Targeted temperature management in patients with severe heatstroke: Three case reports and treatment recommendations

Analysis of clinical characteristics and risk factors for patients with heat stroke in western China in 2022: a multicenter retrospective study

Objectives

To analyzed the clinical characteristics and treatment modalities of heat stroke (HS) and to identify risk factors for a poor prognosis of HS and provide reference suggestions for its treatment and prevention.

Measurements and main results

We enrolled a total of 247 patients, with hypertension, diabetes, and psychosis being the top three comorbidities associated with HS. The incidence of HS was higher among males and older individuals. Compared to the control group, the poor prognosis group experienced higher temperatures, a higher incidence of cerebral edema, and gastrointestinal bleeding (all p < 0.05). The poor prognosis group had significantly higher blood pH, HCO3-, Lac, Scr, AST, ALT, DBIL, CKMB, PT, DD, and PLT (all p < 0.05). Furthermore, logistic regression analysis revealed that Lac, Scr, and APACHE II were risk factors for poor prognosis (p < 0.05). The AUC values for the combined diagnostic model were 0.848 (95% CI: 0.781-0.914). Male morbidity, the number of patients with combined hypertension, the prognosis, and the APACHE II score and ALT level were all greater (p < 0.05) in the CHS group. The Kaplan-Meier analysis revealed that the CHS group had a significantly higher mortality rate than the EHS group.

Conclusion

A high incidence of hypertension, diabetes, psychosis, men, and older persons may be associated with HS. HS patients with high blood cell counts, impaired coagulation, liver and kidney diseases, and those with a specific type of CHS may face a poor prognosis. In patients with heart failure, APACHE II, Lac, and Scr were independent risk factors for a poor prognosis.

Severe heat stroke with multiorgan failure following collapse in a sauna

Heat stroke is characterised by hyperthermia and acute encephalopathy. We describe a rare case of classical heat stroke secondary to prolonged sauna use with multiorgan sequelae including seizures, liver injury, kidney injury, disseminated intravascular coagulation, rhabdomyolysis and type 2 myocardial infarction. The patient was treated with external cooling, intravenous fluid therapy and blood products, and made a full recovery without need for advanced organ support. We discuss the evidence base surrounding the immediate treatment of heat stroke in the emergency department.

The Clinical Profile of Heatstroke Patients Admitted to the Intensive Care Unit: A Case Series From a Tertiary Care Center in New Delhi, India

Heat-related illnesses include a spectrum of disorders ranging from heat syncope, muscle cramps, and heat exhaustion to heat emergencies such as heatstroke. Severe heatwaves can lead to extremely high environmental temperatures and a spurt of cases of heat-related illnesses and heatstroke. The incidence of such heat-related medical emergencies was much higher in 2024 compared to previous years throughout North and Central India. Here, we are describing a case series of five patients admitted to the intensive care unit of a tertiary care center in New Delhi during the month of June 2024.

Proteomics analyses of acute kidney injury biomarkers in a rat exertional heat stroke model

The frequency of exertional heat stroke (EHS) increases with the gradual elevation of global temperatures during summer. Acute kidney injury (AKI) is a common complication of EHS, and its occurrence often indicates the worsening of a patient's condition or a poor prognosis. In this study, a rat model of AKI caused by EHS was established, and the reliability of the model was evaluated by HE staining and biochemical assays. The expression of kidney tissue proteins in the EHS rats was analyzed using label-free liquid chromatography-tandem mass spectrometry. A total of 3,129 differentially expressed proteins (DEPs) were obtained, and 10 key proteins were finally identified, which included three upregulated proteins (Ahsg, Bpgm, and Litaf) and seven downregulated proteins (medium-chain acyl-CoA synthetase 2 (Acsm2), Hadha, Keg1, Sh3glb1, Eif3d, Ambp, and Ddah2). The qPCR technique was used to validate these 10 potential biomarkers in rat kidney and urine. In addition, Acsm2 and Ahsg were double-validated by Western blotting. Overall, this study identified 10 reliable biomarkers that may provide potential targets for the treatment of AKI caused by EHS.

PULMONARY VASCULAR ENDOTHELIAL GLYCOCALYX DEGRADATION CONTRIBUTES TO ACUTE LUNG INJURY IN EXPERIENCING HEATSTROKE

ABSTRACT

Objectives: This study investigated the role and potential involvement of pulmonary vascular glycocalyx degradation in acute lung injury in rats with severe heatstroke (HS). Methods: Rats in an established HS model were exposed to a heated environment for 60 min in an incubator (temperature, 40°C ± 2°C; humidity, 65% ± 5%). Following pretreatment with heparanase III (HPSE III) or heparin, pathological lung injury, arterial blood gas, alveolar barrier disruption, and hemodynamic changes were evaluated. The vascular endothelial structures of the lungs were examined using electron microscopy. The concentration of Evans blue dye in the lungs and arterial blood gas were assessed. An enzyme-linked immunosorbent assay was used to quantify the plasma concentration of heparan sulfate proteoglycan. The expression of glypican-1 and syndecan-1 in pulmonary vessels was measured using immunofluorescence. Western blots were used to detect the expression of TNF-α, IL-6, and vascular endothelial biomarkers in the rat lungs. Pulmonary apoptosis was assessed using a TUNEL (terminal dUTP nick end labeling) assay, and the concentrations of malondialdehyde were measured. Results: Glycocalyx shedding aggravated lung injuries. Severe histopathological damage was observed, and indexes of lung function deviated from abnormal ranges. In addition, pulmonary vascular endothelial cells were disrupted. Compared with the HS group, the plasma concentration of heparan sulfate proteoglycan significantly increased in the HPSE group ( P < 0.05). The expression of glypican-1 and syndecan-1 decreased, and the extravasation of Evans blue dye increased ( P < 0.01). Endothelial biomarker expression increased in the lung tissue, whereas occludin expression decreased. Moreover, TNF-α and IL-6 were overexpressed following heat stress. Furthermore, apoptosis of pulmonary tissues and the concentration of malondialdehyde in rat lungs increased in the HS and HPSE groups. Conclusions : Heatstroke induced pulmonary glycocalyx degradation, which increased vascular permeability and aggravated vascular endothelial dysfunction, contributing to apoptosis, inflammation, and oxidation in the pulmonary tissues.

Application of diffusion tensor imaging and functional alterations in evaluating brain alterations related to heatstroke in a rat model

OBJECTIVES

To assess the alterations in resting-state functions and neural structures in the brain of a heatstroke rat model and explore the underlying relationship.

METHODS

In total, 17 male Sprague Dawley rats were randomly divided into a control group (CTRL, n = 7) and a heatstroke group (HS, n = 10). All rats underwent 7.0 T magnetic resonance imaging (MRI). T2-weighted imaging, resting-state functional MRI (rs-fMRI), and diffusion tensor imaging (DTI) were obtained. On day 25, the surviving HS group rats (the follow-up group, FU, n = 7) were scanned again.

RESULTS

Heatstroke resulted in functional alterations and structural damage in the cerebellar molecular layer (CML), right perirhinal area (PA), pretectal region (PR), right dentate gyrus, and external cortex of the inferior colliculus (ECIC). Further functional changes occur in the right temporal associative cortex (TAC), left retrosplenial cortex (RC), and CML during convalescence. The fractional anisotropy values were significantly positively correlated with the amplitude of low-frequency fluctuation (ALFF) (HS-CML: r = 0.746, p = 0.034; right PR: r = 0.648, p = 0.049; FU-right PA: r = 0.817, p = 0.025)/regional homogeneity (ReHo) ratio (HS-CML: r = 0.833, p = 0.008; ECIC: r = 0.678, p = 0.045) and negatively correlated with the ALFF (FU-left RC: r = -0.818, p = 0.024; right TAC: r = -0.813, p = 0.049).

CONCLUSION

DTI and rs-fMRI allow meticulous monitoring of the progression of neurological and functional alterations in the brain after heatstroke.