Diagnosis and Management of Heatstroke.

Heatstroke is a life-threatening  and the most severe form of heat-related illnesses, characterized by body temperature >40ºC and central nervous system dysfunction. Heatstroke is classified into Non-Exertional Heatstroke (NEHS) and Exertional Heatstroke (EHS). The pathophysiology of heatstroke involves a combination of direct heat effects on the host, the systemic inflammatory and coagulopathic response. The diagnosis of heatstroke based on Bouchama's definition or Japan Association of Acute Medicine (JAAM) criteria. The basic principle of heatstroke management is early resuscitation and immediate cooling. Cold water immersion or convection evaporation method can be implemented based on the specific patient characteristic. Preventive strategies are early recognition by health workers, socialization to vulnerable groups and adequate acclimatization.

Health status, heat preparation strategies and medical events among elite cyclists who competed in the heat at the 2016 UCI Road World Cycling Championships in Qatar.

PURPOSE: Assess the health status and heat preparation strategies of athletes competing in a World Cycling Championships held in hot ambient conditions (37°C, 25% relative humidity, wet-bulb-globe-temperature 27°C) and monitor the medical events arising during competition. METHODS: 69 cyclists (~9% of the world championships participants) completed a pre-competition questionnaire. Illnesses and injuries encountered by the Athlete Medical Centre (AMC) were extracted from the race reports. RESULTS: 22% of respondents reported illness symptoms in the 10 days preceding the Championships. 57% of respondents had previously experienced heat-related symptoms (cramping most commonly) while 17% had previously been diagnosed with exertional heat illness. 61% of the respondents had undergone some form of heat exposure prior to the Championships, with 38% acclimating for 5 to 30 days. In addition, several respondents declared to live in warm countries and all arrived in Qatar ~5 days prior to their event. 96% of the respondents used a pre-cooling strategy for the time trials and 74% did so before the road race (p<0.001), with ice vests being the most common. The AMC assessed 46 injuries and 26 illnesses in total, with three cyclists diagnosed with heat exhaustion. CONCLUSIONS: The prevalence of previous heat illness in elite cyclists calls for team and event organisation doctors to be trained on heat illness management, including early diagnosis and rapid on-site cooling. Some cyclists had been exposed to the heat prior to the Championships, but few had a dedicated plan, calling for additional education on the importance of heat acclimation. Pre-cooling was widely adopted.

Heat-Related Illnesses.

Heat-related illnesses comprise a spectrum of syndromes resulting from disruption of thermoregulation in people exposed to high environmental heat. Symptoms range from heat edema and exercise-associated muscle cramps to exercise-associated collapse, heat exhaustion, and life-threatening heat stroke. Athletes, outdoor laborers, and military personnel are at greatest risk. Several intrinsic and extrinsic factors increase the risk of heat-related illness, including medical conditions, environmental factors, medication use, and inadequate acclimatization. Proper recognition and treatment are effective in preventing adverse outcomes. Management of the mildest forms of heat-related illness (e.g., heat edema, exercise-associated muscle cramps) is largely supportive, and sequelae are rare. Heat exhaustion is characterized by cardiovascular hypoperfusion and a rectal core temperature up to 104°F without central nervous dysfunction. Mild cooling, rest, and hydration are recommended. Heat stroke is a medical emergency in which patients present with rectal core temperature of 105°F or greater, multiorgan damage, and central nervous dysfunction. Ice water or cold water immersion is recommended. Patients adequately cooled within 30 minutes have excellent outcomes. Patients with heat stroke generally require hospitalization to monitor for medical complications despite rapid cooling. People diagnosed with heat stroke or severe heat-related illness should refrain from physical activity for at least seven days after release from medical care, then gradually begin activity over two to four weeks. Acclimatization, adequate hydration, and avoidance of activities during extreme heat are the most effective measures to reduce the incidence of heat-related illnesses.

Beat the heat: Identification and Tx of heat-related illness.

The prompt identification and treatment of heat-related illnesses and expedited transport to a higher level of care can be lifesaving. This article serves as a go-to guide.

Recognition and treatment of exertional heat illness at a marathon race.

Exertional heat illness is rarely encountered by individual EMS providers but can be common in certain settings and events. The notion that significantly altered mental status must accompany elevated core temperature in heat illness may delay recognition and treatment. We report on a series of marathon and half-marathon runners who suffered exertional heat illness during a marathon race in relatively mild conditions. Altered mental status was not uniformly present. All patients were treated in the finish line medical tent and responded well to cooling. More than half were discharged from the medical tent without being transported to the hospital. This case series demonstrates that many runners respond to early identification and treatment of exertional heat illness. Significant preparation is required by the medical providers to handle the rapid influx of patients at the conclusion of the event.

Consenso sobre utilización de la vía parenteral en el deporte. El tratamiento de los trastornos por calor. Documento de Consenso de la Federación Española de Medicina del Deporte / Consensus on the use of parenteral route in sport. Heat illness treatment. Consensus document of Spanish Federation of Sports Medicine

El ejercicio físico provoca una elevación de la temperatura corporal, que en condiciones ambientales desfavorables (temperatura y humedad elevadas, radiación solar intensa o ausencia de viento) y otros factores provocan un mayor estrés térmico lo que puede conducir al deportista a una situación de deshidratación. Si no hay una adecuada reposición de líquidos y electrolitos que pueda desencadenar deshidratación y/o hiponatremia, se pueden producir efectos adversos sobre el rendimiento y también sobre la salud. Este documento de consenso presenta los cuadros clínicos relacionados con el calor que pueden aparecer durante la práctica de actividades deportivas y que pueden requerir el tratamiento urgente del paciente en el propio lugar de la actividad. Idealmente el tratamiento debe realizarse en un medio sanitario, pero la urgencia de algunos cuadros, puede requerir una actuación médica inmediata que, desde un punto de vista deontológico no puede demorarse aunque ello requiera desatender normas de origen deportivo, como las normas de lucha contra el dopaje y las normas de algunas federaciones que prohíben la utilización de la vía parenteral en deportistas. Se describen especialmente las indicaciones para uso de la administración parenteral de fluidos en el contexto deportivo para tratar la deshidratación, calambres musculares por esfuerzo, agotamiento por calor, síncope por calor, hiponatremia por esfuerzo y golpe de calor por esfuerzo. La administración de perfusiones endovenosas está indicada en tratamiento del golpe de calor y ante su sospecha diagnóstica, de forma inmediata, lo que no permite la demora en su aplicación y que se debe realizar en el propio terreno. Además, la perfusiones endovenosas están indicadas en el tratamiento del resto de situaciones patológicas cuando el estado de conciencia del paciente no permite la administración de fluidos orales o cuando se presentan nauseas o vómitos. Por último se describe la rehidratación como ayuda ergogénica con las ventajas e inconvenientes de las vías oral y parenteral (AU)

Exercise causes a rise in body temperature, which in unfavorable environmental conditions (high temperature and humidity, intense solar radiation or absence of wind) and other factors causes higher thermal stress which can cause a dehydration situation on the athlete. If there is no suitable replacement of fluids and electrolytes, which can cause dehydration and / or hyponatremia, adverse effects may occur on performance and health. This consensus document shows clinical symptoms related to heat that can occur while practicing sport activities and may require urgent treatment in the patient’s activity place. Ideally, treatment should be done in a sanitary environment, but the urgency of some symptoms may require immediate medical intervention which, due to the medical ethics involved, cannot be delayed even if this implies neglecting sports rules, such anti-doping rules or some federations regulations that forbid the use of parenteral route in athlete. Indications for using the parenteral fluids administration in sports are specially described, which are used to treat dehydration, exertional muscle cramps caused by effort, heat exhaustion, heat syncope, exertional hyponatremia and exertional heat stroke. The administration of intravenous infusions is indicated in the heat stroke treatment and must be immediately applied when its diagnosis is suspected, being no delay allowed and performing it in the field. Furthermore, intravenous infusions are indicated in the treatment of other pathological situations where the consciousn ess state of the patient does not permitoral administration of fluids or in case of nausea or vomiting. Finally, rehydration is described as an ergogenic aid with the advantages and disadvantages of oral and parenteral routes (AU)

Heat-related illness.

Heat-related illness is a set of preventable conditions ranging from mild forms (e.g., heat exhaustion, heat cramps) to potentially fatal heat stroke. Hot and humid conditions challenge cardiovascular compensatory mechanisms. Once core temperature reaches 104°F (40°C), cellular damage occurs, initiating a cascade of events that may lead to organ failure and death. Early recognition of symptoms and accurate measurement of core temperature are crucial to rapid diagnosis. Milder forms of heat-related illness are manifested by symptoms such as headache, weakness, dizziness, and an inability to continue activity. These are managed by supportive measures including hydration and moving the patient to a cool place. Hyperthermia and central nervous system symptoms should prompt an evaluation for heat stroke. Initial treatments should focus on lowering core temperature through cold water immersion. Applying ice packs to the head, neck, axilla, and groin is an alternative. Additional measures include transporting the patient to a cool environment, removing excess clothing, and intravenous hydration. Delayed access to cooling is the leading cause of morbidity and mortality in persons with heat stroke. Identification of at-risk groups can help physicians and community health agencies provide preventive measures.

A practical cooling strategy for reducing the physiological strain associated with firefighting activity in the heat.

The aim of this study was to establish whether a practical cooling strategy reduces the physiological strain during simulated firefighting activity in the heat. On two separate occasions under high ambient temperatures (49.6 +/- 1.8 degrees C, relative humidity (RH) 13 +/- 2%), nine male firefighters wearing protective clothing completed two 20-min bouts of treadmill walking (5 km/h, 7.5% gradient) separated by a 15-min recovery period, during which firefighters were either cooled (cool) via application of an ice vest and hand and forearm water immersion ( approximately 19 degrees C) or remained seated without cooling (control). There was no significant difference between trials in any of the dependent variables during the first bout of exercise. Core body temperature (37.72 +/- 0.34 vs. 38.21 +/- 0.17 degrees C), heart rate (HR) (81 +/- 9 vs. 96 +/- 17 beats/min) and mean skin temperature (31.22 +/- 1.04 degrees C vs. 33.31 +/- 1 degrees C) were significantly lower following the recovery period in cool compared with control (p < 0.05). Core body temperature remained consistently lower (0.49 +/- 0.02 degrees C; p < 0.01) throughout the second bout of activity in cool compared to control. Mean skin temperature, HR and thermal sensation were significantly lower during bout 2 in cool compared with control (p < 0.05). It is concluded that this practical cooling strategy is effective at reducing the physiological strain associated with demanding firefighting activity under high ambient temperatures.

A treatment algorithm for mass heat casualties.

Although thankfully rare,heat related illness has significant implications for the effective fighting force available to commanders. This is especially pertinent in the current theatres of operations, as previously soldiers have not routinely been subjected to the rigors of operating in hot climates. In addition to Iraq and Afghanistan, various training exercises are undertaken throughout the world where extreme temperatures may be encountered. Individual medical officers may be faced with heat casualties remote from all but the most basic facilities or the number of heat casualties may overwhelm limited resources. We present a simple treatment algorithm that has been used successfully in the treatment of mass heat casualties.

[Characteristics of heat illness in older people].

AIM: As summer become hotter due to rapid climate change, older people suffering from heat illness are increasing. The aim of our study was to examine the characteristics of older people who suffered from heat illness. METHODS: We analyzed the 65 years or older patients admitted for acute care of Nagoya Ekisaikai Hospital via the emergency department (ED) during the summer seasons of 2006 and 2007. Demographic data, functional status, use situation of care services, climate of the onset day, use of an air conditioners, and cognitive status, length of hospital stay and disposition following their discharge were recorded. RESULTS: During the study period, 104 patients visited the ED because of heat illness. Twenty older patients were admitted for acute care. In hospitalized patients, the mean length of stay was 27.5+/-18.6 days. Sixty percent of patients were discharged to long-term care facilities (12/20). Sixteen patients suffered from heat illness inside their home. Most of the patients had characteristics such as living alone or with their spouses only (14/16), cognitive dysfunction (12/16), lack or no use of an air conditioner (11/16) , no use of care service (11/16) , and preserved functional status (10/16) . CONCLUSIONS: Many older patients suffered from heat illness in their home, and their ED visits were associated with prolonged admissions and post-discharge institutionalizations. It is important to give education to prevent heat illness in older people.