Successful treatment of severe heatstroke with therapeutic hypothermia by a noninvasive external cooling system

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2024 Update

The Wilderness Medical Society (WMS) convened an expert panel in 2011 to develop a set of evidence-based guidelines for the recognition, prevention, and treatment of heat illness. The current panel retained 5 original members and welcomed 2 new members, all of whom collaborated remotely to provide an updated review of the classifications, pathophysiology, evidence-based guidelines for planning and preventive measures, and recommendations for field- and hospital-based therapeutic management of heat illness. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each modality. This is an updated version of the WMS clinical practice guidelines for the prevention and treatment of heat illness published in Wilderness & Environmental Medicine. 2019;30(4):S33-S46.

Unraveling quad fever: Severe hyperthermia after traumatic cervical spinal cord injury

PURPOSE

There are many infectious and inflammatory causes for elevated core-body temperatures, though they rarely pass 40 ℃ (104 ℉). The term "quad fever" is used for extreme hyperpyrexia in the setting of acute cervical spinal cord injuries (SCIs). The traditional methods of treating hyperpyrexia are often ineffective and reported morbidity and mortality rates approach 100%. This study aims to identify the incidence of elevated temperatures in SCIs at our institution and assess the effectiveness of using a non-invasive dry water temperature management system as a treatment modality with mortality.

METHODS

A retrospective analysis of acute SCI patients requiring surgical intensive care unit admission who experienced fevers ≥ 40 ℃ (104 ℉) were compared to patients with maximum temperatures < 40 ℃. Patients ≥18 years old who sustained an acute traumatic SCI were included in this study. Patients who expired in the emergency department; had a SCI without radiologic abnormality; had neuropraxia; were admitted to any location other than the surgical intensive care unit; or had positive blood cultures were excluded. SAS 9.4 was used to conduct statistical analysis.

RESULTS

Over the 9-year study period, 35 patients were admitted to the surgical intensive care unit with a verified SCI. Seven patients experienced maximum temperatures of ≥ 40 ℃. Six of those patients were treated with the dry water temperature management system with an overall mortality of 57.1% in this subgroup. The mortality rate for the 28 patients who experienced a maximum temperature of ≤ 40 ℃ was 21.4% (p = 0.16).

CONCLUSION

The diagnosis of quad fever should be considered in patients with cervical SCI in the presence of hyperthermia. In this study, there was no significant difference in mortality between quad fever patients treated with a dry water temperature management system versus SCI patients without quad fever. The early use of a dry water temperature management system appears to decrease the mortality rate of quad fever.

ACSM Expert Consensus Statement on Exertional Heat Illness: Recognition, Management, and Return to Activity

ABSTRACT

Exertional heat stroke (EHS) is a true medical emergency with potential for organ injury and death. This consensus statement emphasizes that optimal exertional heat illness management is promoted by a synchronized chain of survival that promotes rapid recognition and management, as well as communication between care teams. Health care providers should be confident in the definitions, etiologies, and nuances of exertional heat exhaustion, exertional heat injury, and EHS. Identifying the athlete with suspected EHS early in the course, stopping activity (body heat generation), and providing rapid total body cooling are essential for survival, and like any critical life-threatening situation (cardiac arrest, brain stroke, sepsis), time is tissue. Recovery from EHS is variable, and outcomes are likely related to the duration of severe hyperthermia. Most exertional heat illnesses can be prevented with the recognition and modification of well-described risk factors ideally addressed through leadership, policy, and on-site health care.

Using Esophageal Temperature Management to Treat Severe Heat Stroke: A Case Report

BACKGROUND: Exertional heat stroke (EHS) is defined by a core body temperature that exceeds 40°C with associated central nervous system dysfunction, skeletal muscle injury, and multiple organ damage. The most important initial focus of treatment involves reduction of patient temperature. First approaches to achieve temperature reduction often include ice packs, water blankets, and cold intravenous fluid administration. When these measures fail, more advanced temperature management methods may be deployed but often require surgical expertise. Esophageal temperature management (ETM) has recently emerged as a new temperature management modality in which an esophageal heat transfer device replaces the standard orogastric tube routinely placed after endotracheal intubation and adds a temperature modulation capability. The objective of this case study is to report the first known use of ETM driven by bedside nursing staff in the treatment of EHS. METHOD: An ETM device was placed after endotracheal intubation in a 28-year-old man experiencing EHS over a 5-day course of treatment. RESULTS: Because the ETM device was left in place, when the patient experienced episodes of increasing temperature as high as 39.1°C, which required active cooling, nursing staff were able to immediately adjust the external heat exchange unit settings to achieve aggressive cooling at bedside. CONCLUSION: This nurse-driven technology offers a new means to rapidly deploy cooling to critically ill patients without needing to implement advanced surgical approaches or obstruct access to the patient, freeing the provider to continue optimal care in high-morbidity conditions.

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.

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.

Cooling Methods in Heat Stroke

BACKGROUND

Heat stroke is an illness with a high risk of mortality or morbidity, which can occur in the young and fit (exertional heat stroke) as well as the elderly and infirm (nonexertional heat stroke). In the United States, from 2006 to 2010, there were at least 3332 deaths attributed to heat stroke.

OBJECTIVE

To summarize the available evidence on the principal cooling methods used in the treatment of heat stroke.

DISCUSSION

Although it is generally agreed that rapid, effective cooling increases survival in heat stroke, there continues to be debate on the optimal cooling method. Large, controlled clinical trials on heat stroke are lacking. Cooling techniques applied to healthy volunteers in experimental models of heat stroke have not worked as rapidly in actual patients with heat stroke. The best available evidence has come from large case series using ice-water immersion or evaporation plus convection to cool heat-stroke patients.

CONCLUSIONS

Ice-water immersion has been shown to be highly effective in exertional heat stroke, with a zero fatality rate in large case series of younger, fit patients. In older patients with nonexertional heat stroke, studies have more often promoted evaporative plus convective cooling. Evaporative plus convective cooling may be augmented by crushed ice or ice packs applied diffusely to the body. Chilled intravenous fluids may also supplement primary cooling. Based on current evidence, ice packs applied strategically to the neck, axilla, and groin; cooling blankets; and intravascular or external cooling devices are not recommended as primary cooling methods in heat stroke.

Exertional Heat Illness: Emerging Concepts and Advances in Prehospital Care

Exertional heat illness is a classification of disease with clinical presentations that are not always diagnosed easily. Exertional heat stroke is a significant cause of death in competitive sports, and the increasing popularity of marathons races and ultra-endurance competitions will make treating many heat illnesses more common for Emergency Medical Services (EMS) providers. Although evidence is available primarily from case series and healthy volunteer studies, the consensus for treating exertional heat illness, coupled with altered mental status, is whole body rapid cooling. Cold or ice water immersion remains the most effective treatment to achieve this goal. External thermometry is unreliable in the context of heat stress and direct internal temperature measurement by rectal or esophageal probes must be used when diagnosing heat illness and during cooling. With rapid recognition and implementation of effective cooling, most patients suffering from exertional heat stroke will recover quickly and can be discharged home with instructions to rest and to avoid heat stress and exercise for a minimum of 48 hours; although, further research pertaining to return to activity is warranted.

PryorRR,RothRN,SuyamaJ,HostlerD.Exertional heat illness: emerging concepts and advances in prehospital care.Prehosp Disaster Med.2015;30(3):19.

Use of an external-cooling device for the treatment of heat stroke

Heat stroke is caused by losing control of one’s body temperature. It can be life threatening without proper treatment. In this case report, we describe a heat stroke patient treated with an external-cooling device, which is commonly used for therapeutic hypothermia after cardiac arrest. A 67-year-old woman was found unconscious with spontaneous breathing in a sauna. Her body temperature was 40.5°C when she arrived at the emergency department, and she was diagnosed with heat stroke. At seven hours after applying the Arctic Sun Temperature Management System (Medivance), her body temperature declined to 36.5°C, with neurologic improvement (Glasgow Coma Scale score increased from 3 to 12). She was admitted to an intensive care unit and discharged 14 days after admission without any neurological sequelae. In conclusion, an external-cooling device can be used effectively for heat stroke, in addition to therapeutic hypothermia after cardiac arrest.

Successful management of heat stroke associated with multiple-organ dysfunction by active intravascular cooling

Heat stroke is a life-threatening condition requiring immediate initiation of rapid and effective cooling. We report successful cooling with initial intravascular cooling use that rapidly achieved the target temperature with continued normothermia thereafter. A 39-year-old previously healthy man collapsed on a hot, humid day and presented with a disturbance of consciousness. On initial examination, Glasgow Coma Scale score was 6/15, and his body temperature was 40.7°C. He was therefore intubated, and fluid resuscitation was initiated. A Cool Line catheter (Asahi KASEI ZOLL Medical, Tokyo, Japan) was inserted, and aggressive cooling was started using the intravascular balloon-catheter system (The Thermogard XP system; Asahi KASEI ZOLL Medical) within 32 minutes of arrival. His core temperature reached 38.8°C after 17 minutes of intravascular cooling at an average cooling rate of 0.10°C/min. Further investigation revealed impaired liver function and renal failure. His hemodynamic condition was stabilized, and no vasoactive agents were administrated during hospitalization. The cooling catheter was removed on day 2 of admission, and no bleeding, infection, or thrombosis associated with catheter placement was observed. Blood and urine cultures remained negative. Extubation was performed on day 3, and he was discharged on day 5 without further complication or sequelae. It is essential in the treatment of heat stroke to cool as quickly as possible and to provide cardiovascular support. In patients with severe heat stroke and multiple-organ dysfunction, initial use of the active intravascular cooling technique is warranted for aggressive cooling.

Heat-related illness

Environmental exposure to high temperatures can result in abnormalities ranging from mild heat exhaustion to heat stroke with multiorgan system failure. An understanding of the mechanisms of thermoregulation and how those mechanisms fail with extreme heat stress is critical for management of the patient with elevated body temperature in the emergency department.