Successful treatment of exertional heat stroke using continuous plasma diafiltration

Efficacy and safety of plasma diafiltration: Review of case reports and case series

Plasma diafiltration (PDF), a blood purification procedure that combines dialysis with plasma filtration by a selective membrane, has been used to treat acute liver failure, sepsis, and other acute conditions. We reviewed 14 eligible case reports and case series that examined PDF in 357 patients to assess its efficacy and safety. Fourteen diseases may be indications for PDF. The primary indication in the included studies was acute liver failure without obvious inducement or cause not mentioned. Eighty-three patients reached the primary endpoint (31 deaths, 52 recoveries) and the efficacy was 62.7%. There were large changes in 16 toxins or clinical markers after PDF, including total bilirubin, IL-18, IL-6. In conclusion, PDF appears to be an effective treatment for clearance of bilirubin and other inflammatory mediators in patients with acute liver injury or a disease characterized by a systemic inflammatory state. Randomized controlled trials are needed to compare PDF with other blood purification methods, such as plasma exchange and the Molecular Adsorbent Recirculating System™.

Metabolomic profiling identifies a novel mechanism for heat stroke‑related acute kidney injury

Heat stroke can induce a systemic inflammatory response, which may lead to multi‑organ dysfunction including acute kidney injury (AKI) and electrolyte disturbances. To investigate the pathogenesis of heat stroke (HS)‑related AKI, a mouse model of HS was induced by increasing the animal's core temperature to 41˚C. Blood samples obtained from the tail vein were used to measure plasma glucose and creatinine levels. Micro‑positron emission tomography‑computed tomography (micro‑PET/CT), H&E staining and transmission electron microscopy were conducted to examine metabolic and morphological changes in the mouse kidneys. Immunohistochemistry (IHC) and western blot analyses were performed to investigate the expression of apoptosis‑inducing factor mitochondria‑associated 2 (Aifm2), high‑mobility group box 1 (HMGB1) and receptor for advanced glycosylation end products (RAGE). Liquid chromatography‑mass spectrometry analysis was conducted to find differential metabolites and signaling pathways. The HS mouse model was built successfully, with significantly increased creatinine levels detected in the serum of HS mice compared with controls, whereas micro‑PET/CT revealed active metabolism in the whole body of HS mice. H&E and TUNEL staining revealed that the kidneys of HS mice exhibited signs of hemorrhage and apoptosis. IHC and western blotting demonstrated significant upregulation of Aifm2, HMGB1 and RAGE in response to HS. Finally, 136 differential metabolites were screened out, and enrichment of the 'biosynthesis of unsaturated fatty acids' pathway was detected. HS‑associated AKI is the renal manifestation of systemic inflammatory response syndrome, and may be triggered by the HMGB1/RAGE pathway. Metabolomics indicated increased adrenic acid, docosahexaenoic acid and eicosapentaenoic acid may serve as metabolic biomarkers for AKI in HS. The findings suggested that a correlation between the HMGB1/RAGE pathway and biosynthesis of unsaturated fatty acids may contribute to the progression of HS‑related AKI.

Establishment and effectiveness evaluation of a scoring system for exertional heat stroke by retrospective analysis

BACKGROUND

Heat stroke (HS) is a serious, life-threatening disease. However, there is no scoring system for HS so far. This research is to establish a scoring system that can quantitatively assess the severity of exertional heat stroke (EHS).

METHODS

Data were collected from a total of 170 exertional heat stroke (EHS) patients between 2005 and 2016 from 52 hospitals in China. Univariate statistical methods and comparison of the area under the receiver operating characteristic (ROC) curve (AUC) were used to screen exertional heat stroke score (EHSS) parameters, including but not limited body temperature (T), Glasgow Coma Scale (GCS) and others. By comparing the sizes of the AUCs of the APACHE II, SOFA and EHSS assessments, the effectiveness of EHSS in evaluating the prognosis of EHS patients was verified.

RESULTS

Through screening with a series of methods, as described above, the present study determined 12 parameters - body temperature (T), GCS, pH, lactate (Lac), platelet count (PLT), prothrombin time (PT), fibrinogen (Fib), troponin I (TnI), aspartate aminotransferase (AST), total bilirubin (TBIL), creatinine (Cr) and acute gastrointestinal injury (AGI) classification - as EHSS parameters. It is a 0-47 point system designed to reflect increasing severity of heat stroke. Low (EHSS< 20) and high scores (EHSS> 35) showed 100% survival and 100% mortality, respectively. We found that AUCEHSS > AUCSOFA > AUCAPACHE II.

CONCLUSION

A total of 12 parameters - T, GCS, pH, Lac, PLT, PT, Fib, TnI, AST, TBIL, Cr and gastrointestinal AGI classification - are the EHSS parameters with the best effectiveness in evaluating the prognosis of EHS patients. As EHSS score increases, the mortality rate of EHS patients gradually increases.

The Fire from Within: Multiorgan Failure with Bimodal Rhabdomyolysis from Exertional Heat Stroke

Heat stroke (HS) is a condition characterized by a rise in core body temperature and central nervous system dysfunction. It is divided into two types: classical and exertional. Exertional heat stroke (EHS) is accompanied by organ failure. Liver injury, presenting only with a rise in liver enzymes, is common but in rare conditions, acute liver failure (ALF) may ensue, leading to a potentially lethal condition. Most cases of EHS-induced ALF are managed conservatively. However, liver transplantation is considered for cases refractory to supportive treatment. Identifying patients eligible for liver transplantation in the context of an EHS-induced ALF becomes a medical dilemma since the conventional prognostic criterion may be difficult to apply, and there is paucity of literature about these specific sets of individuals. Recently, extracorporeal liver support has been gaining popularity for patients with liver failure as a bridge to liver transplant. In this case report, we present a young Filipino athlete with symptoms and clinical course consistent with EHS that developed multiorgan failure, initially considered a candidate for liver transplant and total plasma exchange, but clinically improved with supportive management alone. This patient was also found to have bimodal rhabdomyolysis during the course of his hospital stay as manifested by the bimodal rise in his creatine kinase enzymes.

Heat stroke

Background

Heat stroke is a life-threatening injury requiring neurocritical care; however, heat stroke has not been completely examined due to several possible reasons, such as no universally accepted definition or classification, and the occurrence of heat wave victims every few years. Thus, in this review, we elucidate the definition/classification, pathophysiology, and prognostic factors related to heat stroke and also summarize the results of current studies regarding the management of heat stroke, including the use of intravascular balloon catheter system, blood purification therapy, continuous electroencephalogram monitoring, and anticoagulation therapy.

Main body

Two systems for the definition/classification of heat stroke are available, namely Bouchama’s definition and the Japanese Association for Acute Medicine criteria. According to the detailed analysis of risk factors, prevention strategies for heat stroke, such as air conditioner use, are important. Moreover, hematological, cardiovascular, neurological, and renal dysfunctions on admission are associated with high mortality, which thus represent the potential targets for intensive and specific therapies for patients with heat stroke. No prospective, comparable study has confirmed the efficacy of intravascular cooling devices, anticoagulation, or blood purification in heat stroke.

Conclusion

The effectiveness of cooling devices, drugs, and therapies in heat stroke remains inconclusive. Further large studies are required to continue to evaluate these treatment strategies.