Hosokawa Yuri, Belval Luke N, Adams William M, Vandermark Lesley W, Casa Douglas J
Faculty of Sport Sciences, Waseda University, Saitama 359-1192, Japan.
Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, TX 75231, USA.
Medicina (Kaunas). 2020 Oct 14;56(10):539. doi: 10.3390/medicina56100539.
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 or greater) for EHS treatment. It was hypothesized that a cooling vest will not meet the established cooling criteria for EHS treatment. Fourteen recreationally active participants (mean ± SD; male, = 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 m. female, = 6; 22 ± 2 years; 61.3 ± 6.7 kg; 22.8 ± 4.4%; 1.66 ± 0.11 m) 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) >39 °C (mean T, 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 reached 38.25 °C. Trials were assigned using randomized, counter-balanced crossover design. There was a main effect of cooling modality type on cooling rates (F[1, 24] = 10.46, < 0.01, η = 0.30), with a greater cooling rate observed in VEST (0.06 ± 0.02 °C·min) than PASS (0.04 ± 0.01 °C·min) (MD = 0.02, 95% CI = [0.01, 0.03]). There were also main effects of sex (F[1, 24] = 5.97, = 0.02, η = 0.20) and cooling modality type (F[1, 24] = 4.38, = 0.047, η = 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, = 0.03); however, this association was not significant in vest (r = -0.252, = 0.39). 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.
劳力性热射病（EHS）是一种潜在致命的高热病症，需要立即降温以优化患者预后。本研究旨在检验一种便携式冷却背心是否符合EHS治疗既定的降温标准（每分钟0.15°C或更高）。研究假设冷却背心不符合EHS治疗既定的降温标准。14名有运动习惯的参与者（均值±标准差；男性8名，年龄25±4岁，体重86.7±10.5千克，体脂16.5±5.2%，体表面积2.06±0.15平方米；女性6名，年龄22±2岁，体重61.3±6.7千克，体脂22.8±4.4%，体表面积1.66±0.11平方米）在炎热气候舱（环境温度39.8±1.9°C，相对湿度37.4±6.9%）的电动跑步机上运动，直至直肠温度（T）>39°C（平均T，39.59±0.38°C）。运动后，参与者在气候舱中使用冷却背心（VEST）或被动休息（PASS）进行降温，直至T降至38.25°C。试验采用随机、交叉平衡设计。冷却方式类型对降温速率有主要影响（F[1, 24]=10.46，P<0.01，η=0.30），VEST组（0.06±0.02°C·min）的降温速率高于PASS组（0.04±0.01°C·min）（平均差值=0.02，95%可信区间=[0.01, 0.03]）。性别（F[1, 24]=5.97，P=0.02，η=0.20）和冷却方式类型（F[1, 24]=4.38，P=0.047，η=0.15）对降温持续时间也有主要影响，女性参与者（26.9分钟）的降温时间比男性参与者（42.2分钟）更快（平均差值=15.3分钟，95%可信区间=[2.4, 28.2]），VEST组的降温持续时间比PASS组更快（平均差值=13.1分钟，95%可信区间=[0.2, 26.0]）。体重增加与PASS组的降温速率降低相关（r=-0.580，P=0.03）；然而，这种关联在冷却背心组不显著（r=-0.252，P=0.39）。尽管VEST的冷却能力比PASS更强，但VEST远低于EHS治疗可接受的降温速率。当怀疑发生EHS时，冷却背心不应替代立即进行的全身冷水浸泡。
