Acute Liver Impairment in a Young, Healthy Athlete: Hypoxic Hepatitis and Rhabdomyolysis following Heat Stroke

A Systematic Review on Outcomes of Patients with Heatstroke and Heat Exhaustion

Introduction

Heatstroke (HS) is a severe form of heat-related illness (HRI) associated with high morbidity and mortality, representing a condition that includes long-term multiorgan dysfunction and susceptibility to further heat illness.

Methods

In a systematic review searching Medline PubMed from the studies conducted between 2009 and 2020, 16 papers were identified.

Results

A hallmark symptom of heat stroke is CNS dysfunction (a hallmark sign of HS) which manifests as mental status changes, including agitation, delirium, epilepsy, or coma at the time of the collapse. Acute kidney injury (AKI), gut ischemia, blood clots in the stomach and small intestine, cytoplasmic protein clumps in the spleen, and injury of skeletal muscle (rhabdomyolysis) are all characteristics of peripheral tissue damage. Severe heat stroke tends to be complicated by rhabdomyolysis, especially in patients with exertional heat stroke. Rhabdomyolysis may lead to systemic effects, including the local occurrence of compartment syndrome, hyperkalemic cardiac arrest, and/or lethal disseminated intravascular coagulopathy. Untreated heat stroke might exacerbate psychosis, lactic acidosis, consumptive coagulopathy, hematuria, pulmonary edema, renal failure, and other metabolic abnormalities. Core body temperature and level of consciousness are the most significant indicators to diagnose the severity of heat stroke and prevent unfavorable consequences. Heatstroke is a life-threatening illness if not promptly recognized and effectively treated.

Discussion

This review highlighted that core body temperature and white blood cell count are significant contributing factors affecting heat stroke outcomes. Other factors contributing to the poor outcome include old age, low GCS, and prolonged hospital stay. The prevalence of both classic and exertional heatstroke can be reduced by certain simple preventive measures, such as avoiding strenuous activity in hot environments and reducing exposure to heat stress.

The pathogenesis and therapeutic strategies of heat stroke-induced liver injury

Heat stroke (HS) is a life-threatening systemic disease characterized by an elevated core body temperature of more than 40 ℃ and subsequent multiple organ dysfunction syndrome. With the growing frequency of global heatwaves, the incidence rate of HS has increased significantly, which has caused a huge burden on people's lives and health. Liver injury is a well-documented complication of HS and usually constitutes the direct cause of patient death. In recent years, a lot of research has been carried out on the pathogenesis and treatment strategies of HS-induced liver injury. In this review, we summarized the important pathogenesis of HS-induced liver injury that has been confirmed so far. In addition to the comprehensive effect of systemic factors such as heat cytotoxicity, coagulopathy, and systemic inflammatory response syndrome, excessive hepatocyte cell pyroptosis, dysfunction of Kupffer cells, abnormal expression of heat shock protein expression, and other factors are also involved in the pathogenesis of HS-induced liver injury. Furthermore, we have also established the current therapeutic strategies for HS-induced liver injury. Our study is of great significance in promoting the understanding of the pathogenesis and treatment of HS-induced liver injury.

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.

N-Acetylcysteine (NAC) for the Prevention of Liver Failure in Heat Injury-Mediated Ischemic Hepatitis

Exertional Heat Illness with associated ischemic hepatitis (IH) is a common occurrence among military trainees; however, few specific therapies exist if unresponsive to appropriate supportive measures.

A 27-year-old basic combat trainee presented with altered mental status, renal insufficiency, rhabdomyolysis, and a core temp of 107.9 °F after collapsing during a run, leading to the diagnosis of heat stroke. While the patient’s azotemia and creatinine kinase levels rapidly improved with aggressive intravenous hydration, transaminases continued to increase to nearly 155 times the upper limit of normal. Further laboratory evaluation revealed coagulopathy and thrombocytopenia suggestive of acute liver failure (ALF). On hospital day three, the patient was started on N-acetylcysteine (NAC). Evaluation for infectious and autoimmune etiologies of ALF was unremarkable; thus, the patient’s symptomatology was attributed to IH resulting from heat stroke. Liver function normalized on NAC.

Heat Injury is common among US Army recruits and results in thousands of hospitalizations in recent years. IH is characterized by diffuse hepatocyte necrosis following an episode of hemodynamic instability, and is an established sequela of Heat Injury. The mortality of IH among critically ill patients has been estimated to be as high as 60%, with those demonstrating coagulopathy especially at risk. NAC is shown to improve the transplant-free survival rate in non-acetaminophen related ALF, consistent with its proposed mechanisms of improving hepatic blood flow and conjugating toxic metabolites. NAC therapy should be considered early in the course of heat injury-mediated IH to reduce reperfusion injury, improving transplant free outcomes.

Athlete's Hepatitis in a Young Healthy Marathon Runner

Athlete's hepatitis is an uncommon clinical condition characterized by a significant ischemic insult to the liver. The most likely pathogenesis is decreased blood supply to the liver resulting in significant hypoxic hepatocyte injury. We report a case of a 48-year-old healthy young male who presented with athlete's hepatitis confirmed by liver biopsy after a 14-mile marathon run. To our knowledge, this is the second case of athlete's ischemic hepatitis reported in the literature. It is a diagnosis worth considering in patients involved in extreme exercise programs.

Hypoxic hepatitis - its biochemical profile, causes and risk factors of mortality in critically-ill patients: A cohort study of 565 patients

PURPOSE

A retrospective analysis of critically-ill patients with hypoxic hepatitis (HH) to characterize the biochemical profile and to identify predictors of mortality using the Medical Information Mart for Intensive Care III database.

METHODS

HH was defined as a rapid increase in AST/ALT≥800IU/L after exclusion of other causes. We investigated the correlation between various clinical and laboratory parameters and mortality rates using regression models.

RESULTS

Among 38,645 ICU-patients, 565 (1.46%) were diagnosed with HH; 57.9% were males; median age was 63years. The unique biochemical profile of HH was confirmed; lactate dehydrogenase (LDH) was higher than both ALT and AST; AST>ALT for the first 2days then the ratio is reversed until recovery. All-cause hospital mortality was 44.1%. All-cause hospital mortality was 44.1%. On multivariate analysis, older age, higher SAPS-II, higher INR, higher bilirubin, higher LDH, acute kidney injury (AKI), and the need for vasopressors were independently associated with mortality.

CONCLUSION

Older age, higher SAPS-II, LDH, INR and bilirubin levels, concomitant AKI and the need for vasopressors were all factors associated with increased mortality. The diagnosis of HH was an important harbinger of mortality in this population, which appears to be driven mainly by the severity of the underlying conditions.

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.

Heat stroke with bimodal rhabdomyolysis: a case report and review of the literature

BACKGROUND

Severe heat stroke tends to be complicated with rhabdomyolysis, especially in patients with exertional heat stroke. Rhabdomyolysis usually occurs in the acute phase of heat stroke. We herein report a case of heat stroke in a patient who experienced bimodal rhabdomyolysis in the acute and recovery phases.

CASE PRESENTATION

A 34-year-old male patient was found lying unconscious on the road after participating in a half marathon in the spring. It was a sunny day with a maximum temperature of 24.2 °C. His medical and family history was unremarkable. Upon arrival, his Glasgow Coma Scale score was 10. However, the patient's marked restlessness and confusion returned. A sedative was administered and tracheal intubation was performed. On the second day of hospitalization, a blood analysis was compatible with a diagnosis of acute hepatic failure; thus, he received fresh frozen plasma and a platelet transfusion was performed, following plasma exchange and continuous hemodiafiltration. The patient's creatinine phosphokinesis (CPK) level increased to 8832 IU/L on the fifth day of hospitalization and then showed a tendency to transiently decrease. The patient was extubated on the eighth day of hospitalization after the improvement of his laboratory data. From the ninth day of hospitalization, gradual rehabilitation was initiated. However, he felt pain in both legs and his CPK level increased again. Despite the cessation of all drugs and rehabilitation, his CPK level increased to 105,945 IU/L on the 15th day of hospitalization. Fortunately, his CPK level decreased with a fluid infusion. The patient's rehabilitation was restarted after his CPK level fell to <10,000 IU/L. On the 31st day of hospitalization, his CK level decreased to 623 IU/L and he was discharged on foot. Later, a genetic analysis revealed that he had a thermolabile genetic phenotype of carnitine palmitoyltransferase II (CPT II).

CONCLUSIONS

Physicians should pay special attention to the stress of rehabilitation exercises, which may cause collapsed muscles that are injured by severe heat stroke to repeatedly flare up.