HMGB1 released from pyroptotic vascular endothelial cells promotes immune disorders in exertional heatstroke.

BACKGROUND AND OBJECTIVE: Exertional heatstroke (EHS) mainly occurs in healthy young people with rapid onset and high mortality. EHS immune disorders can cause systemic inflammatory responses and multiple organ failure; however, the underlying mechanisms remain unclear. As high mobility group box 1 (HMGB1) is a prototypical alarmin that activates inflammatory and immune responses, this study aimed to investigate the effect and mechanism of HMGB1 in the pathogenesis of EHS. METHODS: Peripheral blood mononuclear cell (PBMC) transcriptome sequencing of healthy volunteers, classical heatstroke patients, and EHS patients was performed. A mouse model of EHS was established and murine tissue damage was evaluated by H&E staining. HMGB1 localization and release were visualized using immunofluorescence staining. Human umbilical vein endothelial cells (HUVECs) and THP-1 cells were co-cultured to study the effects of HMGB1 on macrophages. A neutralizing anti-HMGB1 antibody was used to evaluate the efficacy of EHS treatment in mice. RESULTS: Plasma and serum HMGB1 levels were significantly increased in EHS patients or mice. EHS-induced endothelial cell pyroptosis promoted HMGB1 release in mice. HMGB1 derived from endothelial cell pyroptosis enhanced macrophage pyroptosis, resulting in immune disorders under EHS conditions. Administration of anti-HMGB1 markedly alleviated tissue injury and systemic inflammatory responses after EHS. CONCLUSIONS: The release of HMGB1 from pyroptotic endothelial cells after EHS promotes pyroptosis of macrophages and systemic inflammatory response, and HMGB1-neutralizing antibody therapy has good application prospects for EHS.

Machine learning-based analysis and prediction of meteorological factors and urban heatstroke diseases.

Introduction: Heatstroke is a serious clinical condition caused by exposure to high temperature and high humidity environment, which leads to a rapid increase of the core temperature of the body to more than 40°C, accompanied by skin burning, consciousness disorders and other organ system damage. This study aims to analyze the effect of meteorological factors on the incidence of heatstroke using machine learning, and to construct a heatstroke forecasting model to provide reference for heatstroke prevention. Methods: The data of heatstroke incidence and meteorological factors in a city in South China from May to September 2014-2019 were analyzed in this study. The lagged effect of meteorological factors on heatstroke incidence was analyzed based on the distributed lag non-linear model, and the prediction model was constructed by using regression decision tree, random forest, gradient boosting trees, linear SVRs, LSTMs, and ARIMA algorithm. Results: The cumulative lagged effect found that heat index, dew-point temperature, daily maximum temperature and relative humidity had the greatest influence on heatstroke. When the heat index, dew-point temperature, and daily maximum temperature exceeded certain thresholds, the risk of heatstroke was significantly increased on the same day and within the following 5 days. The lagged effect of relative humidity on the occurrence of heatstroke was different with the change of relative humidity, and both excessively high and low environmental humidity levels exhibited a longer lagged effect on the occurrence of heatstroke. With regard to the prediction model, random forest model had the best performance of 5.28 on RMSE and dropped to 3.77 after being adjusted. Discussion: The incidence of heatstroke in this city is significantly correlated with heat index, heatwave, dew-point temperature, air temperature and zhongfu, among which the heat index and dew-point temperature have a significant lagged effect on heatstroke incidence. Relevant departments need to closely monitor the data of the correlated factors, and adopt heat prevention measures before the temperature peaks, calling on citizens to reduce outdoor activities.

Cardiac MR Feature Tracking Derived Strain Analysis can Predict Return to Training following Exertional Heatstroke.

BACKGROUND: Exertional heatstroke (EHS) is increasingly common in young trained soldiers. However, the prognosis marker in EHS patients remains unclear. To evaluate cardiac MRI feature tracking (CMR-FT) derived left ventricle (LV) strain as a biomarker for return to training (RTT) in trained soldiers with EHS in a prospective CMR cohort. METHODS: Trained soldiers (participants) with EHS underwent cardiac MR cine sequences between June 2020 and August 2023. Two-dimensional (2D) LV strain parameters were derived. At 3 months after index CMR, the participants with persistent cardiac symptoms including chest pain, dyspnea, palpitations, syncope, and recurrent heat-related illness were defined as non-RTT. Multivariable logistic regression analysis is used to develop a predictive RTT model. The performance of different models was compared using the area under curve (AUC). RESULTS: A total of 80 participants (median age, 21 years; interquartile range (IQR), 20-23 years) and 27 health controls (median age, 21 years; IQR, 20-22 years) were prospectively included. Of the 77 participants, 32 (41.6%) had persistent cardiac symptoms and were not able to RTT at 3 months follow-up after experiencing EHS. The 2D global longitudinal strain (GLS) was significantly impaired in EHS participants compared to the healthy control group (-15.81 ± 1.67% vs -16.93 ± 1.22%, P =.001), which also showed significantly statistical differences between participants with RTT and non-RTT (-14.99 ± 3.54% vs -16.53 ± 1.43%, P <.001). 2D-GLS (≤ -15.00%) (odds ratio, 1.53; 95% confidence interval (CI): 1.08, 2.17; P =.016) was an independent predictor for RTT even after adjusting known risk factors. 2D-GLS provided incremental prognostic value over the clinical model and conventional CMR parameters model (AUCs: 0.72 vs 0.88, P =.013; 0.79 vs 0.88, P =.023; respectively). CONCLUSIONS: Two-dimensional global longitudinal strain (≤ -15.00%) is an incremental prognostic CMR biomarker to predict return to training in exertional heatstroke soldiers.

Heatstroke death identification using ATR-FTIR spectroscopy combined with a novel multi-organ machine learning approach.

With global warming, the number of deaths due to heatstroke has drastically increased. Nevertheless, there are still difficulties with the forensic assessment of heatstroke deaths, including the absence of particular organ pathological abnormalities and obvious traces of artificial subjective assessment. Thus, determining the cause of death for heatstroke has become a challenging task in forensic practice. In this study, hematoxylin-eosin (HE) staining, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and machine learning algorithms were utilized to screen the target organs of heatstroke and generate a multi-organ combination identification model of the cause of death. The hypothalamus (HY), hippocampus (HI), lung, and spleen are thought to be the target organs among the ten organs in relation to heatstroke death. Subsequently, the single-organ and multi-organ combined models were established, and it was found that the multi-organ combined approach yielded the most precise model, with a cross-validation accuracy of 1 and a test-set accuracy of 0.95. Additionally, the primary absorption peaks in the spectrum that differentiate heatstroke from other common causes of death are found in Amide I, Amide II, δ CH2, and vas PO2- in HI, δ CH2, vs PO2-, v C-O, and vs C-N+-C in HY, Amide I, δ CH2, vs COO-, and Amide III in lung, Amide I and Amide II in spleen, respectively. Overall, this research offers a novel technical approach for determining the heatstroke death as well as crucial evidence for judicial identification.

Effect of platelet dynamic changes on disseminated intravascular coagulation and prognosis in severe heatstroke patients.

OBJECTIVE: This study aimed to investigate the dynamic changes in the platelets of patients with severe heatstroke and the impact of these changes on the occurrence of disseminated intravascular coagulation (DIC) and prognosis in them. METHODS: This retrospective cohort study conducted at two tertiary hospitals recruited 264 patients with severe heatstroke. Logistic regression was used to analyze the association between platelet counts and DIC. The receiver operating characteristic (ROC) curve was used to evaluate the predictive performance of platelets count for DIC occurrence. We used mediation effect to analysis the role of DIC as a mediating variable to mediate the relationship between platelet count decrease after 24 hours and death. RESULTS: There were 214 patients with lower platelet counts compared to admission (107 × 109/L[69,168] vs.171 × 109/L[126,215], p < 0.001). The DIC patients had lower platelet counts than the non-DIC patients when measured in the emergency department and after 24 hours. The platelet count decrease after 24 hours was a risk factor for DIC (odds ratio [OR] = 2.710, 95% confidence interval [CI] = 1.069-6.869). The results of the ROC curve revealed that the predictive performance of the platelet count after 24 hours (area under the curve [AUC] = 0.8685, 95% CI = 0.8173-0.9197) was significantly better than that of the platelet count measured in the emergency department (AUC = 0.7080, 95% CI = 0.6345-0.7815). Mediation analyses showed that PLT decrease after 24 hours did not directly lead to death, but can indirectly cause death by inducing the development of DIC. CONCLUSIONS: Decreased platelet count is an independent risk factor for DIC in patients with severe heatstroke. Although the platelet counts measured in the emergency department and after 24 hours show a good predictive performance for DIC occurrence, the prediction performance of the latter is better.

Hyperbaric oxygen therapy attenuates heatstroke-induced hippocampal injury by inhibiting microglial pyroptosis.

Background: Central nervous system (CNS) injury is the most prominent feature of heatstroke and the hippocampus is prone to damage. However, the mechanisms underlying the heatstroke-induced hippocampal injury remain unclear. Hyperbaric oxygen (HBO) therapy prevents CNS injury in heatstroke mice. However, the underlying mechanisms of HBO in heatstroke-induced hippocampal injury remain unclear. This study aimed to elucidate the protective effects of HBO against hippocampal injury and its potential role in microglial pyroptosis in heatstroke rats.Methods: A rat heatstroke model and a heat stress model with a mouse microglial cell line (BV2) were, respectively, used to illustrate the effect of HBO on heat-induced microglial pyroptosis in vivo and in vitro. We used a combination of molecular and histological methods to assess microglial pyroptosis and neuroinflammation both in vivo and in vitro.Results: The results revealed that HBO improved heatstroke-induced survival outcomes, hippocampal injury, and neurological dysfunction in rats. In addition, HBO mitigates microglial pyroptosis and reduces the expression of pro-inflammatory cytokines in the hippocampus of heatstroke rats. In vitro experiments showed that HBO attenuated BV2 cell injury under heat stress. Furthermore, HBO prevented heat-induced pyroptosis of BV2 cells, and the expression of pro-inflammatory cytokines IL-18 and IL-1ß was reduced. Mechanistically, HBO alleviates heatstroke-induced neuroinflammation and hippocampal injury by preventing microglial pyroptosis. Conclusions: In conclusion, HBO attenuates heatstroke-induced neuroinflammation and hippocampal injury by inhibiting microglial pyroptosis.

Heat stress-induced platelet dysfunction is associated with loss of fibrinogen and is improved by fibrinogen supplementation.

INTRODUCTION: Heatstroke is a critical heat-related condition characterized by coagulopathy and multiple organ dysfunction. One of the most severe complications of heatstroke is disseminated intravascular coagulation. This condition manifests as excessive clot formation and bleeding that are primarily due to platelet depletion and dysfunction. Fibrinogen plays a crucial role in hemostasis because it links integrin αIIbß3 on adjacent platelets, thereby promoting the platelet activation and aggregation necessary for clot formation. However, reduced fibrinogen levels may impair the formation of the initial platelet plug and increase the risk of bleeding. The current study explored the effect of fibrinogen on platelet dysfunction in a heatstroke model. MATERIALS AND METHODS: Male Wistar rats were subjected to heat stress, and subsequent changes in hemodynamic, biochemical, and coagulation parameters were analyzed. Platelet viability, aggregation, adhesion, spreading and fibrin clot retraction were assessed. RESULTS: The rats with heatstroke exhibited a variety of clinical symptoms, including hypotension, tachycardia, multiple organ dysfunction, and coagulopathy. Platelet viability in the heatstroke group was comparable to that in the healthy control group. However, the heatstroke group exhibited significant reductions in plasma fibrinogen levels and platelet aggregation, adhesion, spreading, and fibrin clot retraction. Notably, fibrinogen supplementation markedly augmented the aggregation responses of platelets in the heatstroke group. The impairment of platelet adhesion, spreading, and fibrin clot retraction in the rats with heatstroke was partially ameliorated by fibrinogen supplementation. CONCLUSIONS: An early use of fibrinogen replacement may serve as a therapeutic intervention to alleviate platelet hyporeactivity and prevent the complications in patients with heatstroke.

The significant mechanism and treatments of cell death in heatstroke.

With global warming, extreme environmental heat is becoming a social issue of concern, which can cause adverse health results including heatstroke (HS). Severe heat stress is characterized by cell death of direct heat damage, excessive inflammatory responses, and coagulation disorders that can lead to multiple organ dysfunction (MODS) and even death. However, the significant pathophysiological mechanism and treatment of HS are still not fully clear. Various modes of cell death, including apoptosis, pyroptosis, ferroptosis, necroptosis and PANoptosis are involved in MODS induced by heatstroke. In this review, we summarized molecular mechanism, key transcriptional regulation as for HSF1, NRF2, NF-κB and PARP-1, and potential therapies of cell death resulting in CNS, liver, intestine, reproductive system and kidney injury induced by heat stress. Understanding the mechanism of cell death provides new targets to protect multi-organ function in HS.

TRPV1/cPLA2/AA pathway contributes to ferroptosis-mediated acute liver injury in heatstroke.

With the increasing frequency of global heatwaves, the incidence of heatstroke (HS) is significantly rising. The liver plays a crucial role in metabolism and is an organ highly sensitive to temperature. Acute liver injury (ALI) frequently occurs in patients with HS, yet the exact mechanisms driving ALI in HS are still unknown. In this basic study, we investigated the specific molecular mechanisms by which cytosolic phospholipase A2 (cPLA2) mediates ferroptosis, contributing to the development of ALI following HS. We utilized a mouse model of HS and divided the mice into healthy control and HS groups for a series of experiments. Firstly, we assessed oxidative damage markers in tissues and cells, as well as ferroptosis biomarkers. Additionally, we conducted a non-targeted metabolomics analysis to validate the role of key enzymes in metabolism and the ferroptosis pathway. Our results indicated that ferroptosis contributed to the progression of ALI after HS. Administering the ferroptosis inhibitor liproxstatin-1 (10 mg/kg) post-HS onset significantly inhibits HS-induced ALI progression. Mechanistically, heatstroke triggered cPLA2 activation and increased the levels of its metabolic product, arachidonic acid, thereby further promoted the occurrence of ferroptosis. Furthermore, heatstroke mediated cPLA2 activation might involve enhancing transient receptor potential vanilloid subtype 1 (TRPV1) receptor function. Overall, these results highlighted the critical role that cPLA2-mediated ferroptosis plays in the development of ALI following HS, indicating that inhibiting cPLA2 may present a novel therapeutic approach to prevent ALI after HS by limiting liver cell death.

Heatstroke Comorbid with SARS-CoV-2 Infection: A Case Report and Literature Review.

Background: Hyperthermia and multiple organ dysfunction syndrome (MODS) are the main characteristics of heatstroke and COVID-19. Differentiating between these illnesses is crucial during a summer COVID-19 pandemic, but cases of heatstroke comorbid with COVID-19 are rarely reported. Case description: We report the first case of heatstroke comorbid with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in a 52-year-old male. After receiving intravenous antibiotics, organ protection measures, and treatment for coagulation disorders, his fever and coma resolved. However, he developed dyspnea and cerebral hemorrhage after several days. This patient experienced a multi-pathogen pulmonary infection and an intractable coagulopathy that ultimately resulted in MODS and death. Conclusion: The combination of heatstroke and SARS-CoV-2 infection exacerbated inflammation, immune abnormalities, and coagulation disorders. The interaction between inflammation and coagulation disturbances contributed to the underlying mechanism in this case, highlighting the importance of early anti-infection, treatment for coagulopathy, immune regulation, and organ protection as crucial interventions.

Knowledge, attitudes, and practices among the general community population toward heatstroke.

Background and objective: Heatstroke (HS) is a life-threatening condition resulting from thermal injury within the body, and it is associated with a significantly high mortality rate. This study aimed to assess the knowledge, attitudes and practices (KAP) among the general community population toward heatstroke. Methods: The web-based cross-sectional study was conducted between September 2023 and October 2023 at the Emergency Department of Dongyang People's Hospital. A self-designed questionnaire was developed to collect demographic information of the general community population and to assess their knowledge, attitudes and practices toward heatstroke. Results: A total of 1,356 valid questionnaires were collected. Among the participants, 875 (64.53%) were female, and 496 (36.58%) had regular exercise. The mean knowledge, attitudes and practices scores were 12.73 ± 1.42 (possible range: 0-14), 33.74 ± 2.91 (possible range: 8-40) and 34.65 ± 5.30 (possible range: 8-40), respectively. The structural equation model demonstrated that education had direct effects on knowledge (ß = 0.017, p < 0.001), attitudes (ß = 0.123, p < 0.001), and practices (ß = -0.094, p < 0.001). Moreover, knowledge had direct effects on attitudes (ß = 1.920, p < 0.001), and attitudes had direct effects on practices (ß = 0.642, p < 0.001). Conclusion: The findings revealed that the general community population have sufficient knowledge, active attitudes and proactive practices toward the heatstroke. However, there is still room for improvement and it is necessary to develop and implement educational initiatives and interventions designed to further enhance their KAP toward heatstroke.

Severe Hyperthermia in Mountaineering: Coincidence of Heat Stroke and Infection.

Heat illness is a condition that is sometimes seen in those undertaking physical activities. This case report focuses on a female hiker who developed heat stroke during a trek in the Dachstein region of Upper Austria. The patient's presentation was initially unclear and could only be confirmed by the use of a thermometer. This had a significant impact on the medical decision-making process during a complex rescue operation.

Epidemiology of heat-related illness in dogs under UK emergency veterinary care in 2022.

BACKGROUND: Dogs are exposed to increasing environmental risk for developing heat-related illness (HRI), with 2022 recorded as the hottest year to date in the UK and most of Europe. METHODS: This study used VetCompass data to report the incidence risk, event fatality rate and canine risk factors for HRI in dogs presenting to Vets Now emergency care practices in the UK during 2022. RESULTS: From the clinical records of 167,751 dogs under care at Vets Now emergency clinics in 2022, 384 HRI events were identified. The 2022 incidence risk of HRI within the Vets Now caseload was 0.23% (95% confidence interval [CI]: 0.21%‒0.25%), with an event fatality rate of 26.56% (95% CI: 21.66%-32.25%). Multivariable analysis identified breed, age and sex/neuter status as risk factors for HRI. Brachycephalic dogs had 4.21 times the odds of HRI compared to mesocephalic dogs (95% CI: 3.22‒5.49, p < 0.001). LIMITATIONS: The clinical data used in this study were not primarily recorded for research and had some substantial levels of missing data (especially patient bodyweight). CONCLUSION: In order to protect canine welfare, improved long-term mitigation strategies are urgently needed to minimise HRI risk and associated fatality in UK dogs.

Heatstroke: a multicenter study in Southwestern China.

Background: An increase in Heatstroke cases occurred in southwest China in 2022 due to factors like global warming, abnormal temperature rise, insufficient power supply, and other contributing factors. This resulted in a notable rise in Heatstroke patients experiencing varying degrees of organ dysfunction. This descriptive study aims to analyze the epidemiology and clinical outcomes of Heatstroke patients in the ICU, providing support for standardized diagnosis and treatment, ultimately enhancing the prognosis of Heatstroke. Methods: A retrospective, multicenter, descriptive analysis was conducted on Heatstroke patients admitted to ICUs across 83 hospitals in southwest China. Electronic medical records were utilized for data collection, encompassing various aspects such as epidemiological factors, onset symptoms, complications, laboratory data, concurrent infections, treatments, and patient outcomes. Results: The dataset primarily comprised classic heatstroke, with 477 males (55% of total). The patient population had a median age of 72 years (range: 63-80 years). The most common initial symptoms were fever, mental or behavioral abnormalities, and fainting. ICU treatment involved respiratory support, antibiotics, sedatives, and other interventions. Among the 700 ICU admissions, 213 patients had no infection, while 487 were diagnosed with infection, predominantly lower respiratory tract infection. Patients presenting with neurological symptoms initially (n = 715) exhibited higher ICU mortality risk compared to those without neurological symptoms (n = 104), with an odds ratio of 2.382 (95% CI 1.665, 4.870) (p = 0.017). Conclusion: In 2022, the majority of Heatstroke patients in southwest China experienced classical Heatstroke, with many acquiring infections upon admission to the ICU. Moreover, Heatstroke can result in diverse complications.

Predictive value of serum myoglobin and lactate dehydrogenase in rhabdomyolysis-induced acute kidney injury from severe heatstroke.

OBJECTIVE: To explore the predictive utility of serum myoglobin (Mb) and lactate dehydrogenase (LDH) for acute kidney injury (AKI) secondary to rhabdomyolysis (RM) in severe heatstroke patients. METHODS: A retrospective analysis of 58 RM patients with severe heatstroke at Shanghai Ninth People's Hospital from June 2019 to May 2022 was conducted. Patients were categorized into AKI and non-AKI groups. Laboratory indices were compared, and receiver operating characteristic (ROC) curves were used to assess the predictive value of serum biomarkers for AKI. RESULTS: Creatine kinase, Mb, LDH, creatinine, and blood urea nitrogen levels were significantly higher in the AKI group (P<0.05). Serum Mb and LDH were positively correlated with serum creatinine (r=0.6772 and r=0.6816, respectively; P<0.05). The area under the ROC curve (AUC) for serum Mb was 0.6692 (95% CI: 0.5253-0.8131) with a cut-off of 1024 ng/ml, while for LDH it was 0.8277 (95% CI: 0.7182-0.9371) with a cut-off of 1342 U/L. Combining serum Mb and LDH improved the AUC to 0.9116 (95% CI: 0.8219-1.001). CONCLUSION: Serum Mb and LDH levels are elevated in RM-induced AKI following severe heatstroke, and their combination offers substantial predictive value for AKI in these patients.

Monocyte HLA-DR level on admission predicting in-hospital mortality rate in exertional heatstroke: A 12-year retrospective study.

BACKGROUND: Exertional heatstroke (EHS), a fatal illness, pronounces multiple organ dysfunction syndrome (MODS) and high mortality rate. Currently, no ideal factor prognoses EHS. Decreased monocyte human leukocyte-DR antigen (mHLA-DR) has been observed in critically ill individuals, particularly in those with sepsis. While most research focus on the pro-inflammatory response exploration in EHS, there are few studies related to immunosuppression, and no report targeted on mHLA-DR in EHS. The present study tried to explore the prognostic value of mHLA-DR levels in EHS patients. METHODS: This was a single-center retrospective study. Clinical data of EHS patients admitted to the intensive care unit of the General Hospital of Southern Theatre Command between January 1, 2008, and December 31, 2020, were recorded and analyzed. RESULTS: Seventy patients with 54 survivors and 16 nonsurvivors were ultimately enrolled. Levels of mHLA-DR in the nonsurvivors (41.8% [38.1-68.1]%) were significantly lower than those in the survivors (83.1% [67.6-89.4]%, p < 0.001). Multivariate logistic regression indicated that mHLA-DR (odds ratio [OR] = 0.939; 95% confidence interval [CI]: 0.892-0.988; p = 0.016) and Glasgow coma scale (GCS) scores (OR = 0.726; 95% CI: 0.591-0.892; p = 0.002) were independent risk factors related with in-hospital mortality rate in EHS. A nomogram incorporated mHLA-DR with GCS demonstrated excellent discrimination and calibration abilities. Compared to the traditional scoring systems, the prediction model incorporated mHLA-DR with GCS had the highest area under the curve (0.947, 95% CI: [0.865-0.986]) and Youden index (0.8333), with sensitivity of 100% and specificity of 83.33%, and a greater clinical net benefit. CONCLUSION: Patients with EHS were at a risk of early experiencing decreased mHLA-DR early. A nomogram based on mHLA-DR with GCS was developed to facilitate early identification and timely treatment of individuals with potentially poor prognosis.

Case report and literature review: Acute rhabdomyolysis caused by overheating of electric blanket complicated with Guillain-Barré syndrome.

Rhabdomyolysis (RM) induced by electric blankets is exceedingly rare, with only three cases identified in our literature review. Both RM and Guillain-Barré syndrome (GBS) present with similar clinical manifestations of myalgia and muscle weakness, posing a potential challenge for accurate diagnosis in clinical settings. This report presents the case of a 22-year-old man who developed RM subsequent to the use of an electric blanket. Despite undergoing plasma exchange and renal replacement therapy, the patient continued to exhibit poor muscle strength in both lower limbs. Subsequent comprehensive evaluation revealed the presence of concurrent GBS. Following a 5-day course of intravenous gamma globulin treatment, the patient experienced rapid recovery of muscle strength and was discharged. Additionally, we reviewed seven cases from the literature of coexistent RM and GBS. This indicated that investigation of the timing of onset of muscle strength decline in RM patients could help to identify potential concurrent neurological or muscular disorders. In cases in which concurrent GBS and RM cannot be definitively ascertained during early hospitalization, prioritizing plasma exchange treatment may lead to improved patient outcomes.

Multimodal imaging shows acute multilayered retinal hemorrhages in heatstroke-a rare case report.

Background: Heatstroke is a life-threatening disease clinically characterized by central nervous system dysfunction, multiorgan failure, and extreme hyperthermia. There are no reports about eye involvement in heat stroke. Here, we report a rare case of multilayered retinal hemorrhages in a patient with heatstroke. Case presentation: A 55-year-old male with a one-month history of blurry vision in both eyes presented at our department after suffering from heatstroke. His visual acuity was 5/20 OD and 10/20 OS. Fundus examination revealed retinal hemorrhages in both eyes. Fundus autofluorescence images and near-infrared reflectance images revealed well-defined retinal lesions. Optical coherence tomography helped to accurately locate the different layers of the lesions, including the nerve fiber layer, sub-inner limiting membrane, outer plexiform layer, ellipsoid zone and Henle fiber layer hemorrhages. We followed up with the patient for 8 months. At the last follow-up, his visual acuity was 20/20 in both eyes, and fundus examination showed that retinal hemorrhages were almost completely absorbed. Conclusion: To our knowledge, this is the first report on multilayered retinal hemorrhages secondary to heat stroke. Intraretinal and preretinal hemorrhages can gradually resolve, and the patient's vision will improve with the absorption of the retinal hemorrhages. Multimodal imaging may help to reveal additional details about retinal lesions and monitor the course of the disease.

Lactate combined with SOFA score for improving the predictive efficacy of SOFA score in patients with severe heatstroke.

BACKGROUND: The relationship between lactate levels and multiple organ dysfunction in patients with severe heatstroke remains unclear. In this study, we aimed to elucidate the clinical significance of lactate in severe heatstroke prognosis and assess whether incorporating lactate in the SOFA score improves its predictive efficacy. METHODS: This study was a multicenter retrospective cohort investigation included 275 patients. Logistic regression analysis was performed to examine the relationship between lactate levels and patient outcomes and complications, including acute kidney injury (AKI), disseminated intravascular coagulation (DIC), and myocardial injury. Further, receiver operating characteristic (ROC) curves and clinical decision curve analysis (DCA) were used to evaluate the predictive power of lactate and SOFA scores in severe heatstroke-associated death. Lastly, the Kaplan-Meier survival curve was employed to differentiate the survival rates among the various patient groups. RESULTS: After adjusting for confounding factors, lactate was demonstrated as an independent risk factor for death (OR = 1.353, 95% CI [1.170, 1.569]), AKI (OR = 1.158, 95% CI [1.007, 1.332]), DIC (OR = 1.426, 95% CI [1.225, 1.659]), and myocardial injury (OR = 2.039, 95% CI [1.553, 2.679]). The area under the curve (AUC) of lactate for predicting death from severe heatstroke was 0.7540, with a cutoff of 3.35. The Kaplan-Meier survival curve analysis showed that patients with elevated lactate levels had higher mortality rates. Additionally, the ROC curves demonstrated that combining lactate with the SOFA score provided better predictive efficacy than the SOFA score alone in patients with severe heatstroke (AUC: 0.9025 vs. 0.8773, DeLong test, P < 0.001). Finally, the DCA curve revealed a higher net clinical benefit rate for lactate combined with the SOFA score. CONCLUSIONS: Lactate is an independent risk factor for severe heatstroke-related death as well as a risk factor for AKI, DIC, and myocardial injury associated with severe heatstroke. Thus, combining lactate with the SOFA score can significantly improve its predictive efficacy in patients with severe heatstroke.