Successful out-of-hospital therapy for heatstroke in three marathon runners with a novel core body cooling device: CAERvest(®)

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.

Nutrition-Related Adverse Outcomes in Endurance Sports Competitions: A Review of Incidence and Practical Recommendations

During the last few years, the numbers of competitors in endurance and ultra-endurance sports modalities have increased significantly. This type of competition is an extreme challenge for athletes. Therefore, they have an increased the risk of developing medical and nutritional problems. The aim of the work is to estimate the incidence of nutrition-related adverse outcomes in endurance and ultra-endurance sports, considering the variables that influence them. A critical review was carried out based on the PubMed database, by means of a search strategy based on keywords separated by Boolean connectors. For all the results obtained in a period from 2008 to 2019, a series of inclusion/exclusion criteria was applied to select only the studies that fitted the objective of the present study. Results and discussion: Of the 871 publications identified, 33 met the inclusion criteria. The adverse outcomes found included exercise-associated hyponatremia (EAH), heat stroke by exertion (EHS), gastrointestinal (GI) problems, dehydration, and hypothermia; the provision of misinformation to athletes about nutrient intake and hydration during competition was identified as the main cause. Conclusions: The main adverse outcomes in endurance and ultra-endurance sports modalities are EAH, GI inconveniences, and EHS. These problems can affect the performance and health status of the athlete during and post-competition. Several nutritional guidelines have been suggested that can prevent these adverse outcomes, and it is essential to individualize and adjust the nutritional intake and hydration status according to the characteristics of each competition.

Outcome and risk factors associated with extent of central nervous system injury due to exertional heat stroke

To explore the relationship between the extent of central nervous system (CNS) injury and patient outcomes meanwhile research the potential risk factors associated with neurologic sequelae. In this retrospective cohort study, we analyzed data from 117 consecutive patients (86 survivors, 31 nonsurvivors) with exertional heat stroke (EHS) who had been admitted to intensive care unit (ICU) at 48 Chinese hospitals between April 2003 and July 2015. Extent of CNS injury was dichotomized according to Glasgow coma scale (GCS) score (severe 3-8, not severe 9-15). We then assessed differences in hospital mortality based on the extent of CNS injury by comparing 90-day survival time between the patient groups. Exploring the risk factors of neurologic sequelae. The primary outcomewas the 90-day survival ratewhich differed between the 2 groups (P = .023). The incidence of neurologic sequelae was 24.4%. For its risk factors, duration of recurrent hyperthermia (OR = 1.73, 95% CI: 1.20-2.49, P = .003), duration of CNS injury (OR = 1.39, 95% CI: 1.04-1.85, P = .025), and low GCS in the first 24 hours after admission (OR = 2.39, 95% CI: 1.11-5.15, P = .025) were selected by multivariable logistic regression. Cooling effect was eliminated as a factor (OR = 2641.27, 95% CI 0.40-1.73_107, P = .079). Significant differences in 90-day survival ratewere observed based on the extent of CNS injury in patients with EHS, and incidence was 24.4% for neurologic sequelae. Duration of recurrent hyperthermia, duration of CNS injury, and low GCS score in the first 24 hours following admission may be independent risk factors of neurologic sequelae. Cooling effect should be validated in the further studies.