Liver transplantation in exertional heat stroke: a medical dilemma

Thromboelastometry for assessment of hemostasis and disease severity in 42 dogs with naturally-occurring heatstroke

BACKGROUND

Thromboelastometry (TEM) provides a comprehensive overview of the entire coagulation process and has not been evaluated in heatstroke-induced coagulopathies in dogs.

OBJECTIVES

To determine the diagnostic and prognostic utility of TEM in dogs with heatstroke.

ANIMALS

Forty-two client-owned dogs with heatstroke.

METHODS

Prospective observational study. Blood samples for intrinsic and extrinsic TEM (INTEM and EXTEM, respectively) were collected at presentation and every 12 to 24 hours for 48 hours. Coagulation phenotype (hypo-, normo-, or hypercoagulable) was defined based on TEM area under the 1st derivative curve (AUC).

RESULTS

Case fatality rate was 31%. Median TEM variables associated with death (P < .05 for all) included longer INTEM clotting time, lower AUC at presentation and at 12 to 24 hours postpresentation (PP), lower INTEM alpha angle, maximum clot firmness, and maximum lysis (ML) at 12 to 24 hours PP, and lower EXTEM ML at 12 to 24 hours PP. Most dogs were normo-coagulable on presentation (66% and 63% on EXTEM and INTEM, respectively), but hypo-coagulable 12 to 24 PP (63% for both EXTEM and INTEM). A hypo-coagulable INTEM phenotype was more frequent at presentation and 12 to 24 PP among nonsurvivors compared to survivors (55% vs 15% and 100% vs 50%, P = .045 and .026, respectively). AKI was more frequent (P = .015) in dogs with hypo-coagulable INTEM tracings at 12 to 24 hours. Disseminated intravascular coagulation was more frequent (P < .05) in dogs with a hypo-coagulable INTEM phenotype and in nonsurvivors at all timepoints.

CONCLUSIONS AND CLINICAL RELEVANCE

Hypocoagulability, based on INTEM AUC, is predictive of worse prognosis and occurrence of secondary complications.

Human temperature regulation under heat stress in health, disease, and injury

The human body constantly exchanges heat with the environment. Temperature regulation is a homeostatic feedback control system that ensures deep body temperature is maintained within narrow limits despite wide variations in environmental conditions and activity-related elevations in metabolic heat production. Extensive research has been performed to study the physiological regulation of deep body temperature. This review focuses on healthy and disordered human temperature regulation during heat stress. Central to this discussion is the notion that various morphological features, intrinsic factors, diseases, and injuries independently and interactively influence deep body temperature during exercise and/or exposure to hot ambient temperatures. The first sections review fundamental aspects of the human heat stress response, including the biophysical principles governing heat balance and the autonomic control of heat loss thermoeffectors. Next, we discuss the effects of different intrinsic factors (morphology, heat adaptation, biological sex, and age), diseases (neurological, cardiovascular, metabolic, and genetic), and injuries (spinal cord injury, deep burns, and heat stroke), with emphasis on the mechanisms by which these factors enhance or disturb the regulation of deep body temperature during heat stress. We conclude with key unanswered questions in this field of research.

Exertional Heat Stroke-Induced Acute Liver Failure and Liver Transplantation

Exertional heat stroke is a medical emergency characterized by excessive heat production and inadequate heat dissipation usually after heavy exertion in hot and humid climates and can be associated with multiorgan failure. Treatment is largely supportive, but liver transplantation (LT) may be necessary in select patients. Here, we report the case of a 44-year-old runner who was found unconscious after a 5-mile run and developed acute liver failure. He underwent successful LT 1 week later when he developed encephalopathy. This case report illustrates the importance of early LT referral in patients with exertional heat stroke-induced acute liver failure.

Machine learning-based mortality prediction model for heat-related illness

In this study, we aimed to develop and validate a machine learning-based mortality prediction model for hospitalized heat-related illness patients. After 2393 hospitalized patients were extracted from a multicentered heat-related illness registry in Japan, subjects were divided into the training set for development (n = 1516, data from 2014, 2017–2019) and the test set (n = 877, data from 2020) for validation. Twenty-four variables including characteristics of patients, vital signs, and laboratory test data at hospital arrival were trained as predictor features for machine learning. The outcome was death during hospital stay. In validation, the developed machine learning models (logistic regression, support vector machine, random forest, XGBoost) demonstrated favorable performance for outcome prediction with significantly increased values of the area under the precision-recall curve (AUPR) of 0.415 [95% confidence interval (CI) 0.336–0.494], 0.395 [CI 0.318–0.472], 0.426 [CI 0.346–0.506], and 0.528 [CI 0.442–0.614], respectively, compared to that of the conventional acute physiology and chronic health evaluation (APACHE)-II score of 0.287 [CI 0.222–0.351] as a reference standard. The area under the receiver operating characteristic curve (AUROC) values were also high over 0.92 in all models, although there were no statistical differences compared to APACHE-II. This is the first demonstration of the potential of machine learning-based mortality prediction models for heat-related illnesses.

Chemically Activated Cooling Vest's Effect on Cooling Rate Following Exercise-Induced Hyperthermia: A Randomized Counter-Balanced Crossover Study

Background and objectives: Exertional heat stroke (EHS) is a potentially lethal, hyperthermic condition that warrants immediate cooling to optimize the patient outcome. The study aimed to examine if a portable cooling vest meets the established cooling criteria (0.15 °C·min⁻¹ or greater) for EHS treatment. It was hypothesized that a cooling vest will not meet the established cooling criteria for EHS treatment. Materials and Methods: Fourteen recreationally active participants (mean ± SD; male, n = 8; age, 25 ± 4 years; body mass, 86.7 ± 10.5 kg; body fat, 16.5 ± 5.2%; body surface area, 2.06 ± 0.15 m². female, n = 6; 22 ± 2 years; 61.3 ± 6.7 kg; 22.8 ± 4.4%; 1.66 ± 0.11 m²) exercised on a motorized treadmill in a hot climatic chamber (ambient temperature 39.8 ± 1.9 °C, relative humidity 37.4 ± 6.9%) until they reached rectal temperature (T_RE) >39 °C (mean T_RE, 39.59 ± 0.38 °C). Following exercise, participants were cooled using either a cooling vest (VEST) or passive rest (PASS) in the climatic chamber until T_RE reached 38.25 °C. Trials were assigned using randomized, counter-balanced crossover design. Results: There was a main effect of cooling modality type on cooling rates (F[1, 24] = 10.46, p < 0.01, η²_p = 0.30), with a greater cooling rate observed in VEST (0.06 ± 0.02 °C·min⁻¹) than PASS (0.04 ± 0.01 °C·min⁻¹) (MD = 0.02, 95% CI = [0.01, 0.03]). There were also main effects of sex (F[1, 24] = 5.97, p = 0.02, η²_p = 0.20) and cooling modality type (F[1, 24] = 4.38, p = 0.047, η²_p = 0.15) on cooling duration, with a faster cooling time in female (26.9 min) than male participants (42.2 min) (MD = 15.3 min, 95% CI = [2.4, 28.2]) and faster cooling duration in VEST than PASS (MD = 13.1 min, 95% CI = [0.2, 26.0]). An increased body mass was associated with a decreased cooling rate in PASS (r = −0.580, p = 0.03); however, this association was not significant in vest (r = −0.252, p = 0.39). Conclusions: Although VEST exhibited a greater cooling capacity than PASS, VEST was far below an acceptable cooling rate for EHS treatment. VEST should not replace immediate whole-body cold-water immersion when EHS is suspected.

A Case of Exertional Heat Stroke Complicated by Hypoxic Hepatitis

Background

Exertional heat stroke is a life-threatening condition often complicated by multiorgan failure. We hereby present a case of a 25-year-old male presenting with syncope after a 10  km run in 28°C outside temperature who developed acute liver failure. Case Presentation. Initial temperature was found to be 41.1°C, and cooling measures were rapidly applied. He suffered from acute renal failure and rhabdomyolysis and proceeded to acute liver failure (ASAT 6100 U/l and ALAT 6561 U/l) due to hypoxic hepatitis on day 3. He did not meet criteria for emergency liver transplantation and recovered on supportive care.

Conclusions

Acute liver failure due to heat stroke is a life-threatening condition with often delayed onset, which nevertheless resolves on supportive care in the majority of cases; thus, a delayed referral to transplant seems to be reasonable.

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.

Expert consensus on the diagnosis and treatment of heat stroke in China

Heat stroke (HS) is a fatal disease caused by thermal damage in the body, and it has a very high mortality rate. In 2015, the People's Liberation Army Professional Committee of Critical Care Medicine published the first expert consensus on HS in China, Expert consensus on standardized diagnosis and treatment for heat stroke. With an increased understanding of HS and new issues that emerged during the HS treatment in China in recent years, the 2015 consensus no longer meet the requirements for HS prevention and treatment. It is necessary to update the consensus to include the latest research evidence and establish a new consensus that has broader coverage, is more practical and is more in line with China's national conditions. This new expert consensus includes new concept of HS, recommendations for laboratory tests and auxiliary examinations, new understanding of diagnosis and differential diagnosis, On-site emergency treatment and In-hospital treatment, translocation of HS patients and prevention of HS.

Controversies in exertional heat stroke diagnosis, prevention, and treatment

During the past several decades, the incidence of exertional heat stroke (EHS) has increased dramatically. Despite an improved understanding of this syndrome, numerous controversies still exist within the scientific and health professions regarding diagnosis, pathophysiology, risk factors, treatment, and return to physical activity. This review examines the following eight controversies: 1) reliance on core temperature for diagnosing and assessing severity of EHS; 2) hypothalamic damage induces heat stroke and this mediates “thermoregulatory failure” during the immediate recovery period; 3) EHS is a predictable condition primarily resulting from overwhelming heat stress; 4) heat-induced endotoxemia mediates systemic inflammatory response syndrome in all EHS cases; 5) nonsteroidal anti-inflammatory drugs for EHS prevention; 6) EHS shares similar mechanisms with malignant hyperthermia; 7) cooling to a specific body core temperature during treatment for EHS; and 8) return to physical activity based on physiological responses to a single-exercise heat tolerance test. In this review, we present and discuss the origins and the evidence for each controversy and propose next steps to resolve the misconception.

Fulminant liver failure following a marathon: Five case reports and review of literature

BACKGROUND

The growing popularity of marathon and half-marathon runs has led to an increased number of patients presenting with exertion-induced heat stroke. Mild hepatic involvement is often observed in these patients; however, fulminant liver failure may occur in approximately 5% of all cases. Liver transplantation is a potentially curative approach for exertion-induced liver failure, although there is a lack of consensus regarding the criteria and optimal timing of this intervention.

CASE SUMMARY

This paper describes 5 patients (4 men and 1 woman) who were referred to the department where this study was performed with the diagnosis of exertion-induced acute liver failure. Three patients underwent liver transplantation, 1 recovered spontaneously, and 1 patient died on day 11 following the exertion.

CONCLUSION

Exertion-induced heat stroke may present as fulminant liver failure. These patients may recover with conservative treatment, may require liver transplantation, or may die. No definitive criteria are available to determine patient suitability for a conservative vs surgical approach.

Liver transplantation in patients with liver failure related to exertional heatstroke

BACKGROUND & AIMS

Severe acute liver injury is a grave complication of exertional heatstroke. Liver transplantation (LT) may be a therapeutic option, but the criteria for LT and the optimal timing of LT have not been clearly established. The aim of this study was to define the profile of patients who require transplantation in this context.

METHODS

This was a multicentre, retrospective study of patients admitted with a diagnosis of exertional heatstroke-related severe acute liver injury with a prothrombin time (PT) of less than 50%. A total of 24 male patients were studied.

RESULTS

Fifteen of the 24 patients (median nadir PT: 35% [29.5-40.5]) improved under medical therapy alone and survived. Nine of the 24 were listed for emergency LT. At the time of registration, the median PT was 10% (5-12) and all had numerous dysfunctional organs. Five patients (nadir PT: 12% [9-12]) were withdrawn from the list because of an elevation of PT values that mainly occurred between day 2 and day 3. Ultimately, 4 patients underwent transplantation as their PT persisted at <10%, 3 days (2.75-3.25) after the onset of exertional heatstroke, and they had more than 3 organ dysfunctions. Of these 4 patients, 3 were still alive 1 year later. Histological analysis of the 4 explanted livers demonstrated massive or sub-massive necrosis, and little potential for effective mitoses, characterised by a "mitonecrotic" appearance.

CONCLUSION

The first-line treatment for exertional heatstroke-related severe acute liver injury is medical therapy. LT is only a rare alternative and such a decision should not be taken too hastily. A persistence of PT <10%, without any signs of elevation after a median period of 3  days following the onset of heatstroke, was the trigger that prompted LT, was the trigger adopted in order to decide upon LT.

LAY SUMMARY

Acute liver injury due to heatstroke can progress to acute liver failure with organ dysfunction despite medical treatment; in such situations, liver transplantation (LT) may offer a therapeutic option. The classic criteria for LT appear to be poorly adapted to heatstroke-related acute liver failure. We confirmed thatmedication is the first-line therapy acute liver injury caused by heatstroke, with LT only rarely necessary. A decision to perform LT should not be made hastily. Fluctuations in prothrombin time and the patient's clinical status should be considered even in the event of severe liver failure.

Liver Transplantation for Fulminant Hepatic Failure Due to Heat Stroke: A Case Report

Heat stroke is a condition caused by an excessive increase in body temperature in a relatively short period of time, and is clinically characterized by central nervous system dysfunction, including delirium, seizures, coma, and severe hyperthermia. In this context, the resulting fulminant hepatic failure makes liver transplant the best choice when there are no guarantees of better results with conservative treatment. We present our experience in this case, possible alternative choices, and the current role of liver transplantation in the resolution of fulminant liver failure due to heat stroke. CASE REPORT: We report the case of a 32-year-old man with a history of malabsorption syndrome and unconfirmed celiac disease controlled with a gluten-free diet, who, while working on a typical summer midday in southern Spain (approximately 40°C), abruptly presented with loss of consciousness, coma, and a temperature of 42°C, as well as seizures at the initial medical assessment that subsided after the administration of diazepam. On the third day, the patient presented with multiple organ dysfunction syndrome, requiring mechanical ventilation, hemodialysis, and inotropic support. He did not improve with the support of conservative treatment, therefore it was decided to perform an urgent liver transplant, after which he recovered completely. CONCLUSIONS: Liver transplantation should be a main choice of treatment for cases in which, despite intensive medical treatment, there is still clinical and analytical evidence of massive and/or irreversible hepatocellular damage.

Molecular Adsorbent Recirculating System Support Followed by Liver Transplantation for Multiorgan Failure From Heatstroke

BACKGROUND

Exertional heatstroke is an extremely rare cause of fulminant hepatic failure. Maximal supportive care has failed to provide adequate survival in earlier studies. This is particularly true in cases accompanied by multiorgan failure.

METHODS AND MATERIALS

Our prospectively collected transplant database was retrospectively reviewed to identify patients undergoing liver transplantation for heatstroke between January 1, 2012, and December 31, 2016. We report 3 consecutive cases of male patients with fulminant hepatic failure from exertional heatstroke.

RESULTS

All patients developed multiorgan failure and required intubation, vasopressor support, and renal replacement therapy. All patients were listed urgently for liver transplantation and were supported with the molecular adsorbent recirculating system while awaiting transplantation. All patients underwent liver transplantation alone and are alive and well, with recovered renal function, normal liver allograft function, and no chronic sequelae of their multiorgan failure at more than one year.

CONCLUSION

Extreme heatstroke leading to whole-body organ dysfunction and fulminant liver failure is a complex entity that may benefit from therapy using the Molecular Adsorbent Recirculating System while waiting for liver transplantation as a component of a multidisciplinary, multiorgan system approach.

Acute liver failure and hepatic encephalopathy in exertional heat stroke

A 31-year-old man was brought to Accident & Emergency after collapsing during a race. On presentation, the patient had a temperature of 41.7°C (rectal). External cooling was started immediately. The patient was intubated in view of a Glasgow Coma Scale of 7 and was transferred to theintensive therapy unit. Laboratory results revealed an acute kidney injury, rhabdomyolysis, disseminated intravascular coagulopathy and acute liver failure. The patient was encephalopathic, jaundiced and difficult to sedate. His liver function continued to deteriorate with alanine aminotransferase (ALT) levels reaching 9207 U/L. King's Hospital Liver Centre, London was contacted for a possible liver transplant, and they advised an infusion of N-acetylcysteine. The following day liver function tests improved; thus, transplantation was not performed. The patient failed multiple sedation holds and required a tracheostomy. He continued to spike a fever. Despite no source of sepsis being found, the patient remained on broad spectrum antibiotics to cover for any potential infective causes until day 27. After 15 days, the patient's encephalopathy gradually improved. He was weaned off the ventilator and underwent intense physiotherapy. The patient was discharged from hospital one month after admission.

Liver transplantation for non-exertional heat stroke-related acute liver failure

Heat stroke is a life-threatening condition characterised by hyperthermia leading to multiple organ dysfunction. Acute liver failure is a rare and potentially fatal consequence of heat stroke. Management of heat stroke is mainly supportive but liver transplantation can be considered as the treatment of acute liver failure in heat stroke. However, literature on liver transplantation as a treatment for acute liver failure in heat stroke is scarce. Until now, no cases of liver transplantation for acute liver failure in non-exertional heat stroke have been reported. Here, we present the first case report of a successful liver transplantation in a patient with acute liver failure caused by non-exertional heat stroke after a sauna visit.

Non-Exertional Heatstroke: A Case Report and Review of the Literature

BACKGROUND Heatstroke (HS) is a life-threatening condition characterized by an elevation of the core body temperature above 40°C, central nervous system dysfunction, and possible multi-organ failure. HS can trigger systemic inflammation, disseminated intravascular coagulation (DIC), rhabdomyolysis, cerebral edema and seizures, pulmonary edema, heart dysfunctions, and renal and hepatic failure. CASE REPORT We report the case of a 41-year-old Romanian woman with a history of alcoholism who developed HS after arriving by bus in Verona, Italy in June 2016. The patient developed consecutive multi-organ dysfunction, including liver and renal failure, rhabdomyolysis, DIC, and arrhythmia. The patient was successfully treated with conservative measures. After 17 days, she recovered completely. CONCLUSIONS The exact mechanism of HS-related multiple organ dysfunction is not completely understood and its pathogenesis is complex. It involves inflammation, oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Development of a model in which chronic alcohol abuse alters oxidative, inflammatory, and ER stress response could also be a conceivable solution to the positive prognosis of severe HS patients, in which liver failure has a prominent role.

Heat stroke leading to acute liver injury & failure: A case series from the Acute Liver Failure Study Group

BACKGROUND & AIMS

In the United States, nearly 1000 annual cases of heat stroke are reported but the frequency and outcome of severe liver injury in such patients is not well described. The aim of this study was to describe cases of acute liver injury (ALI) or failure (ALF) caused by heat stroke in a large ALF registry.

METHODS

Amongst 2675 consecutive subjects enrolled in a prospective observational cohort of patients with ALI or ALF between January 1998 and April 2015, there were eight subjects with heat stroke.

RESULTS

Five patients had ALF and three had ALI. Seven patients developed acute kidney injury, all eight had lactic acidosis and rhabdomyolysis. Six patients underwent cooling treatments, three received N-acetyl cysteine (NAC), three required mechanical ventilation, three required renal replacement therapy, two received vasopressors, one underwent liver transplantation, and two patients died-both within 48 hours of presentation. All cases occurred between May and August, mainly in healthy young men because of excessive exertion.

CONCLUSIONS

Management of ALI and ALF secondary to heat stroke should focus on cooling protocols and supportive care, with consideration of liver transplantation in refractory patients.

Hemostatic abnormalities in dogs with naturally occurring heatstroke

OBJECTIVE

To investigate hemostatic analyte abnormalities and their association with mortality in dogs with naturally occurring heatstroke.

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

ANIMALS

Thirty client-owned dogs with naturally occurring heatstroke.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Citrated and EDTA blood samples were collected at presentation and at 4, 12, 24, 36, and 48 hours postpresentation (PP). Hemostatic tests performed included platelet count, prothrombin and activated partial thromboplastin times (PT and aPTT, respectively), antithrombin activity (ATA), total protein C activity (tPCA), fibrinogen, and D-dimer concentrations. The overall survival rate was 60% (18/30 dogs). Older age, higher heart rate and rectal temperature at presentation, and time from onset of clinical signs to presentation were significantly associated with mortality. Hemostatic analytes at presentation were not associated with mortality. Prolonged PT and aPTT at 12-24 hours PP, lower tPCA at 12 hours PP, and hypofibrinogenemia at 24 hours PP were significantly (P < 0.05) associated with mortality. Increased D-dimer concentration and low ATA were common at all time points, but were not associated with mortality. The frequency of disseminated intravascular coagulation (DIC) increased in nonsurvivors throughout hospitalization, but the development of DIC was not associated with mortality. The number of abnormal coagulation disturbances during the first 24 hours was significantly higher in nonsurvivors (P = 0.04).

CONCLUSIONS

Hemostatic derangements are common in dogs with naturally occurring heatstroke. Alterations in PT, aPTT, tPCA, and fibrinogen concentrations appear to be associated with the outcome at 12-24 hours PP, exemplifying the need for serial measurement of multiple laboratory hemostatic tests during hospitalization, even when within reference interval on presentation. The development of DIC, as defined in this cohort, was not associated with mortality; however, nonsurvivors had significantly more coagulation abnormalities during the first 24 hours PP.

Unexpected extrapyramidal symptoms and pulmonary aspergillosis in exertional heatstroke with fulminant liver failure: a case report

Background

Exertional heatstroke is a life-threatening condition with high mortality because of the rapid progress of multiple organ dysfunction syndrome even if aggressive treatments are initiated rapidly. Mild to moderate hepatic injury is common in exertional heatstroke, while fulminant liver failure is rare. Extrapyramidal symptoms and pulmonary aspergillosis secondary to liver failure induced by exertional heatstroke have never been reported in prior cases.

Case presentation

A 25-year-old Han Chinese man presented with exertional heatstroke with fulminant liver failure, subsequent pulmonary aspergillosis, and extrapyramidal symptoms. Moreover, he also presented with coma, rhabdomyolysis, acute kidney injury, and disseminated intravascular coagulation. He recovered under conservative treatment including therapeutic plasma exchange plus continuous veno-venous hemofiltration, fluid resuscitation, antibiotics, and other support therapy.

Conclusions

Therapeutic plasma exchange plus continuous veno-venous hemofiltration could be effective for patients with heatstroke who suffer liver failure and other organ failure. Patients with liver failure are at high risk for pulmonary aspergillosis. Movement disorder in these patients might be extrapyramidal symptoms induced by consistent low level of cholinesterase resulted from hepatic injury besides brain injury.

Diagnostic value of coagulation factor and intracranial pressure monitoring in acute liver failure from heat stroke: case report and review of the literature

BACKGROUND

Exertional heat stroke (HS) with resultant acute liver failure (ALF) is a rare condition with high mortality. Diagnosis of ALF in the context of HS is confounded by numerous laboratory abnormalities related to multisystem organ dysfunction.

CASE REPORT

We present the case of a 20-year-old male athlete with exertional HS who developed ALF and was treated successfully with orthotopic liver transplantation. He remained well after 1 year with normal liver function and no permanent neurologic impairment. Diagnosis and treatment was guided by serial monitoring of coagulation factors and intracranial pressure (ICP).

CONCLUSIONS

Currently, there are no well validated prognostic tools that predict the need for or survival with orthotopic liver transplantation for HS. We propose that serial monitoring of coagulation factors and, when safe and feasible, ICP monitoring may help to guide clinical decision making in this context.

Heat stroke

Heat stroke is a life-threatening condition clinically diagnosed as a severe elevation in body temperature with central nervous system dysfunction that often includes combativeness, delirium, seizures, and coma. Classic heat stroke primarily occurs in immunocompromised individuals during annual heat waves. Exertional heat stroke is observed in young fit individuals performing strenuous physical activity in hot or temperature environments. Long-term consequences of heat stroke are thought to be due to a systemic inflammatory response syndrome. This article provides a comprehensive review of recent advances in the identification of risk factors that predispose to heat stroke, the role of endotoxin and cytokines in mediation of multi-organ damage, the incidence of hypothermia and fever during heat stroke recovery, clinical biomarkers of organ damage severity, and protective cooling strategies. Risk factors include environmental factors, medications, drug use, compromised health status, and genetic conditions. The role of endotoxin and cytokines is discussed in the framework of research conducted over 30 years ago that requires reassessment to more clearly identify the role of these factors in the systemic inflammatory response syndrome. We challenge the notion that hypothalamic damage is responsible for thermoregulatory disturbances during heat stroke recovery and highlight recent advances in our understanding of the regulated nature of these responses. The need for more sensitive clinical biomarkers of organ damage is examined. Conventional and emerging cooling methods are discussed with reference to protection against peripheral organ damage and selective brain cooling.

Extreme heatstroke causing fulminant hepatic failure requiring liver transplantation: a case report

INTRODUCTION

Exertional heatstroke with liver involvement is a rare and potentially fatal condition. In this setting, fulminant hepatic failure (FHF) occurs as a result of severe hypoxic hepatitis.

CASE REPORT

We report the case of a young male athlete who developed exertional heatstroke associated with rhabdomyolysis and hypoxic hepatitis while running the final stages of an ultra-marathon (62 km). The patient rapidly developed multiorgan failure, including fulminant hepatic failure, requiring intensive care admission for mechanical ventilation, hemodialysis, and inotropic support. He failed to improve with supportive measures and underwent an emergency hepatectomy followed by orthotopic liver transplant, after which he recovered completely.

CONCLUSIONS

We discuss the rationale for liver transplantation in this setting, possible alternative treatments, and the pathophysiology of fulminant liver failure in this rare case.

Therapeutic plasma exchange in the treatment of exertional heat stroke and multiorgan failure

BACKGROUND

Exertional heat stroke (EHS) results in a constellation of systemic inflammatory responses resulting in multiorgan failure and an extremely high mortality.

CASE DIAGNOSIS AND TREATMENTS

We present the case of an 11-year-old obese male who suffered EHS with rhabdomyolysis and concurrent renal, pulmonary, and hepatic failure. Conventional therapies including continuous veno-venous hemodiafiltration (CVVHDF) were ineffective in preventing ongoing deterioration in clinical status. Liver biopsy was reported as "extensive hepatocyte ballooning" and liver-kidney transplantation was tentatively planned.

CONCLUSIONS

The addition of therapeutic plasma exchange using the Prismaflex® system (Gambro, Lakewood, CO, USA) resulted in a reversal of the inflammatory process and recovery from multiorgan failure. Liver biopsy was not a reliable indicator of irreversible hepatic injury.

Exertional Heat Stroke – The Athlete's Nemesis

Heat stroke represents the extreme end of a spectrum of heat-related illnesses. It can occur in endurance athletes. Its incidence is probably under-reported. Patients present confused, drowsy or comatose, with a raised core temperature, but often a falsely reassuring peripheral temperature. Treatment is centred on reducing the core temperature as rapidly as possible and appropriate supportive management. Even with prompt treatment, it is associated with multi-organ dysfunction and death. Patients are often misdiagnosed, or diagnosed late. This is probably exacerbated by a wide differential diagnosis, the need for a core temperature measurement to reach the diagnosis and clinicians being unfamiliar with the disease. The need for immediate recognition, and immediate treatment compounds the problem. Survivors may experience long-term neurological disability and may be at risk of a further episode. Patients should return to sport gradually and only when they feel well. Its epidemiology, pathophysiology and clinical management are reviewed.

Acute hepatic failure as a leading manifestation in exertional heat stroke

Background. Acute hepatic failure (AHF) is uncommon as a leading symptom in patients with exertional heat stroke (EHS). Which stage to perform the liver transplantation for severe hepatic failure in EHS is still obscure at clinical setting. The conservative management has been reported to be successful in treating heat-stroke-associated AHF even in the presence of accepted criteria for emergency liver transplantation. Case Presentation. Here, we reported a 35-year-old male who presented with very high transaminases, hyperbilirubinemia, significant prolongation of the prothrombin time, and coma. No other causes for AHF could be identified but physical exhaustion and hyperthermia. Although the current patient fulfilled London criteria for emergency liver transplantation, he spontaneously recovered under conservative treatment including intravenous fluids, cooling, diuretics as mannitol, and hepatocyte growth-promoting factors. Conclusions. Meticulous supportive management could be justified in some selected cases of AHF due to EHS.

Cardiovascular diseases and the liver

The dual blood supply of the liver, originating from the portal vein and the hepatic artery, makes it relatively resistant to minor circulatory disturbances. However, hepatic manifestations of common cardiovascular disorders are frequently encountered in both the inpatient and outpatient setting. Beginning with the macro- and microcirculation of the liver, this article reviews the pathophysiology of hepatic blood flow and gives a detailed appraisal of ischemic hepatitis, congestive hepatopathy, and other less common hepatic conditions that arise when cardiovascular function is impaired.

Multiple organ failure caused by non-exertional heat stroke after bathing in a hot spring

Heat stroke is a life-threatening illness, and the disease spectrum can include the involvement of multiple organs to varying degrees. Rhabdomyolysis with renal function impairment is frequently noted in this disease. However, acute hepatic failure has been rarely reported in non-exertional heat stroke. We report a case of acute hepatic failure combined with disseminated intravascular coagulopathy, acute renal failure, and neurological deficit caused by heat stroke after bathing in a hot spring. Molecular adsorbent recirculating system (MARS) treatment was performed daily on days 10-12 of admission. As a result of progressive azotemia, hemodialysis was performed. Unfortunately, after a long course of intensive care, the patient died from septic shock and multiple organ failure. According to available evidence, MARS and hemodialysis are beneficial in treating exertional heat stroke. However, a limited number of studies have treated non-exertional heat-stroke-related acute hepatic failure. Early cooling to reduce the overwhelming heat-stress-related cytokine storm, and advanced MARS to eliminate circulating toxin might have a role in treating this rare but fatal illness.

Insuficiência hepática fulminante por intermação induzida por exercício

Intermação induzida por exercício é uma condição potencialmente fatal causada pela elevação extrema da temperatura corporal central. Envolvimento hepático leve a moderado afeta todos os pacientes e manifesta-se pela elevação das enzimas hepáticas. A ocorrência de falência hepática no curso da intermação por exercício é rara e tem prognóstico reservado. Relata-se um caso de insuficiência hepática fulminante em um homem de 36 anos após correr 8km em corrida de rua (corrida rústica) na cidade de Manaus (AM). O paciente desenvolveu insuficiência renal aguda, rabdomiólise e achados compatíveis com insuficiência hepática fulminante (elevação importante das aminotransferases, coagulopatia, letargia e episódios de confusão). As funções hepáticas e renais apresentaram melhora gradual e espontânea sem necessidade de diálise. Três meses após o paciente encontrava-se bem, com enzimas hepáticas normais e com retorno gradual à prática de esportes. Embora rara, a falência hepática aguda deve ser incluída nas complicações da intermação induzida por exercício, a qual pode ter resolução espontânea com medidas conservadoras.

[Liver and sport]

The liver is a vital organ and plays a central role in energy exchange, protein synthesis as well as the elimination of waste products from the body. Acute and chronic injury may disturb a variety of liver functions to different degrees. Over the last three decades, the effects of physical activity and competitive sport on the liver have been described by various investigators. These include viral hepatitis and drug-induced liver disorders. Herein, we review acute and chronic liver diseases potentially caused by sport. Team physicians, trainers and others, responsible for the health of athletes, should be familiar with the risk factors, clinical features, and consequences of liver diseases that occur in sports.

Effects of colon hydrotherapy on liver injury induced by hyperthermia in dogs

AIM: To investigate the effect of colon hydrothe-rapy on the liver injury induced by hyperthermia in dogs.

METHODS: After the dog models of heat stroke were set up, the dogs were randomly divided into two groups, receiving colon hydrotherapy and conventional therapy, respectively. Cooling time as well as serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD) levels before heat stroke, 6, 24 and 48 h after heat stroke were determined. The dogs were sacrificed 48 h after heat stroke. The contents of liver MDA and SOD were also measured and pathological changes were observed by light and electron microscopy.

RESULTS: In compared with those in conventional therapy group, the cooling time of dogs in colon hydrotherapy group was decreased (t = 5.39, P < 0.01), accompanied with reduced ALT, AST, MDA and elevated SOD at the 24^th (t = 3.46, P < 0.01; t = 3.74, P < 0.01; t = 2.43, P < 0.05; t = 2.44, P < 0.05) and 48^th (t = 3.33, P < 0.01; t = 2.97, P < 0.05; t = 3.32, P < 0.01; t = 4.34, P < 0.01) after heat stroke. The content of liver MDA was decreased (t = 4.08, P < 0.01) while that of SOD was increased (t = 6.52, P < 0.01) in colon hydrotherapy group. The values of LDH were similar between the two groups (P > 0.05). Light microscopy showed that hepatocellular cholestasis, fatty changes and focal necrosis were lessened, accompanied by lessened congestion of sinus hepaticus and decreased inflammatory cells in colon hydrotherapy group. In addition, ultrastructural observation showed that fusion of mitochondrial cristaes and degranulation of rough endoplasmic reticulum were decreased in colon hydrotherapy group.

CONCLUSION: Colon hydrotherapy is a more rapid cooling technique than conventional therapy, and it can promote the decrease of serum enzymes and relieve the hepatic injury induced by lipid peroxidation and pathological lesion.

Coup de chaleur d'exercice avec hépatite fulminante : intérêt du système MARS® ?

Exertional heat stroke (EHS) is a life-threatening condition caused by an extreme elevation in core body temperature. Acute liver failure has been reported during EHS justifying liver transplantation in some cases. The Molecular Adsorbent Recirculating System (MARS) could be indicated in such situations. We report a case of a 58-year old patient who suffered acute liver failure occurring after EHS. The patient was referred for liver transplantation and benefited of MARS therapy. After three sessions of MARS, liver function improved progressively and the transplantation was not necessary. The patient completely recovered.