Clinical Communications: AdultSuccessful Management of Severe Exertional Heat Stroke with Endovascular Cooling After Failure of Standard Cooling Measures
Introduction
Exertional heat stroke (EHS) is a life-threatening emergency that requires immediate intervention to rapidly reduce core body temperature to prevent permanent organ damage. Reduction in temperature can be achieved through a variety of methods, including evaporative cooling, ice packs, cold water immersion, cold water lavages, and chilled intravenous (i.v.) fluids. Of these, the most effective method is full-body cold water immersion (CWI) 1, 2. However, CWI presents logistical challenges for an emergency department (ED), including lack of adequate space or drainage, the need for electronic patient monitoring, rapid facilitation of patient entry and exit from the immersion tank, and environmental safety concerns surrounding management of spilled ice and water in proximity to electrical equipment.
Ice sheeting (covering the subject with bed linens that have been soaked in ice water) is routinely used at Fort Benning, Georgia, to approximate CWI with fewer logistical constraints. Ice sheets are often initiated at the point of injury, and the Fort Benning Emergency Medical Services (EMS) protocols provide for continued cooling through the use of skin lavage with ice water slurry and adjunctive use of chilled i.v. saline (3). During the period between April and November 2017, this method was used to successfully reduce the elevated core body temperatures of over 200 patients suffering from moderate to severe heat-related illnesses, including 52 cases of EHS (4). We report a case of EHS that was successfully treated using an endovascular cooling device after prolonged attempts at cooling with ice sheets, ice slurry, and chilled i.v. fluids failed to achieve satisfactory reduction in core body temperature.
Section snippets
Case Report
A previously healthy 24-year old white male Army Ranger participating in the Ranger Assessment and Selection Program (body mass index 27.7) collapsed while performing a 12-mile foot march while carrying a 40-pound backpack. Upon initial evaluation by onsite medical personnel, his rectal temperature was 43.1°C (109.6°F). He was immediately stripped of all gear and clothing and ice sheets were applied. EMS arrived 19 min after the initial application of ice sheets; his repeat rectal temperature
Discussion
EHS is defined as an elevated core temperature, generally > 40°C (104°F), with associated encephalopathy in a patient who has been participating in strenuous exercise (6). These individuals require immediate and rapid cooling and continuous monitoring. Rapid cooling is best accomplished by full body (except the head) immersion in an ice water bath, which produces cooling rates up to 0.35°C/min 1, 7, 8. There have been reports of successfully treating EHS with CWI in the field and at endurance
Why Should an Emergency Physician Be Aware of This?
There are very few case reports detailing the use of endovascular cooling in EHS. In this case, standard cooling methods yielded only a marginal decrease of 1.9°C over a 50-min period. Cold water immersion in the ED was neither available nor would it have been practical in this unstable patient. The implementation of endovascular cooling rapidly lowered the patient's core temperature to normal range within 30 min of initiation and is only the second published use of this application in the
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The views expressed in this manuscript are those of the authors and do not reflect the official policy or position of the Department of the Army, Department of Defense, or the U.S. Government.