the pathological disruption and ultrastructural damage to small intestine tissues. Moreover, 4-PBA pretreatment reduced GRP78, CHOP , NLRP3 and cleaved caspase-1 protein expression ( t=9.080, P<0.01; t=7.152, P<0.01; t=4.249, P=0.005; t=3.650, P=0.011). Conclusions:Endoplasmic reticulum stress and NLRP3 inflammasome are involved in intestinal mucosal injury induced by severe heat stroke. 4-PBA plays a protective role by alleviating endoplasmic reticulum stress and NLRP3 inflammasome activation.